Barrier methods These involve a physical barrier which prevents sperm (see SPERMATOZOON) from reaching the cervix (see CERVIX UTERI). Barrier methods reduce the risk of spreading sexually transmitted diseases, and the sheath is the best protection against HIV infection (see AIDS/HIV) for sexually active people. The e?ciency of barrier methods is improved if they are used in conjunction with a spermicidal foam or jelly, but care is needed to ensure that the preparation chosen does not damage the rubber barrier or cause an allergic reaction in the users. CONDOM OR SHEATH This is the most commonly used barrier contraceptive. It consists of a rubber sheath which is placed over the erect penis before intromission and removed after ejaculation. The failure rate, if properly used, is about 4 per cent. DIAPHRAGM OR CAP A rubber dome that is inserted into the vagina before intercourse and ?ts snugly over the cervix. It should be used with an appropriate spermicide and is removed six hours after intercourse. A woman must be measured to ensure that she is supplied with the correct size of diaphragm, and the ?t should be checked annually or after more than about 7 lbs. change in weight. The failure rate, if properly used, is about 2 per cent.
Non-barrier methods These do not provide a physical barrier between sperm and cervix and so do not protect against sexually transmitted diseases, including HIV. COITUS INTERRUPTUS This involves the man’s withdrawing his penis from the vagina before ejaculation. Because some sperm may leak before full ejaculation, the method is not very reliable. SAFE PERIOD This involves avoiding intercourse around the time when the woman ovulates and is at risk of pregnancy. The safe times can be predicted using temperature charts to identify the rise in temperature before ovulation, or by careful assessment of the quality of the cervical mucus. This method works best if the woman has regular menstrual cycles. If used carefully it can be very e?ective but requires a highly disciplined couple to succeed. It is approved by the Catholic church.
SPERMICIDAL GELS, CREAMS, PESSARIES, ETC.
These are supposed to prevent pregnancy by killing sperm before they reach the cervix, but they are unreliable and should be used only in conjunction with a barrier method.
INTRAUTERINE CONTRACEPTIVE DEVICE (COIL) This is a small metal or plastic shape, placed inside the uterus, which prevents pregnancy by disrupting implantation. Some people regard it as a form of abortion, so it is not acceptable to all religious groups. There is a risk of pelvic infection and eventual infertility in women who have used coils, and in many countries their use has declined substantially. Coils must be inserted by a specially trained health worker, but once in place they permit intercourse at any time with no prior planning. Increased pain and bleeding may be caused during menstruation. If severe, such symptoms may indicate that the coil is incorrectly sited, and that its position should be checked. HORMONAL METHODS Steroid hormones have dominated contraceptive developments during the past 40 years, with more than 200 million women worldwide taking or having taken ‘the pill’. In the past 20 years, new developments have included modifying existing methods and devising more e?ective ways of delivering the drugs, such as implants and hormone-releasing devices in the uterus. Established hormonal contraception includes the combined oestrogen and progesterone and progesterone-only contraceptive pills, as well as longer-acting depot preparations. They modify the woman’s hormonal environment and prevent pregnancy by disrupting various stages of the menstrual cycle, especially ovulation. The combined oestrogen and progesterone pills are very e?ective and are the most popular form of contraception. Biphasic and triphasic pills contain di?erent quantities of oestrogen and progesterone taken in two or three phases of the menstrual cycle. A wide range of preparations is available and the British National Formulary contains details of the commonly used varieties.
The main side-e?ect is an increased risk of cardiovascular disease. The lowest possible dose of oestrogen should be used, and many preparations are phasic, with the dose of oestrogen varying with the time of the cycle. The progesterone-only, or ‘mini’, pill does not contain any oestrogen and must be taken at the same time every day. It is not as e?ective as the combined pill, but failure rates of less than 1-per-100 woman years can be achieved. It has few serious side-effects, but may cause menstrual irregularities. It is suitable for use by mothers who are breast feeding.
Depot preparations include intramuscular injections, subcutaneous implants, and intravaginal rings. They are useful in cases where the woman cannot be relied on to take a pill regularly but needs e?ective contraception. Their main side-e?ect is their prolonged action, which means that users cannot suddenly decide that they would like to become pregnant. Skin patches containing a contraceptive that is absorbed through the skin have recently been launched.
HORMONAL CONTRACEPTION FOR MEN There is a growing demand by men worldwide for hormonal contraception. Development of a ‘male pill’, however, has been slow because of the potentially dangerous side-effects of using high doses of TESTOSTERONE (the male hormone) to suppress spermatogenesis. Progress in research to develop a suitable ANDROGEN-based combination product is promising, including the possibility of long-term STEROID implants. STERILISATION See also STERILISATION – Reproductive sterilisation. The operation is easier and safer to perform on men than on women. Although sterilisation can sometimes be reversed, this cannot be guaranteed and couples should be counselled in advance that the method is irreversible. There is a small but definite failure rate with sterilisation, and this should also be made clear before the operation is performed. POSTCOITAL CONTRACEPTION Also known as emergency contraception or the ‘morning after pill’, postcoital contraception can be e?ected by two di?erent hormonal methods. Levonorgesterol (a synthetic hormone similar to the natural female sex hormone PROGESTERONE) can be used alone, with one pill being taken within 72 hours of unprotected intercourse, but preferably as soon as possible, and a second one 12 hours after the ?rst. Alternatively, a combined preparation comprising ETHINYLESTRADIOL and levonorgesterol can be taken, also within 72 hours of unprotected intercourse. The single constituent pill has fewer side-effects than the combined version. Neither version should be taken by women with severe liver disease or acute PORPHYRIAS, but the ethinylestradiol/levonorgesterol combination is unsuitable for women with a history of THROMBOSIS.
In the UK the law allows women over the age of 16 to buy the morning-after pill ‘over the counter’ from a registered pharmacist.... contraception
Habitat: A common plant in the United States and Canada, the root is imported into this country in large quantities for medicinal purposes.
Features ? The rhizome (as the part used should more strictly be termed) is reddish- brown in colour, fairly smooth, and has knotty joints at distances of about two inches. The fracture shows whitish and mealy.American Mandrake is an entirely different plant from White Bryony or English Mandrake, dealt with elsewhere. Preparations of the rhizome of the American Mandrake are found in practice to be much more effective than those of the resin. This is one of the many confirmations of one of the basic postulates of herbal medicine—the nearer we can get to natural conditions the better the results. Therapeutic principles are never the same when taken from their proper environment.Podophyllum is a very valuable hepatic, and a thorough but slow-acting purgative. Correctly compounded with other herbs it is wonderfully effective in congested conditions of the liver, and has a salutary influence on other parts of the system, the glands in particular being helped to normal functioning. Although apparently unrecognised in Coffin's day, the modern natural healer highly appreciates the virtues of this medicine and has many uses for it.As American Mandrake is so powerful in certain of its actions, and needs such skillful combination with other herbs, it should not be used by the public without the advice of one experienced in prescribing it toindividual needs.... mandrake, americanFor long it had been realised that in certain cases of ASTHMA, adrenaline had not the usual bene?cial e?ect of dilating the bronchi during an attack; rather it made the asthma worse. This was due to its acting on both the alpha and beta adrenergic receptors. A derivative, isoprenaline, was therefore produced which acted only on the beta receptors. This had an excellent e?ect in dilating the bronchi, but unfortunately also affected the heart, speeding it up and increasing its output – an undesirable e?ect which meant that isoprenaline had to be used with great care. In due course drugs were produced, such as salbutamol, which act predominantly on the beta2 adrenergic receptors in the bronchi and have relatively little e?ect on the heart.
The converse of this story was the search for what became known as BETA-ADRENOCEPTORBLOCKING DRUGS, or beta-adrenergic-blocking drugs. The theoretical argument was that if such drugs could be synthesised, they could be of value in taking the strain o? the heart – for example: stress ? stimulation of the output of adrenaline ? stimulation of the heart ? increased work for the heart. A drug that could prevent this train of events would be of value, for example in the treatment of ANGINA PECTORIS. Now there is a series of beta-adrenoceptor-blocking drugs of use not only in angina pectoris, but also in various other heart conditions such as disorders of rhythm, as well as high blood pressure. They are also proving valuable in the treatment of anxiety states by preventing disturbing features such as palpitations. Some are useful in the treatment of migraine.... adrenergic receptors
(2) A drug that acts through receptors on the surface of the cell or within the cell and provokes a biological response. As the body contains natural agonists that combine with cell receptors, any ‘occupation’ of these cell receptors by drug molecules will have a pharmacological e?ect on the individual. The intensity of that pharmacological e?ect is believed to be directly proportional to the number of receptors on the cell that combine with the drug molecule. For example, the natural agonist noradrenaline contracts the smooth muscle of blood vessels; the drug agonist phenylnephrine has a similar e?ect.
Antagonists are drugs which will combine with the receptor site to prevent another agent from producing its greatest e?ect. If the drug has no e?cacy of its own, but simply prevents the agonist from acting at the receptor site, it is called a full antagonist. A partial antagonist is a drug that provokes some activity at the receptor site. An example of an antagonist is prazosin, which acts against the natural agonist noradrenaline at the receptor site of the cells of blood-vessel muscle and prevents the vascular muscle from contracting.... agonist
Unconjugated testosterone is rarely used clinically because its derivatives have a more powerful and prolonged e?ect, and because testosterone itself requires implantation into the subcutaneous fat using a trocar and cannula for maximum therapeutic bene?t. Testosterone propionate is prepared in an oily solution, as it is insoluble in water; it is e?ective for three days and is therefore administered intramuscularly twice weekly. Testosterone phenyl-propionate is a long-acting microcrystalline preparation which, when given by intramuscular or subcutaneous injection, is e?ective for four weeks. Testosterone enantate is another long-acting intramuscular preparation. Mesterolone is an e?ective oral androgen and is less hepatoxic: it does not inhibit pituitary gonadotrophic production and hence spermatogenesis is unimpaired. Testosterone undecanoate is also an e?ective oral form.... androgen
The drugs are much more e?ective in the treatment and prevention of venous clotting – for example, deep vein thrombosis (DVT), see under VEINS, DISEASES OF – than in preventing thrombosis formation in arteries with their fast-?owing blood in which thrombi contain little ?brin (against which the anticoagulants work) and many PLATELETS.
The main anticoagulants now in use are the natural agent HEPARIN (a quick-acting variety and a low-molecular-weight long-acting type); synthetic oral anticoagulants such as WARFARIN and the less-often-used acenocoumarol and PHENINDIONE; and antiplatelet compounds such as ASPIRIN, clopidogrel dipyridamole and ticlopidines. Fondaparinux is an extract of heparin which can be given once daily by injection; ximelagatran, an inhibitor of thrombin, is being trialled as the ?rst new oral anticoagulant since heparin.
Patients taking anticoagulants need careful medical monitoring and they should carry an Anticoagulant Card with instructions about the use of whatever drug they may be receiving – essential information should the individual require treatment for other medical conditions as well as for thrombosis.... anticoagulants
There is little evidence that any one antihistamine is superior to another, and patients vary considerably in their response to them. The antihistamines di?er in their duration of action and in the incidence of side-effects such as drowsiness. Most are short-acting, but some (such as promethazine) work for up to 12 hours. They all cause sedation but promethazine, trimeprazine and dimenhydrinate tend to be more sedating while chlorpheniramine and cyclizine are less so, as are astemizole, oxatomide and terfenadine. Patients should be warned that their ability to drive or operate machinery may be impaired when taking these drugs, and that the effects of ALCOHOL may be increased.... antihistamine drugs
Bone fractures These occur when there is a break in the continuity of the bone. This happens either as a result of violence or because the bone is unhealthy and unable to withstand normal stresses.
SIMPLE FRACTURES Fractures where the skin remains intact or merely grazed. COMPOUND FRACTURES have at least one wound which is in communication with the fracture, meaning that bacteria can enter the fracture site and cause infection. A compound fracture is also more serious than a simple fracture because there is greater potential for blood loss. Compound fractures usually need hospital admission, antibiotics and careful reduction of the fracture. Debridement (cleaning and excising dead tissue) in a sterile theatre may also be necessary.
The type of fracture depends on the force which has caused it. Direct violence occurs when an object hits the bone, often causing a transverse break – which means the break runs horizontally across the bone. Indirect violence occurs when a twisting injury to the ankle, for example, breaks the calf-bone (the tibia) higher up. The break may be more oblique. A fall on the outstretched hand may cause a break at the wrist, in the humerus or at the collar-bone depending on the force of impact and age of the person. FATIGUE FRACTURES These occur after the bone has been under recurrent stress. A typical example is the march fracture of the second toe, from which army recruits suffer after long marches. PATHOLOGICAL FRACTURES These occur in bone which is already diseased – for example, by osteoporosis (see below) in post-menopausal women. Such fractures are typically crush fractures of the vertebrae, fractures of the neck of the femur, and COLLES’ FRACTURE (of the wrist). Pathological fractures also occur in bone which has secondary-tumour deposits. GREENSTICK FRACTURES These occur in young children whose bones are soft and bend, rather than break, in response to stress. The bone tends to buckle on the side opposite to the force. Greenstick fractures heal quickly but still need any deformity corrected and plaster of Paris to maintain the correction. COMPLICATED FRACTURES These involve damage to important soft tissue such as nerves, blood vessels or internal organs. In these cases the soft-tissue damage needs as much attention as the fracture site. COMMINUTED FRACTURES A fracture with more than two fragments. It usually means that the injury was more violent and that there is more risk of damage to vessels and nerves. These fractures are unstable and take longer to unite. Rehabilitation tends to be protracted. DEPRESSED FRACTURES Most commonly found in skull fractures. A fragment of bone is forced inwards so that it lies lower than the level of the bone surrounding it. It may damage the brain beneath it.
HAIR-LINE FRACTURES These occur when the bone is broken but the force has not been severe enough to cause visible displacement. These fractures may be easily missed. Symptoms and signs The fracture site is usually painful, swollen and deformed. There is asymmetry of contour between limbs. The limb is held uselessly. If the fracture is in the upper
limb, the arm is usually supported by the patient; if it is in the lower limb then the patient is not able to bear weight on it. The limb may appear short because of muscle spasm.
Examination may reveal crepitus – a bony grating – at the fracture site. The diagnosis is con?rmed by radiography.
Treatment Healing of fractures (union) begins with the bruise around the fracture being resorbed and new bone-producing cells and blood vessels migrating into the area. Within a couple of days they form a bridge of primitive bone across the fracture. This is called callus.
The callus is replaced by woven bone which gradually matures as the new bone remodels itself. Treatment of fractures is designed to ensure that this process occurs with minimal residual deformity to the bone involved.
Treatment is initially to relieve pain and may involve temporary splinting of the fracture site. Reducing the fracture means restoring the bones to their normal position; this is particularly important at the site of joints where any small displacement may limit movement considerably.
with plaster of Paris. If closed traction does not work, then open reduction of the fracture may
be needed. This may involve ?xing the fracture with internal-?xation methods, using metal plates, wires or screws to hold the fracture site in a rigid position with the two ends closely opposed. This allows early mobilisation after fractures and speeds return to normal use.
External ?xators are usually metal devices applied to the outside of the limb to support the fracture site. They are useful in compound fractures where internal ?xators are at risk of becoming infected.
Consolidation of a fracture means that repair is complete. The time taken for this depends on the age of the patient, the bone and the type of fracture. A wrist fracture may take six weeks, a femoral fracture three to six months in an adult.
Complications of fractures are fairly common. In non-union, the fracture does not unite
– usually because there has been too much mobility around the fracture site. Treatment may involve internal ?xation (see above). Malunion means that the bone has healed with a persistent deformity and the adjacent joint may then develop early osteoarthritis.
Myositis ossi?cans may occur at the elbow after a fracture. A big mass of calci?ed material develops around the fracture site which restricts elbow movements. Late surgical removal (after 6–12 months) is recommended.
Fractured neck of FEMUR typically affects elderly women after a trivial injury. The bone is usually osteoporotic. The leg appears short and is rotated outwards. Usually the patient is unable to put any weight on the affected leg and is in extreme pain. The fractures are classi?ed according to where they occur:
subcapital where the neck joins the head of the femur.
intertrochanteric through the trochanter.
subtrochanteric transversely through the upper end of the femur (rare). Most of these fractures of the neck of femur
need ?xing by metal plates or hip replacements, as immobility in this age group has a mortality of nearly 100 per cent. Fractures of the femur shaft are usually the result of severe trauma such as a road accident. Treatment may be conservative or operative.
In fractures of the SPINAL COLUMN, mere damage to the bone – as in the case of the so-called compression fracture, in which there is no damage to the spinal cord – is not necessarily serious. If, however, the spinal cord is damaged, as in the so-called fracture dislocation, the accident may be a very serious one, the usual result being paralysis of the parts of the body below the level of the injury. Therefore the higher up the spine is fractured, the more serious the consequences. The injured person should not be moved until skilled assistance is at hand; or, if he or she must be removed, this should be done on a rigid shutter or door, not on a canvas stretcher or rug, and there should be no lifting which necessitates bending of the back. In such an injury an operation designed to remove a displaced piece of bone and free the spinal cord from pressure is often necessary and successful in relieving the paralysis. DISLOCATIONS or SUBLUXATION of the spine are not uncommon in certain sports, particularly rugby. Anyone who has had such an injury in the cervical spine (i.e. in the neck) should be strongly advised not to return to any form of body-contact or vehicular sport.
Simple ?ssured fractures and depressed fractures of the skull often follow blows or falls on the head, and may not be serious, though there is always a risk of damage which is potentially serious to the brain at the same time.
Compound fractures may result in infection within the skull, and if the skull is extensively broken and depressed, surgery is usually required to check any intercranial bleeding or to relieve pressure on the brain.
The lower jaw is often fractured by a blow on the face. There is generally bleeding from the mouth, the gum being torn. Also there are pain and grating sensations on chewing, and unevenness in the line of the teeth. The treatment is simple, the line of teeth in the upper jaw forming a splint against which the lower jaw is bound, with the mouth closed.
Congenital diseases These are rare but may produce certain types of dwar?sm or a susceptibility to fractures (osteogenesis imperfecta).
Infection of bone (osteomyelitis) may occur after an open fracture, or in newborn babies with SEPTICAEMIA. Once established it is very di?cult to eradicate. The bacteria appear capable of lying dormant in the bone and are not easily destroyed with antibiotics so that prolonged treatment is required, as might be surgical drainage, exploration or removal of dead bone. The infection may become chronic or recur.
Osteomalacia (rickets) is the loss of mineralisation of the bone rather than simple loss of bone mass. It is caused by vitamin D de?ciency and is probably the most important bone disease in the developing world. In sunlight the skin can synthesise vitamin D (see APPENDIX 5: VITAMINS), but normally rickets is caused by a poor diet, or by a failure to absorb food normally (malabsorbtion). In rare cases vitamin D cannot be converted to its active state due to the congenital lack of the speci?c enzymes and the rickets will fail to respond to treatment with vitamin D. Malfunction of the parathyroid gland or of the kidneys can disturb the dynamic equilibrium of calcium and phosphate in the body and severely deplete the bone of its stores of both calcium and phosphate.
Osteoporosis A metabolic bone disease resulting from low bone mass (osteopenia) due to excessive bone resorption. Su?erers are prone to bone fractures from relatively minor trauma. With bone densitometry it is now possible to determine individuals’ risk of osteoporosis and monitor their response to treatment.
By the age of 90 one in two women and one in six men are likely to sustain an osteoporosis-related fracture. The incidence of fractures is increasing more than would be expected from the ageing of the population, which may re?ect changing patterns of exercise or diet.
Osteoporosis may be classi?ed as primary or secondary. Primary consists of type 1 osteoporosis, due to accelerated trabecular bone loss, probably as a result of OESTROGENS de?ciency. This typically leads to crush fractures of vertebral bodies and fractures of the distal forearm in women in their 60s and 70s. Type 2 osteoporosis, by contrast, results from the slower age-related cortical and travecular bone loss that occurs in both sexes. It typically leads to fractures of the proximal femur in elderly people.
Secondary osteoporosis accounts for about 20 per cent of cases in women and 40 per cent of cases in men. Subgroups include endocrine (thyrotoxicosis – see under THYROID GLAND, DISEASES OF, primary HYPERPARATHYROIDISM, CUSHING’S SYNDROME and HYPOGONADISM); gastrointestinal (malabsorption syndrome, e.g. COELIAC DISEASE, or liver disease, e.g. primary biliary CIRRHOSIS); rheumatological (RHEUMATOID ARTHRITIS or ANKYLOSING SPONDYLITIS); malignancy (multiple MYELOMA or metastatic CARCINOMA); and drugs (CORTICOSTEROIDS, HEPARIN). Additional risk factors for osteoporosis include smoking, high alcohol intake, physical inactivity, thin body-type and heredity.
Individuals at risk of osteopenia, or with an osteoporosis-related fracture, need investigation with spinal radiography and bone densitometry. A small fall in bone density results in a large increase in the risk of fracture, which has important implications for preventing and treating osteoporosis.
Treatment Antiresorptive drugs: hormone replacement therapy – also valuable in treating menopausal symptoms; treatment for at least ?ve years is necessary, and prolonged use may increase risk of breast cancer. Cyclical oral administration of disodium etidronate – one of the bisphosphonate group of drugs – with calcium carbonate is also used (poor absorption means the etidronate must be taken on an empty stomach). Calcitonin – currently available as a subcutaneous injection; a nasal preparation with better tolerance is being developed. Calcium (1,000 mg daily) seems useful in older patients, although probably ine?ective in perimenopausal women, and it is a safe preparation. Vitamin D and calcium – recent evidence suggests value for elderly patients. Anabolic steroids, though androgenic side-effects (masculinisation) make these unacceptable for most women.
With established osteoporosis, the aim of treatment is to relieve pain (with analgesics and physical measures, e.g. lumbar support) and reduce the risk of further fractures: improvement of bone mass, the prevention of falls, and general physiotherapy, encouraging a healthier lifestyle with more daily exercise.
Further information is available from the National Osteoporosis Society.
Paget’s disease (see also separate entry) is a common disease of bone in the elderly, caused by overactivity of the osteoclasts (cells concerned with removal of old bone, before new bone is laid down by osteoblasts). The bone affected thickens and bows and may become painful. Treatment with calcitonin and bisphosphonates may slow down the osteoclasts, and so hinder the course of the disease, but there is no cure.
If bone loses its blood supply (avascular necrosis) it eventually fractures or collapses. If the blood supply does not return, bone’s normal capacity for healing is severely impaired.
For the following diseases see separate articles: RICKETS; ACROMEGALY; OSTEOMALACIA; OSTEOGENESIS IMPERFECTA.
Tumours of bone These can be benign (non-cancerous) or malignant (cancerous). Primary bone tumours are rare, but secondaries from carcinoma of the breast, prostate and kidneys are relatively common. They may form cavities in a bone, weakening it until it breaks under normal load (a pathological fracture). The bone eroded away by the tumour may also cause problems by causing high levels of calcium in the plasma.
EWING’S TUMOUR is a malignant growth affecting long bones, particularly the tibia (calfbone). The presenting symptoms are a throbbing pain in the limb and a high temperature. Treatment is combined surgery, radiotherapy and chemotherapy.
MYELOMA is a generalised malignant disease of blood cells which produces tumours in bones which have red bone marrow, such as the skull and trunk bones. These tumours can cause pathological fractures.
OSTEOID OSTEOMA is a harmless small growth which can occur in any bone. Its pain is typically removed by aspirin.
OSTEOSARCOMA is a malignant tumour of bone with a peak incidence between the ages of ten and 20. It typically involves the knees, causing a warm tender swelling. Removal of the growth with bone conservation techniques can often replace amputation as the de?nitive treatment. Chemotherapy can improve long-term survival.... bone, disorders of
The speciality of anaesthesia broadly covers its provision for SURGERY, intensive therapy (intensive care), chronic pain management, acute pain management and obstetric analgesia. Anaesthetists in Britain are trained specialists with a medical degree, but in many countries some anaesthetists may be nurse practitioners working under the supervision of a medical anaesthetist.
The anaesthetist will assess the patient’s ?tness for anaesthesia, choose and perform the appropriate type of anaesthetic while monitoring and caring for the patient’s well-being, and, after the anaesthetic, supervise recovery and the provision of post-operative pain relief.
Anaesthesia may be broadly divided into general and local anaesthesia. Quite commonly the two are combined to allow continued relief of pain at the operation site after the patient awakens.
General anaesthesia is most often produced by using a combination of drugs to induce a state of reversible UNCONSCIOUSNESS. ‘Balanced’ anaesthesia uses a combination of drugs to provide unconsciousness, analgesia, and a greater or lesser degree of muscle relaxation.
A general anaesthetic comprises induction, maintenance and recovery. Historically, anaesthesia has been divided into four stages (see below), but these are only clearly seen during induction and maintenance of anaesthesia using inhalational agents alone.
(1) Onset of induction to unconsciousness
(2) Stage of excitement
(3) Surgical anaesthesia
(4) Overdosage
Induction involves the initial production of unconsciousness. Most often this is by INTRAVENOUS injection of a short-acting anaesthetic agent such as PROPOFOL, THIOPENTONE or ETOMIDATE, often accompanied by additional drugs such as ANALGESICS to smooth the process. Alternatively an inhalational technique may be used.
Maintenance of anaesthesia may be provided by continuous or intermittent use of intravenous drugs, but is commonly provided by administration of OXYGEN and NITROUS OXIDE or air containing a volatile anaesthetic agent. Anaesthetic machines are capable of providing a constant concentration of these, and have fail-safe mechanisms and monitors which guard against the patient’s receiving a gas mixture with inadequate oxygen (see HYPOXIC). The gases are adminstered to the patient via a breathing circuit either through a mask, a laryngeal mask or via ENDOTRACHEAL INTUBATION. In recent years, concerns about side-effects and pollution caused by volatile agents have led to increased popularity of total intravenous anaesthesia (TIVA).
For some types of surgery the patient is paralysed using muscle relaxants and then arti?cially ventilated by machine (see VENTILATOR). Patients are closely monitored during anaesthesia by the anaesthetist using a variety of devices. Minimal monitoring includes ELECTROCARDIOGRAM (ECG), blood pressure, PULSE OXIMETRY, inspired oxygen and end-tidal carbon-dioxide concentration – the amount of carbon dioxide breathed out when the lungs are at the ‘empty’ stage of the breathing cycle. Analgesic drugs (pain relievers) and local or regional anaesthetic blocks are often given to supplement general anaesthesia.
Volatile anaesthetics are either halogenated hydrocarbons (see HALOTHANE) or halogenated ethers (iso?urane, en?urane, des?urane and sevo?urane). The latter two are the most recently introduced agents, and produce the most rapid induction and recovery – though on a worldwide basis halothane, ether and chloroform are still widely used.
Despite several theories, the mode of action of these agents is not fully understood. Their e?cacy is related to how well they dissolve into the LIPID substances in nerve cells, and it is thought that they act at more than one site within brain cells – probably at the cell membrane. By whatever method, they reversibly depress the conduction of impulses within the CENTRAL NERVOUS SYSTEM and thereby produce unconsciousness.
At the end of surgery any muscle relaxant still in the patient’s body is reversed, the volatile agent is turned o? and the patient breathes oxygen or oxygen-enriched air. This is the reversal or recovery phase of anaesthesia. Once the anaesthetist is satis?ed with the degree of recovery, patients are transferred to a recovery area within the operating-theatre complex where they are cared for by specialist sta?, under the supervision of an anaesthetist, until they are ready to return to the ward. (See also ARTIFICIAL VENTILATION OF THE LUNGS.) Local anaesthetics are drugs which reversibly block the conduction of impulses in nerves. They therefore produce anaesthesia (and muscle relaxation) only in those areas of the body served by the nerve(s) affected by these drugs. Many drugs have some local anaesthetic action but the drugs used speci?cally for this purpose are all amide or ester derivatives of aromatic acids. Variations in the basic structure produce drugs with di?erent speeds of onset, duration of action and preferential SENSORY rather than MOTOR blockade (stopping the activity in the sensory or motor nerves respectively).
The use of local rather than general anaesthesia will depend on the type of surgery and in some cases the unsuitability of the patient for general anaesthesia. It is also used to supplement general anaesthesia, relieve pain in labour (see under PREGNANCY AND LABOUR) and in the treatment of pain in persons not undergoing surgery. Several commonly used techniques are listed below:
LOCAL INFILTRATION An area of anaesthetised skin or tissue is produced by injecting local anaesthetic around it. This technique is used for removing small super?cial lesions or anaesthetising surgical incisions.
NERVE BLOCKS Local anaesthetic is injected close to a nerve or nerve plexus, often using a peripheral nerve stimulator to identify the correct point. The anaesthetic di?uses into the nerve, blocking it and producing anaesthesia in the area supplied by it.
SPINAL ANAESTHESIA Small volumes of local anaesthetic are injected into the cerebrospinal ?uid through a small-bore needle which has been inserted through the tissues of the back and the dura mater (the outer membrane surrounding the spinal cord). A dense motor and sensory blockade is produced in the lower half of the body. How high up in the body it reaches is dependent on the volume and dose of anaesthetic, the patient’s position and individual variation. If the block is too high, then respiratory-muscle paralysis and therefore respiratory arrest may occur. HYPOTENSION (low blood pressure) may occur because of peripheral vasodilation caused by sympathetic-nerve blockade. Occasionally spinal anaesthesia is complicated by a headache, perhaps caused by continuing leakage of cerebrospinal ?uid from the dural puncture point.
EPIDURAL ANAESTHESIA Spinal nerves are blocked in the epidural space with local anaesthetic injected through a ?ne plastic tube (catheter) which is introduced into the space using a special needle (Tuohy needle). It can be used as a continuous technique either by intermittent injections, an infusion or by patient-controlled pump. This makes it ideal for surgery in the lower part of the body, the relief of pain in labour and for post-operative analgesia. Complications include hypotension, spinal headache (less than 1:100), poor e?cacy, nerve damage (1:12,000) and spinal-cord compression from CLOT or ABSCESS (extremely rare).... anaesthesia
Adrenal glands These two glands, also known as suprarenal glands, lie immediately above the kidneys. The central or medullary portion of the glands forms the secretions known as ADRENALINE (or epinephrine) and NORADRENALINE. Adrenaline acts upon structures innervated by sympathetic nerves. Brie?y, the blood vessels of the skin and of the abdominal viscera (except the intestines) are constricted, and at the same time the arteries of the muscles and the coronary arteries are dilated; systolic blood pressure rises; blood sugar increases; the metabolic rate rises; muscle fatigue is diminished. The super?cial or cortical part of the glands produces steroid-based substances such as aldosterone, cortisone, hydrocortisone, and deoxycortone acetate, for the maintenance of life. It is the absence of these substances, due to atrophy or destruction of the suprarenal cortex, that is responsible for the condition known as ADDISON’S DISEASE. (See CORTICOSTEROIDS.)
Ovaries and testicles The ovary (see OVARIES) secretes at least two hormones – known, respectively, as oestradiol (follicular hormone) and progesterone (corpus luteum hormone). Oestradiol develops (under the stimulus of the anterior pituitary lobe – see PITUITARY GLAND below, and under separate entry) each time an ovum in the ovary becomes mature, and causes extensive proliferation of the ENDOMETRIUM lining the UTERUS, a stage ending with shedding of the ovum about 14 days before the onset of MENSTRUATION. The corpus luteum, which then forms, secretes both progesterone and oestradiol. Progesterone brings about great activity of the glands in the endometrium. The uterus is now ready to receive the ovum if it is fertilised. If fertilisation does not occur, the corpus luteum degenerates, the hormones cease acting, and menstruation takes place.
The hormone secreted by the testicles (see TESTICLE) is known as TESTOSTERONE. It is responsible for the growth of the male secondary sex characteristics.
Pancreas This gland is situated in the upper part of the abdomen and, in addition to the digestive enzymes, it produces INSULIN within specialised cells (islets of Langerhans). This controls carbohydrate metabolism; faulty or absent insulin production causes DIABETES MELLITUS.
Parathyroid glands These are four minute glands lying at the side of, or behind, the thyroid (see below). They have a certain e?ect in controlling the absorption of calcium salts by the bones and other tissues. When their secretion is defective, TETANY occurs.
Pituitary gland This gland is attached to the base of the brain and rests in a hollow on the base of the skull. It is the most important of all endocrine glands and consists of two embryologically and functionally distinct lobes.
The function of the anterior lobe depends on the secretion by the HYPOTHALAMUS of certain ‘neuro-hormones’ which control the secretion of the pituitary trophic hormones. The hypothalamic centres involved in the control of speci?c pituitary hormones appear to be anatomically separate. Through the pituitary trophic hormones the activity of the thyroid, adrenal cortex and the sex glands is controlled. The anterior pituitary and the target glands are linked through a feedback control cycle. The liberation of trophic hormones is inhibited by a rising concentration of the circulating hormone of the target gland, and stimulated by a fall in its concentration. Six trophic (polypeptide) hormones are formed by the anterior pituitary. Growth hormone (GH) and prolactin are simple proteins formed in the acidophil cells. Follicle-stimulating hormone (FSH), luteinising hormone (LH) and thyroid-stimulating hormone (TSH) are glycoproteins formed in the basophil cells. Adrenocorticotrophic hormone (ACTH), although a polypeptide, is derived from basophil cells.
The posterior pituitary lobe, or neurohypophysis, is closely connected with the hypothalamus by the hypothalamic-hypophyseal tracts. It is concerned with the production or storage of OXYTOCIN and vasopressin (the antidiuretic hormone).
PITUITARY HORMONES Growth hormone, gonadotrophic hormone, adrenocorticotrophic hormone and thyrotrophic hormones can be assayed in blood or urine by radio-immunoassay techniques. Growth hormone extracted from human pituitary glands obtained at autopsy was available for clinical use until 1985, when it was withdrawn as it is believed to carry the virus responsible for CREUTZFELDT-JAKOB DISEASE (COD). However, growth hormone produced by DNA recombinant techniques is now available as somatropin. Synthetic growth hormone is used to treat de?ciency of the natural hormone in children and adults, TURNER’S SYNDROME and chronic renal insu?ciency in children.
Human pituitary gonadotrophins are readily obtained from post-menopausal urine. Commercial extracts from this source are available and are e?ective for treatment of infertility due to gonadotrophin insu?ciency.
The adrenocorticotrophic hormone is extracted from animal pituitary glands and has been available therapeutically for many years. It is used as a test of adrenal function, and, under certain circumstances, in conditions for which corticosteroid therapy is indicated (see CORTICOSTEROIDS). The pharmacologically active polypeptide of ACTH has been synthesised and is called tetracosactrin. Thyrotrophic hormone is also available but it has no therapeutic application.
HYPOTHALAMIC RELEASING HORMONES which affect the release of each of the six anterior pituitary hormones have been identi?ed. Their blood levels are only one-thousandth of those of the pituitary trophic hormones. The release of thyrotrophin, adrenocorticotrophin, growth hormone, follicle-stimulating hormone and luteinising hormone is stimulated, while release of prolactin is inhibited. The structure of the releasing hormones for TSH, FSH-LH, GH and, most recently, ACTH is known and they have all been synthesised. Thyrotrophin-releasing hormone (TRH) is used as a diagnostic test of thyroid function but it has no therapeutic application. FSH-LH-releasing hormone provides a useful diagnostic test of gonadotrophin reserve in patients with pituitary disease, and is now used in the treatment of infertility and AMENORRHOEA in patients with functional hypothalamic disturbance. As this is the most common variety of secondary amenorrhoea, the potential use is great. Most cases of congenital de?ciency of GH, FSH, LH and ACTH are due to defects in the hypothalamic production of releasing hormone and are not a primary pituitary defect, so that the therapeutic implication of this synthesised group of releasing hormones is considerable.
GALACTORRHOEA is frequently due to a microadenoma (see ADENOMA) of the pituitary. DOPAMINE is the prolactin-release inhibiting hormone. Its duration of action is short so its therapeutic value is limited. However, BROMOCRIPTINE is a dopamine agonist with a more prolonged action and is e?ective treatment for galactorrhoea.
Thyroid gland The functions of the thyroid gland are controlled by the pituitary gland (see above) and the hypothalamus, situated in the brain. The thyroid, situated in the front of the neck below the LARYNX, helps to regulate the body’s METABOLISM. It comprises two lobes each side of the TRACHEA joined by an isthmus. Two types of secretory cells in the gland – follicular cells (the majority) and parafollicular cells – secrete, respectively, the iodine-containing hormones THYROXINE (T4) and TRI-IODOTHYRONINE (T3), and the hormone CALCITONIN. T3 and T4 help control metabolism and calcitonin, in conjunction with parathyroid hormone (see above), regulates the body’s calcium balance. De?ciencies in thyroid function produce HYPOTHYROIDISM and, in children, retarded development. Excess thyroid activity causes thyrotoxicosis. (See THYROID GLAND, DISEASES OF.)... endocrine glands
Kody, Kodie, Kodee, Kodey, Kodea, Kodia... kodi
Cause Asthma runs in families, so that parents with asthma have a strong risk of having children with asthma, or with other atopic (see ATOPY) illnesses such as HAY FEVER or eczema (see DERMATITIS). There is therefore a great deal of interest in the genetic basis of the condition. Several GENES seem to be associated with the condition of atopy, in which subjects have a predisposition to form ANTIBODIES of the IgE class against allergens (see ALLERGEN) they encounter – especially inhaled allergens.
The allergic response in the lining of the airway leads to an in?ammatory reaction. Many cells are involved in this in?ammatory process, including lymphocytes, eosinophils, neutrophils and mast cells. The cells are attracted and controlled by a complex system of in?ammatory mediators. The in?amed airway-wall produced in this process is then sensitive to further allergic stimuli or to non-speci?c challenges such as dust, smoke or drying from the increased respiration during exercise. Recognition of this in?ammation has concentrated attention on anti-in?ammatory aspects of treatment.
Continued in?ammation with poor control of asthma can result in permanent damage to the airway-wall such that reversibility is reduced and airway-narrowing becomes permanent. Appropriate anti-in?ammatory therapy may help to prevent this damage.
Many allergens can be important triggers of asthma. House-dust mite, grass pollen and animal dander are the commonest problems. Occupational factors such as grain dusts, hard-metals fumes and chemicals in the plastic and paint industry are important in some adults. Viral infections are another common trigger, especially in young children.
The prevalence of asthma appears to be on the increase in most countries. Several factors have been linked to this increase; most important may be the vulnerability of the immature immune system (see IMMUNITY) in infants. High exposure to allergens such as house-dust mite early in life may prime the immune system, while reduced exposure to common viral infections may delay the maturation of the immune system. In addition, maternal smoking in pregnancy and infancy increases the risk.
Clinical course The major symptoms of asthma are breathlessness and cough. Occasionally cough may be the only symptom, especially in children, where night-time cough may be mistaken for recurrent infection and treated inappropriately with antibiotics.
The onset of asthma is usually in childhood, but it may begin at any age. In childhood, boys are affected more often than girls but by adulthood the sex incidence is equal. Children who have mild asthma are more likely to grow out of the condition as they go through their teenaged years, although symptoms may recur later.
The degree of airway-narrowing, and its change with time and treatment, can be monitored by measuring the peak expiratory ?ow with a simple monitor at home – a peak-?ow meter. The typical pattern shows the peak ?ow to be lowest in the early morning and this ‘morning dipping’ is often associated with disturbance of sleep.
Acute exacerbations of asthma may be provoked by infections or allergic stimuli. If they do not respond quickly and fully to medication, expert help should be sought urgently since oxygen and higher doses of drugs will be necessary to control the attack. In a severe attack the breathing rate and the pulse rate rise and the chest sounds wheezy. The peak-?ow rate of air into the lungs falls. Patients may be unable to talk in full sentences without catching their breath, and the reduced oxygen in the blood in very severe attacks may produce the blue colour of CYANOSIS in the lips and tongue. Such acute attacks can be very frightening for the patient and family.
Some cases of chronic asthma are included in the internationally agreed description CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) – a chronic, slowly progressive disorder characterised by obstruction of the air?ow persisting over several months.
Treatment The ?rst important consideration in the treatment of asthma is avoidance of precipitating factors. When this is a speci?c animal or occupational exposure, this may be possible; it is however more di?cult for house-dust mite or pollens. Exercise-induced asthma should be treated adequately rather than avoiding exercise.
Desensitisation injections using small quantities of speci?c allergens are used widely in some countries, but rarely in the UK as they are considered to have limited value since most asthma is precipitated by many stimuli and controlled adequately with simple treatment.
There are two groups of main drugs for the treatment of asthma. The ?rst are the bronchodilators which relax the smooth muscle in the wall of the airways, increase their diameter and relieve breathlessness. The most useful agents are the beta adrenergic agonists (see ADRENERGIC RECEPTORS) such as salbutamol and terbutaline. They are best given by inhalation into the airways since this reduces the general side-effects from oral use. These drugs are usually given to reverse airway-narrowing or to prevent its onset on exercise. However, longer-acting inhaled beta agonists such as salmeterol and formoterol or the theophyllines given in tablet form can be used regularly as prevention. The beta agonists can cause TREMOR and PALPITATION in some patients.
The second group of drugs are the antiin?ammatory agents that act to reduce in?ammation of the airway. The main agents in this group are the CORTICOSTEROIDS. They must be taken regularly, even when symptoms are absent. Given by inhalation they have few side-effects. In acute attacks, short courses of oral steroids are used; in very severe disease regular oral steroids may be needed. Other drugs have a role in suppressing in?ammation: sodium cromoglycate has been available for some years and is generally less e?ective than inhaled steroids. Newer agents directed at speci?c steps in the in?ammatory pathway, such as leukotriene receptor-antagonists, are alternative agents.
Treatment guidelines have been produced by various national and international bodies, such as the British Thoracic Society. Most have set out treatment in steps according to severity, with objectives for asthma control based on symptoms and peak ?ow. Patients should have a management plan that sets out their regular treatment and their appropriate response to changes in their condition.
Advice and support for research into asthma is provided by the National Asthma Campaign.
See www.brit-thoracic.org.uk
Prognosis Asthma is diagnosed in 15–20 per cent of all pre-school children in the developed world. Yet by the age of 15 it is estimated that fewer than 5 per cent still have symptoms. A study in 2003 reported on a follow-up of persons born in 1972–3 who developed asthma and still had problems at the age of nine. By the time these persons were aged 26, 27 per cent were still having problems; around half of that number had never been free from the illness and the other half had apparently lost it for a few years but it had returned.... asthma
There are few signi?cant di?erences between the various antimuscarinic drugs available, but some patients may tolerate one drug better than another or ?nd that they need to adjust their drug regimen in relation to food.... benzhexol
Benzodiazepines act at a speci?c centralnervous-system receptor or by potentiating the action of inhibitory neuro-transmitters. They have advantages over other sedatives by having some selectivity for anxiety rather than general sedation. They are safer in overdose. Unfortunately they may cause aggression, amnesia, excessive sedation, or confusion in the elderly. Those with long half-lives or with metabolites having long half-lives may produce a hangover e?ect, and DEPENDENCE on these is now well recognised, so they should not be prescribed for more than a few weeks. Commonly used benzodiazepines include nitrazepam, ?unitrazepam (a controlled drug), loprazolam, temazepam (a controlled drug) and chlormethiazole, normally con?ned to the elderly. All benzodiazepines should be used sparingly because of the risk of dependence.... benzodiazepines
The control centre of the whole nervous system is the brain, which is located in the skull or cranium. As well as controlling the nervous system it is the organ of thought, speech and emotion. The central nervous system controls the body’s essential functions such as breathing, body temperature (see HOMEOSTASIS) and the heartbeat. The body’s various sensations, including sight, hearing, touch, pain, positioning and taste, are communicated to the CNS by nerves distributed throughout the relevant tissues. The information is then sorted and interpreted by specialised areas in the brain. In response these initiate and coordinate the motor output, triggering such ‘voluntary’ activities as movement, speech, eating and swallowing. Other activities – for example, breathing, digestion, heart contractions, maintenance of BLOOD PRESSURE, and ?ltration of waste products from blood passing through the kidneys – are subject to involuntary control via the autonomic system. There is, however, some overlap between voluntary and involuntary controls.... brain
Habitat: The Himalayas from Kumaon to Khasia Hills. Cultivated in Indian gardens.
English: Squirrel Corn. (A related species, Corydalis cucullaria, known as Turkey Pea, occurs in Canada and the USA.)Action: Diuretic, alterative, anti- scrofula. Used for torpid and sluggish conditions, menstrual disorders and diseases due to vitiated blood. Also employed as a sedative for the relief of paralysis agitans and other muscular tremors.
A large number of physiologically active isoquinoline alkaloids have been isolated from the tubers of many species of Dicentra, but the use of Corydalis is not linked with the alkaloids they contain, only bulbocapnine, present in the tubers, exhibits therapeutic activity. It produces catalepsy in mammals and possesses sympathetic as well as parasympathetic central effects.It has been employed for the relief of paralysis agitans and other muscular tremors, vesticular nystagmus and similar conditions.The root contains protopine, cory- deline, bulbocapnine, cancentrine, de- hydrocancentrines A and B. Bicucul- line (an isoquinoline alkaloid) isolated from the tuber of Dicentra cucullaria, is a centrally-acting, spasmogenic antagonist of GABA.... dicentra canadensisPsychiatrists like to categorise mental illnesses because mental signs and symptoms do occur together in clusters or syndromes, each tending to respond to certain treatments. The idea that illnesses can be diagnosed simply by recognising their symptom patterns may not seem very scienti?c in these days of high technology. For most common mental illnesses, however, this is the only method of diagnosis; whatever is going wrong in the brain is usually too poorly understood and too subtle to show up in laboratory tests or computed tomography scans of the brain. And symptom-based definitions of mental illnesses are, generally, a lot more meaningful than the vague lay term ‘nervous breakdown’, which is used to cover an attack of anything from AGORAPHOBIA to total inability to function.
There is still a lot to learn about the workings of the brain, but psychiatry has developed plenty of practical knowledge about the probable causes of mental illness, ways of relieving symptoms, and ways of aiding recovery. Most experts now believe that mental illnesses generally arise from di?erent combinations of inherited risk and psychological STRESS, sometimes with additional environmental exposure – for example, viruses, drugs or ALCOHOL.
The range of common mental illnesses includes anxiety states, PHOBIA, DEPRESSION, alcohol and drug problems, the EATING DISORDERS anorexia and bulimia nervosa, MANIC DEPRESSION, SCHIZOPHRENIA, DEMENTIA, and a group of problems related to coping with life that psychiatrists call personality disorders.
Of these mental illnesses, dementia is the best understood. It is an irreversible and fatal form of mental deterioration (starting with forgetfulness and eventually leading to severe failure of all the brain’s functions), caused by rapid death of brain cells and consequent brain shrinkage. Schizophrenia is another serious mental illness which disrupts thought-processes, speech, emotions and perception (how the brain handles signals from the ?ve senses). Manic depression, in which prolonged ‘highs’ of extremely elevated mood and overexcitement alternate with abject misery, has similar effects on the mental processes. In both schizophrenia and manic depression the sufferer loses touch with reality, develops unshakeable but completely unrealistic ideas (delusions), and hallucinates (vividly experiences sensations that are not real, e.g. hears voices when there is nobody there). This triad of symptoms is called psychosis and it is what lay people, through fear and lack of understanding, sometimes call lunacy, madness or insanity.
The other mental illnesses mentioned above are sometimes called neuroses. But the term has become derogatory in ordinary lay language; indeed, many people assume that neuroses are mild disorders that only affect weak people who cannot ‘pull themselves together’, while psychoses are always severe. In reality, psychoses can be brief and reversible and neuroses can cause lifelong disability.
However de?ned and categorised, mental illness is a big public-health problem. In the UK, up to one in ?ve women and around one in seven men have had mental illness. About half a million people in Britain suffer from schizophrenia: it is three times commoner than cancer. And at any one time, up to a tenth of the adult population is ill with depression.
Treatment settings Most people with mental-health problems get the help they need from their own family doctor(s), without ever seeing a psychiatrist. General practictitioners in Britain treat nine out of ten recognised mental-health problems and see around 12 million adults with mental illness each year. Even for the one in ten of these patients referred to psychiatrists, general practitioners usually handle those problems that continue or recur.
Psychiatrists, psychiatric nurses, social workers, psychologists, counsellors and therapists often see patients at local doctors’ surgeries and will do home visits if necessary. Community mental-health centres – like general-practice health centres but catering solely for mental-health problems – o?er another short-cut to psychiatric help. The more traditional, and still more common, route to a psychiatrist for many people, however, is from the general practititioner to a hospital outpatient department.
Specialist psychiatric help In many ways, a visit to a psychiatrist is much like any trip to a hospital doctor – and, indeed, psychiatric clinics are often based in the outpatient departments of general hospitals. First appointments with psychiatrists can last an hour or more because the psychiatrist – and sometimes other members of the team such as nurses, doctors in training, and social workers – need to ask lots of questions and record the whole consultation in a set of con?dential case notes.
Psychiatric assessment usually includes an interview and an examination, and is sometimes backed up by a range of tests. The interview begins with the patient’s history – the personal story that explains how and, to some extent, why help is needed now. Mental-health problems almost invariably develop from a mixture of causes – emotional, social, physical and familial – and it helps psychiatrists to know what the people they see are normally like and what kind of lives they have led. These questions may seem unnecessarily intrusive, but they allow psychiatrists to understand patients’ problems and decide on the best way to help them.
The next stage in assessment is the mental-state examination. This is how psychiatrists examine minds, or at least their current state. Mental-state examination entails asking more questions and using careful observation to assess feelings, thoughts and mental symptoms, as well as the way the mind is working (for example, in terms of memory and concentration). During ?rst consultations psychiatrists usually make diagnoses and explain them. The boundary between a life problem that will clear up spontaneously and a mental illness that needs treatment is sometimes quite blurred; one consultation may be enough to put the problem in perspective and help to solve it.
Further assessment in the clinic may be needed, or some additional tests. Simple blood tests can be done in outpatient clinics but other investigations will mean referral to another department, usually on another day.
Further assessment and tests
PSYCHOLOGICAL TESTS Psychologists work in or alongside the psychiatric team, helping in both assessment and treatment. The range of psychological tests studies memory, intelligence, personality, perception and capability for abstract thinking. PHYSICAL TESTS Blood tests and brain scans may be useful to rule out a physical illness causing psychological symptoms. SOCIAL ASSESSMENT Many patients have social diffculties that can be teased out and helped by a psychiatric social worker. ‘Approved social workers’ have special training in the use of the Mental Health Act, the law that authorises compulsory admissions to psychiatric hospitals and compulsory psychiatric treatments. These social workers also know about all the mental-health services o?ered by local councils and voluntary organisations, and can refer clients to them. The role of some social workers has been widened greatly in recent years by the expansion of community care. OCCUPATIONAL THERAPY ASSESSMENT Mental-health problems causing practical disabilities – for instance, inability to work, cook or look after oneself – can be assessed and helped by occupational therapists.
Treatment The aims of psychiatric treatment are to help sufferers shake o?, or at least cope with, symptoms and to gain or regain an acceptable quality of life. A range of psychological and physical treatments is available.
COUNSELLING This is a widely used ‘talking cure’, particularly in general practice. Counsellors listen to their clients, help them to explore feelings, and help them to ?nd personal and practical solutions to their problems. Counsellors do not probe into clients’ pasts or analyse them. PSYCHOTHERAPY This is the best known ‘talking cure’. The term psychotherapy is a generalisation covering many di?erent concepts. They all started, however, with Sigmund Freud (see FREUDIAN THEORY), the father of modern psychotherapy. Freud was a doctor who discovered that, as well as the conscious thoughts that guide our feelings and actions, there are powerful psychological forces of which we are not usually aware. Applying his theories to his patients’ freely expressed thoughts, Freud was able to cure many illnesses, some of which had been presumed completely physical. This was the beginning of individual analytical psychotherapy, or PSYCHOANALYSIS. Although Freud’s principles underpin all subsequent theories about the psyche, many di?erent schools of thought have emerged and in?uenced psychotherapists (see ADLER; JUNGIAN ANALYSIS; PSYCHOTHERAPY). BEHAVIOUR THERAPY This springs from theories of human behaviour, many of which are based on studies of animals. The therapists, mostly psychologists, help people to look at problematic patterns of behaviour and thought, and to change them. Cognitive therapy is very e?ective, particularly in depression and eating disorders. PHYSICAL TREATMENTS The most widely used physical treatments in psychiatry are drugs. Tranquillising and anxiety-reducing BENZODIAZEPINES like diazepam, well known by its trade name of Valium, were prescribed widely in the 1960s and 70s because they seemed an e?ective and safe substitute for barbiturates. Benzodiazepines are, however, addictive and are now recommended only for short-term relief of anxiety that is severe, disabling, or unacceptably distressing. They are also used for short-term treatment of patients drying out from alcohol.
ANTIDEPRESSANT DRUGS like amitriptyline and ?uoxetine are given to lift depressed mood and to relieve the physical symptoms that sometimes occur in depression, such as insomnia and poor appetite. The side-effects of antidepressants are mostly relatively mild, when recommended doses are not exceeded – although one group, the monoamine oxidase inhibitors, can lead to sudden and dangerous high blood pressure if taken with certain foods.
Manic depression virtually always has to be treated with mood-stabilising drugs. Lithium carbonate is used in acute mania to lower mood and stop psychotic symptoms; it can also be used in severe depression. However lithium’s main use is to prevent relapse in manic depression. Long-term unwanted effects may include kidney and thyroid problems, and short-term problems in the nervous system and kidney may occur if the blood concentration of lithium is too high – therefore it must be monitored by regular blood tests. Carbamazepine, a treatment for EPILEPSY, has also been found to stabilise mood, and also necessitates blood tests.
Antipsychotic drugs, also called neuroleptics, and major tranquillisers are the only e?ective treatments for relieving serious mental illnesses with hallucinations and delusions. They are used mainly in schizophrenia and include the short-acting drugs chlorpromazine and clozapine as well as the long-lasting injections given once every few weeks like ?uphenazine decanoate. In the long term, however, some of the older antipsychotic drugs can cause a brain problem called TARDIVE DYSKINESIA that affects control of movement and is not always reversible. And the antipsychotic drugs’ short-term side-effects such as shaking and sti?ness sometimes have to be counteracted by other drugs called anticholinergic drugs such as procyclidine and benzhexol. Newer antipsychotic drugs such as clozapine do not cause tardive dyskinesia, but clozapine cannot be given as a long-lasting injection and its concentration in the body has to be monitored by regular blood tests to avoid toxicity. OTHER PHYSICAL TREATMENTS The other two physical treatments used in psychiatry are particularly controversial: electroconvulsive therapy (ECT) and psychosurgery. In ECT, which can be life-saving for patients who have severe life-threatening depression, a small electric current is passed through the brain to induce a ?t or seizure. Before the treatment the patient is anaesthetised and given a muscle-relaxing injection that reduces the magnitude of the ?t to a slight twitching or shaking. Scientists do not really understand how ECT works, but it does, for carefully selected patients. Psychosurgery – operating on the brain to alleviate psychiatric illness or di?cult personality traits – is extremely uncommon these days. Stereo-tactic surgery, in which small cuts are made in speci?c brain ?bres under X-ray guidance, has super-seded the more generalised lobotomies of old. The Mental Health Act 1983 ensures that psychosurgery is performed only when the patient has given fully informed consent and a second medical opinion has agreed that it is necessary. For all other psychiatric treatments (except another rare treatment, hormone implantation for reducing the sex drive of sex o?enders), either consent or a second opinion is needed – not both. TREATMENT IN HOSPITAL Psychiatric wards do not look like medical or surgical wards and sta? may not wear uniforms. Patients do not need to be in their beds during the day, so the beds are in separate dormitories. The main part of most wards is a living space with a day room, an activity and television room, quiet rooms, a dining room, and a kitchen. Ward life usually has a certain routine. The day often starts with a community meeting at which patients and nurses discuss issues that affect the whole ward. Patients may go to the occupational therapy department during the day, but there may also be some therapy groups on the ward, such as relaxation training. Patients’ symptoms and problems are assessed continuously during a stay in hospital. When patients seem well enough they are allowed home for trial periods; then discharge can be arranged. Patients are usually followed up in the outpatient clinic at least once.
TREATING PATIENTS WITH ACUTE PSYCHIATRIC ILLNESS Psychiatric emergencies – patients with acute psychiatric illness – may develop from psychological, physical, or practical crises. Any of these crises may need quick professional intervention. Relatives and friends often have to get this urgent help because the sufferer is not ?t enough to do it or, if psychotic, does not recognise the need. First, they should ring the person’s general practitioner. If the general practitioner is not available and help is needed very urgently, relatives or friends should phone the local social-services department and ask for the duty social worker (on 24-hour call). In a dire emergency, the police will know what to do.
Any disturbed adult who threatens his or her own or others’ health and safety and refuses psychiatric help may be moved and detained by law. The Mental Health Act of 1983 authorises emergency assessment and treatment of any person with apparent psychiatric problems that ful?l these criteria.
Although admission to hospital may be the best solution, there are other ways that psychiatric services can respond to emergencies. In some districts there are ‘crisis intervention’ teams of psychiatrists, nurses, and social workers who can visit patients urgently at home (at a GP’s request) and, sometimes, avert unnecessary admission. And research has shown that home treatment for a range of acute psychiatric problems can be e?ective.
LONG-TERM TREATMENT AND COMMUNITY CARE Long-term treatment is often provided by GPs with support and guidance from psychiatric teams. That is ?ne for people whose problems allow them to look after themselves, and for those with plenty of support from family and friends. But some people need much more intensive long-term treatment and many need help with running their daily lives.
Since the 1950s, successive governments have closed the old psychiatric hospitals and have tried to provide as much care as possible outside hospital – in ‘the community’. Community care is e?ective as long as everyone who needs inpatient care, or residential care, can have it. But demand exceeds supply. Research has shown that some homeless people have long-term mental illnesses and have somehow lost touch with psychiatric services. Many more have developed more general long-term health problems, particularly related to alcohol, without ever getting help.
The NHS and Community Care Act 1990, in force since 1993, established a new breed of professionals called care managers to assess people whose long-term illnesses and disabilities make them unable to cope completely independently with life. Care managers are given budgets by local councils to assess people’s needs and to arrange for them tailor-made packages of care, including services like home helps and day centres. But co-ordination between health and social services has sometimes failed – and resources are limited – and the government decided in 1997 to tighten up arrangements and pool community-care budgets.
Since 1992 psychiatrists have had to ensure that people with severe mental illnesses have full programmes of care set up before discharge from hospital, to be overseen by named key workers. And since 1996 psychiatrists have used a new power called Supervised Discharge to ensure that the most vulnerable patients cannot lose touch with mental-health services. There is not, however, any law that allows compulsory treatment in the community.
There is ample evidence that community care can work and that it need not cost more than hospital care. Critics argue, however, that even one tragedy resulting from inadequate care, perhaps a suicide or even a homicide, should reverse the march to community care. And, according to the National Schizophrenia Fellowship, many of the 10–15 homicides a year carried out by people with severe mental illnesses result from inadequate community care.
Further information can be obtained from the Mental Health Act Commission, and from MIND, the National Association for Mental Health. MIND also acts as a campaigning and advice organisation on all aspects of mental health.... mental illness
Special needs The Children Act 1989, Education Acts 1981, 1986 and 1993, and the Chronically Sick and Disabled Persons Legislation 1979 impose various statutory duties to identify and provide assistance for children with special needs. They include the chronically ill as well as those with impaired development or disabilities such as CEREBRAL PALSY, or hearing, vision or intellectual impairment. Many CDTs keep a register of such children so that services can be e?ciently planned and evaluated. Parents of disabled children often feel isolated and neglected by society in general; they are frequently frustrated by the lack of resources available to help them cope with the sheer hard work involved. The CDT, through its key workers, does its best to absorb anger and divert frustration into constructive actions.
There are other groups of children who come to the attention of child health services. Community paediatricians act as advisers to adoption and fostering agencies, vital since many children needing alternative homes have special medical or educational needs or have behavioural or psychiatric problems. Many see a role in acting as advocates, not just for those with impairments but also for socially disadvantaged children, including those ‘looked after’ in children’s homes and those of travellers, asylum seekers, refugees and the homeless.
Child protection Regrettably, some children come to the attention of child health specialists because they have been beaten, neglected, emotionally or nutritionally starved or sexually assaulted by their parents or carers. Responsibility for the investigation of these children is that of local-authority social-services departments. However, child health professionals have a vital role in diagnosis, obtaining forensic evidence, advising courts, supervising the medical aspects of follow-up and teaching doctors, therapists and other professionals in training. (See CHILD ABUSE.)
School health services Once children have reached school age, the emphasis changes. The prime need becomes identifying those with problems that may interfere with learning – including those with special needs as de?ned above, but also those with behavioural problems. Teachers and parents are advised on how to manage these problems, while health promotion and health education are directed at children. Special problems, especially as children reach secondary school (aged 11–18) include accidents, substance abuse, psychosexual adjustment, antisocial behaviour, eating disorders and physical conditions which loom large in the minds of adolescents in particular, such as ACNE, short stature and delayed puberty.
There is no longer, in the UK, a universal school health service as many of its functions have been taken over by general practitioners and hospital and community paediatricians. However, most areas still have school nurses, some have school doctors, while others do not employ speci?c individuals for these tasks but share out aspects of the work between GPs, health visitors, community nurses and consultant paediatricians in child health.
Complementing their work is the community dental service whose role is to monitor the whole child population’s dental health, provide preventive programmes for all, and dental treatment for those who have di?culty using general dental services – for example, children with complex disability. All children in state-funded schools are dentally screened at ages ?ve and 15.
Successes and failures Since the inception of the NHS, hospital services for children have had enormous success: neonatal and infant mortality rates have fallen by two-thirds; deaths from PNEUMONIA have fallen from 600 per million children to a handful; and deaths from MENINGITIS have fallen to one-?fth of the previous level. Much of this has been due to the revolution in the management of pregnancy and labour, the invention of neonatal resuscitation and neonatal intensive care, and the provision of powerful antibiotics.
At the same time, some children acquire HIV infection and AIDS from their affected mothers (see AIDS/HIV); the prevalence of atopic (see ATOPY) diseases (ASTHMA, eczema – see DERMATITIS, HAY FEVER) is rising; more children attend hospital clinics with chronic CONSTIPATION; and little can be done for most viral diseases.
Community child health services can also boast of successes. The routine immunisation programme has wiped out SMALLPOX, DIPHTHERIA and POLIOMYELITIS and almost wiped out haemophilus and meningococcal C meningitis, measles and congenital RUBELLA syndrome. WHOOPING COUGH outbreaks continue but the death and chronic disability rates have been greatly reduced. Despite these huge health gains, continuing public scepticism about the safety of immunisation means that there can be no relaxation in the educational and health-promotion programme.
Services for severely and multiply disabled children have improved beyond all recognition with the closure of long-stay institutions, many of which were distinctly child-unfriendly. Nonetheless, scarce resources mean that families still carry heavy burdens. The incidence of SUDDEN INFANT DEATH SYNDROME (SIDS) has more than halved as a result of an educational programme based on ?rm scienti?c evidence that the risk can be reduced by putting babies to sleep on their backs, avoidance of parental smoking, not overheating, breast feeding and seeking medical attention early for illness.
Children have fewer accidents and better teeth but new problems have arisen: in the 1990s children throughout the developed world became fatter. A UK survey in 2004 found that one in ?ve children are overweight and one in 20 obese. Lack of exercise, the easy availability of food at all times and in all places, together with the rise of ‘snacking’, are likely to provoke signi?cant health problems as these children grow into adult life. Adolescents are at greater risk than ever of ill-health through substance abuse and unplanned pregnancy. Child health services are facing new challenges in the 21st century.... child development teams (cdts)
The potential side-effects of diuretics are HYPOKALAEMIA, DEHYDRATION, and GOUT (in susceptible individuals).
Extra-renal mechanisms (a) Inhibiting release of antidiuretic hormone (e.g. water, alcohol); (b) increased renal blood ?ow (e.g. dopamine in renal doses).
Renal mechanisms (a) Osmotic diuretics act by ‘holding’ water in the renal tubules and preventing its reabsorption (e.g. mannitol); (b) loop diuretics prevent sodium, and therefore water, reabsorption (e.g. FRUSEMIDE); (c) drugs acting on the cortical segment of the Loop of Henle prevent sodium reabsorption, but are ‘weaker’ than loop diuretics (e.g. THIAZIDES); (d) drugs acting on the distal tubule prevent sodium reabsorption by retaining potassium
(e.g. spironalactone).... diuretics
Electrocardiography
A method of recording the electrical activity of the heart muscles. Electrodes from a recording machine (electrocardiograph) are placed on the skin of the chest wall, arms and legs. The record of the electrical changes is called an ECG (electrocardiogram). The number of electrodes used depends on the complexity of the heart disorder being monitored. The procedure can be done in hospital, doctors’ surgeries and the patient’s home, and should not cause any discomfort.
In certain circumstances – for example, where a person has had bouts of chest pain – an exercise ECG may be performed under medical supervision. The patient walks on a treadmill while the ECG is recorded continuously.... electrocardiogram (ecg)
Habitat: Hedgerows, in better soils.
Features ? Up to six inches in height, the whole plant rather hairy. Leaves small, trifid higher up the stem, palmate lower down. Axillary tufts of small, greenish flowers.Part used ? Herb.Action: Diuretic, demulcent.
A widely-used diuretic acting directly on the parts. The 1 ounce to 1 pint infusion may be given in teacupful doses thrice daily in all kidney and bladder irregularities.... parsley piertAerosols Asthmatic patients (see ASTHMA) ?nd aerosol devices to be of value in controlling their attacks. They provide an e?ective and convenient way of applying drugs directly to the bronchi, thus reducing the risks of unwanted effects accompanying SYSTEMIC therapy. BRONCHODILATOR aerosols contain either a beta-sympathomimetic agent or ipratropium bromide, which is an ANTICHOLINERGIC drug.
ISOPRENALINE was the ?rst compound to be widely used as an aerosol. It did however stimulate beta1 receptors in the heart as well as beta2 receptors in the bronchi, and so produced palpitations and even dangerous cardiac arrhythmias. Newer beta-adrenoceptor agonists are speci?c for the beta2 receptors and thus have a greater safety margin. They include SALBUTAMOL, TERBUTALINE, rimiterol, fenoterol and reproterol. Unwanted effects such as palpitations, tremor and restlessness are uncommon with these, more speci?c preparations. In patients who get insu?cient relief from the beta-adrenoreceptor agonist, the drug ipratropium bromide is worth adding. Salmeterol is a longer-acting choice for twice-daily administration: it is not intended for the relief of acute attacks, for which shorter-acting beta2 stimulants such as salbutamol should be used. Salmeterol should be added to existing corticosteroid therapy (see CORTICOSTEROIDS), rather than replacing it.
Patients must be taught carefully and observed while using their inhalers. It is important for them to realise that if the aerosol no longer gives more than slight transient relief, they should not increase the dose but seek medical help.... inhalants
Tariane, Tarianne, Taryan, Taryanne... tarian
Most GPs work in groups of self-employed individuals, who contract their services to the local Primary Care Trust (PCT) – see below. Those in full partnership are called principals, but an increasing number now work as non-principals – that is, they are employees rather than partners in a practice. Alternatively, they might be salaried employees of a PCT. The average number of patients looked after by a full-time GP is 1,800 and the average duration of consultation about 10 minutes. GPs need to be able to deal with all common medical conditions and be able to recognise conditions that require specialist help, especially those requiring urgent action.
Until the new General Medical Services Contract was introduced in 2004, GPs had to take individual responsibility for providing ‘all necessary medical services’ at all times to their patient list. Now, practices rather than individuals share this responsibility. Moreover, the contract now applies only to the hours between
8.00 a.m. and 6.30 p.m., Mondays to Fridays; out-of-hours primary care has become the responsibility of PCTs. GPs still have an obligation to visit patients at home on weekdays in case of medical need, but home-visiting as a proportion of GP work has declined steadily since the NHS began. By contrast, the amount of time spent attending to preventive care and organisational issues has steadily increased. The 2004 contract for the ?rst time introduced payment for speci?c indicators of good clinical care in a limited range of conditions.
A telephone advice service, NHS Direct, was launched in 2000 to give an opportunity for patients to ‘consult’ a trained nurse who guides the caller on whether the symptoms indicate that self-care, a visit to a GP or a hospital Accident & Emergency department, or an ambulance callout is required. The aim of this service is to give the patient prompt advice and to reduce misuse of the skills of GPs, ambulance sta? and hospital facilities.
Training of GPs Training for NHS general practice after quali?cation and registration as a doctor requires a minimum of two years’ post-registration work in hospital jobs covering a variety of areas, including PAEDIATRICS, OBSTETRICS, care of the elderly and PSYCHIATRY. This is followed by a year or more working as a ‘registrar’ in general practice. This ?nal year exposes registrars to life as a GP, where they start to look after their own patients, while still closely supervised by a GP who has him- or herself been trained in educational techniques. Successful completion of ‘summative assessment’ – regular assessments during training – quali?es registrars to become GPs in their own right, and many newly quali?ed GPs also sit the membership exam set by the Royal College of General Practitioners (see APPENDIX 8: PROFESSIONAL ORGANISATIONS).
A growing number of GP practices o?er educational attachments to medical students. These attachments provide experience of the range of medical and social problems commonly found in the community, while also o?ering them allocated time to learn clinical skills away from the more specialist environment of the hospital.
In addition to teaching commitments, many GPs are also choosing to spend one or two sessions away from their practices each week, doing other kinds of work. Most will work in, for example, at least one of the following: a hospital specialist clinic; a hospice; occupational medicine (see under OCCUPATIONAL HEALTH, MEDICINE AND DISEASES); family-planning clinics; the police or prison services. Some also become involved in medical administration, representative medicopolitics or journalism. To help them keep up to date with advances and changes in medicine, GPs are required to produce personal-development plans that outline any educational activities they have completed or intend to pursue during the forthcoming year.
NHS GPs are allowed to see private patients, though this activity is not widespread (see PRIVATE HEALTH CARE).
Primary Care Trusts (PCTs) Groups of GPs (whether working alone, or in partnership with others) are now obliged by the NHS to link communally with a number of other GPs in the locality, to form Primary Care Trusts (PCTs). Most have a membership of about 30 GPs, working within a de?ned geographical area, in addition to the community nurses and practice counsellors working in the same area; links are also made to local council social services so that health and social needs are addressed together. Some PCTs also run ambulance services.
One of the roles of PCTs is to develop primary-care services that are appropriate to the needs of the local population, while also occupying a powerful position to in?uence the scope and quality of secondary-care services. They are also designed to ensure equity of resources between di?erent GP surgeries, so that all patients living in the locality have access to a high quality and uniform standard of service.
One way in which this is beginning to happen is through the introduction of more overt CLINICAL GOVERNANCE. PCTs devise and help their member practices to conduct CLINICAL AUDIT programmes and also encourage them to participate in prescribing incentive schemes. In return, practices receive payment for this work, and the funds are used to improve the services they o?er their patients.... general practitioner (gp)
Sulphonylureas The main group of hypoglycaemic agents, these act on the beta cells to stimulate insulin release; consequently they are e?ective only when there is some residual pancreatic beta-cell activity (see INSULIN). They also act on peripheral tissues to increase sensitivity, although this is less important. All sulphonylureas may lead to HYPOGLYCAEMIA four hours or more after food, but this is relatively uncommon, and usually an indication of overdose.
There are several di?erent sulphonylureas; apart from some di?erences in their duration or action (and hence in their suitability for individual patients) there is little di?erence in their e?ectiveness. Only chlorpropamide has appreciably more side-effects – mainly because of its prolonged duration of action and consequent risk of hypoglycaemia. There is also the common and unpleasant chlorpropamide/ alcohol-?ush phenomenon when the patient takes alcohol. Selection of an individual sulphonylurea depends on the patient’s age and renal function, and often just on personal preference. Elderly patients are particularly prone to the risks of hypoglycaemia when long-acting drugs are used. In these patients chlorpropamide, and preferably glibenclamide, should be avoided and replaced by others such as gliclazide or tolbutamide.
These drugs may cause weight gain and are indicated only if poor control persists despite adequate attempts at dieting. They should not be used during breast feeding, and caution is necessary in the elderly and in those with renal or hepatic insu?ciency. They should also be avoided in porphyria (see PORPHYRIAS). During surgery and intercurrent illness (such as myocardial infarction, COMA, infection and trauma), insulin therapy should be temporarily substituted. Insulin is generally used during pregnancy and should be used in the presence of ketoacidosis.
Side-effects Chie?y gastrointestinal disturbances and headache; these are generally mild and infrequent. After drinking alcohol, chlorpropamide may cause facial ?ushing. It also may enhance the action of antidiuretic hormone (see VASOPRESSIN), very rarely causing HYPONATRAEMIA.
Sensitivity reactions are very rare, usually occurring in the ?rst six to eight weeks of therapy. They include transient rashes which rarely progress to erythema multiforme (see under ERYTHEMA) and exfoliate DERMATITIS, fever and jaundice; chlorpropamide may also occasionally result in photosensitivity. Rare blood disorders include THROMBOCYTOPENIA, AGRANULOCYTOSIS and aplastic ANAEMIA.
Biguanides Metformin, the only available member of this group, acts by reducing GLUCONEOGENESIS and by increasing peripheral utilisation of glucose. It can act only if there is some residual insulin activity, hence it is only of value in the treatment of non-insulin dependent (type 2) diabetics. It may be used alone or with a sulphonylurea, and is indicated when strict dieting and sulphonylurea treatment have failed to control the diabetes. It is particularly valuable in overweight patients, in whom it may be used ?rst. Metformin has several advantages: hypoglycaemia is not usually a problem; weight gain is uncommon; and plasma insulin levels are lowered. Gastrointestinal side-effects are initially common and persistent in some patients, especially when high doses are being taken. Lactic acidosis is a rarely seen hazard occurring in patients with renal impairment, in whom metformin should not be used.
Other antidiabetics Acarbose is an inhibitor of intestinal alpha glucosidases (enzymes that process GLUCOSIDES), delaying the digestion of starch and sucrose, and hence the increase in blood glucose concentrations after a meal containing carbohydrate. It has been introduced for the treatment of type 2 patients inadequately controlled by diet or diet with oral hypoglycaemics.
Guar gum, if taken in adequate doses, acts by delaying carbohydrate absorption, and therefore reducing the postprandial blood glucose levels. It is also used to relieve symptoms of the DUMPING SYNDROME.... hypoglycaemic agents
The difference between German (wild) and Roman:– German is stronger, acting beneficially on mucous surfaces. Roman Chamomile, is less bitter, more soothing to the lungs, and more directly hastens menstrual flow.
Externally as a compress of the pulped flowers (fresh), both kinds are used for lumbago, gouty joints, sciatica, neuralgia and local inflammation. ... chamomile
In men, superficial adipose tissue accumulates around the shoulders, waist, and abdomen; in women, it occurs on the breasts, hips, and thighs.... adipose tissue
Acquired immunity depends upon the immune system recognising a substance as foreign the ?rst time it is encountered, storing this information so that it can mount a reaction the next time the substance enters the body. This is the usual outcome of natural infection or prophylactic IMMUNISATION. What happens is that memory of the initiating ANTIGEN persists in selected lymphocytes (see LYMPHOCYTE). Further challenge with the same antigen stimulates an accelerated, more vigorous secondary response by both T- and B-lymphocytes (see below). Priming the immune system in this manner forms the physiological basis for immunisation programmes.
Foreign substances which can provoke an immune response are termed ‘antigens’. They are usually proteins but smaller molecules such as drugs and chemicals can also induce an immune response. Proteins are taken up and processed by specialised cells called ‘antigenpresenting cells’, strategically sited where microbial infection may enter the body. The complex protein molecules are broken down into short amino-acid chains (peptides – see PEPTIDE) and transported to the cell surface where they are presented by structures called HLA antigens (see HLA SYSTEM).
Foreign peptides presented by human leucocyte antigen (HLA) molecules are recognised by cells called T-lymphocytes. These originate in the bone marrow and migrate to the THYMUS GLAND where they are educated to distinguish between foreign peptides, which elicit a primary immune response, and self-antigens (that is, constituents of the person themselves) which do not. Non-responsiveness to self-antigens is termed ‘tolerance’ (see AUTOIMMUNITY). Each population or clone of T-cells is uniquely responsive to a single peptide sequence because it expresses a surface molecule (‘receptor’) which ?ts only that peptide. The responsive T-cell clone induces a speci?c response in other T-and B-lymphocyte populations. For example, CYTOTOXIC T-cells penetrate infected tissues and kill cells which express peptides derived from invading micro-organisms, thereby helping to eliminate the infection.
B-lymphocytes secrete ANTIBODIES which are collectively termed IMMUNOGLOBULINS (Ig)
– see also GAMMA-GLOBULIN. Each B-cell population (clone) secretes antibody uniquely speci?c for antigens encountered in the blood, extracellular space, and the LUMEN of organs such as the respiratory passages and gastrointestinal tract.
Antibodies belong to di?erent Ig classes; IgM antibodies are synthesised initially, followed by smaller and therefore more penetrative IgG molecules. IgA antibodies are adapted to cross the surfaces of mucosal tissues so that they can adhere to organisms in the gut, upper and lower respiratory passages, thereby preventing their attachment to the mucosal surface. IgE antibodies also contribute to mucosal defence but are implicated in many allergic reactions (see ALLERGY).
Antibodies are composed of constant portions, which distinguish antibodies of di?erent class; and variable portions, which confer unique antigen-binding properties on the product of each B-cell clone. In order to match the vast range of antigens that the immune system has to combat, the variable portions are synthesised under the instructions of a large number of encoding GENES whose products are assembled to make the ?nal antibody. The antibody produced by a single B-cell clone is called a monoclonal antibody; these are now synthesised and used for diagnostic tests and in treating certain diseases.
Populations of lymphocytes with di?erent functions, and other cells engaged in immune responses, carry distinctive protein markers. By convention these are classi?ed and enumerated by their ‘CD’ markers, using monoclonal antibodies speci?c for each marker.
Immune responses are in?uenced by cytokines which function as HORMONES acting over a short range to accelerate the activation and proliferation of other cell populations contributing to the immune response. Speci?c immune responses collaborate with nonspeci?c defence mechanisms. These include the COMPLEMENT SYSTEM, a protein-cascade reaction designed to eliminate antigens neutralised by antibodies and to recruit cell populations which kill micro-organisms.... immunity
Insulin is extracted mainly from pork pancreas and puri?ed by crystallisation; it may be made biosynthetically by recombinant DNA technology using Escherichia coli, or semisynthetically by enzymatic modi?cation of porcine insulin to produce human insulin. The latter is the form now generally used, although some patients ?nd it unsuitable and have to return to porcine insulin.
The hormone acts by enabling the muscles and other tissues requiring sugar for their activity to take up this substance from the blood. All insulin preparations are to a greater or lesser extent immunogenic in humans, but immunological resistance to insulin action is uncommon.
Previously available in three strengths, of 20, 40, and 80 units per millilitre (U/ml), these have now largely been replaced by a standard strength of 100 U/ml (U100). Numerous different insulin preparations are listed; these differ in their speed of onset and duration of action, and hence vary in their suitability for individual patients.
Insulin is inactivated by gastrointestinal enzymes and is therefore generally given by subcutaneous injection, usually into the upper arms, thighs, buttocks, or abdomen. Some insulins are also available in cartridge form, which may be administered by injection devices (‘pens’). The absorption may vary from di?erent sites and with strenuous activity. About 25 per cent of diabetics require insulin treatment: most children from the onset, and all patients presenting with ketoacidosis. Insulin is also often needed by those with a rapid onset of symptoms such as weight loss, weakness, and sometimes vomiting, often associated with ketonuria.
The aim of treatment is to maintain good control of blood glucose concentration, while avoiding severe HYPOGLYCAEMIA; this is usually achieved by a regimen of preprandial injections of short-acting insulin (often with a bedtime injection of long-acting insulin). Insulin may also be given by continuous subcutaneous infusion with an infusion pump. This technique has many disadvantages: patients must be well motivated and able to monitor their own blood glucose, with access to expert advice both day and night; it is therefore rarely used.
Hypoglycaemia is a potential hazard for many patients converting from porcine to human insulin, because human insulin may result in them being unaware of classical hypoglycaemic warning symptoms. Drivers must be particularly careful, and individuals may be forbidden to drive if they have frequent or severe hypoglycaemic attacks. For this reason, insurance companies should be warned, and diabetics should – after taking appropriate medical advice – either return to porcine insulin or consider stopping driving.... insulin
Habitat: Throughout the warmer parts of India.
Ayurvedic: Granthiparni, Kaaka- puchha.Folk: Gathivan, Deepamaal (Maharashtra).Action: Leaves—spasmolytic. Ash of flower head—applied to burns and scalds, in ringworm and other skin diseases.
The Ayurvedic Pharmacopoeia ofIn- dia recommends the root in cough, bronchitis and dyspnoea.The root contains n-octacosanol, n-octacosanoic acid, quercetin, 4,6,7- trimethoxy-5-methylchromene-2-one, campesterol and beta-sitosterol-beta- D-glucopyranoside.The plant contains 4,6,7-trimethoxy- 5-methyl-chromene-2-one.The leaves contain neptaefolin, nep- taefuran, neptaefuranol, neptaefolinol, leonitin, neptaefolinin and (-)-55, 6- octadecadienoic acid.The seed oil contains oleic, linoleic, palmitic and stearic acids. The fattyFamily: Labiatae; Lamiaceae.Habitat: Native to Europe; also distributed in Himalayas from Kashmir to Kumaon.
English: Common Motherwort, Lion's Tail.Unani: Baranjaasif. (Also equated with Artemesia vulgaris Linn; and Achillea millifolium Linn.)Action: Stomachic, laxative, antispasmodic, diaphoretic, em- menagogue (used in absent or painful menstruation, premenstrual tension, menopausal flushes). Hypnotic, sedative. Used as a cardiac tonic. (Studies in China have shown that Motherwort extracts show antiplatelet aggregation actions and decrease the levels of blood lipids.)
Key application: In nervous cardiac disorders and as adjuvant for thyroid hyperfunction. (German Commission E.) As antispasmodic. (The British Herbal Pharmacopoeia.) The British Herbal Compendium indicated its use for patients who have neuropathic cardiac disorders and cardiac complaints of nervous origin.The plant contains diterpene bitter principles, iridoid monoterpenes, flavonoids including rutin and querci- trin, leonurin, betaine, caffeic acid derivatives, tannins and traces of a volatile oil.The herb is a slow acting adjuvant in functional and neurogenic heart diseases. Its sedative and spasmolytic properties combine well with Valeriana officinalis or other cardioactive substances.The herb contains several components with sedative effects—alpha- pinene, benzaldehyde, caryophyllene, limonene and oleanolic acid. (Sharon M. Herr.)Habitat: Western Europe. Seeds are imported into India from Persia.
English: Pepper-Grass.Unani: Bazr-ul-khumkhum, Todari (white var.).Action: Seeds—blood purifier; prescribed in bronchitis.
The fatty acid of the oil are: oleic 12.9, linoleic 47.87, linolenic 5.43, erucic 31.97, stearic 0.54 and palmitic 1.22%.The seed mucilage on hydrolysis gave galactose, arabinose, rhamnose and galacturonic acid.Flowering tops and seeds contain a bitter principle, lepidin.The plant yield a sulphur-containing volatile oil.... leonurus cardiacaForm and position Each lung is a sponge-like cone, pink in children and grey in adults. Its apex projects into the neck, with the base resting on the DIAPHRAGM. Each lung is enveloped by a closed cavity, the pleural cavity, consisting of two layers of pleural membrane separated by a thin layer of ?uid. In healthy states this allows expansion and retraction as breathing occurs.
Heart/lung connections The HEART lies in contact with the two lungs, so that changes in lung volume inevitably affect the pumping action of the heart. Furthermore, both lungs are connected by blood vessels to the heart. The pulmonary artery passes from the right ventricle and divides into two branches, one of which runs straight outwards to each lung, entering its substance along with the bronchial tube at the hilum or root of the lung. From this point also emerge the pulmonary veins, which carry the blood oxygenated in the lungs back to the left atrium.
Fine structure of lungs Each main bronchial tube, entering the lung at the root, divides into branches. These subdivide again and again, to be distributed all through the substance of the lung until the ?nest tubes, known as respiratory bronchioles, have a width of only 0·25 mm (1/100 inch). All these tubes consist of a mucous membrane surrounded by a ?brous sheath. The surface of the mucous membrane comprises columnar cells provided with cilia (hair-like structures) which sweep mucus and unwanted matter such as bacteria to the exterior.
The smallest divisions of the bronchial tubes, or bronchioles, divide into a number of tortuous tubes known as alveolar ducts terminating eventually in minute sacs, known as alveoli, of which there are around 300 million.
The branches of the pulmonary artery accompany the bronchial tubes to the furthest recesses of the lung, dividing like the latter into ?ner and ?ner branches, and ending in a dense network of capillaries. The air in the air-vesicles is separated therefore from the blood only by two delicate membranes: the wall of the air-vesicle, and the capillary wall, through which exchange of gases (oxygen and carbon dioxide) readily takes place. The essential oxygenated blood from the capillaries is collected by the pulmonary veins, which also accompany the bronchi to the root of the lung.
The lungs also contain an important system of lymph vessels, which start in spaces situated between the air-vesicles and eventually leave the lung along with the blood vessels, and are connected with a chain of bronchial glands lying near the end of the TRACHEA.... lungs
(See also caries, dental.)... decalcification, dental
Methadone is valuable as a suppressant for non-productive cough, acting on the medullary ‘cough centre’ in the central nervous system. It is also helpful in weaning addicts o? morphine and heroin, having a slower onset of DEPENDENCE and a less severe withdrawal syndrome. When used for prolonged periods, methadone should not be given more often than twice daily, to avoid the risks of accumulation and opioid overdosage.... methadone hydrochloride
Side-effects include suppression of myelocytes in bone marrow, in?ammation of mucous membranes, and, rarely, PNEUMONITIS. It should be avoided whenever signi?cant renal impairment is present, while signi?cant pleural e?usion or ascites is also a contraindication. Blood counts should be carefully monitored whenever intrathecal methotrexate is given. Oral or parenteral folinic acid helps to prevent, or to speed recovery from, myelosuppression or mucositis.
Methotrexate is used in dermatology, where it may be indicated for cases of severe uncontrolled PSORIASIS unresponsive to conventional therapy; it may also be indicated for severe active RHEUMATOID ARTHRITIS. Because of its potentially severe haematological, pulmonary, gastrointestinal, and other toxicities it should be used only by specialists and appropriate renal and liver function tests carried out before and during treatment. It should be avoided in pregnancy, and conception should be avoided for at least six months after stopping, as should breast feeding. Concurrent administration of aspirin or other NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) reduces methotrexate excretion, increasing its toxicity, and should therefore be avoided whenever possible.... methotrexate
The phrase “sick role” describes the type of passive behaviour expected and allowed of a patient; people with social or emotional problems may unconsciously adopt this role to gain sympathy and understanding.... role-playing
Sensory These carry signals to the central nervous system (CNS) – the BRAIN and SPINAL CORD – from sensory receptors. These receptors respond to di?erent stimuli such as touch, pain, temperature, smells, sounds and light.
Motor These carry signals from the CNS to activate muscles or glands.
Interneurons These provide the interconnecting ‘electrical network’ within the CNS.
Structure Each neurone comprises a cell body, several branches called dendrites, and a single ?lamentous ?bre called an AXON. Axons may be anything from a few millimetres to a metre long; at their end are several branches acting as terminals through which electrochemical signals are sent to target cells, such as those of muscles, glands or the dendrites of another axon.
Axons of several neurones are grouped
together to form nerve tracts within the brain or spinal cord or nerve-?bres outside the CNS. Each nerve is surrounded by a sheath and contains bundles of ?bres. Some ?bres are medullated, having a sheath of MYELIN which acts as insulation, preventing nerve impulses from spreading beyond the ?bre conveying them.
The cellular part of the neurones makes up the grey matter of the brain and spinal cord – the former containing 600 million neurones. The dendrites meet with similar outgrowths from other neurones to form synapses. White matter is the term used for that part of the system composed of nerve ?bres.
Functions of nerves The greater part of the bodily activity originates in the nerve cells (see NERVE). Impulses are sent down the nerves which act simply as transmitters. The impulse causes sudden chemical changes in the muscles as the latter contract (see MUSCLE). The impulses from a sensory ending in the skin pass along a nerve-?bre to affect nerve cells in the spinal cord and brain, where they are perceived as a sensation. An impulse travels at a rate of about 30 metres (100 feet) per second. (See NERVOUS IMPULSE.)
The anterior roots of spinal nerves consist of motor ?bres leading to muscles, the posterior roots of sensory ?bres coming from the skin. The terms, EFFERENT and AFFERENT, are applied to these roots, because, in addition to motor ?bres, ?bres controlling blood vessels and secretory glands leave the cord in the anterior roots. The posterior roots contain, in addition to sensory ?bres, the nerve-?bres that transmit impulses from muscles, joints and other organs, which among other neurological functions provide the individual with his or her
proprioceptive faculties – the ability to know how various parts of the body are positioned.
The connection between the sensory and motor systems of nerves is important. The simplest form of nerve action is that known as automatic action. In this, a part of the nervous system, controlling, for example, the lungs, makes rhythmic discharges to maintain the regular action of the respiratory muscles. This controlling mechanism may be modi?ed by occasional sensory impressions and chemical changes from various sources.
Re?ex action This is an automatic or involuntary activity, prompted by fairly simple neurological circuits, without the subject’s consciousness necessarily being involved. Thus a painful pinprick will result in a re?ex withdrawal of the affected ?nger before the brain has time to send a ‘voluntary’ instruction to the muscles involved.
Voluntary Actions are more complicated than re?ex ones. The same mechanism is involved, but the brain initially exerts an inhibitory or blocking e?ect which prevents immediate re?ex action. Then the impulse, passing up to the cerebral hemispheres, stimulates cellular activity, the complexity of these processes depending upon the intellectual processes involved. Finally, the inhibition is removed and an impulse passes down to motor cells in the spinal cord, and a muscle or set of muscles is activated by the motor nerves. (Recent advances in magnetic resonance imaging (MRI) techniques have provided very clear images of nerve tracts in the brain which should lead to greater understanding of how the brain functions.) (See BRAIN; NERVOUS SYSTEM; SPINAL CORD.)... neuron(e)
Common side effects include constipation, dry mouth, and hypertension.
People taking this drug should have regular follow-ups and have their blood pressure and pulse monitored.... sibutramine
risk of an embolism. It is also prescribed to prevent emboli from developing on replacement valves (see heart-valve surgery). A faster-acting anticoagulant, such as heparin, may also be prescribed for the first few days following a deep-vein thrombosis or pulmonary embolism.
Warfarin may cause abnormal bleeding in different parts of the body, so regular tests are carried out to allow careful regulation of dosage.
Warfarin may also cause nausea, diarrhoea and a rash.... warfarin
Prostaglandins play an important part in the production of PAIN, and it is now known that ASPIRIN relieves pain by virtue of the fact that it prevents, or antagonises, the formation of certain prostaglandins. In addition, they play some, although as yet incompletely de?ned, part in producing in?ammatory changes. (See INFLAMMATION; NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS).)
Thus prostaglandins have potent biological effects, but their instability and rapid metabolism make them short-acting. They are produced but not stored by most living cells and act locally. The two most important prostaglandins are prostacycline and thromboxane: prostacycline is a vasodilator and an inhibitor of platelet aggregation; thromboxanes have the opposite effects and cause vasoconstriction and platelet aggregation. The NSAIDs act by blocking an ENZYME called cyclo-oxygenase which converts arachidonic acid to the precursors of the various prostaglandins. Despite their potent pharmacological properties, the role of prostaglandins in current therapeutics is limited and controversial. They have been used most successfully as an inhibitor of platelet aggregation in extra-corporeal haemoperfusion systems. The problems with the prostacyclines is that they have to be given intravenously as they are inactive by mouth, and continuous infusion is required because the drug is rapidly eliminated with a half-life of minutes. Side-effects tend to be severe because the drug is usually given at the highest dose the patient can tolerate. The hope for the future lies in the exploitation of the compound to generate, synthetically, stable orally active prostacycline analogues which will inhibit platelet aggregation and hence thrombotic events, and yet have minimal effects on the heart and blood vessels.... prostaglandins
Habitat: Native to China; cultivated in Kashmir, Himachal Pradesh and Kumaon.
English: Peach.Ayurvedic: Aaluka, Aaruka, Aru, Pichuka.Action: Fruit—mild tranquillizer, expectorant, diuretic, antipyretic. Bark or leaves—used as tea for morning sickness, dry and hard cough, whooping cough and bronchitis. Leaves—used in leucoderma.
Flowers—galactagogue. Peach seeds are a constituent of a traditional Chinese herbal drug which has been used for the treatment of gynaecological disorders such as hypermen- orrhea, dysmenorrhoea and infertility.Peach fruit extract containing nitrile glycosides, such as prunasin and amyg- dalin, has been reported to inhibit the growth of Sarcoma-180 cells in culture.Fast-acting, wrinkle-eliminating cosmetic formulations contain peach kernel extract as one of the components.The heartwood contains beta-sitos- terol and its D-glucoside, hentriacon- tane, hentriacontanol, and the flavo- noids naringenin, dihydrokaempferol, kaempferol and quercetin.... prunus persicaCauses There is a major immunogenetic predisposition to rheumatoid arthritis in people carrying the HLA-DR4 antigen (see HLA SYSTEM). Other minor immunogenetic factors have also been implicated. In addition, there is a degree of familial clustering which suggests other unidenti?ed genetic factors. Genetic factors cannot alone explain aetiology, and environmental and chance factors must be important, but these have yet to be identi?ed.
Epidemiology Rheumatoid arthritis more commonly occurs in women from the age of 30 onwards, the sex ratio being approximately 4:1. Typical rheumatoid arthritis may occur in adolescence, but in childhood chronic SYNOVITIS usually takes one of a number of di?erent patterns, classi?ed under juvenile chronic arthritis.
Pathology The primary lesion is an in?ammation of the synovial membrane of joints. The synovial ?uid becomes diluted with in?ammatory exudate: if this persists for months it leads to progressive destruction of articular CARTILAGE and BONE. Cartilage is replaced by in?ammatory tissue known as pannus; a similar tissue invades bone to form erosions. Synovitis also affects tendon sheaths, and may lead to adhesion ?brosis or attrition and rupture of tendons. Subcutaneous and other bursae may be involved. Necrobiotic nodules also occur at sites outside synovium, including the subcutaneous tissues, the lungs, the pericardium and the pleura.
Clinical features Rheumatoid arthritis varies from the very mild to the severely disabling. Many mild cases probably go undiagnosed. At least 50 per cent of patients continue to lead a reasonably normal life; around 25 per cent are signi?cantly disabled in terms of work and leisure activities; and a minority become markedly disabled and are limited in their independence. There is often an early acute phase, followed by substantial remission, but in other patients gradual step-wise deterioration may occur, with progressive involvement of an increasing number of joints.
The diagnosis of rheumatoid arthritis is largely based on clinical symptoms and signs. Approximately 70 per cent of patients have rheumatoid factor ANTIBODIES in the SERUM but, because of the large number of false positives and false negatives, this test has very little value in clinical practice. It may be a useful pointer to a worse prognosis in early cases if the level is high. X-RAYS may help in diagnosing early cases and are particularly helpful when considering surgery or possible complications such as pathological fracture. Patients commonly develop ANAEMIA, which may be partly due to gastrointestinal blood loss from antiin?ammatory drug treatment (see below).
Treatment involves physical, pharmacological, and surgical measures, together with psychological and social support tailored to the individual patient’s needs. Regular activity should be maintained. Resting of certain joints such as the wrist with splints may be helpful at night or to assist prolonged manual activities. Sound footwear is important. Early use of antirheumatic drugs reduces long-term disability. Drug treatment includes simple ANALGESICS, NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), and slow-acting drugs including GOLD SALTS (in the form of SODIUM AUROTHIOMALATE), PENICILLAMINE, SULFASALAZINE, METHOTREXATE and AZATHIOPRINE.
The non-steroidal agents are largely e?ective in reducing pain and early-morning sti?ness, and have no e?ect on the chronic in?ammatory process. It is important, especially in the elderly, to explain to patients the adverse effects of NSAIDs, the dosage of which can be cut by prescribing paracetamol at the same time. Combinations of anti-rheumatic drugs seem better than single agents. The slow-acting drugs take approximately three months to act but have a more global e?ect on chronic in?ammation, with a greater reduction in swelling and an associated fall in erythrocyte sedimentation rate (ESR) and rise in the level of HAEMOGLOBIN. Local CORTICOSTEROIDS are useful, given into individual joints. Systemic corticosteroids carry serious problems if continued long term, but may be useful under special circumstances. Much research is currently going on into the use of tumour necrosis factor antagonists such as INFLIXIMAB and etanercept, but their precise role remains uncertain.... rheumatoid arthritis
Habitat: China.
Rheum palmatum was once transported from China through Persia to Turkey and was consequently known as "Turkey Rhubarb" ; when conveyed via India it was called "East Indian Rhubarb." This Chinese root is the popular medicinal Turkey Rhubarb of to-day, the best kind being that from the Shansi province of China.Features ? The root is smooth and heavy, and arrives in this country peeled. It is identifiable by the dark brown spots and a reticulation of white lines. The Canton rhubarb is more fibrous, unspotted, and the white network is less prominent than that from Shansi. The quality of these roots is judged by the fracture, which should show bright, the inferior kinds being a dull brown.Action: Aperient, stomachic, astringent, tonic.
Small doses of the powdered root are used in diarrhea, larger quantities acting as a thorough yet gentle purgative. Dose of powdered root, 3 to 30 grains.... rhubarb, turkeyThe human backbone is about 70 cm (28
inches) in length, and varies little in full-grown people; di?erences in height depend mainly upon the length of the lower limbs. The number of vertebrae is 33 in children, although in adult life ?ve of these fuse together to form the sacrum, and the lowest four unite in the coccyx, so that the number of separate bones is reduced to 26. Of these there are seven in the neck, known as cervical vertebrae; 12 with ribs attached, in the region of the thorax known as thoracic or dorsal vertebrae; ?ve in the loins, called lumbar vertebrae; ?ve fused to form the sacrum; and four joined in the coccyx. These numbers are expressed in a formula thus: C7, D12, L5, S5, Coc4=33.
Although the vertebrae in each of these regions have distinguishing features, all the vertebrae are constructed on the same general plan. Each has a thick, rounded, bony part in front, known as the body, and these bodies form the main thickness of the column. Behind the body of each is a ring of bone, the neural ring, these rings placed one above another forming the bony canal which lodges the spinal cord. From each side of the ring a short process of bone known as the transverse process stands out, and from the back of the ring a larger process, the spinous process, projects. These processes give attachment to the strong ligaments and muscles which unite, support, and bend the column. The spines can be seen or felt beneath the skin of the back lying in the centre of a groove between the muscular masses of the two sides, and they give to the column its name of the spinal column. One of these spines, that of the seventh cervical vertebra, is especially large and forms a distinct bony prominence, where the neck joins the back. Between the bodies of the vertebrae lies a series of thick discs of ?brocartilage known as intervertebral discs. Each disc consists of an outer portion, known as the annulus ?brosus, and an inner core, known as the nucleus pulposus. These 23 discs provide the upper part of the spine with pliability and resilience.
The ?rst and second cervical vertebrae are specially modi?ed. The ?rst vertebra, known as the atlas, is devoid of a body, but has a specially large and strong ring with two hollows upon which the skull rests, thus allowing forward and backward movements (nodding). The second vertebra, known as the axis, has a pivot on its body which ?ts into the ?rst vertebra and thus allows free rotation of the head from side to side. The spinal column has four natural curves (see diagram) which help to cushion the shocks of walking and running.
The neural rings of the vertebrae form a canal, which is wide in the neck, smaller and almost round in the dorsal region, and wide again in the lumbar vertebrae. Down the canal runs the spinal cord, and the nerves leaving the cord do so through openings between the vertebrae which are produced by notches on the upper and lower margins of each ring. The intervertebral foramina formed by these notches are so large in comparison with the nerves passing through them that there is no chance of pressure upon the latter, except in very serious injuries which dislocate and fracture the spine.... spinal column
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