Function The chief function of the thyroid gland is to produce a hormone (see HORMONES) rich in iodine – THYROXINE, which controls the rate of body METABOLISM. Thus, if it is de?cient in infants they fail to grow and suffer LEARNING DISABILITY, a condition formerly known as CRETINISM. If the de?ciency develops in adult life, the individual becomes obese, lethargic, and develops a coarse skin, a condition known as hypothyroidism (see under THYROID GLAND, DISEASES OF). Overactivity of the thyroid, or hyperthyroidism, results in loss of weight, rapid heart action, anxiety, overactivity and increased appetite. (See THYROID GLAND, DISEASES OF – Thyrotoxicosis.)
The production of the thyroid hormone is controlled by a hormone of the PITUITARY GLAND – the thyrotrophic hormone.... thyroid gland
The windpipe leads into the chest and divides above the heart into two bronchi, one of which goes to each lung, in which it splits into ?ner and ?ner tubes (see LUNGS). The larynx is enclosed in two strong cartilages: the thyroid (of which the most projecting part, the Adam’s apple, is a prominent point on the front of the neck), and the cricoid (which can be felt as a hard ring about an inch below the thyroid). Beneath this, the trachea – which is sti?ened by rings of cartilage so that it is never closed, no matter what position the body is in – can be traced down until it disappears behind the breastbone.... air passages
Contents The trachea divides into right and left main bronchi which go to the two LUNGS. The left lung is slightly smaller than the right. The right has three lobes (upper, middle and lower) and the left lung has two lobes (upper and lower). Each lung is covered by two thin membranes lubricated by a thin layer of ?uid. These are the pleura; similar structures cover the heart (pericardium). The heart lies in the middle, displaced slightly to the left. The oesophagus passes right through the chest to enter the stomach just below the diaphragm. Various nerves, blood vessels and lymph channels run through the thorax. The thoracic duct is the main lymphatic drainage channel emptying into a vein on the left side of the root of the neck. (For diseases affecting the chest and its contents, see HEART, DISEASES OF; LUNGS, DISEASES OF; CHEST, DEFORMITIES OF.)... chest
Structure of bone Bone is composed partly of ?brous tissue, partly of bone matrix comprising phosphate and carbonate of lime, intimately mixed together. The bones of a child are about two-thirds ?brous tissue, whilst those of the aged contain one-third; the toughness of the former and the brittleness of the latter are therefore evident.
The shafts of the limb bones are composed of dense bone, the bone being a hard tube surrounded by a membrane (the periosteum) and enclosing a fatty substance (the BONE MARROW); and of cancellous bone, which forms the short bones and the ends of long bones, in which a ?ne lace-work of bone ?lls up the whole interior, enclosing marrow in its meshes. The marrow of the smaller bones is of great importance. It is red in colour, and in it red blood corpuscles are formed. Even the densest bone is tunnelled by ?ne canals (Haversian canals) in which run small blood vessels, nerves and lymphatics, for the maintenance and repair of the bone. Around these Haversian canals the bone is arranged in circular plates called lamellae, the lamellae being separated from one another by clefts, known as lacunae, in which single bone-cells are contained. Even the lamellae are pierced by ?ne tubes known as canaliculi lodging processes of these cells. Each lamella is composed of very ?ne interlacing ?bres.
GROWTH OF BONES Bones grow in thickness from the ?brous tissue and lime salts laid down by cells in their substance. The long bones grow in length from a plate of cartilage (epiphyseal cartilage) which runs across the bone about 1·5 cm or more from its ends, and which on one surface is also constantly forming bone until the bone ceases to lengthen at about the age of 16 or 18. Epiphyseal injury in children may lead to diminished growth of the limb.
REPAIR OF BONE is e?ected by cells of microscopic size, some called osteoblasts, elaborating the materials brought by the blood and laying down strands of ?brous tissue, between which bone earth is later deposited; while other cells, known as osteoclasts, dissolve and break up dead or damaged bone. When a fracture has occurred, and the broken ends have been brought into contact, these are surrounded by a mass of blood at ?rst; this is partly absorbed and partly organised by these cells, ?rst into ?brous tissue and later into bone. The mass surrounding the fractured ends is called the callus, and for some months it forms a distinct thickening which is gradually smoothed away, leaving the bone as before the fracture. If the ends have not been brought accurately into contact, a permanent thickening results.
VARIETIES OF BONES Apart from the structural varieties, bones fall into four classes: (a) long bones like those of the limbs; (b) short bones composed of cancellous tissue, like those of the wrist and the ankle; (c) ?at bones like those of the skull; (d) irregular bones like those of the face or the vertebrae of the spinal column (backbone).
The skeleton consists of more than 200 bones. It is divided into an axial part, comprising the skull, the vertebral column, the ribs with their cartilages, and the breastbone; and an appendicular portion comprising the four limbs. The hyoid bone in the neck, together with the cartilages protecting the larynx and windpipe, may be described as the visceral skeleton.
AXIAL SKELETON The skull consists of the cranium, which has eight bones, viz. occipital, two parietal, two temporal, one frontal, ethmoid, and sphenoid; and of the face, which has 14 bones, viz. two maxillae or upper jaw-bones, one mandible or lower jaw-bone, two malar or cheek bones, two nasal, two lacrimal, two turbinal, two palate bones, and one vomer bone. (For further details, see SKULL.) The vertebral column consists of seven vertebrae in the cervical or neck region, 12 dorsal vertebrae, ?ve vertebrae in the lumbar or loin region, the sacrum or sacral bone (a mass formed of ?ve vertebrae fused together and forming the back part of the pelvis, which is closed at the sides by the haunch-bones), and ?nally the coccyx (four small vertebrae representing the tail of lower animals). The vertebral column has four curves: the ?rst forwards in the neck, the second backwards in the dorsal region, the third forwards in the loins, and the lowest, involving the sacrum and coccyx, backwards. These are associated with the erect attitude, develop after a child learns to walk, and have the e?ect of diminishing jars and shocks before these reach internal organs. This is aided still further by discs of cartilage placed between each pair of vertebrae. Each vertebra has a solid part, the body in front, and behind this a ring of bone, the series of rings one above another forming a bony canal up which runs the spinal cord to pass through an opening in the skull at the upper end of the canal and there join the brain. (For further details, see SPINAL COLUMN.) The ribs – 12 in number, on each side – are attached behind to the 12 dorsal vertebrae, while in front they end a few inches away from the breastbone, but are continued forwards by cartilages. Of these the upper seven reach the breastbone, these ribs being called true ribs; the next three are joined each to the cartilage above it, while the last two have their ends free and are called ?oating ribs. The breastbone, or sternum, is shaped something like a short sword, about 15 cm (6 inches) long, and rather over 2·5 cm (1 inch) wide.
APPENDICULAR SKELETON The upper limb consists of the shoulder region and three segments – the upper arm, the forearm, and the wrist with the hand, separated from each other by joints. In the shoulder lie the clavicle or collar-bone (which is immediately beneath the skin, and forms a prominent object on the front of the neck), and the scapula or shoulder-blade behind the chest. In the upper arm is a single bone, the humerus. In the forearm are two bones, the radius and ulna; the radius, in the movements of alternately turning the hand palm up and back up (called supination and pronation respectively), rotating around the ulna, which remains ?xed. In the carpus or wrist are eight small bones: the scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate and hamate. In the hand proper are ?ve bones called metacarpals, upon which are set the four ?ngers, each containing the three bones known as phalanges, and the thumb with two phalanges.
The lower limb consists similarly of the region of the hip-bone and three segments – the thigh, the leg and the foot. The hip-bone is a large ?at bone made up of three – the ilium, the ischium and the pubis – fused together, and forms the side of the pelvis or basin which encloses some of the abdominal organs. The thigh contains the femur, and the leg contains two bones – the tibia and ?bula. In the tarsus are seven bones: the talus (which forms part of the ankle joint); the calcaneus or heel-bone; the navicular; the lateral, intermediate and medial cuneiforms; and the cuboid. These bones are so shaped as to form a distinct arch in the foot both from before back and from side to side. Finally, as in the hand, there are ?ve metatarsals and 14 phalanges, of which the great toe has two, the other toes three each.
Besides these named bones there are others sometimes found in sinews, called sesamoid bones, while the numbers of the regular bones may be increased by extra ribs or diminished by the fusion together of two or more bones.... bone
Reasons for operation The cause of laryngeal obstruction should be treated but, if obstruction is acute and endangering the patient’s life, urgent intervention is necessary. In most cases the insertion of an endotracheal tube either through the nose or mouth and down the pharynx through the larynx to bypass the obstruction is e?ective (see ENDOTRACHEAL INTUBATION). If not, tracheostomy is performed. The majority of tracheostomies performed nowadays are for patients in intensive-therapy-unit situations. These patients require airway intervention for prolonged periods to facilitate arti?cial ventilation which is performed by means of a mechanical ventilator. The presence of a tube passing through the larynx for a prolonged period of time is associated with long-term damage to the larynx, and therefore any patients requiring prolonged intubation usually undergo a tracheostomy to prevent further damage. Endotracheal intubation is also the preferred method of airway-intervention for acute in?ammatory disorders of the upper airway (as opposed to tracheostomy); tracheostomy in these cases is performed only in the emergency situation if facilities for endotracheal intubation are not available or if they are unsuccessful. Tracheostomy may also be performed for large tumours which obstruct the larynx until some form of treatment is instituted. Similarly it may be needed in conditions whereby the nerve supply to the larynx has been jeopardised, impairing its protective function of the upper airway and its respiratory function.
Tracheostomy tubes When the trachea has been opened – by an incision through the skin between the Adam’s apple and the clavicles; another through the THYROID GLAND followed by a small vertical incision in the trachea
– a metal or plastic tube is inserted to maintain the opening. There is always an outer tube which is ?xed in position by tapes passing round the neck, and an inner tube which slides freely out of and into the other, so that it may be removed at any time for cleansing, and is readily coughed-out should it happen to become blocked by mucus.
After-treatment When the operation has been performed for some permanent obstruction, the tube must be worn permanently; and the double metal tube is in such cases replaced after a short time by a soft plastic single one. When the operation has relieved some obstruction caused, say, by diphtheria, the tube is left out now and then for a few hours, and ?nally, at the end of a week or so, is removed altogether, after which the wound quickly heals up.... tracheostomy
Herbalism confirms the Doctrine of Signatures but is not based on it. ... doctrine of signatures
Causes: smoking, mis-use of the voice in talking or singing (Ginseng).
Symptoms: voice husky or absent (aphonia). Talking causes pain. Self-limiting.
Treatment. Stop talking for 2 days. Care is necessary: neglect or ineffective treatment may rouse infection and invade the windpipe and bronchi resulting in croup.
Differential: croup is alerted by high fever and characteristic cough, requiring hospital treatment. Alternatives. Teas: Red Sage. Garden Sage. Thyme, wild or garden.
Effective combination: equal parts, Sage and Raspberry leaves. Used also as a gargle.
Tablets/capsules. Poke root. Lobelia. Iceland Moss.
Cinnamon. Tincture, essence or oil of: 3-5 drops in teaspoon honey.
Horseradish. 1oz freshly scraped root to steep in cold water for two hours. Add 2 teaspoons runny honey. Dose: 2-3 teaspoons every two hours.
Topical. Equal parts water/cider vinegar cold pack round throat. Renew when dry.
Traditional: “Rub soles of the feet with Garlic and lard well-beaten together, overnight. Hoarseness gone in the morning.” (John Wesley) Friar’s balsam.
Aromatherapy. Steam inhalations. Oils: Bergamot, Eucalyptus, Niaouli, Geranium, Lavender, Sandalwood.
Diet. Three-day fruit fast.
Supplements. Daily. Vitamin A (7500iu). Vitamin C (1 gram thrice daily). Beta carotene 200,000iu. Zinc 25mg. ... laryngitis, acute
The term intubation is also used to refer to the placement of a gastric or intestinal tube in the stomach for purposes of suction or the giving of nutrients (see feeding, artificial).... intubation
Strangulation of the neck causes compression of the jugular veins, preventing blood from flowing out of the brain, and compression of the windpipe, which restricts breathing. The victim loses consciousness, and brain damage and death from lack of oxygen follow.... strangulation
The most common cause is a sudden allergic reaction to a food. Less commonly, it results from allergy to a drug (such as penicillin), a reaction to an insect bite or sting, or from infection, emotional stress, or exposure to animals, moulds, pollens, or cold conditions. There is also a hereditary form of the disease.
Angioedema may cause sudden difficulty in breathing, swallowing, and speaking, accompanied by swelling of the lips, face, and neck, depending on the area of the body affected. Angioedema that affects the throat and the larynx is potentially life-threatening because the swelling can block the airway, causing asphyxia.
Severe cases are treated with injections of adrenaline (epinephrine) and may require intubation (passage of a breathing tube via the mouth into the windpipe) or tracheostomy (surgical creation of a hole in the windpipe) to prevent suffocation. Corticosteroid drugs may also be given. In less severe cases, antihistamine drugs may relieve symptoms.... angioedema
The left carotid arises from the aorta and runs up the neck on the left side of the trachea (windpipe). The right carotid arises from the subclavian artery (which branches off the aorta) and follows a similar route on the right side of the
neck. Just above the level of the larynx (voice-box), each carotid artery divides to form an external carotid artery and an internal carotid artery. The external arteries have multiple branches that supply most tissues in the face, scalp, mouth, and jaws; the internal arteries enter the skull to supply the brain and eyes. At the base of the brain, branches of the 2 internal carotids and the basilar artery join to form a ring of vessels called the circle of Willis. Narrowing of these vessels may be associated with transient ischaemic attack (TIA); obstruction of them causes a stroke. carpal tunnel syndrome Numbness, tingling, and pain in the thumb, index finger, and middle fingers caused by compression of the median nerve at the wrist. Symptoms may be worse at night. The condition results from pressure on the nerve where it passes into the hand via a gap (the “carpal tunnel’’) under a ligament at the front of the wrist. It is common among keyboard users. It also occurs without obvious cause in middleaged women, and is associated with pregnancy, initial use of oral contraceptives, premenstrual syndrome, rheumatoid arthritis, myxoedema, and acromegaly.
The condition often disappears without treatment.
Persistent symptoms may be treated with a corticosteroid drug injected under the ligament, or the ligament may be cut to relieve pressure on the nerve.... carotid artery
Initially, automatic contraction of a muscle at the entrance to the windpipe, a mechanism called the laryngeal reflex, prevents water from entering the lungs; instead it enters the oesophagus and stomach.
However, the laryngeal reflex impairs breathing and can quickly lead to hypoxia and to loss of consciousness.
If the person is buoyant at this point and floats face-up, his or her chances of survival are reasonable because the laryngeal reflex begins to relax and normal breathing may resume.
An ambulance should be called and the person’s medical condition assessed.
If breathing and/or the pulse is absent, resuscitative measures should be started (see artificial respiration; cardiopulmonary resuscitation) and continued until an ambulance or doctor arrives.
Victims can sometimes be resuscitated, despite a long period immersed in very cold water (which reduces the body’s oxygen needs) and the initial appearance of being dead.
In all cases of successful resuscitation, the person should be sent to a hospital.... drowning
Many X-ray imaging techniques have been superseded by newer procedures. These include ultrasound scanning, MRI (magnetic resonance imaging), PET scanning, and radionuclide scanning. However, X-rays are used in CT scanning. Some of these techniques use computers to process the raw imaging data and produce the actual image. Others can produce images without a computer, although one may be used to enhance the image. imipramine A tricyclic antidepressant drug most commonly used as a longterm treatment for depression. Possible adverse effects include excessive sweating, blurred vision, dizziness, dry mouth, constipation, nausea, and, in older men, difficulty passing urine.... illusion
The first and most common symptom is a cough. Other symptoms include coughing up blood, shortness of breath, and chest pain. Lung cancer can spread to other parts of the body, especially the liver, brain, and bones. In most cases, the cancer is revealed in a chest X-ray. To confirm the diagnosis, tissue must be examined microscopically for the presence of cancerous cells (see cytology). If lung cancer is diagnosed at an early stage, pneumonectomy (removal of the lung) or lobectomy (removal of part of the lung) may be possible. Anticancer drugs and radiotherapy may also be used. lung, collapse of See atelectasis; pneumothorax.... lung
The neck contains many important structures: the spinal cord (which carries nerve impulses to and from the brain); the trachea (windpipe); the larynx (voice box); the oesophagus; the thyroid and parathyroid glands; lymph nodes; and several major blood vessels. The upper 7 vertebrae of the spine are in the neck; a complex system of muscles is connected to these vertebrae, the clavicles (collarbones), the upper ribs, and lower jaw.
Neck disorders include torticollis (wry neck) in which the head is twisted to one side. Fractures and dislocations of vertebrae in the neck and whiplash injury can injure the spinal cord causing paralysis or even death (see spinal injury). Any condition causing swelling in the neck may interfere with breathing or swallowing.
Degeneration of the joints between the neck vertebrae may occur due to cervical osteoarthritis, causing similar symptoms to those of disc prolapse. In ankylosing spondylitis, fusion of the vertebrae may result in permanent neck rigidity. Cervical rib is a rare congenital defect in which there is a small extra rib in the neck.Neck pain of unknown origin is very common.
As long as neurological symptoms (such as loss of sensation or muscle power) are absent, the condition is unlikely to be serious and usually disappears within a few weeks.... neck