Mullerian Ducts: From 1 Different Sources
The Mullerian and the Wol?an ducts are separate sets of primordia that transiently co-exist in embryos of both sexes (see EMBRYO). In female embryos the Mullerian ducts grow and fuse in the mid line, producing the FALLOPIAN TUBES, the UTERUS and the upper third of the VAGINA, whereas the Wol?an ducts regress. In the male the Wol?an ducts give rise to the VAS DEFERENS, the seminal vesicles and the EPIDIDYMIS, and the Mullerian ducts disappear. This phase of development requires a functioning testis (see TESTICLE) from which an inducer substance di?uses locally over the primordia to bring about the suppression of the Mullerian duct and the development of the Wol?an duct. In the absence of this substance, development proceeds along female lines regardless of the genetic sex.
The presence of bilirubin deposits in the skin, whites of the eyes and mucosa. Bilirubin, the unrecyclable waste products of hemoglobin, are normally excreted in the bile, get carried down the intestinal tract and color our feces its usual comfortable brown. If the bile ducts are blocked, blood breaks down too quickly, or the liver itself is diseased (it performs much of the recycling), then the yellow/orange/brown bilirubin has nowhere to go but out the urine (making it the standard hepatitis color) and into the skin. Jaundice ain’t bad...its the causes that one should worry about.... jaundice
Inflammation of of only bile ducts. This word and the next three describe conditions that may be, subjectively, all the same.... cholangitis
A cancer in the bile ducts of the liver associated with opisthorchiasis. See Opisthorchiasis.... cholangiocarcinoma
The process whereby the bile ducts (see BILE DUCT) and the gall-bladder (see LIVER) are rendered radio-opaque and therefore visible on an X-ray ?lm.... cholangiography
The name applied to a passage leading from a gland into some hollow organ, or on to the surface of the body, by which the secretion of the gland is discharged: for example, the pancreatic duct and the bile duct opening into the duodenum, and the sweat ducts opening on the skin surface.... duct
A thick, bitter, greenish-brown ?uid, secreted by the liver and stored in the gall-bladder (see LIVER). Consisting of water, mucus, bile pigments including BILIRUBIN, and various salts, it is discharged through the bile ducts into the intestine a few centimetres below the stomach. This discharge is increased shortly after eating, and again a few hours later. It helps in the digestion and absorption of food, particularly fats, and is itself reabsorbed, passing back through the blood of the liver. In JAUNDICE, obstruction of the bile ducts prevents discharge, leading to a build-up of bile in the blood and deposition in the tissues. The skin becomes greenish-yellow, while the stools become grey or white and the urine dark. Vomiting of bile is a sign of intestinal obstruction, but may occur in any case of persistent retching or vomiting, and should be fully investigated.... bile
Fasciola hepatica is a parasite infesting sheep and occasionally invading the bile ducts and liver of humans (see FASCIOLIASIS).... liver fluke
A collection of CELLS or an ORGAN with a specialised ability to make and secrete chemical substances such as enzymes and hormones essential for the normal functioning of the body. Glands are classi?ed into two groups: ENDOCRINE and EXOCRINE. The former secrete their products, hormones, straight into the bloodstream; the latter’s secretions are discharged through ducts. (These functional differences are the reason why glands have been de?ned as ductless and ducted.) Examples of endocrine glands are the adrenals, PITUITARY GLAND and THYROID GLAND. Exocrine glands include SEBACEOUS GLANDS (in the skin) and the SALIVARY GLANDS in the mouth whose enzymes start the digestion of food. The BREASTS or mammary glands are exocrine glands that secrete milk. Though strictly speaking not a gland, LYMPH nodes (part of the lymphatic system) are sometimes called that. While they do not produce secretions, lymph glands do release white blood cells, an essential part of the body’s defence system.... gland
All the alimentary canal beyond below the stomach. In it, most DIGESTION is carried on, and through its walls all the food material is absorbed into the blood and lymph streams. The length of the intestine in humans is about 8·5–9 metres (28–30 feet), and it takes the form of one continuous tube suspended in loops in the abdominal cavity.
Divisions The intestine is divided into small intestine and large intestine. The former extends from the stomach onwards for 6·5 metres (22 feet) or thereabouts. The large intestine is the second part of the tube, and though shorter (about 1·8 metres [6 feet] long) is much wider than the small intestine. The latter is divided rather arbitrarily into three parts: the duodenum, consisting of the ?rst 25–30 cm (10–12 inches), into which the ducts of the liver and pancreas open; the jejunum, comprising the next 2·4–2·7 metres (8–9 feet); and ?nally the ileum, which at its lower end opens into the large intestine.
The large intestine begins in the lower part of the abdomen on the right side. The ?rst part is known as the caecum, and into this opens the appendix vermiformis. The appendix is a small tube, closed at one end and about the thickness of a pencil, anything from 2 to 20 cm (average 9 cm) in length, which has much the same structure as the rest of the intestine. (See APPENDICITIS.) The caecum continues into the colon. This is subdivided into: the ascending colon which ascends through the right ?ank to beneath the liver; the transverse colon which crosses the upper part of the abdomen to the left side; and the descending colon which bends downwards through the left ?ank into the pelvis where it becomes the sigmoid colon. The last part of the large intestine is known as the rectum, which passes straight down through the back part of the pelvis, to open to the exterior through the anus.
Structure The intestine, both small and large, consists of four coats, which vary slightly in structure and arrangement at di?erent points but are broadly the same throughout the entire length of the bowel. On the inner surface there is a mucous membrane; outside this is a loose submucous coat, in which blood vessels run; next comes a muscular coat in two layers; and ?nally a tough, thin peritoneal membrane. MUCOUS COAT The interior of the bowel is completely lined by a single layer of pillar-like cells placed side by side. The surface is increased by countless ridges with deep furrows thickly studded with short hair-like processes called villi. As blood and lymph vessels run up to the end of these villi, the digested food passing slowly down the intestine is brought into close relation with the blood circulation. Between the bases of the villi are little openings, each of which leads into a simple, tubular gland which produces a digestive ?uid. In the small and large intestines, many cells are devoted to the production of mucus for lubricating the passage of the food. A large number of minute masses, called lymph follicles, similar in structure to the tonsils are scattered over the inner surface of the intestine. The large intestine is bare both of ridges and of villi. SUBMUCOUS COAT Loose connective tissue which allows the mucous membrane to play freely over the muscular coat. The blood vessels and lymphatic vessels which absorb the food in the villi pour their contents into a network of large vessels lying in this coat. MUSCULAR COAT The muscle in the small intestine is arranged in two layers, in the outer of which all the ?bres run lengthwise with the bowel, whilst in the inner they pass circularly round it. PERITONEAL COAT This forms the outer covering for almost the whole intestine except parts of the duodenum and of the large intestine. It is a tough, ?brous membrane, covered upon its outer surface with a smooth layer of cells.... intestine
An infection of Bartholin’s glands, at the entrance to the vagina, that may be due to a sexually transmitted infection such as gonorrhoea. It causes an intensely painful red swelling at the opening of the ducts. Treatment is with antibiotic drugs, analgesic drugs, and warm baths. Bartholinitis sometimes leads to an abscess or a painless cyst (called a Bartholin’s cyst), which may become infected. Abscesses are drained under general anaesthesia. Recurrent abscesses or infected cysts may need surgery to convert the duct into an open pouch (see marsupialization) or to remove the gland completely... bartholinitis
The liver is the largest gland in the body, serving numerous functions, chie?y involving various aspects of METABOLISM.
Form The liver is divided into four lobes, the greatest part being the right lobe, with a small left lobe, while the quadrate and caudate lobes are two small divisions on the back and undersurface. Around the middle of the undersurface, towards the back, a transverse ?ssure (the porta hepatis) is placed, by which the hepatic artery and portal vein carry blood into the liver, and the right and left hepatic ducts emerge, carrying o? the BILE formed in the liver to the GALL-BLADDER attached under the right lobe, where it is stored.
Position Occupying the right-hand upper part of the abdominal cavity, the liver is separated from the right lung by the DIAPHRAGM and the pleural membrane (see PLEURA). It rests on various abdominal organs, chie?y the right of the two KIDNEYS, the suprarenal gland (see ADRENAL GLANDS), the large INTESTINE, the DUODENUM and the STOMACH.
Vessels The blood supply di?ers from that of the rest of the body, in that the blood collected from the stomach and bowels into the PORTAL VEIN does not pass directly to the heart, but is ?rst distributed to the liver, where it breaks up into capillary vessels. As a result, some harmful substances are ?ltered from the bloodstream and destroyed, while various constituents of the food are stored in the liver for use in the body’s metabolic processes. The liver also receives the large hepatic artery from the coeliac axis. After circulating through capillaries, the blood from both sources is collected into the hepatic veins, which pass directly from the back surface of the liver into the inferior vena cava.
Minute structure The liver is enveloped in a capsule of ?brous tissue – Glisson’s capsule – from which strands run along the vessels and penetrate deep into the organ, binding it together. Subdivisions of the hepatic artery, portal vein, and bile duct lie alongside each other, ?nally forming the interlobular vessels,
which lie between the lobules of which the whole gland is built up. Each is about the size of a pin’s head and forms a complete secreting unit; the liver is built up of hundreds of thousands of such lobules. These contain small vessels, capillaries, or sinusoids, lined with stellate KUPFFER CELLS, which run into the centre of the lobule, where they empty into a small central vein. These lobular veins ultimately empty into the hepatic veins. Between these capillaries lie rows of large liver cells in which metabolic activity occurs. Fine bile capillaries collect the bile from the cells and discharge it into the bile ducts lying along the margins of the lobules. Liver cells are among the largest in the body, each containing one or two large round nuclei. The cells frequently contain droplets of fat or granules of GLYCOGEN – that is, animal starch.
Functions The liver is, in e?ect, a large chemical factory and the heat this produces contributes to the general warming of the body. The liver secretes bile, the chief constituents of which are the bile salts (sodium glycocholate and taurocholate), the bile pigments (BILIRUBIN and biliverdin), CHOLESTEROL, and LECITHIN. These bile salts are collected and formed in the liver and are eventually converted into the bile acids. The bile pigments are the iron-free and globin-free remnant of HAEMOGLOBIN, formed in the Kup?er cells of the liver. (They can also be formed in the spleen, lymph glands, bone marrow and connective tissues.) Bile therefore serves several purposes: it excretes pigment, the breakdown products of old red blood cells; the bile salts increase fat absorption and activate pancreatic lipase, thus aiding the digestion of fat; and bile is also necessary for the absorption of vitamins D and E.
The other important functions of the liver are as follows:
In the EMBRYO it forms red blood cells, while the adult liver stores vitamin B12, necessary for the proper functioning of the bone marrow in the manufacture of red cells.
It manufactures FIBRINOGEN, ALBUMINS and GLOBULIN from the blood.
It stores IRON and copper, necessary for the manufacture of red cells.
It produces HEPARIN, and – with the aid of vitamin K – PROTHROMBIN.
Its Kup?er cells form an important part of the RETICULO-ENDOTHELIAL SYSTEM, which breaks down red cells and probably manufactures ANTIBODIES.
Noxious products made in the intestine and absorbed into the blood are detoxicated in the liver.
It stores carbohydrate in the form of glycogen, maintaining a two-way process: glucose
glycogen.
CAROTENE, a plant pigment, is converted to vitamin A, and B vitamins are stored.
It splits up AMINO ACIDS and manufactures UREA and uric acids.
It plays an essential role in the storage and metabolism of FAT.... liver
A deposit on the teeth (see calculus, dental) or a small, hard, crystalline mass that is formed in a body cavity from certain substances in fluids such as bile, urine, or saliva. Calculi can occur in the gallbladder and bile ducts (see gallstones), the kidneys, ureters, or bladder (see calculus, urinary tract), or in the salivary ducts.... calculus
A disease affecting the liver and bile ducts that is caused by infestation with the liver fluke species FASCIOLA HEPATICA.... fascioliasis
An irritating skin rash that is associated with profuse sweating. The medical name is miliaria rubra. Multiple tiny, red, itchy spots cover the affected areas of skin and are accompanied by prickling sensations. The irritation tends to affect areas where sweat collects, such as the armpits. The cause is not fully known, but unevaporated sweat is an important factor. Sweat ducts become blocked with debris and leak sweat into the skin. Frequent cool showers and sponging of the affected areas relieve the itching.... prickly heat
Every man has two testicles or testes which are the sexual glands. In the fetus, they develop in the abdomen, but before birth they descend into a fold or pouch of skin known as the SCROTUM. Each testicle consists of up to 1,000 minute tubes lined by cells from which the spermatozoa (see SPERMATOZOON) are formed. Around 4·5 million spermatozoa are produced per gram of testicle per day. These tubes communicate with one another near the centre of the testicle, and are connected by a much coiled tube, the EPIDIDYMIS, with the ductus, or VAS DEFERENS, which enters the abdomen and passes on to the base of the bladder. This duct, after joining a reservoir known as the seminal vesicle, opens, close to the duct from the other side of the body, into the URETHRA where it passes through the PROSTATE GLAND. Owing to the convolutions of these ducts leading from the testicles to the urethra, and their indirect route, the passage from testicle to urethra is over 6 metres (20 feet) in length. In addition to producing spermotozoa, the testicle also forms the hormone TESTOSTERONE which is responsible for the development of male characteristics.... testicle
Stagnation of bile in the small bile ducts within the liver, leading to jaundice and liver disease. The obstruction to the flow of bile may be intrahepatic (within the liver) or extrahepatic (in the bile ducts outside the liver). Intrahepatic cholestasis may occur as a result of viral hepatitis (see hepatitis, viral) or as a side effect of a number of drugs. The flow of bile improves gradually as the inflammation from the hepatitis resolves or the drug is discontinued. The bile ducts outside the liver can become obstructed by, for example, gallstones or tumours (see bile duct obstruction); rarely, the ducts are absent from birth (see biliary atresia). Bile duct obstruction and biliary atresia are often treated surgically.... cholestasis
The lower part of the trunk. Above, and separated from it by the diaphragm, lies the thorax or chest, and below lies the PELVIS, generally described as a separate cavity though continuous with that of the abdomen. Behind are the SPINAL COLUMN and lower ribs, which come within a few inches of the iliac bones. At the sides the contained organs are protected by the iliac bones and down-sloping ribs, but in front the whole extent is protected only by soft tissues. The latter consist of the skin, a varying amount of fat, three layers of broad, ?at muscle, another layer of fat, and ?nally the smooth, thin PERITONEUM which lines the whole cavity. These soft tissues allow the necessary distension when food is taken into the STOMACH, and the various important movements of the organs associated with digestion. The shape of the abdomen varies; in children it may protrude considerably, though if this is too marked it may indicate disease. In healthy young adults it should be either slightly prominent or slightly indrawn, and should show the outline of the muscular layer, especially of the pair of muscles running vertically (recti), which are divided into four or ?ve sections by transverse lines. In older people fat is usually deposited on and inside the abdomen. In pregnancy the abdomen enlarges from the 12th week after conception as the FETUS in the UTERUS grows (see PREGNANCY AND LABOUR; ANTENATAL CARE).
Contents The principal contents of the abdominal cavity are the digestive organs, i.e. the stomach and INTESTINE, and the associated glands, the LIVER and PANCREAS. The position
of the stomach is above and to the left when the individual is lying down, but may be much lower when standing. The liver lies above and to the right, largely under cover of the ribs, and occupying the hollow of the diaphragm. The two KIDNEYS lie against the back wall on either side, protected by the last two ribs. From the kidneys run the URETERS, or urinary ducts, down along the back wall to the URINARY BLADDER in the pelvis. The pancreas lies across the spine between the kidneys, and on the upper end of each kidney is a suprarenal gland
(see ADRENAL GLANDS). The SPLEEN is positioned high up on the left and partly behind the stomach. The great blood vessels and nerves lie on the back wall, and the remainder of the space is taken up by the intestines or bowels (see INTESTINE). The large intestine lies in the ?anks on either side in front of the kidneys, crossing below the stomach from right to left, while the small intestine hangs from the back wall in coils which ?ll up the spaces between the other organs. Hanging down from the stomach in front of the bowels is the OMENTUM, or apron, containing much fat and helping to protect the bowels. In pregnancy the UTERUS, or womb, rises up from the pelvis into the abdomen as it increases in size, lifting the coils of the small intestine above it.
The PELVIS is the part of the abdomen within the bony pelvis (see BONE), and contains the rectum or end part of the intestine, the bladder, and in the male the PROSTATE GLAND; in the female the uterus, OVARIES, and FALLOPIAN TUBES.... abdomen
An agent that impedes the impulses or actions of the nerves or fibers of the parasympathetic ganglia, competing with, and blocking the release of acetycholine at what are called the muscarinic sites. Cholinergic functions affected are those that induce spasms and cramps of the intestinal tracts and allied ducts. Examples: Atropine, Datura, Garrya.... anticholinergic
Lindl.
Synonym: A. belladonna auct. non L.
Family: Solanaceae.
Habitat: Kashmir and Himachal Pradesh up to 2,500 m.
English: Indian Belladonna, Indian Atropa.
Ayurvedic: Suuchi.
Unani: Luffaah, Luffaah-Barri, Yabaruj, Shaabiraj.
Action: Highly poisonous; sedative, narcotic, anodyne, nervine, antispasmodic (used in paralysis); parkinsonism; encephalitis; carcinoma; spastic dysmenorrhoea; whooping cough, spasmodic asthma; colic of intestines, gall bladder or kidney, spasm of bladder and ureters; contraindicated in enlarged prostate.
Key application: In spasm and colic-like pain in the areas of the gastrointestinal tract and bile ducts. (German Commission E, The British Herbal Pharmacopoeia.) It is contraindicated in tachycardiac arrhythmias, prostate adenoma, glaucoma, acute oedema of lungs.A. belladonna L. (European sp. Belladonna, Deadly Nightshade) is cultivated in Kashmir and Himachal Pradesh.The herb contains tropane (tropine) or solanaceous alkaloids (up to 0.6%), including hyoscamine and atropine; flavonoids; coumarins; volatile bases (nicotine).Tropane alkaloids inhibit the para- sympathetic nervous system, which controls involuntary bodily activities; reduces saliva, gastric, intestinal and bronchial secretions, and also the activity of urinary tubules. Tropane alkaloids also increase the heart rate and dilate the pupils. These alkaloids are used as an additive to compound formulations for bronchitis, asthma, whooping cough, gastrointestinal hy- permotility, dysmenorrhoea, nocturnal enuresis and fatigue syndrome.Atropine provides relief in parkin- sonism and neurovegetative dystonia.The root is the most poisonous, the leaves and flowers less, and the berries the least. (Francis Brinker.)
Dosage: Leaf, root—30-60 mg powder. (CCRAS.)... atropa acuminata royle ex
Cramps or tenesmus of the gall bladder or bile ducts.... cholecystalgia
Inflammation of the gall bladder and ducts, sometimes from the presence of passing stones, sometimes following fasting or anorexia, sometimes because of a spreading intestinal tract infection....sometimes just because you eat three avocado sandwiches before going to bed.... cholecystitis
See under STOMACH, DISEASES OF; INTESTINE, DISEASES OF; DIARRHOEA; LIVER, DISEASES OF; PANCREAS, DISEASES OF; GALL-BLADDER, DISEASES OF; KIDNEYS, DISEASES OF; URINARY BLADDER, DISEASES OF; HERNIA; PERITONITIS; APPENDICITIS; TUMOUR.
Various processes that can occur include in?ammation, ulceration, infection or tumour. Abdominal disease may be of rapid onset, described as acute, or more long-term when it is termed chronic.
An ‘acute abdomen’ is most commonly caused by peritonitis – in?ammation of the membrane that lines the abdomen. If any structure in the abdomen gets in?amed, peritonitis may result. Causes include injury, in?ammation of the Fallopian tubes (SALPINGITIS), and intestinal disorders such as APPENDICITIS, CROHN’S DISEASE, DIVERTICULITIS or a perforated PEPTIC ULCER. Disorders of the GALLBLADDER or URINARY TRACT may also result in acute abdominal pain.
General symptoms of abdominal disease include:
Pain This is usually ill-de?ned but can be very unpleasant, and is termed visceral pain. Pain is initially felt near the mid line of the abdomen. Generally, abdominal pain felt high up in the mid line originates from the stomach and duodenum. Pain that is felt around the umbilicus arises from the small intestine, appendix and ?rst part of the large bowel, and low mid-line pain comes from the rest of the large bowel. If the diseased organ secondarily in?ames or infects the lining of the abdominal wall – the PERITONEUM – peritonitis occurs and the pain becomes more de?ned and quite severe, with local tenderness over the site of the diseased organ itself. Hence the pain of appendicitis begins as a vague mid-line pain, and only later moves over to the right iliac fossa, when the in?amed appendix has caused localised peritonitis. PERFORATION of one of the hollow organs in the abdomen – for example, a ruptured appendix or a gastric or duodenal ulcer (see STOMACH, DISEASES OF) eroding the wall of the gut – usually causes peritonitis with resulting severe pain.
The character of the pain is also important. It may be constant, as occurs in in?ammatory diseases and infections, or colicky (intermittent) as in intestinal obstruction.
Swelling The commonest cause of abdominal swelling in women is pregnancy. In disease, swelling may be due to the accumulation of trapped intestinal contents within the bowel, the presence of free ?uid (ascites) within the abdomen, or enlargement of one or more of the abdominal organs due to benign causes or tumour.
Constipation is the infrequent or incomplete passage of FAECES; sometimes only ?atus can be passed and, rarely, no bowel movements occur (see main entry for CONSTIPATION). It is often associated with abdominal swelling. In intestinal obstruction, the onset of symptoms is usually rapid with complete constipation and severe, colicky pain. In chronic constipation, the symptoms occur more gradually.
Nausea and vomiting may be due to irritation of the stomach, or to intestinal obstruction when it may be particularly foul and persistent. There are also important non-abdominal causes, such as in response to severe pain or motion sickness.
Diarrhoea is most commonly due to simple and self-limiting infection, such as food poisoning, but may also indicate serious disease, especially if it is persistent or contains blood (see main entry for DIARRHOEA).
Jaundice is a yellow discoloration of the skin and eyes, and may be due to disease in the liver or bile ducts (see main entry for JAUNDICE).
Diagnosis and treatment Abdominal diseases are often di?cult to diagnose because of the multiplicity of the organs contained within the abdomen, their inconstant position and the vagueness of some of the symptoms. Correct diagnosis usually requires experience, often supplemented by specialised investigations such as ULTRASOUND. For this reason sufferers should obtain medical advice at an early stage, particularly if the symptoms are severe, persistent, recurrent, or resistant to simple remedies.... abdomen, diseases of
The presence of gall-stones in the bile ducts and/or in the gall-bladder. (See GALL-BLADDER, DISEASES OF.)... cholelithiasis
The removal of gall-stones from the gallbladder or bile ducts (see GALL-BLADDER, DISEASES OF), when CHOLECYSTECTOMY or LITHOTRIPSY are inappropriate or not possible. It involves a cholecystomy, an operation to open the gall-bladder.... cholelithotomy
Also known as the bulbourethral glands, these are a pair of glands whose ducts open into the urethra at the base of the PENIS. They secrete a ?uid that is one of the constituents of the SEMEN which carries the spermatozoa and is ejaculated into the VAGINA during coitus (sexual intercourse).... cowper’s glands
The tube that runs from the gall-bladder (see LIVER) and joins up with the hepatic duct (formed from the bile ducts) to form the common BILE DUCT. The BILE produced by the liver cells is drained through this system and enters the small intestine to help in the digestion of food.... cystic duct
Hollow tumours (see TUMOUR), containing ?uid or soft material. They are almost always simple in nature.
Retention cysts In these, in consequence of irritation or another cause, some cavity which ought naturally to contain a little ?uid becomes distended, or the natural outlet from the cavity becomes blocked. Wens are caused by the blockage of the outlet from sebaceous glands in the skin, so that an accumulation of fatty matter takes place. RANULA is a clear swelling under the tongue, due to a collection of saliva in consequence of an obstruction to a salivary duct. Cysts in the breasts are, in many cases, the result of blockage in milk ducts, due to in?ammation; they should be assessed to exclude cancer (see BREASTS, DISEASES OF). Cysts also form in the kidney as a result of obstruction to the free out?ow of the urine.
Developmental cysts Of these, the most important are the huge cysts that originate in the OVARIES. The cause is doubtful, but the cyst probably begins at a very early period of life, gradually enlarges, and buds o? smaller cysts from its wall. The contents are usually a clear gelatinous ?uid. Very often both ovaries are affected, and the cysts may slowly reach a great size – often, however, taking a lifetime to do so.
A similar condition sometimes occurs in the KIDNEYS, and the tumour may have reached a great size in an infant even before birth (congenital cystic kidney).
Dermoid cysts are small cavities, which also originate probably early in life, but do not reach any great size until fairly late in life. They appear about parts of the body where clefts occur in the embryo and close up before birth, such as the corner of the eyes, the side of the neck, and the middle line of the body. They contain hair, fatty matter, fragments of bone, scraps of skin, even numerous teeth.
Hydatid cysts are produced in many organs, particularly in the liver, by a parasite which is the larval stage of a tapeworm found in dogs. They occur in people who keep dogs and allow them to contaminate their food. (See TAENIASIS.)... cysts
This is a procedure in which a catheter (see CATHETERS) is passed via an ENDOSCOPE into the AMPULLA OF VATER of the common BILE DUCT. The duct is then injected with a radio-opaque material to show up the ducts radiologically. The technique is used to diagnose pancreatic disease as well as obstructive jaundice.... endoscopic retrograde cholangiopancreatography (ercp)
An oblong body attached to the upper part of each TESTICLE, composed of convoluted vessels and ducts, that connects the VASA EFFERENTIA to the VAS DEFERENS. Sperm cells produced in the testis pass along the epididymis, maturing as they go, to be stored in the seminal vesicles until EJACULATION occurs. The epididymis may be damaged by trauma or infection resulting sometimes in sterility. Cysts may also occur.... epididymis
Inadequate drainage of tears in the eyes with the result that they ‘over?ow’ down the cheeks. The condition is caused by an abnormality of the tear ducts which drain away the normal secretions that keep the eyeball moist (see EYE).... epiphora
The eye is the sensory organ of sight. It is an elaborate photoreceptor detecting information, in the form of light, from the environment and transmitting this information by a series of electrochemical changes to the BRAIN. The visual cortex is the part of the brain that processes this information (i.e. the visual cortex is what ‘sees’ the environment). There are two eyes, each a roughly spherical hollow organ held within a bony cavity (the orbit). Each orbit is situated on the front of the skull, one on each side of the nose. The eye consists of an outer wall of three main layers and a central cavity divided into three.
The outer coat consists of the sclera and the cornea; their junction is called the limbus. SCLERA This is white, opaque, and constitutes the posterior ?ve-sixths of the outer coat. It is made of dense ?brous tissue. The sclera is visible anteriorly, between the eyelids, as the ‘white of the eye’. Posteriorly and anteriorly it is covered by Tenons capsule, which in turn is covered by transparent conjunctiva. There is a hole in the sclera through which nerve ?bres from the retina leave the eye in the optic nerve. Other smaller nerve ?bres and blood vessels also pass through the sclera at di?erent points. CORNEA This constitutes the transparent, colourless anterior one-sixth of the eye. It is transparent in order to allow light into the eye and is more steeply curved than the sclera. Viewed from in front, the cornea is roughly circular. Most of the focusing power of the eye is provided by the cornea (the lens acts as the ‘?ne adjustment’). It has an outer epithelium, a central stroma and an inner endothelium. The cornea is supplied with very ?ne nerve ?bres which make it exquisitely sensitive to pain. The central cornea has no blood supply – it relies mainly on aqueous humour for nutrition. Blood vessels and large nerve ?bres in the cornea would prevent light from entering the eye. LIMBUS is the junction between cornea and sclera. It contains the trabecular meshwork, a sieve-like structure through which aqueous humour leaves the eye.
The middle coat (uveal tract) consists of the choroid, ciliary body and iris. CHOROID A highly vascular sheet of tissue lining the posterior two-thirds of the sclera. The network of vessels provides the blood supply for the outer half of the retina. The blood supply of the choroid is derived from numerous ciliary vessels which pierce the sclera in front and behind. CILIARY BODY A ring of tissue extending 6 mm back from the anterior limitation of the sclera. The various muscles of the ciliary body by their contractions and relaxations are responsible for changing the shape of the lens during ACCOMMODATION. The ciliary body is lined by cells that secrete aqueous humour. Posteriorly, the ciliary body is continuous with the choroid; anteriorly it is continuous with the iris. IRIS A ?attened muscular diaphragm that is attached at its periphery to the ciliary body, and has a round central opening – the pupil. By contraction and relaxation of the muscles of the iris, the pupil can be dilated or constricted (dilated in the dark or when aroused; constricted in bright light and for close work). The iris forms a partial division between the anterior chamber and the posterior chamber of the eye. It lies in front of the lens and forms the back wall of the anterior chamber. The iris is visible from in front, through the transparent cornea, as the ‘coloured part of the eye’. The amount and distribution of iris pigment determine the colour of the iris. The pupil is merely a hole in the centre of the iris and appears black.
The inner layer The retina is a multilayered tissue (ten layers in all) which extends from the edges of the optic nerve to line the inner surface of the choroid up to the junction of ciliary body and choroid. Here the true retina ends at the ora serrata. The retina contains light-sensitive cells of two types: (i) cones – cells that operate at high and medium levels of illumination; they subserve ?ne discrimination of vision and colour vision; (ii) rods – cells that function best at low light intensity and subserve black-and-white vision.
The retina contains about 6 million cones and about 100 million rods. Information from them is conveyed by the nerve ?bres which are in the inner part of the retina, and leave the eye in the optic nerve. There are no photoreceptors at the optic disc (the point where the optic nerve leaves the eye) and therefore there is no light perception from this small area. The optic disc thus produces a physiological blind spot in the visual ?eld.
The retina can be subdivided into several areas: PERIPHERAL RETINA contains mainly rods and a few scattered cones. Visual acuity from this area is fairly coarse. MACULA LUTEA So-called because histologically it looks like a yellow spot. It occupies an area 4·5 mm in diameter lateral to the optic disc. This area of specialised retina can produce a high level of visual acuity. Cones are abundant here but there are few rods. FOVEA CENTRALIS A small central depression at the centre of the macula. Here the cones are tightly packed; rods are absent. It is responsible for the highest levels of visual acuity.
The chambers of the eye There are three: the anterior and posterior chambers, and the vitreous cavity. ANTERIOR CHAMBER Limited in front by the inner surface of the cornea, behind by the iris and pupil. It contains a transparent clear watery ?uid, the aqueous humour. This is constantly being produced by cells of the ciliary body and constantly drained away through the trabecular meshwork. The trabecular meshwork lies in the angle between the iris and inner surface of the cornea. POSTERIOR CHAMBER A narrow space between the iris and pupil in front and the lens behind. It too contains aqueous humour in transit from the ciliary epithelium to the anterior chamber, via the pupil. VITREOUS CAVITY The largest cavity of the eye. In front it is bounded by the lens and behind by the retina. It contains vitreous humour.
Lens Transparent, elastic and biconvex in cross-section, it lies behind the iris and in front of the vitreous cavity. Viewed from the front it is roughly circular and about 10 mm in diameter. The diameter and thickness of the lens vary with its accommodative state. The lens consists of: CAPSULE A thin transparent membrane surrounding the cortex and nucleus. CORTEX This comprises newly made lens ?bres that are relatively soft. It separates the capsule on the outside from the nucleus at the centre of the lens. NUCLEUS The dense central area of old lens ?bres that have become compacted by new lens ?bres laid down over them. ZONULE Numerous radially arranged ?bres attached between the ciliary body and the lens around its circumference. Tension in these zonular ?bres can be adjusted by the muscles of the ciliary body, thus changing the shape of the lens and altering its power of accommodation. VITREOUS HUMOUR A transparent jelly-like structure made up of a network of collagen ?bres suspended in a viscid ?uid. Its shape conforms to that of the vitreous cavity within which it is contained: that is, it is spherical except for a shallow concave depression on its anterior surface. The lens lies in this depression.
Eyelids These are multilayered curtains of tissue whose functions include spreading of the tear ?lm over the front of the eye to prevent desiccation; protection from injury or external irritation; and to some extent the control of light entering the eye. Each eye has an upper and lower lid which form an elliptical opening (the palpebral ?ssure) when the eyes are open. The lids meet at the medial canthus and lateral canthus respectively. The inner medial canthus is ?xed; the lateral canthus more mobile. An epicanthus is a fold of skin which covers the medial canthus in oriental races.
Each lid consists of several layers. From front to back they are: very thin skin; a sheet of muscle (orbicularis oculi, whose ?bres are concentric around the palpebral ?ssure and which produce closure of the eyelids); the orbital septum (modi?ed near the lid margin to form the tarsal plates); and ?nally, lining the back surface of the lid, the conjunctiva (known here as tarsal conjunctiva). At the free margin of each lid are the eyelashes, the openings of tear glands which lie within the lid, and the lacrimal punctum. Toward the medial edge of each lid is an elevation known as the papilla: the lacrimal punctum opens into this papilla. The punctum forms the open end of the cannaliculus, part of the tear-drainage mechanism.
Orbit The bony cavity within which the eye is held. The orbits lie one on either side of the nose, on the front of the skull. They a?ord considerable protection for the eye. Each is roughly pyramidal in shape, with the apex pointing backwards and the base forming the open anterior part of the orbit. The bone of the anterior orbital margin is thickened to protect the eye from injury. There are various openings into the posterior part of the orbit – namely the optic canal, which allows the optic nerve to leave the orbit en route for the brain, and the superior orbital and inferior orbital ?ssures, which allow passage of nerves and blood vessels to and from the orbit. The most important structures holding the eye within the orbit are the extra-ocular muscles, a suspensory ligament of connective tissue that forms a hammock on which the eye rests and which is slung between the medial and lateral walls of the orbit. Finally, the orbital septum, a sheet of connective tissue extending from the anterior margin of the orbit into the lids, helps keep the eye in place. A pad of fat ?lls in the orbit behind the eye and acts as a cushion for the eye.
Conjunctiva A transparent mucous membrane that extends from the limbus over the anterior sclera or ‘white of the eye’. This is the bulbar conjunctiva. The conjunctiva does not cover the cornea. Conjunctiva passes from the eye on to the inner surface of the eyelid at the fornices and is continuous with the tarsal conjunctiva. The semilunar fold is the vertical crescent of conjunctiva at the medial aspect of the palpebral ?ssure. The caruncle is a piece of modi?ed skin just within the inner canthus.
Eye muscles The extra-ocular muscles. There are six in all, the four rectus muscles (superior, inferior, medial and lateral rectus muscles) and two oblique muscles (superior and inferior oblique muscles). The muscles are attached at various points between the bony orbit and the eyeball. By their combined action they move the eye in horizontal and vertical gaze. They also produce torsional movement of the eye (i.e. clockwise or anticlockwise movements when viewed from the front).
Lacrimal apparatus There are two components: a tear-production system, namely the lacrimal gland and accessory lacrimal glands; and a drainage system.
Tears keep the front of the eye moist; they also contain nutrients and various components to protect the eye from infection. Crying results from excess tear production. The drainage system cannot cope with the excess and therefore tears over?ow on to the face. Newborn babies do not produce tears for the ?rst three months of life. LACRIMAL GLAND Located below a small depression in the bony roof of the orbit. Numerous tear ducts open from it into predominantly the upper lid. Accessory lacrimal glands are found in the conjunctiva and within the eyelids: the former open directly on to the surface of the conjunctiva; the latter on to the eyelid margin. LACRIMAL DRAINAGE SYSTEM This consists of: PUNCTUM An elevated opening toward the medial aspect of each lid. Each punctum opens into a canaliculus. CANALICULUS A ?ne tube-like structure run-ning within the lid, parallel to the lid margin. The canaliculi from upper and lower lid join to form a common canaliculus which opens into the lacrimal sac. LACRIMAL SAC A small sac on the side of the nose which opens into the nasolacrimal duct. During blinking, the sac sucks tears into itself from the canaliculus. Tears then drain by gravity down the nasolacrimal duct. NASOLACRIMAL DUCT A tubular structure which runs down through the wall of the nose and opens into the nasal cavity.
Visual pathway Light stimulates the rods and cones of the retina. Electrochemical messages are then passed to nerve ?bres in the retina and then via the optic nerve to the optic chiasm. Here information from the temporal (outer) half of each retina continues to the same side of the brain. Information from the nasal (inner) half of each retina crosses to the other side within the optic chiasm. The rearranged nerve ?bres then pass through the optic tract to the lateral geniculate body, then the optic radiation to reach the visual cortex in the occipital lobe of the brain.... eye
Arcus senilis The white ring or crescent which tends to form at the edge of the cornea with age. It is uncommon in the young, when it may be associated with high levels of blood lipids (see LIPID).
Astigmatism (See ASTIGMATISM.)
Blepharitis A chronic in?ammation of the lid margins. SEBORRHOEA and staphylococcal infection are likely contributors. The eyes are typically intermittently red, sore and gritty over months or years. Treatment is di?cult and may fail. Measures to reduce debris on the lid margins, intermittent courses of topical antibiotics, steroids or systemic antibiotics may help the sufferer.
Blepharospasm Involuntary closure of the eye. This may accompany irritation but may also occur without an apparent cause. It may be severe enough to interfere with vision. Treatment involves removing the source of irritation, if present. Severe and persistent cases may respond to injection of Botulinum toxin into the orbicularis muscle.
Cataract A term used to describe any opacity in the lens of the eye, from the smallest spot to total opaqueness. The prevalence of cataracts is age-related: 65 per cent of individuals in their sixth decade have some degree of lens opacity, while all those over 80 are affected. Cataracts are the most important cause of blindness worldwide. Symptoms will depend on whether one or both eyes are affected, as well as the position and density of the cataract(s). If only one eye is developing a cataract, it may be some time before the person notices it, though reading may be affected. Some people with cataracts become shortsighted, which in older people may paradoxically ‘improve’ their ability to read. Bright light may worsen vision in those with cataracts.
The extent of visual impairment depends on the nature of the cataracts, and the ?rst symptoms noticed by patients include di?culty in recognising faces and in reading, while problems watching television or driving, especially at night, are pointers to the condition. Cataracts are common but are not the only cause of deteriorating vision. Patients with cataracts should be able to point to the position of a light and their pupillary reactions should be normal. If a bright light is shone on the eye, the lens may appear brown or, in advanced cataracts, white (see diagram).
While increasing age is the commonest cause of cataract in the UK, patients with DIABETES MELLITUS, UVEITIS and a history of injury to the eye can also develop the disorder. Prolonged STEROID treatment can result in cataracts. Children may develop cataracts, and in them the condition is much more serious as vision may be irreversibly impaired because development of the brain’s ability to interpret visual signals is hindered. This may happen even if the cataracts are removed, so early referral for treatment is essential. One of the physical signs which doctors look for when they suspect cataract in adults as well as in children is the ‘red re?ex’. This is observable when an ophthalmoscopic examination of the eye is made (see OPHTHALMOSCOPE). Identi?cation of this red re?ex (a re?ection of light from the red surface of the retina –see EYE) is a key diagnostic sign in children, especially young ones.
There is no e?ective medical treatment for established cataracts. Surgery is necessary and the decision when to operate depends mainly on how the cataract(s) affect(s) the patient’s vision. Nowadays, surgery can be done at any time with limited risk. Most patients with a vision of 6/18 – 6/10 is the minimum standard for driving – or worse in both eyes should
E
bene?t from surgery, though elderly people may tolerate visual acuity of 6/18 or worse, so surgery must be tailored to the individual’s needs. Younger people with a cataract will have more demanding visual requirements and so may opt for an ‘earlier’ operation. Most cataract surgery in Britain is now done under local anaesthetic and uses the ‘phaco-emulsi?cation’ method. A small hole is made in the anterior capsule of the lens after which the hard lens nucleus is liqui?ed ultrasonically. A replacement lens is inserted into the empty lens bag (see diagram). Patients usually return to their normal activities within a few days of the operation. A recent development under test in the USA for children requiring cataract operations is an intra-ocular ?exible implant whose magnifying power can be altered as a child develops, thus precluding the need for a series of corrective operations as happens now.
Chalazion A ?rm lump in the eyelid relating to a blocked meibomian gland, felt deep within the lid. Treatment is not always necessary; a proportion spontaneously resolve. There can be associated infection when the lid becomes red and painful requiring antibiotic treatment. If troublesome, the chalazion can be incised under local anaesthetic.
Conjunctivitis In?ammation of the conjunctiva (see EYE) which may affect one or both eyes. Typically the eye is red, itchy, sticky and gritty but is not usually painful. Redness is not always present. Conjunctivitis can occasionally be painful, particularly if there is an associated keratitis (see below) – for example, adenovirus infection, herpetic infection.
The cause can be infective (bacteria, viruses or CHLAMYDIA), chemical (e.g. acids, alkalis) or allergic (e.g. in hay fever). Conjunctivitis may also be caused by contact lenses, and preservatives or even the drugs in eye drops may cause conjunctival in?ammation. Conjunctivitis may addtionally occur in association with other illnesses – for example, upper-respiratory-tract infection, Stevens-Johnson syndrome (see ERYTHEMA – erythema multiforme) or REITER’S SYNDROME. The treatment depends on the cause. In many patients acute conjunctivitis is self-limiting.
Dacryocystitis In?ammation of the lacrimal sac. This may present acutely as a red, painful swelling between the nose and the lower lid. An abscess may form which points through the skin and which may need to be drained by incision. Systemic antibiotics may be necessary. Chronic dacryocystitis may occur with recurrent discharge from the openings of the tear ducts and recurrent swelling of the lacrimal sac. Obstruction of the tear duct is accompanied by watering of the eye. If the symptoms are troublesome, the patient’s tear passageways need to be surgically reconstructed.
Ectropion The lid margin is everted – usually the lower lid. Ectropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the skin of the lids such as happens with scarring or mechanical factors – for example, a tumour pulling the skin of the lower lid downwards. Ectropion tends to cause watering and an unsightly appearance. The treatment is surgical.
Entropion The lid margin is inverted – usually the lower lid. Entropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the inner surfaces of the lids due to scarring – for example, TRACHOMA or chemical burns. The inwardly directed lashes cause irritation and can abrade the cornea. The treatment is surgical.
Episcleritis In?ammation of the EPISCLERA. There is usually no apparent cause. The in?ammation may be di?use or localised and may affect one or both eyes. It sometimes recurs. The affected area is usually red and moderately painful. Episcleritis is generally not thought to be as painful as scleritis and does not lead to the same complications. Treatment is generally directed at improving the patient’s symptoms. The in?ammation may respond to NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) or topical CORTICOSTEROIDS.
Errors of refraction (Ametropia.) These will occur when the focusing power of the lens and cornea does not match the length of the eye, so that rays of light parallel to the visual axis are not focused at the fovea centralis (see EYE). There are three types of refractive error: HYPERMETROPIA or long-sightedness. The refractive power of the eye is too weak, or the eye is too short so that rays of light are brought to a focus at a point behind the retina. Longsighted people can see well in the distance but generally require glasses with convex lenses for reading. Uncorrected long sight can lead to headaches and intermittent blurring of vision following prolonged close work (i.e. eye strain). As a result of ageing, the eye becomes gradually long-sighted, resulting in many people needing reading glasses in later life: this normal process is known as presbyopia. A particular form of long-sightedness occurs after cataract extraction (see above). MYOPIA(Short sight or near sight.) Rays of light are brought to a focus in front of the retina because the refractive power of the eye is too great or the eye is too short. Short-sighted people can see close to but need spectacles with concave lenses in order to see in the distance. ASTIGMATISMThe refractive power of the eye is not the same in each meridian. Some rays of light may be focused in front of the retina while others are focused on or behind the retina. Astigmatism can accompany hypermetropia or myopia. It may be corrected by cylindrical lenses: these consist of a slice from the side of a cylinder (i.e. curved in one meridian and ?at in the meridian at right-angles to it).
Keratitis In?ammation of the cornea in response to a variety of insults – viral, bacterial, chemical, radiation, or mechanical trauma. Keratitis may be super?cial or involve the deeper layers, the latter being generally more serious. The eye is usually red, painful and photophobic. Treatment is directed at the cause.
Nystagmus Involuntary rhythmic oscillation of one or both eyes. There are several causes including nervous disorders, vestibular disorders, eye disorders and certain drugs including alcohol.
Ophthalmia In?ammation of the eye, especially the conjunctiva (see conjunctivitis, above). Ophthalmia neonatorum is a type of conjunctivitis that occurs in newborn babies. They catch the disease when passing through an infected birth canal during their mother’s labour (see PREGNANCY AND LABOUR). CHLAMYDIA and GONORRHOEA are the two most common infections. Treatment is e?ective with antibiotics: untreated, the infection may cause permanent eye damage.
Pinguecula A benign degenerative change in the connective tissue at the nasal or temporal limbus (see EYE). This is visible as a small, ?attened, yellow-white lump adjacent to the cornea.
Pterygium Overgrowth of the conjunctival tissues at the limbus on to the cornea (see EYE). This usually occurs on the nasal side and is associated with exposure to sunlight. The pterygium is surgically removed for cosmetic reasons or if it is thought to be advancing towards the visual axis.
Ptosis Drooping of the upper lid. May occur because of a defect in the muscles which raise the lid (levator complex), sometimes the result of ageing or trauma. Other causes include HORNER’S SYNDROME, third cranial nerve PALSY, MYASTHENIA GRAVIS, and DYSTROPHIA MYOTONICA. The cause needs to be determined and treated if possible. The treatment for a severely drooping lid is surgical, but other measures can be used to prop up the lid with varying success.
Retina, disorders of The retina can be damaged by disease that affects the retina alone, or by diseases affecting the whole body.
Retinopathy is a term used to denote an abnormality of the retina without specifying a cause. Some retinal disorders are discussed below. DIABETIC RETINOPATHY Retinal disease occurring in patients with DIABETES MELLITUS. It is the commonest cause of blind registration in Great Britain of people between the ages of 20 and 65. Diabetic retinopathy can be divided into several types. The two main causes of blindness are those that follow: ?rst, development of new blood vessels from the retina, with resultant complications and, second, those following ‘water logging’ (oedema) of the macula. Treatment is by maintaining rigid control of blood-sugar levels combined with laser treatment for certain forms of the disease – in particular to get rid of new blood vessels. HYPERTENSIVE RETINOPATHY Retinal disease secondary to the development of high blood pressure. Treatment involves control of the blood pressure (see HYPERTENSION). SICKLE CELL RETINOPATHY People with sickle cell disease (see under ANAEYIA) can develop a number of retinal problems including new blood vessels from the retina. RETINOPATHY OF PREMATURITY (ROP) Previously called retrolental ?broplasia (RLF), this is a disorder affecting low-birth-weight premature babies exposed to oxygen. Essentially, new blood vessels develop which cause extensive traction on the retina with resultant retinal detachment and poor vision. RETINAL ARTERY OCCLUSION; RETINAL VEIN OCCLUSION These result in damage to those areas of retina supplied by the affected blood vessel: the blood vessels become blocked. If the peripheral retina is damaged the patient may be completely symptom-free, although areas of blindness may be detected on examination of ?eld of vision. If the macula is involved, visual loss may be sudden, profound and permanent. There is no e?ective treatment once visual loss has occurred. SENILE MACULAR DEGENERATION (‘Senile’ indicates age of onset and has no bearing on mental state.) This is the leading cause of blindness in the elderly in the western world. The average age of onset is 65 years. Patients initially notice a disturbance of their vision which gradually progresses over months or years. They lose the ability to recognise ?ne detail; for example, they cannot read ?ne print, sew, or recognise people’s faces. They always retain the ability to recognise large objects such as doors and chairs, and are therefore able to get around and about reasonably well. There is no e?ective treatment in the majority of cases. RETINITIS PIGMENTOSAA group of rare, inherited diseases characterised by the development of night blindness and tunnel vision. Symptoms start in childhood and are progressive. Many patients retain good visual acuity, although their peripheral vision is limited. One of the characteristic ?ndings on examination is collections of pigment in the retina which have a characteristic shape and are therefore known as ‘bone spicules’. There is no e?ective treatment. RETINAL DETACHMENTusually occurs due to the development of a hole in the retina. Holes can occur as a result of degeneration of the retina, traction on the retina by the vitreous, or injury. Fluid from the vitreous passes through the hole causing a split within the retina; the inner part of the retina becomes detached from the outer part, the latter remaining in contact with the choroid. Detached retina loses its ability to detect light, with consequent impairment of vision. Retinal detachments are more common in the short-sighted, in the elderly or following cataract extraction. Symptoms include spots before the eyes (?oaters), ?ashing lights and a shadow over the eye with progressive loss of vision. Treatment by laser is very e?ective if caught early, at the stage when a hole has developed in the retina but before the retina has become detached. The edges of the hole can be ‘spot welded’ to the underlying choroid. Once a detachment has occurred, laser therapy cannot be used; the retina has to be repositioned. This is usually done by indenting the wall of the eye from the outside to meet the retina, then making the retina stick to the wall of the eye by inducing in?ammation in the wall (by freezing it). The outcome of surgery depends largely on the extent of the detachment and its duration. Complicated forms of detachment can occur due to diabetic eye disease, injury or tumour. Each requires a specialised form of treatment.
Scleritis In?ammation of the sclera (see EYE). This can be localised or di?use, can affect the anterior or the posterior sclera, and can affect one or both eyes. The affected eye is usually red and painful. Scleritis can lead to thinning and even perforation of the sclera, sometimes with little sign of in?ammation. Posterior scleritis in particular may cause impaired vision and require emergency treatment. There is often no apparent cause, but there are some associated conditions – for example, RHEUMATOID ARTHRITIS, GOUT, and an autoimmune disease affecting the nasal passages and lungs called Wegener’s granulomatosis. Treatment depends on severity but may involve NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), topical CORTICOSTEROIDS or systemic immunosuppressive drugs.
Stye Infection of a lash follicle. This presents as a painful small red lump at the lid margin. It often resolves spontaneously but may require antibiotic treatment if it persists or recurs.
Sub-conjunctival haemorrhage Haemorrhage between the conjunctiva and the underlying episclera. It is painless. There is usually no apparent cause and it resolves spontaneously.
Trichiasis Inward misdirection of the lashes. Trichiasis occurs due to in?ammation of or trauma to the lid margin. Treatment involves removal of the patient’s lashes. Regrowth may be prevented by electrolysis, by CRYOTHERAPY to the lid margin, or by surgery.
For the subject of arti?cial eyes, see under PROSTHESIS; also GLAUCOMA, SQUINT and UVEITIS.... eye, disorders of
The main cell type present in the LIVER. A large cell, it has several important metabolic functions: these include synthesis and storage of biochemical products; detoxi?cation of poisons and unwanted substances; and the manufacture of BILE, the liver secretion that passes through the bile ducts to the small intestine and helps in the digestion of fat.... hepatocyte
The female breasts may be expected to undergo hormone-controlled enlargement at puberty, and later in pregnancy, and the glandular part of the breast undergoes evolution (shrinkage) after the menopause. The breast can also be affected by many di?erent diseases, with common symptoms being pain, nipple discharge or retraction, and the formation of a lump within the breast.
Benign disease is much more common than cancer, particularly in young women, and includes acute in?ammation of the breast (mastitis); abscess formation; and benign breast lumps, which may be ?broadenosis – di?use lumpiness also called chronic mastitis or ?brocystic disease – in which one or more ?uid-?lled sacs (cysts) develop.
Women who are breast feeding are particularly prone to mastitis, as infection may enter the breast via the nipple. The process may be arrested before a breast abscess forms by prompt treatment with antibiotics. Non-bacterial in?ammation may result from mammary duct ectasia (dilatation), in which abnormal or
blocked ducts may over?ow. Initial treatments should be with antibiotics, but if an abscess does form it should be surgically drained.
Duct ectasia, with or without local mastitis, is the usual benign cause of various nipple complaints, with common symptoms being nipple retraction, discharge and skin change.
Breast lumps form the chief potential danger and may be either solid or cystic. Simple examination may fail to distinguish the two types, but aspiration of a benign cyst usually results in its disappearance. If the ?uid is bloodstained, or if a lump still remains, malignancy is possible, and all solid lumps need histological (tissue examination) or cytological (cell examination) assessment. As well as having their medical and family history taken, any women with a breast lump should undergo triple assessment: a combination of clinical examination, imaging
– mammography for the over-35s and ultrasonagraphy for the under-35s – and ?ne-needle aspiration. The medical history should include details of any previous lumps, family history (up to 10 per cent of breast cancer in western countries is due to genetic disposition), pain, nipple discharge, change in size related to menstrual cycle and parous state, and any drugs being taken by the patient. Breasts should be inspected with the arms up and down, noting position, size, consistency, mobility, ?xity, and local lymphadenopathy (glandular swelling). Nipples should be examined for the presence of inversion or discharge. Skin involvement (peau d’orange) should be noted, and, in particular, how long changes have been present. Fine-needle aspiration and cytological examination of the ?uid are essential with ULTRASOUND, MAMMOGRAPHY and possible BIOPSY being considered, depending on the patient’s age and the extent of clinical suspicion that cancer may be present.
The commonest solid benign lump is a ?broadenoma, particularly in women of childbearing age, and is a painless, mobile lump. If small, it is usually safe to leave it alone, provided that the patient is warned to seek medical advice if its size or character changes or if the lump becomes painful. Fibroadenosis (di?use lumpiness often in the upper, outer quadrant) is a common (benign) lump. Others include periductal mastitis, fat NECROSIS, GALACTOCELE, ABSCESS, and non-breast-tissue lumps – for example, a LIPOMA (fatty tissue) or SEBACEOUS CYST. A woman with breast discharge should have a mammograph, ductograph, or total duct excision until the cause of any underlying duct ectasia is known. Appropriate treatment should then be given.
Malignant disease most commonly – but not exclusively – occurs in post-menopausal women, classically presenting as a slowly growing, painless, ?rm lump. A bloodstained nipple discharge or eczematous skin change may also be suggestive of cancer.
The most commonly used classi?cation of invasive cancers has split them into two types, ductal and lobular, but this is no longer suitable. There are also weaknesses in the tumour node metastases (TNM) system and the International Union Against Cancer (UICC) classi?cation.
The TNM system – which classi?es the lump by size, ?xity and presence of affected axillary glands and wider metastatic spread – is best combined with a pathological classi?cation, when assessing the seriousness of a possibly cancerous lump. Risk factors for cancer include nulliparity (see NULLIPARA), ?rst pregnancy over the age of 30 years, early MENARCHE, late MENOPAUSE and positive family history. The danger should be considered in women who are not breast feeding or with previous breast cancer, and must be carefully excluded if the woman is taking any contraceptive steroids or is on hormone-replacement therapy (see under MENOPAUSE).
Screening programmes involving mammography are well established, the aim being to detect more tumours at an early and curable stage. Pick-up rate is ?ve per 1,000 healthy women over 50 years. Yearly two-view mammograms could reduce mortality by 40 per cent but may cause alarm because there are ten false positive mammograms for each true positive result. In premenopausal women, breasts are denser, making mammograms harder to interpret, and screening appears not to save lives. About a quarter of women with a palpable breast lump turn out to have cancer.
Treatment This remains controversial, and all options should be carefully discussed with the patient and, where appropriate, with her partner. Locally contained disease may be treated by local excision of the lump, but sampling of the glands of the armpit of the same side should be performed to check for additional spread of the disease, and hence the need for CHEMOTHERAPY or RADIOTHERAPY. Depending on the extent of spread, simple mastectomy or modi?ed radical mastectomy (which removes the lymph nodes draining the breast) may be required. Follow-up chemotherapy, for example, with TAMOXIFEN (an oestrogen antagonist), much improves survival (it saves 12 lives over 100 women treated), though it may occasionally cause endometrial carcinoma. Analysis in the mid-1990s of large-scale international studies of breast-cancer treatments showed wide variations in their e?ectiveness. As a result the NHS has encouraged hospitals to set up breast-treatment teams containing all the relevant health professional experts and to use those treatments shown to be most e?ective.
As well as the physical treatments provided, women with suspected or proven breast cancer should be o?ered psychological support because up to 30 per cent of affected women develop an anxiety state or depressive illness within a year of diagnosis. Problems over body image and sexual diffculties occur in and around one-quarter of patients. Breast conservation and reconstructive surgery can improve the physical effects of mastectomy, and women should be advised on the prostheses and specially designed brassieres that are available. Specialist nurses and self-help groups are invaluable in supporting affected women and their partners with the problems caused by breast cancer and its treatment. Breast Cancer Care, British Association of Cancer United Patients (BACUP), Cancerlink, and Cancer Relief Macmillan Fund are among voluntary organisations providing support.... breasts, diseases of
The presence of endometrial tissue outside of the uterus. The endometrium is the mucus membrane inner lining of the uterus, with glandular cells and structural cells, both responding to estrogen by increasing in size (the proliferative phase), the first responding to progesterone (the secretory phase); if there is endometrial tissue outside of the uterus, the tissue expands and shrinks in response to the estrus cycle, but the normal shedding of the menstrual phase can be difficult. The most common type of endometriosis is found in the fallopian tubes; the abnormal fallopian endometrial tissue can shed and drain into the uterus, but it hurts! It’s funny, but little tiny ducts, like the ureters, bile ducts, and fallopian tubes really cramp. The colon and uterus are big muscular tubes and, when cramped up, cause rather strong pain. When one of those little bitty things gets tenesmus, your face gets white (or light tan), you start to sweat, shiver, and revert to a fetal position. Endometriosis that occurs around the ovaries or inside the belly and therefore can NEVER drain is a purely physical and medical condition, but fallopian presence of endometrium usually reaches its peak in the early thirties. It can be helped by ensuring a strong estrogen and progesterone balance, thereby decreasing the tendency to form clots in the tubes, and to experience severe cramps every month... endometriosis
Epithelium is the cellular layer which forms the epidermis on the skin, covers the inner surface of the bowels, and forms the lining of ducts and hollow organs, like the bladder. It consists of one or more layers of cells which adhere to one another, and is one of the simplest tissues of the body. It is of several forms: for example, the epidermis is formed of scaly epithelium, the cells being in several layers and more or less ?attened. (See SKIN.) The bowels are lined by a single layer of columnar epithelium, the cells being long and narrow in shape. The air passages are lined by ciliated epithelium: that is to say, each cell is provided with ?agellae (lashes) which drive the ?uid upon the surface of the passages gradually upwards.... epithelium
Labill.
Family: Myrtaceae.
Habitat: Native to Australia; now cultivated mainly at the hill-stations of India.
English: Blue-Gum tree, Australian Gum tree.
Ayurvedic: Tilaparna, Tailaparna, Sugandhapatra, Haritaparna Neela- niryaasa, Tribhandi, Triputaa, Sar- alaa, Suvahaa, Rechani, Nishotraa.
Unani: Neelgiri oil.
Siddha/Tamil: Karpooramaram.
Action: Essential oil from leaves— antiseptic, antibiotic, antiviral, antifungal, antispasmodic, decon- gestant, antiasthmatic, expectorant, antirheumatic, diaphoretic. Used in chronic, bronchitis, migraine, congestive headache, neuralgia and ague, as an inhalant or internal medicine. Root—purgative.
Key application: Leaf tea for catarrhs of the respiratory tract. Oil used externally for rheumatic complaints, contraindicated internally in inflammatory diseases of the gastrointestinal tract, bile ducts, and in severe liver diseases. (German Commission E.) Oil—internally as adjuvant treatment of chronic obstructive respiratory complaints, including bronchitis and bronchial asthma, also for symptomatic relief of colds and catarrh of the upper respiratory tract; externally for symptomatic treatment of colds and rheumatic complaints. (ESCOP.) Leaf—antiseptic. (The British Herbal Pharmacopoeia.)E. globulus is the main commercial source of Eucalyptus leaf oil; yield is 2.12%; 1,8-cineole exceeds 70% (pharmaceutical grade oil requires a minimum cineole content of 70%).Several potent euglobals, having closely related acyl-phloroglucinol- monoterpene (or sesquiterpene) structures, are isolated from the leaves and flower buds. These compounds showed strong granulation-inhibiting activity and inhibition of TPA induced EBV (Epstein-Barr Virus) activation.Phloroglucin derivatives, isolated from leaves, showed better antiinflammatory activity than indomethacin.Natural antioxidants have also been isolated from the plant.
Dosage: Leaf—50-100 ml infusion. (CCRAS.)... eucalyptus globules
(also Lacrimitis) Inflamed lacrimal or tear ducts.... lachrymitis
The general name given to the membrane which lines many of the hollow organs of the body. These membranes vary widely in structure in di?erent sites, but all have the common character of being lubricated by MUCUS – derived in some cases from isolated cells on the surface of the membrane, but more generally from de?nite glands placed beneath the membrane, and opening here and there through it by ducts. The air passages, the gastrointestinal tract and the ducts of glands which open into it, and also the urinary passages, are all lined by mucous membrane.... mucous membrane
A pair of salivary glands tucked into the notch in front of each ear and emptying through parotid ducts by each upper 2nd molar. Although the fluid has some of the thick viscous lubricant nature of saliva from the glands in the floor of the mouth, the parotids secrete high levels of ptyelin and amylase (starch-digesting enzymes) lysozymes (antimicrobial enzymes) and a group of proteins loosely called parotin that stimulate epithelial and nerve cell growth...a lot more here than just spit.... parotid
A technique for displaying the bile ducts (see BILE DUCT) and pancreatic ducts (see PANCREAS) with radio-opaque dyes. These are introduced via a catheter (see CATHETERS) inserted into the ducts through an incision in the skin. An X-ray is then taken of the area.... percutaneous transhepatic cholangiopancreatography (ptc)
An organic iodine salt that is radio-opaque and therefore used as a contrast medium to outline various organs in the body in X-ray ?lms (see XRAYS). It is given intravenously. Its main use is in PYELOGRAPHY – that is, in rendering the kidneys radio-opaque – but it is also used to outline the blood vessels (ANGIOGRAPHY) and the gall-bladder and bile ducts (CHOLANGIOGRAPHY).... sodium diatrizoate
The painful expelling cramps of the tubular smooth muscles and ducts. Normal peristalsis of various types produce no pain or sensation (except for the dreaded borborygmies); only the energetic expulsion contraction can induce referred pain. Examples: Nausea, gas pain, uterine cramps, gall bladder pain.... tenesmus
Spasm or pain of the ureters, the ducts that milk urine from the kidneys to the bladder.... ureteralgia
E?erent seminal ducts of the testis (see TESTICLE); these carry SEMEN from the testis to the head of the EPIDIDYMIS.... vasa efferentia
Cancer of the mammary ducts (rare). Nipple: encrusted, red, inflamed. See: CANCER OF THE BREAST. ... paget’s disease of the nipple
A pair of oval, peasized glands whose ducts open into the vulva (the folds of flesh that surround the opening of the vagina). During sexual arousal, these glands secrete a fluid to lubricate the vulval region. Infection of the glands causes bartholinitis.... bartholin’s glands
A hard, crust-like deposit (also known as tartar) found on the crowns and roots of the teeth. Calculus forms when mineral salts in saliva are deposited in existing plaque. Supragingival calculus is a yellowish or white deposit that forms above the gum margin, on the crowns of teeth near the openings of salivary gland ducts. Subgingival calculus forms below the gum margin and is brown or black. Toxins in calculus cause gum inflammation (see gingivitis), which may progress to destruction of the supporting tissues (see periodontitis). Calculus is removed by professional scaling. Attention to oral hygiene reduces recurrence.... calculus, dental
The LIVER may be extensively diseased without any obviously serious symptoms, unless the circulation through it is impeded, the out?ow of BILE checked, or neighbouring organs implicated. JAUNDICE is a symptom of several liver disorders, and is discussed under its separate heading. ASCITES, which may be caused by interference with the circulation through the portal vein of the liver, as well as by other reasons, is also considered separately. The presence of gallstones is a complication of some diseases connected with the liver, and is treated under GALLBLADDER, DISEASES OF. For hydatid cyst of the liver, see TAENIASIS. Liver diseases in a tropical environment are dealt with later in this section.
In?ammation of the liver, or HEPATITIS, may occur as part of a generalised infection or may be a localised condition. Infectious hepatitis, which is the result of infection with a virus, is one of the most common forms. Many di?erent viruses can cause hepatitis, including that responsible for glandular fever (see MONONUCLEOSIS). Certain spirochaetes may also be the cause, particularly that responsible for LEPTOSPIROSIS, as can many drugs. Hepatitis may also occur if there is obstruction of the BILE DUCT, as by a gall-stone.
Cirrhosis of the liver A disorder caused by chronic damage to liver cells. The liver develops areas of ?brosis or scarring; in response, the remaining normal liver cells increase and form regeneration nodules. Those islands of normality, however, suffer from inadequate blood supply, thus adversely affecting liver function. Alcohol is the most common cause of cirrhosis in the United Kingdom and the USA, and the incidence of the disorder among women in the UK has recently risen sharply as a consequence of greater consumption of alcohol by young women in the latter decades of the 20th century. In Africa and many parts of Asia, infection with hepatitis B virus is a common cause. Certain drugs – for example, PARACETAMOL – may damage the liver if taken in excess. Unusual causes of cirrhosis include defects of the bile ducts, HAEMOCHROMATOSIS (raised iron absorption from the gut), CYSTIC FIBROSIS, cardiac cirrhosis (the result of heart failure causing circulatory congestion in the liver), and WILSON’S DISEASE (raised copper absorption).
Symptoms Some people with cirrhosis have no signs or symptoms and the disease may be diagnosed at a routine medical examination. Others may develop jaundice, OEDEMA (including ascites – ?uid in the abdomen), fever, confusion, HAEMATEMESIS (vomiting blood), loss of appetite and lethargy. On examination, cirrhotic patients often have an enlarged liver and/ or SPLEEN, and HYPERTENSION. Liver function tests, cholangiography (X-ray examination of the bile ducts) and biopsy of liver tissue will help to reach a diagnosis.
Treatment Nothing can be done to repair a cirrhosed organ, but the cause, if known, must be removed and further advance of the process thus prevented. In the case of the liver, a high-protein, high-carbohydrate, low-fat diet is given, supplemented by liver extract and vitamins B and K. The consumption of alcohol should be banned. In patients with liver failure and a poor prognosis, liver TRANSPLANTATION is worthwhile but only after careful consideration.
Abscess of the liver When an ABSCESS develops in the liver, it is usually a result of amoebic DYSENTERY, appearing sometimes late in the disease – even after the diarrhoea is cured (see below). It may also follow upon in?ammation of the liver due to other causes. In the case of an amoebic abscess, treatment consists of oral metronidazole.
Acute hepatic necrosis is a destructive and often fatal disease of the liver which is very rare. It may be due to chemical poisons, such as carbontetrachloride, chloroform, phosphorus and industrial solvents derived from benzene. It may also be the cause of death in cases of poisoning with fungi. Very occasionally, it may be a complication of acute infectious hepatitis.
Cancer of the liver is not uncommon, although it is rare for the disease to begin in the liver – the involvement of this organ being usually secondary to disease situated somewhere in the stomach or bowels. Cancer originating in the liver is more common in Asia and Africa. It usually arises in a ?brotic (or cirrhotic) liver and in carriers of the hepatitis B virus. There is great emaciation, which increases as the disease progresses. The liver is much enlarged, and its margin and surface are rough, being studded with hard cancer masses of varying size, which can often be felt through the abdominal wall. Pain may be present. Jaundice and oedema often appear.... liver, diseases of
Positioned in the chest, the lungs serve primarily as respiratory organs (see RESPIRATION), also acting as a ?lter for the blood.
Form 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
Linn. emend. Huds.
Family: Labiatae; Lamiaceae.
Habitat: Native to Europe; cultivated in Maharashtra, Kashmir and Punjab.
English: Peppermint, Brandy Mint.
Ayurvedic: Vilaayati Pudinaa.
Action: Oil—digestive, carminative, chloretic, antispasmodic, diuretic, antiemetic, mild sedative, diaphoretic, antiseptic, antiviral, used in many mixtures of indigestion and colic and cough and cold remedies.
Key application: Leaf—internally for spastic complaints of the gastrointestinal tract, gallbladder and bile ducts. (German Commission E, ESCOP.) The British Herbal Compendium indicates peppermint leaf for dyspepsia, flatulence, intestinal colic, and biliary disorders.
Key application: Oil—as a carminative. (The British Herbal Pharmacopoeia.) In spastic discomfort fo the upper gastrointestinal tract and bile ducts, irritable colon, the respiratory tract and inflammation of the oral mucosa. Externally, for myalgia and neuralgia. (German Commission E.) ESCOP indicates its use for irritable bowel syndrome, coughs and colds. Externally, for coughs and colds, rheumatic complaints, pruritus, urticaria, and pain in irritable skin conditions. (ESCOP.)The essential oil has both antibacterial and antifungal properties.The major constituents of the essential oil are: menthol, menthone, pulegone, menthofuran, 1,8-cineole, men- thyl acetate, isomenthone. The leaves contain flavonoid glycosides, erioc- itrin, luteolin 7-O-rutinoside, hesperi- din, isorhoifolin, diosmin, eriodictyol 7-O-glucoside and narirutin, besides rosmarinic acid, azulenes, cholene, carotenes.Peppermint oil relaxed carvachol- contracted guinea-pig tenia coli, and inhibited spontaneous activity in guinea-pig colon and rabbit jejunum. It relaxes gastrointestinal smooth muscle by reducing calcium influx. Peppermint oil reduced gastric emptying time in dyspeptics.The aqueous and ethanolic extracts exhibited antiviral activity against RPV (rinder pest virus), a highly contagious viral disease of cattle.... mentha piperata
The first part of the small intestine extending from the pylorus (the muscular valve at the lower end of the stomach) to the ligament of Treitz, which marks the boundary between the duodenum and the jejunum (the second part of the small intestine). It is about 25 cm long and shaped like a C; it forms a loop around the head of the pancreas. Ducts from the pancreas, liver, and gallbladder feed into the duodenum through a small opening. Digestive enzymes in the pancreatic secretions and chemicals in the bile are released into the duodenum through this opening.... duodenum
The layer of cells that lines the heart, blood vessels, and lymphatic ducts (see lymphatic system). The cells are squamous (thin and flat), providing a smooth surface that aids the flow of blood and lymph and helps prevent the formation of blood clots. (See also epithelium.)... endothelium
The mucous membrane of the mouth can indicate the health of the individual and internal organs. For example, pallor or pigmentation may indicate ANAEMIA, JAUNDICE or ADDISON’S DISEASE.
Thrush is characterised by the presence of white patches on the mucous membrane which bleeds if the patch is gently removed. It is caused by the growth of a parasitic mould known as Candida albicans. Antifungal agents usually suppress the growth of candida. Candidal in?ltration of the mucosa is often found in cancerous lesions.
Leukoplakia literally means a white patch. In the mouth it is often due to an area of thickened cells from the horny layer of the epithelium. It appears as a white patch of varying density and is often grooved by dense ?ssures. There are many causes, most of them of minor importance. It may be associated with smoking, SYPHILIS, chronic SEPSIS or trauma from a sharp tooth. Cancer must be excluded.
Stomatitis (in?ammation of the mouth) arises from the same causes as in?ammation elsewhere, but among the main causes are the cutting of teeth in children, sharp or broken teeth, excess alcohol, tobacco smoking and general ill-health. The mucous membrane becomes red, swollen and tender and ulcers may appear. Treatment consists mainly of preventing secondary infection supervening before the stomatitis has resolved. Antiseptic mouthwashes are usually su?cient.
Gingivitis (see TEETH, DISEASES OF) is in?ammation of the gum where it touches the tooth. It is caused by poor oral hygiene and is often associated with the production of calculus or tartar on the teeth. If it is neglected it will proceed to periodontal disease.
Ulcers of the mouth These are usually small and arise from a variety of causes. Aphthous ulcers are the most common; they last about ten days and usually heal without scarring. They may be associated with STRESS or DYSPEPSIA. There is no ideal treatment.
Herpetic ulcers (see HERPES SIMPLEX) are similar but usually there are many ulcers and the patient appears feverish and unwell. This condition is more common in children.
Calculus (a) Salivary: a calculus (stone) may develop in one of the major salivary-gland ducts. This may result in a blockage which will cause the gland to swell and be painful. It usually swells before a meal and then slowly subsides. The stone may be passed but often has to be removed in a minor operation. If the gland behind the calculus becomes infected, then an ABSCESS forms and, if this persists, the removal of the gland may be indicated. (b) Dental, also called TARTAR: this is a calci?ed material which adheres to the teeth; it often starts as the soft debris found on teeth which have not been well cleaned and is called plaque. If not removed, it will gradually destroy the periodontal membrane and result in the loss of the tooth. (See TEETH, DISORDERS OF.)
Ranula This is a cyst-like swelling found in the ?oor of the mouth. It is often caused by mild trauma to the salivary glands with the result that saliva collects in the cyst instead of discharging into the mouth. Surgery may be required.
Mumps is an acute infective disorder of the major salivary glands. It causes painful enlargement of the glands which lasts for about two weeks. (See also main entry for MUMPS.)
Tumours may occur in all parts of the mouth, and may be BENIGN or MALIGNANT. Benign tumours are common and may follow mild trauma or be an exaggerated response to irritation. Polyps are found in the cheeks and on the tongue and become a nuisance as they may be bitten frequently. They are easily excised.
A MUCOCOELE is found mainly in the lower lip.
An exostosis or bone outgrowth is often found in the mid line of the palate and on the inside of the mandible (bone of the lower jaw). This only requires removal if it becomes unduly large or pointed and easily ulcerated.
Malignant tumours within the mouth are often large before they are noticed, whereas those on the lips are usually seen early and are more easily treated. The cancer may arise from any of the tissues found in the mouth including epithelium, bone, salivary tissue and tooth-forming tissue remnants. Oral cancers represent about 5 per cent of all reported malignancies, and in England and Wales around 3,300 people are diagnosed annually as having cancer of the mouth and PHARYNX.
Cancer of the mouth is less common below the age of 40 years and is more common in men. It is often associated with chronic irritation from a broken tooth or ill-?tting denture. It is also more common in those who smoke and those who chew betel leaves. Leukoplakia (see above) may be a precursor of cancer. Spread of the cancer is by way of the lymph nodes in the neck. Early treatment by surgery, radiotherapy or chemotherapy will often be e?ective, except for the posterior of the tongue where the prognosis is very poor. Although surgery may be extensive and potentially mutilating, recent advances in repairing defects and grafting tissues from elsewhere have made treatment more acceptable to the patient.... mouth, diseases of
The reproductive organs, especially those that are external. The male genitalia include the penis, testes (in the scrotum), prostate gland, seminal vesicles, and associated ducts, such as the epididymis and vas deferens. The female genitalia include the ovaries, fallopian tubes, uterus, vagina, clitoris, vulva, and Bartholin’s glands.... genitalia
Muscular tissue is divided, according to its function, into three main groups: voluntary muscle, involuntary muscle, and skeletal muscle – of which the ?rst is under control of the will, whilst the latter two discharge their functions independently. The term ‘striped muscle’ is often given to voluntary muscle, because under the microscope all the voluntary muscles show a striped appearance, whilst involuntary muscle is, in the main, unstriped or plain. Heart muscle is partially striped, while certain muscles of the throat, and two small muscles inside the ear, not controllable by willpower, are also striped.
Structure of muscle Skeletal or voluntary muscle forms the bulk of the body’s musculature and contains more than 600 such muscles. They are classi?ed according to their methods of action. A ?exor muscle closes a joint, an extensor opens it; an abductor moves a body part outwards, an adductor moves it in; a depressor lowers a body part and an elevator raises it; while a constrictor (sphincter) muscle surrounds an ori?ce, closing and opening it. Each muscle is enclosed in a sheath of ?brous tissue, known as fascia or epimysium, and, from this, partitions of ?brous tissue, known as perimysium, run into the substance of the muscle, dividing it up into small bundles. Each of these bundles consists in turn of a collection of ?bres, which form the units of the muscle. Each ?bre is about 50 micrometres in thickness and ranges in length from a few millimetres to 300 millimetres. If the ?bre is cut across and examined under a high-powered microscope, it is seen to be further divided into ?brils. Each ?bre is enclosed in an elastic sheath of its own, which allows it to lengthen and shorten, and is known as the sarcolemma. Within the sarcolemma lie numerous nuclei belonging to the muscle ?bre, which was originally developed from a simple cell. To the sarcolemma, at either end, is attached a minute bundle of connective-tissue ?bres which unites the muscle ?bre to its neighbours, or to one of the connective-tissue partitions in the muscle, and by means of these connections the ?bre affects muscle contraction. Between the muscle ?bres, and enveloped in a sheath of connective tissue, lie here and there special structures known as muscle-spindles. Each of these contains thin muscle ?bres, numerous nuclei, and the endings of sensory nerves. (See TOUCH.) The heart muscle comprises short ?bres which communicate with their neighbours via short branches and have no sarcolemma.
Plain or unstriped muscle is found in the following positions: the inner and middle coats of the STOMACH and INTESTINE; the ureters (see URETER) and URINARY BLADDER; the TRACHEA and bronchial tubes; the ducts of glands; the GALL-BLADDER; the UTERUS and FALLOPIAN TUBES; the middle coat of the blood and lymph vessels; the iris and ciliary muscle of the EYE; the dartos muscle of the SCROTUM; and in association with the various glands and hairs in the SKIN. The ?bres are very much smaller than those of striped muscle, although they vary greatly in size. Each has one or more oval nuclei and a delicate sheath of sarcolemma enveloping it. The ?bres are grouped in bundles, much as are the striped ?bres, but they adhere to one another by cement material, not by the tendon bundles found in voluntary muscle.
Development of muscle All the muscles of the developing individual arise from the central layer (mesoderm) of the EMBRYO, each ?bre taking origin from a single cell. Later on in life, muscles have the power both of increasing in size – as the result of use, for example, in athletes – and also of healing, after parts of them have been destroyed by injury. An example of the great extent to which unstriped muscle can develop to meet the demands made on it is the uterus, whose muscular wall develops so much during pregnancy that the organ increases from the weight of 30–40 g (1–1••• oz.) to a weight of around 1 kg (2 lb.), decreasing again to its former small size in the course of a month after childbirth.
Physiology of contraction A muscle is an elaborate chemico-physical system for producing heat and mechanical work. The total energy liberated by a contracting muscle can be exactly measured. From 25–30 per cent of the total energy expended is used in mechanical work. The heat of contracting muscle makes an important contribution to the maintenance of the heat of the body. (See also MYOGLOBIN.)
The energy of muscular contraction is derived from a complicated series of chemical reactions. Complex substances are broken down and built up again, supplying each other with energy for this purpose. The ?rst reaction is the breakdown of adenyl-pyrophosphate into phosphoric acid and adenylic acid (derived from nucleic acid); this supplies the immediate energy for contraction. Next phosphocreatine breaks down into creatine and phosphoric acid, giving energy for the resynthesis of adenyl-pyrophosphate. Creatine is a normal nitrogenous constituent of muscle. Then glycogen through the intermediary stage of sugar bound to phosphate breaks down into lactic acid to supply energy for the resynthesis of phosphocreatine. Finally part of the lactic acid is oxidised to supply energy for building up the rest of the lactic acid into glycogen again. If there is not enough oxygen, lactic acid accumulates and fatigue results.
All of the chemical changes are mediated by the action of several enzymes (see ENZYME).
Involuntary muscle has several peculiarities of contraction. In the heart, rhythmicality is an important feature – one beat appearing to be, in a sense, the cause of the next beat. Tonus is a character of all muscle, but particularly of unstriped muscle in some localities, as in the walls of arteries.
Fatigue occurs when a muscle is made to act for some time and is due to the accumulation of waste products, especially sarcolactic acid (see LACTIC ACID). These substances affect the end-plates of the nerve controlling the muscle, and so prevent destructive overaction of the muscle. As they are rapidly swept away by the blood, the muscle, after a rest (and particularly if the rest is accompanied by massage or by gentle contractions to quicken the circulation) recovers rapidly from the fatigue. Muscular activity over the whole body causes prolonged fatigue which is remedied by rest to allow for metabolic balance to be re-established.... muscle
Imaging of the pancreas or its ducts using CT scanning, MRI, ultrasound scanning, X-rays (following injection of a radiopaque contrast medium into the pancreatic ducts during exploratory surgery), or with ERCP.... pancreatography
Linn.
Family: Cruciferae; Brassicaceae.
Habitat: Cultivated in Uttar Pradesh, Punjab, Maharashtra and Gujarat.
English: Radish.
Ayurvedic: Muulaka, Laghu- muulaka, Muulakapotikaa, Visra, Shaaleya, Marusambhava. Pods— Sungraa, Singri, Mungraa.
Unani: Muuli, Turb Fajal.
Siddha/Tamil: Mullangi.
Action: Radish—preparations are used in liver, gallbladder and urinary complaints. Green leaves— diuretic and carminative. Seeds— diuretic, purgative, expectorant.
A decoction of dry radish is given orally in piles. Extract of the dry root is given for hiccough, influenza, dysentery, colic and urinary troubles.
Key application: In peptic disorders, especially those related to dyskinesia of the bile ducts; and in catarrhs of the upper respiratory tract. (German Commission E.)The Ayurvedic Pharmacopoeia of India recommends the juice of the whole plant in sinusitis; juice of the root in diseases of the throat and sinusitis; and the seed in amenorrhoea, cough and dyspnoea.The fleshy root and seeds contain trans-4-methyl-thiobutenyl isothio- cyanate glucoside (the pungent principle), cyanidin-5-glucoside-3-sophoro- side, pelargonidin diglycoside, cyani- din diglycoside, 5-methyl-L-cysteine- sulphoxide (methiin), steroidal sa- pogenins and sulphorophene.The enzymes present in the radish are phosphatase, catalase, sucrase, amylase, alcohol dehydrogenase and pyruvic carboxylase.Radish contains caffeic acid and fer- ulic acid which exhibit hepatoprotec- tive and choleretic properties. It contains choline which prevents deposition of fat in liver. Amino acids, or- nithine, citrulline, arginine, glutamic acid and asparatic acid remove toxins from the body and urea acumulation.Radish is a good source of ascorbic acid (15-40 mg/100 g), trace elements include aluminium, barium, lithium, manganese, silicon, titanium, also iodine (upto 18 mcg/100 g) and ascor- bigen.Roots, leaves, flowers and pods are active against Gram-positive bacteria.The seeds are reported to contain a broad spectrum antibiotic, machro- lysin, specific against Mycobacterium tuberculosis. Raphanin, extracted from the seeds, is active against Grampositive and Gram-negative bacteria.A purified basic protein, homologous to nonspecific lipid transfer proteins, from seeds showed antifungal activity.Raphanus caudatus Linn., synonym R. sativus var. caudatus, is known as Rat-Tail Radish.A native to Java, it is cultivated in northern and western India. The root is not used; pods, purple or violet in colour, are consumed for properties attributed to Raphanus sp. These are known as Mungraa or Sungraa.
Dosage: Whole plant-20-40 ml juice; root—15-30 ml juice. (API, Vol. II.) Seed—1-3 g powder. (API, Vol. III.)... raphanus sativus
A solid, chestnutshaped organ that surrounds the 1st part of the male urethra, just below the bladder. It produces secretions that form part of the seminal fluid during ejaculation. The ejaculatory ducts fromthe seminal vesicles pass through the prostate gland to enter the urethra. prostate specific antigen An enzyme, normally produced by the prostate gland. If produced in excess, it may indicate the presence of prostate cancer. prostatism Symptoms resulting from enlargement of the prostate gland (see prostate, enlarged).... prostate gland
A rare condition in which many of the bile ducts are narrowed, causing progressive liver damage for which the only treatment may be a liver transplant. (See also cholangitis.)... sclerosing cholangitis
(arteriohepatic dysplasia) an inherited condition in which the bile ducts, which drain the liver, become progressively smaller, causing increased *jaundice. It is associated with abnormalities of other organs, such as the heart, kidneys, eyes, and spine. [D. Alagille (1925–2005), French physician]... alagille syndrome
any of the ducts that convey bile from the liver. Bile is drained from the liver cells by many small ducts into the right and left hepatic ducts, which unite to form the main bile duct of the liver, the common hepatic duct. This joins the cystic duct, which leads from the *gall bladder, to form the common bile duct, which drains into the duodenum. The bile ducts collectively are known as the biliary tree.... bile duct
an inherited condition in which the bile ducts, which drain the liver, are widened, causing an increased risk of infection or cancer in the gall bladder. Compare Caroli’s syndrome. [J. Caroli (20th century), French physician]... caroli’s disease
an inherited condition in which the bile ducts, which drain the liver, are widened and there are fibrous changes in the liver and cysts within the kidneys. Compare Caroli’s disease. [J. Caroli]... caroli’s syndrome
n. a drug that stimulates the flow of bile from the gall bladder and bile ducts into the duodenum.... cholagogue
n. a flexible optical endoscope using digital video technology to visualize and sample the interior of the bile ducts.... cholangioscope
n. (pl. cisternae) 1. one of the enlarged spaces beneath the *arachnoid that act as reservoirs for cerebrospinal fluid. The largest (cisterna magna) lies beneath the cerebellum and behind the medulla oblongata. 2. a dilatation at the lower end of the thoracic duct, into which the great lymph ducts of the lower limbs drain.... cisterna
A genetic condition in children in which a defective gene is responsible for altered body chemistry, with excess secretion from the mucous glands. Thick mucus in the lungs may cause breathing distress; in the liver it may block ducts and inhibit function. Liver, pancreatic and salivary glands may be involved. Selenium and Vitamin E levels low (supplementation advised).
Symptoms. Respiratory difficulties and irritating cough. Thick sputum changes colour with infection. Sweat is high in salt. Evil-smelling stool. Treatment by or in liaison with general medical practitioner only.
Until recent years the condition was fatal by death from pneumonia. Carriers may be symptomless. Survival is largely in the hands of physiotherapists and osteopaths who give postural drainage. Differential diagnosis. Infant’s asthma, bronchitis, coeliac disease.
Having regards to missing enzymes (digestive and others) a hard look at food proves rewarding. Individuals may lack the necessary enzymes to break down wheat; one reason why wheat products should be avoided. Production of mucous is reduced considerably by the gluten diet in which oats, wheat, rye and barley are avoided. See: GLUTEN-SENSITIVE DISEASE.
To avoid infection, herbal antibiotics: Wild Yam, Echinacea, Wild Indigo, Goldenseal, Myrrh. Alternatives. To stimulate production of pancreatic enzymes, and peristalsis. Daily physiotherapy to prevent retention of viscid secretions.
Supportive treatment. To liquefy mucus.
Teas: Hyssop, White Horehound, Gotu Kola. Fenugreek seed. Alfalfa.
Tablets/capsules. Lobelia. Iceland Moss. Goldenseal. Echinacea. Wild Yam.
Powders. Formula: equal parts: Elecampane, White Horehound, Dandelion; pinch Cayenne. Dose: 500mg (two 00 capsules or one-third teaspoon) thrice daily.
Tinctures. Formula: equal parts: Elecampane, Lobelia, Dandelion. Few drops Tincture Capsicum. One to two 5ml teaspoons in water 3-4 times daily.
Friar’s Balsam. Inhalation helps to thin mucus from the bronchi.
Supplementation. In addition to Selenium and Vitamin E: Vitamins A, B-complex, C, D. Pancreatic enzymes. High calorie intake. ... cystic fibrosis
n. the most posterior part of the embryonic *hindgut. It becomes divided into the rectum and the urinogenital sinus, which receives the bladder together with the urinary and genital ducts.... cloaca
n. a condition caused by the presence of the fluke Clonorchis sinensis in the bile ducts. The infection, common in the Far East, is acquired through eating undercooked, salted, or pickled freshwater fish harbouring the larval stage of the parasite. Symptoms include fever, abdominal pain, diarrhoea, liver enlargement, loss of appetite, emaciation and – in advanced cases – cirrhosis and jaundice. Treatment is unsatisfactory although *praziquantel has proved beneficial in some cases.... clonorchiasis
(corium) n. the true *skin: the thick layer of living tissue that lies beneath the epidermis. It consists mainly of loose connective tissue within which are blood capillaries, lymph vessels, sensory nerve endings, sweat glands and their ducts, hair follicles, sebaceous glands, and smooth muscle fibres. —dermal adj.... dermis
(DCIS) the earliest stage of breast cancer, detectable by mammography, which is confined to the lactiferous (milk) ducts of the breast. See carcinoma in situ.... ductal carcinoma in situ
adj. 1. describing sweat glands that are distributed all over the body. Their ducts open directly onto the surface of the skin and they are densest on the soles of the feet and the palms of the hands. Compare apocrine. 2. see merocrine.... eccrine
adj. 1. designating nerves or neurons that convey impulses from the brain or spinal cord to muscles, glands, and other effectors; i.e. any motor nerve or neuron. 2. designating vessels or ducts that drain fluid (such as lymph) from an organ or part. Compare afferent.... efferent
a gland that discharges its secretion by means of a duct, which opens onto an epithelial surface. An exocrine gland may be simple, with a single unbranched duct, or compound, with branched ducts and multiple secretory sacs. The illustration shows some different types of these glands. Examples of exocrine glands are the sebaceous and sweat glands. See also secretion.... exocrine gland
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