Absent CORNEAL REFLEX
Absent VESTIBULO-OCULAR REFLEX
No cranial motor response to somatic (physical) stimulation
Absent gag and cough re?exes
No respiratory e?ort in response to APNOEA despite adequate concentrations of CARBON DIOXIDE in the arterial blood.... Medical Dictionary
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.... Medical Dictionary
Several diseases and conditions are treated under separate headings. (See APPENDICITIS; CHOLERA; COLITIS; CONSTIPATION; CROHN’S DISEASE; DIARRHOEA; DYSENTERY; ENTERIC FEVER; HAEMORRHOIDS; HERNIA; INFLAMMATORY BOWEL DISEASE (IBD); ILEITIS; INTUSSUSCEPTION; IRRITABLE BOWEL SYNDROME (IBS); PERITONITIS; RECTUM, DISEASES OF; ULCERATIVE COLITIS.)
In?ammation of the outer surface is called peritonitis, a serious disease. That of the inner surface is known generally as enteritis, in?ammation of special parts receiving the names of colitis, appendicitis, irritable bowel syndrome (IBS) and in?ammatory bowel disease (IBD). Enteritis may form the chief symptom of certain infective diseases: for example in typhoid fever (see ENTERIC FEVER), cholera and dysentery. It may be acute, although not connected with any de?nite organism, when, if severe, it is a very serious condition, particularly in young children. Or it may be chronic, especially as the result of dysentery, and then constitutes a less serious if very troublesome complaint.
Perforation of the bowel may take place as the result either of injury or of disease. Stabs and other wounds which penetrate the abdomen may damage the bowel, and severe blows or crushes may tear it without any external wound. Ulceration, as in typhoid fever, or, more rarely, in TUBERCULOSIS, may cause an opening in the bowel-wall also. Again, when the bowel is greatly distended above an obstruction, faecal material may accumulate and produce ulcers, which rupture with the ordinary movements of the bowels. Whatever the cause, the symptoms are much the same.
Symptoms The contents of the bowel pass out through the perforation into the peritoneal cavity, and set up a general peritonitis. In consequence, the abdomen is painful, and after a few hours becomes extremely tender to the touch. The abdomen swells, particularly in its upper part, owing to gas having passed also into the cavity. Fever and vomiting develop and the person passes into a state of circulatory collapse or SHOCK. Such a condition may be fatal if not properly treated.
Treatment All food should be withheld and the patient given intravenous ?uids to resuscitate them and then to maintain their hydration and electrolyte balance. An operation is urgently necessary, the abdomen being opened in the middle line, the perforated portion of bowel found, the perforation stitched up, and appropriate antibiotics given.
Obstruction means a stoppage to the passage down the intestine of partially digested food. Obstruction may be acute, when it comes on suddenly with intense symptoms; or it may be chronic, when the obstructing cause gradually increases and the bowel becomes slowly more narrow until it closes altogether; or subacute, when obstruction comes and goes until it ends in an acute attack. In chronic cases the symptoms are milder in degree and more prolonged.
Causes Obstruction may be due to causes outside the bowel altogether, for example, the pressure of tumours in neighbouring organs, the twisting around the bowel of bands produced by former peritonitis, or even the twisting of a coil of intestine around itself so as to cause a kink in its wall. Chronic causes of the obstruction may exist in the wall of the bowel itself: for example, a tumour, or the contracting scar of an old ulcer. The condition of INTUSSUSCEPTION, where part of the bowel passes inside of the part beneath it, in the same way as one turns the ?nger of a glove outside in, causes obstruction and other symptoms. Bowel within a hernia may become obstructed when the hernia strangulates. Finally some body, such as a concretion, or the stone of some large fruit, or even a mass of hardened faeces, may become jammed within the bowel and stop up its passage.
Symptoms There are four chief symptoms: pain, vomiting, constipation and swelling of the abdomen.
Treatment As a rule the surgeon opens the abdomen, ?nds the obstruction and relieves it or if possible removes it altogether. It may be necessary to form a COLOSTOMY or ILEOSTOMY as a temporary or permanent measure in severe cases.
Tumours are rare in the small intestine and usually benign. They are relatively common in the large intestine and are usually cancerous. The most common site is the rectum. Cancer of the intestine is a disease of older people; it is the second most common cancer (after breast cancer) in women in the United Kingdom, and the third most common (after lung and prostate) in men. Around 25,000 cases of cancer of the large intestine occur in the UK annually, about 65 per cent of which are in the colon. A history of altered bowel habit, in the form of increasing constipation or diarrhoea, or an alternation of these, or of bleeding from the anus, in a middle-aged person is an indication for taking medical advice. If the condition is cancer, then the sooner it is investigated and treated, the better the result.... Medical Dictionary
The haemagglutination inhibition test This, and the subsequent tests to be mentioned, are known as immunological tests. They are based upon the e?ect of the urine from a pregnant woman upon the interaction of red blood cells, which have been sensitised to human gonadotrophin, and anti-gonadotrophin serum. They have the great practical advantage of being performed in a test-tube or even on a slide. Because of their ease and speed of performance, a result can be obtained in two hours.
Enzyme-linked immunosorbent assay (ELISA) This is the basis of many of the pregnancy-testing kits obtainable from pharmacies. It is a highly sensitive antibody test and can detect very low concentrations of human chorionic gonadotrophin. Positive results show up as early as ten days after fertilisation – namely, four days before the ?rst missed period.
Ultrasound The fetal sac can be detected by ULTRASOUND from ?ve weeks, and a fetal echo at around six or seven weeks (see also PRENATAL SCREENING OR DIAGNOSIS).... Medical Dictionary
Static lung volumes and capacities can be measured: these include vital capacity – the maximum volume of air that can be exhaled slowly and completely after a maximum deep breath; forced vital capacity is a similar manoeuvre using maximal forceful exhalation and can be measured along with expiratory ?ow rates using simple spirometry; total lung capacity is the total volume of air in the chest after a deep breath in; functional residual capacity is the volume of air in the lungs at the end of a normal expiration, with all respiratory muscles relaxed.
Dynamic lung volumes and ?ow rates re?ect the state of the airways. The forced expiratory volume (FEV) is the amount of air forcefully exhaled during the ?rst second after a full breath – it normally accounts for over 75 per cent of the vital capacity. Maximal voluntary ventilation is calculated by asking the patient to breathe as deeply and quickly as possible for 12 seconds; this test can be used to check the internal consistency of other tests and the extent of co-operation by the patient, important when assessing possible neuromuscular weakness a?ecting respiration. There are several other more sophisticated tests which may not be necessary when assessing most patients. Measurement of arterial blood gases is also an important part of any assessment of lung function.... Medical Dictionary
(2) The second meaning (also called test feed) applies to a diagnostic procedure for congenital PYLORIC STENOSIS, whereby a paediatrician feels over the baby’s abdomen while he or she is feeding. The pyloric mass can be felt as a ?rm swelling with the consistency of a squash ball, which comes and goes under the examiner’s ?ngers.... Medical Dictionary
Hydrocoele is a collection of ?uid distending one or both sides of the scrotum with ?uid. Treatment is by withdrawal of the ?uid using a sterile syringe and aspiration needle.
Hypogonadism Reduced activity of the testes or ovaries (male and female gonads). The result is impaired development of the secondary sexual characteristics (growth of the genitals, breast and adult hair distribution). The cause may be hereditary or the result of a disorder of the PITUITARY GLAND which produces GONADOTROPHINS that stimulate development of the testes and ovaries.
Varicocoele is distension of the veins of the spermatic cord, especially on the left side, the causes being similar to varicose veins elsewhere (see VEINS, DISEASES OF). The chief symptom is a painful dragging sensation in the testicle, especially after exertion. Wearing a support provides relief; rarely, an operation may be advisable. Low sperm-count may accompany a varicocele, in which case surgical removal may be advisable.
Orchitis or acute in?ammation may arise from CYSTITIS, stone in the bladder, and in?ammation in the urinary organs, especially GONORRHOEA. It may also follow MUMPS. Intense pain, swelling and redness occur; treatment consists of rest, support of the scrotum, analgesics as appropriate, and the administration of antibiotics if a de?nitive microorganism can be identi?ed. In some patients the condition may develop and form an ABSCESS.
Torsion or twisting of the spermatic cord is relatively common in adolescents. About half the cases occur in the early hours of the morning during sleep. Typically felt as pain of varying severity in the lower abdomen or scrotum, the testis becomes hard and swollen. Treatment consists of immediate undoing of the torsion by manipulation. If done within a few hours, no harm should ensue; however, this should be followed within six hours by surgical operation to ensure that the torsion has been relieved and to ?x the testes. Late surgical attention may result in ATROPHY of the testis.
Tuberculosis may occur in the testicle, especially when the bladder is already a?ected. Causing little pain, the infection is often far advanced before attracting attention. The condition generally responds well to treatment with a combination of antituberculous drugs (see also main entry for TUBERCULOSIS).
Tumours of the testes occur in around 600 males annually in the United Kingdom, and are the second most common form of malignant growth in young males. There are two types: SEMINOMA and TERATOMA. When adequately treated the survival rate for the former is 95 per cent, while that for the latter is 50 per cent.
Injuries A severe blow may lead to SHOCK and symptoms of collapse, usually relieved by rest in bed; however, a HAEMATOMA may develop.... Medical Dictionary
– is conjugated or unconjugated. If conjugated, this indicates that HAEMOLYSIS is causing the jaundice; if unconjugated, disease of the LIVER or BILE DUCT is the likely diagnosis.... Medical Dictionary