quack. A person who fraudulently claims training, experience and expertise in management of disease.

quadrant. Usually used for one of the four parts of the abdomen, the right and left upper, and the right and left lower. The appendix is situated in the right lower quadrant. See also regions of the abdomen.

quadriceps. The muscle present in the front of the thigh. So named because it has four points of origin from bone, or 4 heads.

quarantine <L quadraginta=40> To isolate, or restrict freedom of movement, of persons exposed to infectious disease, for the duration of the incubation period of the disease. (The original quarantine period was 40 days, for ships with possible contagious disease on board.)

quinine. An alkaloid derived from cinchona, earlier often used for the treatment of malaria.

quinolone. A class of antibacterial agent, formerly often used for urinary and gastrointestinal infections. Now largely replaced by the fluorquinolones.

quinsy. An abscess in the pharynx, adjacent to the tonsil.


receptor. Certain large molecules or groups of molecules on or in cells act as sites where other substances, such as drugs can bind and/or react. These molecules or groups of molecules are called receptors.

reflux of acid. Acid in the stomach can enter the esophagus. This condition is known as gastroesophageal reflux disease, or GERD.

regional enteritis. Crohn's disease. A chronic granulomatous disorder of the intestines.

regions of the abdomen. One of nine areas into which the abdominal surface is classified.

renal. Pertaining to the kidneys.

retina. The light-sensitive layer at the rear end of the eye.

rifampicin. A drug for tuberculosis. (Diagnosis of tuberculosis)


savlon. An antiseptic.

sciatic nerve. A nerve that runs along the gluteal (hip) region down the leg, and supplies the back of the leg. Sciatica = pain along the path of the sciatic nerve, usually caused by a disease of the spine that presses at the origin of the sciatic nerve.

sclerotherapy. Injection of a sclerosant to occlude dilated veins. Used in portal hypertension, varicose veins and hemorrhoids.

second degree burns. See burn

secondary intention. The manner in which a wound heals slowly and with much scarring, from separated, unhealthy margins.

semicircular canals. These are three tiny, curved structures that detect changes in posture. They are situated in the inner ear.

senile dementia. Atrophy of brain tissue in old age, associated with loss of intellectual ability. cf Alzheimer's disease.

sepsis. The presence of the effects of infection. Usually caused by the toxins produced by bacteria or other micro-organisms, and the effects of the reaction of the body to these organisms. septicemia = the presence of widespread sepsis ("sepsis in the blood"). Septicemia occurs in the presence of infection, when the toxins produced by the bacteria find their way into the blood, and thence into the organs. The toxins affect the function of all the organs. Some patients develop "multiple organ system failure".

seroconversion. The change from a previously negative serological (immunological) test to a positive test. The term is usually used for change from a negative test for HIV infection to a positive test. (Article on AIDS)

shock. A condition in which the circulation does not supply the tissues with enough blood containing oxygen and nutrients. In most cases of shock the blood pressure is low.

shunt. A passage, usually surgically created, that diverts fluid from a high pressure area into a low pressure area. Commonly created shunts are porta-systemic shunts for portal hypertension, and ventriculoperitoneal shunts for hydrocephalus.

sinus. A track (usually from the skin) that ends blindly. cf fistula, in which the track ends in another hollow organ. Pilonidal sinus = a sinus occuring over the back, just above the level of the hips, and is caused by hair forcibly entering the skin.

skin. The tissue covering the body. The skin serves to protect the underlying tissues from infections, and plays an important role in temperature regulation. There are two layers in the skin: the epidermis and the dermis. The epidermis consists of flat, dead cells, that are constantly being shed off and replaced. The dermis consists of a layer of actively dividing cells, and a layer containing nerves, arteries, veins, hair follicles and sweat glands. Injury to the epidermis heals without scarring. Injury to the dermis heals with varying degrees of scarring.

sperm (Gr sperma=seed) Semen, or the cell present in semen. Spermatozoon (pl spermatozoa) = sperm cell. Spermatozoa are produced in the testes, and are the cells that unite with the egg cell in the female to form a zygote. In shape the spermatozoon has an oval or conical head, and a long flagellum or tail.


spinal cord. see spine

spine. The backbone, the vertebral column, which consists of the vertebrae. The structure of a vertebra is such that the column of vertebrae one on top of the other forms a canal within the column, the vertebral canal. The spinal cord is a large pathway of nerve tissue that lies in the vertebral canal, and gives off the spinal nerves. The spinal nerves carry the nerve supply to and from the organs below the neck.

stapes. Stirrup.

steroid. A compound that is structurally related to cholesterol, and has hormonal actions. Cortisol, estradiol and testosterone are steroids.

stirrup. One of the bones of the middle ear.

stress ECG: An ECG taken during exercise. Also popularly known as treadmill test (TMT)

subcutaneous. The layer just under the skin. See cutaneous.

sublingual. Under the tongue. Some drugs are placed sublingually for best effect. They are absorbed into the general blood circulation directly, avoiding metabolic degradation in the liver. They also act more quickly. A typical example is nitrate, a drug for angina pectoris.

suprarenal glands. The adrenal glands.

Sushruta c 500 BC. Indian surgeon. See biographical dictionary.


tachycardia. An abnormally fast heartbeat.

teicoplanin. A glycopeptide antibiotic.

third degree burns. See burn

thoracic. Pertaining to the thorax.

thorax. The part of the body between the neck and the abdomen. The upper border of the thorax is formed by the first ribs, and the lower border by the diaphragm.

thyroid. A gland situated in the front of the neck, and responsible for synthesis of the hormones T3 and T4, also called the thyroid hormones. Thyrotrophic hormone (thyrotrophin) = a hormone secreted by the pituitary, controls the secretions of the thyroid gland.

TNF. tumour necrosis factor

tonometry: A test to measure fluid pressure inside the eye. Increased pressure may be a sign of glaucoma.

transplant. The transfer of tissue or organ from one living being to another. Isotransplant is a transplant where the donor and recipient have the same genetic structure (eg identical twins). In a homotransplant the species is the same but the genetic structure is different (eg two humans other than identical twins). A transplant across different species is a heterotransplant or a xenotransplant (eg transplant of a baboon liver or heart into man).

treadmill test.(TMT) Stress ECG

trismus. An inability to open the mouth properly.

tuberculosis. A disease caused by the bacterium Mycobacterium tuberculosis. It usually affects the lungs and lymph nodes, and less often the abdomen, bones, genital organs or nervous system. It can involve virtually any organ in the body. Miliary tuberculosis is a form of disease in which the tuberculosis is wodespread and characterized by the present of small nodules of tuberculosis in the diseased parts.

tumour necrosis factor (TNF). A chemical (one of several) that is increased during inflammation. Earlier believed to have a major role to play in tumour-related illness. Also called cachexin.

tympanic membrane. The ear drum.