| morphological features | Properties related to the external structure of soil (such as colour and texture) or of plants. (09 Oct 1997) |
|---|---|
| schizophrenia and disorders with psychotic features | Marked disorders of thought (delusions, hallucinations, or other thought disorder accompanied by disordered affect or behaviour), and deterioration from a previous level of functioning. (12 Dec 1998) |
| features | The various parts of the face, forehead, eyes, nose, mouth, chin, cheeks, and ears, that give to it its individuality and character. Origin: through O. Fr., fr. L. Factura, a making, fr. Facio, to do (05 Mar 2000) |
| syndrome, down | A common disorder due to a chromosome abnormality and specfically due to an extra chromosome number 21 (trisomy 21). Down syndrome includes mental retardation, a characteristic face, and multiple malformations. It is associated with a major risk for heart problems, a lesser risk of duodenal atresia (part of the intestines not developed), and a minor but still significant risk of acute leukaemia. The name down syndrome comes from the 19th century english doctor langdon down, a misnomer since he was curiously enough not the first person to describe the condition and, in great error, attributed the condition to a reversion to the mongoloid race. Hence, the old name mongolism, now considered slang. (12 Dec 1998) |
| Down's syndrome | <genetics, syndrome> A congenital disorder in which a person is born with three copies of chromosome 21 (trisomy 21). Clinical features include moderate to severe mental retardation, slanting eyes, a broad short skull, broad hands and short fingers. Other congenital abnormalities include heart defects, oesophageal atresia and an increased incidence of acute lymphocytic leukaemia. Trisomy 21 can be detected in the first few months of pregnancy by amniocentesis. Risk factors include prior child with Down's syndrome and mothers who become pregnant after age 40. This disorder was formerly known as mongolism. Incidence: 1 in 1000 births. (09 Oct 1997) |
| down syndrome | <radiology> Trisomy 21, mongolism, atlantoaxial subluxation, Wormian bones, absent/small paranasal sinuses, endocardial cushion (AV canal) defects, aberrant right subclavian artery, 2 ossification centres for manubrium (90%), 11 or 13 ribs, duodenal atresia / stenosis, tracheo-oesophageal fistula, Hirschsprung disease (12 Dec 1998) |
| bearing down | Expulsive effort of a parturient woman in the second stage of labour. (05 Mar 2000) |
| bearing-down pain | A uterine contraction accompanied by straining and tenesmus; usually appearing in the second stage of labour. (05 Mar 2000) |
| reflex, let down | The let down reflex of the mother is an involuntary reflex during breastfeeding which causes the milk to flow freely. (12 Dec 1998) |
| milk let-down reflex | Release of milk from the breast following tactile stimulation of the nipple; the afferent path is postulated to exist from the nipple to the hypothalamus; the efferent limb is represented by the neurohypophysial release of oxytocin into the systemic circulation; contraction of myoepithelial elements within the breast, caused by oxytocin, moves milk into the collecting ducts and toward the nipple. Synonym: let-down reflex, milk let-down reflex. (05 Mar 2000) |
| cone down | To narrow a beam of X-rays to a region of interest using a collimator or cone; colloq., to delimit one's attention or activities. (05 Mar 2000) |
| head-down tilt | Posture while lying with the head lower than the rest of the body. Extended time in this position is associated with temporary physiologic disturbances. (12 Dec 1998) |
| down | <dermatology, zoology> Fine, soft feathers, soft, fine hair. (04 Mar 1998) |
| Down, John Langdon | <person> English physician, 1828-1896. See: Down's syndrome. (05 Mar 2000) |
| down promoter mutation | <molecular biology> A mutation (a change in base pair sequence) in a promoter region, this results in lower gene expression (less transcription of the gene occurs). (09 Oct 1997) |