| substance withdrawal syndrome | <syndrome> Physiological and psychological symptoms associated with withdrawal from the use of a drug after prolonged administration or habituation. The concept includes withdrawal from smoking or drinking, as well as withdrawal from an administered drug. (12 Dec 1998) |
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| innominate substance | The region of the forebrain that lies ventral to the anterior half or so of the lentiform nucleus, extending in the frontal plane from the lateral preopticohypothalamic zone laterally over the optic tract to the amygdala (amygdaloid body); rostrally it tapers off over the dorsal border of the olfactory tubercle, caudally it ends where the internal capsule reaches the surface to form the cerebral peduncle or pes pedunculi. Notable among its polymorphic cell population is the large-celled basal nucleus of Meynert. These magnocellular elements within the substantia i. Are present in the medial septum and the diagonal band of Broca, but occur in largest numbers ventral to the globus pallidus. Histochemical evidence indicates that magnocellular elements distribute cholinergic fibres widely in the cerebral cortex and that these cells undergo selective degeneration in Alzheimer's disease. Synonym: substantia innominata. (05 Mar 2000) |
| interspongioplastic substance | An obsolete term for cytochylema. (05 Mar 2000) |
| threshold substance | Any material (e.g., glucose) that is excreted in the urine only when its plasma concentration exceeds a certain value, termed its threshold. Synonym: threshold body. (05 Mar 2000) |
| tigroid substance | The material consisting of granular endoplasmic reticulum and ribosomes that occurs in nerve cell bodies and dendrites. Synonym: basophil substance, basophilic substance, chromophil substance, Nissl bodies, Nissl granules, substantia basophilia, tigroid bodies, tigroid substance. (05 Mar 2000) |
| ergastic substance | Metabolically inert products of photosynthesis, such as starch grains and fat globules. (18 Nov 1997) |
| exophthalmos-producing substance | A factor found in crude extract of pituitary tissue that produced exophthalmos in laboratory animals (especially fish). Its existence and role in producing exophthalmopathy in Graves' disease is questioned. (05 Mar 2000) |
| Kendall's substance | A group of corticosteroids. Kendall's compound A (11-dehydrocorticosterone); Kendall's compound B (corticosterone); Kendall's compound E (cortisone); Kendall's compound F (cortisol). Synonym: Kendall's substance. (05 Mar 2000) |
| zymoplastic substance | <haematology> Traditional name for substance in plasma that converts prothrombin to thrombin. Now known not to be a single substance. (See thrombin). (18 Nov 1997) |
| filar substance | A filamentous plasmatic material, beaded with granules, demonstrable by means of vital staining in the immature red blood cells. Synonym: alpha substance, filar mass, filar substance, substantia reticularis, substantia reticulofilamentosa. Synonym: reticular formation. (05 Mar 2000) |