| external branch of accessory nerve | <anatomy, nerve> Portion of the accessory nerve trunk which exits independently from the jugular foramen, carrying fibres from the spinal root of the accessory nerve to the sternocleidomastoid and trapezius muscle. (05 Mar 2000) |
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| alpha 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) |
| anterior perforated substance | A region at the base of the brain through which numerous small branches of the anterior and middle cerebral arteries (lenticulostriate arteries) enter the depth of the cerebral hemisphere; it is bordered medially by the optic chasm and anterior half of the optic tract, rostrally and laterally by the lateral olfactory stria; its anteromedial part corresponds to the olfactory tubercle. Synonym: substantia perforata anterior, locus perforatus anticus, olfactory area. (05 Mar 2000) |
| autacoid substance | A substance formed metabolically by one set of cells, which alters the function of other cells. (This term is sometimes used in place of the term hormone.) (05 Mar 2000) |
| bacteriotropic substance | Opsonin or other substance that alters bacterial cells in such a manner that they are more susceptible to phagocytic action. (05 Mar 2000) |
| basophilic 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) |
| basophil 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) |
| blood group substance | Blood group-specific substances A and B, solution of complexes of polysaccharides and amino acids that reduces the titre of anti-A and anti-B isoagglutinins in serum from group O persons; used to render group O blood reasonably safe for transfusion into persons of group A, B, or AB, but does not affect any incompatibility that results from various other factors, such as Rh. (05 Mar 2000) |
| vasodepressor substance | An incompletely characterised chemical, apparently produced during liver damage, that tends to decrease vascular pressures and relax arterial walls. (05 Mar 2000) |
| gelatinous substance | The apical part of the posterior horn (dorsal horn; posterior gray column) of the spinal cord's gray matter, composed largely of very small nerve cells; its gelatinous appearance is due to its very low content of myelinated nerve fibres. Synonym: substantia gelatinosa, Rolando's gelatinous substance, Rolando's substance. (05 Mar 2000) |
| glandular substance of prostate | The glandular tissue of the prostate as distinct from the stroma and capsule. Synonym: substantia glandularis prostatae. (05 Mar 2000) |
| Reichstein's substance | One of several steroids; e.g., Reichstein's substance F (cortisone), Reichstein's substance H (corticosterone), Reichstein's substance M (cortisol), Reichstein's substance Q (cortexone), and Reichstein's substance S (cortexolone). Synonym: Reichstein's compound. (05 Mar 2000) |
| released substance | <haematology> A polysaccharide precursor molecule which is used to make the antigens on the surface of human blood cells that are classified in the ABO blood group system. (09 Oct 1997) |
| central and lateral intermediate substance | The central gray matter of the spinal cord surrounding the central canal. Synonym: substantia intermedia centralis et lateralis, anterior gray column, Stilling's gelatinous substance, substantia gelatinosa centralis. (05 Mar 2000) |
| central gray substance | In general: the predominantly small-celled gray matter adjoining or surrounding the central canal of the spinal cord and the third and fourth ventricles of the brainstem, in particular: the thick sleeve of gray matter surrounding the cerebral sylvian aqueduct in the midbrain, rostrally continuous with the posterior nucleus of the hypothalamus; in sections stained for myelin it stands out from the adjoining tectum and tegmentum by the poverty of its myelinated fibres. Synonym: substantia grisea centralis. (05 Mar 2000) |