| brain sand | Small calcareous concretions in the stroma of the pineal and other central nervous system tissues. Synonym: acervulus, brain sand, psammoma bodies. (05 Mar 2000) |
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| sand | Particles in siliciclastic sediment that range in size from 0.0625 millimetres (very fine-grained sand) to 2.0 millimetres (very coarse-grained sand), according to the Udden-Wentworth scale. In field geology, to tell the difference between fine-grained sand and coarse silt, the particle in a rock is sand if it can be clearly seen with the naked eye. (09 Oct 1997) |
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| sand bath | In chemistry, an arrangement whereby a substance to be treated is in a vessel protected from the direct action of fire by a layer of sand. (05 Mar 2000) |
| sand bodies | Mineralised body's occurring in the meninges, choroid plexus, and in certain meningiomas; composed usually of a central capillary surrounded by concentric whorls of meningocytes in various stages of hyaline change and mineralization; can also occur in benign and malignant epithelial tumours (often papillary) or with chronic inflammation. Synonym: sand bodies. Synonym: corpora arenacea. Synonym: calcospherite. (05 Mar 2000) |
| sand-crack | A crack or fissure in the hoof of the horse, occurring usually on the inside of the forefoot (quarter-crack) or in the forepart of the hindfoot (toe-crack); when the crack is deep enough to expose the sensitive laminae, or when it extends to the coronary band, lameness results. (05 Mar 2000) |
| sand tumour | <tumour> A firm cellular neoplasm derived from fibrous tissue of the meninges, choroid plexus, and certain other structures associated with the brain, characterised by the formation of multiple, discrete, concentrically laminated, calcareous bodies (psammoma bodies); most of these neoplasms are histologically benign, but may lead to severe symptoms as a result of compressing the brain. Synonym: angiolithic sarcoma, sand tumour, Virchow's psammoma. (05 Mar 2000) |
| hydatid sand | The scoleces of Echinococcus tapeworms in the fluid within a primary or daughter hydatid cyst. (05 Mar 2000) |
| intestinal sand | Minute calculi or gritty material occurring in faeces, composed of soaps, bile pigment, cholesterol, magnesium salts, succinic acid, etc. (05 Mar 2000) |
| urinary sand | Multiple small calculous particles passed in the urine of patients with nephrolithiasis; each particle is usually too small to cause significant symptoms or to be identified as a true calculus. (05 Mar 2000) |
| acute brain syndrome | <syndrome> A condition of severe confusion or rapid change in brain function. This often occurs as the result of a mental illness or physical illness. Symptoms include lethargy, agitation, confusion, disorientation and delirium. (27 Sep 1997) |
| acute organic brain syndrome | <syndrome> A constellation of behavioural or psychological signs and symptoms including problems with attention, concentration, memory, confusion, anxiety, and depression caused by transient or permanent dysfunction of the brain. Synonym: acute organic brain syndrome, OBS, organic mental syndrome. (05 Mar 2000) |
| anterior part of anterior commissure of brain | The anterior part of the anterior or rostral commissure of the brain. Synonym: pars anterior commissurae rostralis, pars anterior commissurae anterioris cerebri. (05 Mar 2000) |
| arachnoid of brain | That portion of the arachnoid which lies within the cranial cavity and surrounds the brain and the cranial portion of the subarachnoid space. In several sites it is relatively widely-separated from the pia mater, creating the cranial subarachnoid cisterns. Synonym: arachnoid mater cranialis, arachnoid mater encephali, cerebral part of arachnoid. (05 Mar 2000) |
| base of brain | The inferior surface of the brain visible when seen from below. Synonym: facies inferior cerebri, basis cerebri, inferior cerebral surface. (05 Mar 2000) |
| big brain | <molecular biology> Neurogenic gene of Drosophila, believed to encode a product involved in cell cell communication, perhaps via gap junctions. Member of the major intrinsic protein family. (18 Nov 1997) |
| blood-brain barrier | <pharmacology, physiology> A protective barrier formed by the blood vessels and glia of the brain. It prevents some substances in the blood from entering brain tissue. The blood vessels of the brain (and the retina) are much more impermeable to large molecules (like antibodies) than blood vessels elsewhere in the body. This has important implications for the ability of the organism to mount an immune response in these tissues, although the basis for the difference in endothelial permeability is not well understood. (16 Dec 1997) |