| SLA | left sacroanterior [fetal position] [Lat. sacrolaeva anterior]; single-cell liquid cytotoxic assay; ... |
|---|---|
| SOA-MCA | superficial occipital artery to middle cerebral artery |
| SPK | serum pyruvate kinase; superficial punctate keratitis |
| SSM | subsynaptic membrane; superficial spreading melanoma |
| STA | second trimester abortion; serum thrombotic accelerator; superficial temporal artery |
| gray rami communicantes | Short nerves arising from the lateral aspect of the sympathetic trunk conducting nonmyelinated postsynaptic sympathetic nerve fibres from the sympathetic trunk to the initial portions of all 31 pairs of ventral primary rami of spinal nerves for distribution by all parts (including the dorsal primary ramus) of the spinal nerve. The gray rami are the parietal branches of the sympathetic trunks since all postsynaptic fibres to be distributed to the body wall (including limbs) must pass through them. Synonym: communicating branches of sympathetic trunk, communicating rami of sympathetic trunk. (05 Mar 2000) |
|---|---|
| gray scale | <microscopy> The various shades of gray or luminance values in a video picture. As industrial test standards, gray wedges are used with discrete steps incrementing in brightness by factors of ~ 7. 3 (05 Aug 1998) |
| gray-scale ultrasonography | The display of the ultrasound echo amplitude or signal intensity as different shades of gray, improving image quality compared to the obsolete black and white presentation. (05 Mar 2000) |
| gray substance | The cortex of the brain which contains nerve cell bodies. The gray matter is in contrast to the white matter, the part of the brain that contains myelinated nerve fibres. The gray matter is so named because it in fact appears gray. The white matter is white because that is the colour of myelin, the insulation covering the nerve fibres. In the mysterious affair at styles (1920), agatha christie first quoted the fictional belgian detective hercule poirot in regard to his gray matter: 'this affair must be unravelled from within.' he tapped his forehead. 'these little grey cells. It is up to them as you say over here.' (12 Dec 1998) |
| gray syndrome | <syndrome> Gray baby syndrome, gray appearance of an infant at birth and during the neonatal period which can be caused by transplacental toxic effects of the drug chloramphenicol taken by the mother during late pregnancy; the syndrome may be fatal. (05 Mar 2000) |
| gray tuber | Layer of gray matter in the hypothalamus that also forms part of the floor of the third ventricle. (12 Dec 1998) |
| gray tubercle | Greater tubercle of humerus, the larger of the two tubercles next to the head of the humerus; it gives attachment to the supraspinatus, infraspinatus, and teres minor muscles. Synonym: tuberculum majus humeri, greater tuberosity of humerus, tuberculum cinereum. (05 Mar 2000) |
| gray wedge | <microscopy> An elongated rectangular pattern whose brightness changes from black through shades of gray to white along its length. In calibration wedges, the brightness may vary linearly or logarithmically in discrete steps. (05 Aug 1998) |
| gray wing | A prominence in the floor of the inferior fovea of the fourth ventricle that overlies the dorsal motor nucleus of the vagus. Synonym: trigonum nervi vagi, ala cinerea, ashen wing, gray wing, trigone of vagus nerve, va'gi eminentia. (05 Mar 2000) |
| pontine gray matter | The massive gray matter filling the basilar pons. The nuclei are of fairly homogeneous architecture and project to the cortex of the contralateral cerebellar hemisphere by way of the middle cerebellar peduncle. Their main afferents come from the entire extent of the cerebral neocortex by way of the longitudinal pontine bundles (corticopontine fibres); thus, the pontine nuclei form a major way-station in the impulse conduction from the cerebral cortex of one hemisphere to the posterior lobe of the opposite cerebellum. Synonym: nuclei pontis, pontine gray matter. (05 Mar 2000) |
| heterotopic gray matter | <radiology> Presence of cortical neurons in an abnormal location secondary to arrest of migrating neuroblasts from ventricular walls to brain surface between 7-24 weeks of gestational age, frequency: 3% of healthy population associated with: agenesis of corpus callosum, aqueductal stenosis, microcephaly, schisencephaly, encephalocele X-ray: single/multiple bilateral subependymal nodules along lateral ventricles Differential diagnosis: subependymal spread of neoplasm, subependymal haemorrhage, vascular malformation, tuberous sclerosis, intraventricular meningioma, neurofibromatosis (12 Dec 1998) |
| digital gray scale | 1. Extent from side to side, or distance sidewise from a given point or line; breadth; width. "Provided the length do not exceed the latitude above one third part." (Sir H. Wotton) 2. Room; space; freedom from confinement or restraint; hence, looseness; laxity; independence. "In human actions there are no degrees and precise natural limits described, but a latitude is indulged." (Jer. Taylor) 3. Extent or breadth of signification, application, etc.; extent of deviation from a standard, as truth, style, etc. "No discreet man will believe Augustine's miracles, in the latitude of monkish relations." (Fuller) 4. Extent; size; amplitude; scope. "I pretend not to treat of them in their full latitude." (Locke) 5. <geography> Distance north or south of the equator, measured on a meridian. 6. <astronomy> The angular distance of a heavenly body from the ecliptic. Ascending latitude, Circle of latitude, Geographical latitude, etc. See Ascending. Circle, etc. High latitude, that part of the earth's surface near either pole, especially. That part within either the arctic or the antarctic circle. Low latitude, that part of the earth's surface which is near the equator. Origin: F. Latitude, L. Latitudo, fr. Latus broad, wide, for older stlatus; perh. Akin to E. Strew. Source: Websters Dictionary (01 Mar 1998) |
| superior branch of the superior gluteal artery | <anatomy, artery> Runs between gluteus medius and minimus muscles, supplying both, and continuing to reach tensor fascia lata muscle. Synonym: ramus superior arteriae gluteae superioris. (05 Mar 2000) |
| superior dental branches of superior dental plexus | Branches passing from the superior dental plexus to the roots of the teeth of the upper jaw. Synonym: rami dentales superiores plexus dentalis superioris. (05 Mar 2000) |
| superior gingival branches of superior dental plexus | Branches of superior dental plexus to gingiva of upper jaw. Synonym: rami gingivales superiores plexus dentalis superioris. (05 Mar 2000) |