| 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) |
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| 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) |
| superior lingular branch of lingular branch of superior lobar left pulmonary artery | <anatomy, artery> Branch (of the lingular branch) of the left pulmonary artery serving the superior lingular segment of the superior lobe of the left lung. Synonym: ramus lingularis superior. (05 Mar 2000) |
| accessory meningeal branch of middle meningeal artery | <anatomy, artery> A branch of either the middle meningeal or maxillary artery in the infratemporal fossa and passing superiorly through the foramen ovale to supply the trigeminal ganglion, dura mater and inner table of bone. Synonym: ramus meningeus accessorius arteriae meningeae mediae. (05 Mar 2000) |
| anastomotic branch of middle meningeal artery to lacrimal artery | <anatomy, artery> A branch of the middle meningeal artery arising in the cranial cavity which runs anteriorly through the superior orbital fissure to anastomose with the lacrimal artery. See: orbital branch of middle meningeal artery. Synonym: ramus anastomoticus arteriae meningeae mediae cum lacrimali. (05 Mar 2000) |
| anterior wall of middle ear | It contains the carotid canal and the opening of the auditory tube. Synonym: paries caroticus cavi tympani, anterior wall of middle ear, carotid wall of middle ear. (05 Mar 2000) |
| carotid wall of middle ear | It contains the carotid canal and the opening of the auditory tube. Synonym: paries caroticus cavi tympani, anterior wall of middle ear, carotid wall of middle ear. (05 Mar 2000) |
| parietal branch of middle meningeal artery | <anatomy, artery> Smaller terminal branch (with frontal branch) of middle meningeal artery supplying posterior portion of lateral and superior dura and cranium. Synonym: ramus parietalis arteriae meningeae mediae. (05 Mar 2000) |
| mastoid wall of middle ear | It contains the opening into the mastoid antrum. Synonym: paries mastoideus cavi tympani, mastoid wall of middle ear, posterior wall of middle ear. (05 Mar 2000) |