| OR | a logical binary relation that is true if any argument is true, and false otherwise; [o]estrogen rec... |
|---|---|
| OT | objective test; oblique talus; occlusion time; occupational therapist, occupational therapy; ocular ... |
| OX | optic chiasma; oxacillin; oxalate; oxide; orthopedic examination; oxytocin |
| PION | posterior ischemic optic neuropathy |
| POA | pancreatic oncofetal antigen; phalangeal osteoarthritis; preoptic area; primary optic atrophy |
| callosomarginal sulcus | A fissure on the mesial surface of the cerebral hemisphere, bounding the upper surface of the cingulate gyrus (callosal convolution); the anterior portion is called the pars subfrontalis; the posterior portion which curves up to the superomedial margin of the hemisphere and borders the paracentral lobule posteriorly, the pars marginalis. Synonym: sulcus cinguli, callosomarginal fissure, callosomarginal sulcus, sulcus callosomarginalis, sulcus of cingulum. (05 Mar 2000) |
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| malleolar sulcus | A broad groove on the posterior surface of the medial malleolus, through which the tendon of the tibialis posterior muscle runs. Synonym: sulcus malleolaris, malleolar sulcus. (05 Mar 2000) |
| paraglenoid sulcus | A groove on the pelvic surface of the ilium just lateral to the auricular surface; it is more pronounced in the female. Synonym: paraglenoid groove, paraglenoid sulcus, preauricular sulcus, sulcus paraglenoidalis. (05 Mar 2000) |
| carotid sulcus | The groove on the body of the sphenoid bone in which the internal carotid artery lies in its course through the cavernous sinus. Synonym: sulcus caroticus, carotid sulcus, cavernous groove. (05 Mar 2000) |
| parieto-occipital sulcus | A very deep, almost vertically oriented fissure on the medial surface of the cerebral cortex, marking the border between the parietal lobe and the cuneus of the occipital lobe; its lower part curves forward and fuses with the anterior extent of the calcarine fissure (sulcus calcarinus); the great depth of this combined fissure causes a bulge in the medial wall of the occipital horn of the lateral ventricle, the calcar avis. Synonym: sulcus parieto-occipitalis, fissura parietooccipitalis, parieto-occipital fissure. (05 Mar 2000) |
| gingival sulcus | The space between the surface of the tooth and the free gingiva. Synonym: sulcus gingivalis, gingival crevice, gingival space, subgingival space. (05 Mar 2000) |
| gingivobuccal sulcus | The upper and lower half of the buccal vestibule on each side. Synonym: alveolobuccal sulcus, gingivobuccal groove, gingivobuccal sulcus. (05 Mar 2000) |
| gingivolabial sulcus | The upper and lower half of the labial vestibule, in the embryo, the groove formed by the deepening of the labial sulcus; its inner wall becomes incorporated with the alveolar process of the mandible or the maxilla, and its outer wall with the lips and cheeks. Synonym: alveololabial sulcus, gingivolabial groove, gingivolabial sulcus. (05 Mar 2000) |
| gingivolingual sulcus | That part of the oral cavity proper, on each side of the frenulum linguae, between the tongue and the mandibular alveolar process or ridge, in the embryo, the groove on each side between the lingual primordium and the alveolar elevations of the mandible. Synonym: alveololingual sulcus, gingivolingual groove, gingivolingual sulcus. (05 Mar 2000) |
| medial sulcus of crus cerebri | A groove in the lateral wall of the interpeduncular fossa of the midbrain from which the rootlets of the oculomotor nerve emerge. Synonym: sulcus medialis cruris cerebri, sulcus nervi oculomotorii, sulcus of the oculomotor nerve. (05 Mar 2000) |
| median frontal sulcus | A relatively shallow sagittal fissure of the brain dividing the middle frontal convolution into an upper and lower part; this sulcus is found only in humans and anthropoid apes; at its anterior extremity it bifurcates, the two branches spreading out laterally and constituting the frontomarginal sulcus. Synonym: median frontal sulcus, sulcus frontalis medius. (05 Mar 2000) |
| median sulcus of fourth ventricle | <anatomy> The shallow midline groove in the floor of the ventricle. Synonym: sulcus medianus ventriculi quarti. (05 Mar 2000) |
| central sulcus | A double-S-shaped fissure extending obliquely upward and backward on the lateral surface of each cerebral hemisphere at the boundary between frontal and parietal lobes. Synonym: sulcus centralis, fissure of Rolando. (05 Mar 2000) |
| vomeral sulcus | The groove on the anterior border of the vomer that receives the septal cartilage. Synonym: sulcus vomeralis, sulcus vomeris, vomeral sulcus. (05 Mar 2000) |
| mentolabial sulcus | The indistinct line separating the lower lip from the chin. Synonym: mentolabial furrow, sulcus mentolabialis. (05 Mar 2000) |