| OCH | oral contraceptive hormone |
|---|---|
| OCM | oral contraceptive medication |
| OCS | occipital condyle syndrome; Ondine's curse syndrome; open canalicular system; oral contraceptive ste... |
| OCT | object classification test; optimal cutting temperature; oral contraceptive therapy; ornithine carba... |
| OES | oral esophageal stethoscope; optical emission spectroscopy |
| nasal reflex | Sneezing caused by irritation of the nasal mucous membrane. (05 Mar 2000) |
|---|---|
| nasal region | The region of the nose. Synonym: regio nasalis. (05 Mar 2000) |
| nasal ridge | An elevation on the lateral wall of the nasal cavity lying between the atrium of the middle meatus and the olfactory sulcus; it is formed by the mucous membrane covering the base of the ethmoidal crest of the maxilla. Synonym: nasal ridge. (05 Mar 2000) |
| nasal sacs | The deepened nasal pits that develop into the definitive nasal cavities. (05 Mar 2000) |
| nasal septal cartilage | A thin cartilaginous plate located between vomer, perpendicular plate of the ethmoid, and nasal bones, and completing the nasal septum anteriorly. Synonym: cartilago septi nasi, cartilage of nasal septum, cartilaginous septum, pars cartilaginea septi nasi, quadrangular cartilage, septal cartilage. (05 Mar 2000) |
| nasal septum | The dividing wall that runs down the middle of the nose so that there are normally two sides to the nose, each ending in a nostril. (12 Dec 1998) |
| nasal spine of frontal bone | A projection from the centre of the nasal part of the frontal bone, which lies between and articulates with the nasal bones and the perpendicular plate of the ethmoid. Synonym: spina nasalis ossis frontalis. (05 Mar 2000) |
| nasal surface of maxilla | The surface of the maxilla that forms part of the lateral nasal wall with a large defect (maxillary hiatus) posteriorly and the lacrimal sulcus in its midportion. Synonym: facies nasalis maxillae. (05 Mar 2000) |
| nasal surface of palatine bone | The nasal surface of the perpendicular lamina of the palatine bone that forms part of the lateral wall of the nasal cavity, the nasal surface of the horizontal lamina of the palatine bone that forms part of the floor of the nasal cavity. Synonym: facies nasalis ossis palatini. (05 Mar 2000) |
| nasal valve | The variable aperture between the nasal septum and the moveable inferior margin of the lower lateral nasal cartilage. (05 Mar 2000) |
| nasal venous arch | An arch formed at the root of the nose by the two supratrochlear veins connected by a transverse vein. (05 Mar 2000) |
| nasal venules of retina | See: inferior nasal venule of retina, superior nasal venule of retina. (05 Mar 2000) |
| superior nasal arteriole of retina | The branch of the central artery of the retina that passes to the upper medial, or nasal, part of the retina. Synonym: arteriola nasalis retinae superior. (05 Mar 2000) |
| superior nasal concha | The upper thin, spongy, bony plate with curved margins, part of the ethmoidal labyrinth, projecting from the lateral wall of the nasal cavity and separating the superior meatus from the sphenoethmoidal recess, the above bony plate and its thick mucoperiosteum, which is less vascular than that of the middle and inferior conchae. Synonym: concha nasalis superior, Morgagni's concha, superior turbinated bone, turbinated body. (05 Mar 2000) |
| superior nasal venule of retina | The small vein that drains blood from the upper medial (nasal) part of the retina; it joins the central vein. Synonym: venula nasalis retinae superior. (05 Mar 2000) |