| AOCl | anodal opening clonus |
|---|---|
| AOO | anodal opening odor; atrial asynchronous (competitive, fixed-rate) [pacemaker] |
| AOP | anodal opening picture; aortic pressure |
| AOS | American Ophthalmological Society; American Otological Society; anodal opening sound; anterior [o]es... |
| AOT | accessory optic tract; Anderson Olsson table; anodal opening tetanus; Association of Occupational Th... |
| lacrimal opening | The minute circular opening of the lacrimal canaliculus, on the margin of each eyelid near the medial commissure. Synonym: punctum lacrimale, lacrimal opening. (05 Mar 2000) |
|---|---|
| bilateral medial orbital ecchymoses | <clinical sign, ophthalmology> The appearance of the eyes produced by subconjunctival haemorrhage and/or periorbital ecchymosis. Synonym: bilateral medial orbital ecchymoses. (21 Jun 2000) |
| cephalo-orbital index | The ratio of the cubic content of the two orbits to that of the cranial cavity multiplied by 100. (05 Mar 2000) |
| granuloma, plasma cell, orbital | A distinctive, chronic inflammatory reaction in the orbital tissues of the eye, of unknown aetiology, that may closely resemble a neoplasm and often becomes bilateral. Symptoms include exophthalmos and congestion of the lids with oedema. When limitation of ocular motility also occurs, it is sometimes called orbital myositis. (12 Dec 1998) |
| spheno-orbital suture | Articulation between the orbital process of the palatine bone and the outer surface of the body of the sphenoid. Synonym: sutura spheno-orbitalis. (05 Mar 2000) |
| superior orbital fissure | A cleft between the greater and the lesser wings of the sphenoid establishing a channel of communication between the middle cranial fossa and the orbit, through which pass the oculomotor and trochlear nerves, the ophthalmic division of the trigeminal nerve, the abducens nerve, and the ophthalmic veins. Synonym: fissura orbitalis superior, foramen lacerum anterius, sphenoidal fissure. (05 Mar 2000) |
| inferior orbital fissure | A cleft between the greater wing of the sphenoid and the orbital plate of the maxilla, through which pass the maxillary division and the orbital branch of the trigeminal nerve, fibres from the pterygopalatine (Meckel's) ganglion, and the infraorbital vessels. Synonym: fissura orbitalis inferior, sphenomaxillary fissure. (05 Mar 2000) |
| orbital | <anatomy> Pertaining to the orbit, which is the bony cavity containing the eyeball. (18 Nov 1997) |
| orbital abscess | A circumscribed collection of pus within the orbit; frequently an extension of purulent infection of the paranasal sinuses, usually the ethmoids. Synonym: retrobulbar abscess. (05 Mar 2000) |
| orbital artery | <anatomy, artery> The medial orbitofrontal branch, the first branch of the pericallosal artery; it supplies the medial half of the inferior surface of the frontal cortex. Synonym: arteria frontobasalis medialis, ramus orbitofrontalis medialis, orbital artery. (05 Mar 2000) |
| orbital axis | The line from the centre of the optic foramen (apex of orbit) extending anteriorly, laterally, and inferiorly to the middle of the orbital opening. (05 Mar 2000) |
| orbital branch of middle meningeal artery | <anatomy, artery> Branch of middle meningeal artery traversing superior orbital fissure and running toward lacrimal gland. See: anastomotic branch of middle meningeal artery to lacrimal artery. Synonym: ramus orbitalis arteriae meningeae mediae. (05 Mar 2000) |
| orbital branch of pterygopalatine ganglion | Branches of pterygopalatine ganglion traversing inferior orbital fissure, distributed in orbit to periorbita and mucosa of ethmoidal and sphenoidal sinuses. Synonym: ramus orbitalis ganglii pterygopalatini. (05 Mar 2000) |
| orbital cavity | 1. <astronomy> The path described by a heavenly body in its periodical revolution around another body; as, the orbit of Jupiter, of the earth, of the moon. 2. An orb or ball. "Roll the lucid orbit of an eye." (Young) 3. <anatomy> The cavity or socket of the skull in which the eye and its appendages are situated. 4. <zoology> The skin which surrounds the eye of a bird. Origin: L. Orbita a track or rut made by a wheel, course, circuit, fr. Orbis a circle: cf. F. Orbite. See Orb. Source: Websters Dictionary (01 Mar 1998) |
| orbital decompression | Removal of a portion of the bony orbit, usually superior (Naffziger operation), lateral (Kronlein operation), or inferior (Ogura operation). (05 Mar 2000) |