| 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) |
| orbital diseases | Diseases of the bony orbit and contents except the eyeball. (12 Dec 1998) |
| orbital exenteration | Removal of the entire contents of the orbit. (05 Mar 2000) |
| orbital fasciae | The fascial layers in the orbit consisting of periorbita, septum orbitale, fascia muscularis musculorum bulbi, and vagina bulbi. Synonym: fasciae orbitales. (05 Mar 2000) |
| orbital fat-pad | The mass of fat contained in the orbit that contributes to the support of the eyeball. Synonym: corpus adiposum orbitae, fat body of orbit. (05 Mar 2000) |
| orbital fractures | Fractures of the bones in the orbit, which include parts of the frontal, ethmoidal, lacrimal, and sphenoid bones and the maxilla and zygoma. (12 Dec 1998) |