| orbital ridge | The bony ridge beneath the eyebrow. (12 Dec 1998) |
|---|---|
| orbital rim | The mostly sharp edge of the orbital opening which is the peripheral border of the base of the pyramid-shaped orbit. The superior half of the orbital rim is the supraorbital margin; the inferior half is the infraorbital margin. The frontal, maxillary, and zygomatic bones contribute to the orbital rim, which is generally strong to protect the orbital contents. Weak, potential fracture sites of the rim coincide with the sutures between the participating bones. Synonym: margin of orbit. (05 Mar 2000) |
| orbital septum | A fibrous membrane attached to the margin of the orbit and extending into the lids, containing the orbital fat and constituting in great part the posterior fascia of the orbicularis oculi muscle. Synonym: septum orbitale. (05 Mar 2000) |
| orbital sulci | A number of irregularly disposed, variable sulci dividing the inferior or orbital surface of each frontal lobe of the cerebrum into the orbital gyri. Synonym: sulci orbitales. (05 Mar 2000) |
| orbital surface | The surface of a bone which contributes to the walls of the orbit. The NA recognises an orbital surface on the following bones: greater wing of the sphenoid bone; the maxilla; the frontal bone; the zygomatic bone. Synonym: facies orbitalis. (05 Mar 2000) |
| orbital syndrome | <syndrome> An obsolete term referring to neoplastic tissue formation involving the apex of the orbit, causing ophthalmoplegia and optic nerve atrophy. (05 Mar 2000) |
| orbital tubercle of zygomatic bone | A small elevation on the orbital surface of the zygomatic bone, just within the orbital margin, about 1 cm below the zygomaticofrontal suture; it gives attachment to the lateral check ligament, the lateral palpebral ligament, and the suspensory ligament of the eyeball. Synonym: eminentia orbitalis ossis zygomatici, orbital eminence of zygomatic bone, Whitnall's tubercle. (05 Mar 2000) |
| orbital width | The distance between the dacryon and the farthest point on the anterior edge of the outer border of the orbit (Broca), or between the latter point and the junction of the frontolacrimal suture and the posterior edge of the lacrimal groove. (05 Mar 2000) |
| tarso-orbital | Relating to the eyelids and the orbit. (05 Mar 2000) |
| zygomatico-orbital | Relating to the zygomatic bone and the orbit. (05 Mar 2000) |
| zygomatico-orbital artery | <anatomy, artery> Origin, superficial temporal, sometimes middle temporal; distribution, orbicularis oculi muscle and portions of the orbit; anastomoses, lacrimal and palpebral branches of ophthalmic. Synonym: arteria zygomatico-orbitalis. (05 Mar 2000) |
| zygomatico-orbital foramen | The common opening on the orbital surface of the zygomatic bone of the canals transmitting the zygomaticofacial and zygomaticotemporal nerves; sometimes each of these canals has a separate opening on the orbital surface. Synonym: foramen zygomatico-orbitale. (05 Mar 2000) |
| fronto-orbital area | The cerebral cortex covering the basal surface of the frontal lobes. Synonym: fronto-orbital area. (05 Mar 2000) |
| abdominal part of aorta | <anatomy> The largest arterial conduit below the diaphragm. This term refers to the portion of the aorta below the diaphragm to the bifurcation into the right and left common iliac arteries. It supplies blood to the abdominal viscera, pelvic organs and lower extremities. (20 Jun 2000) |
| abdominal part of oesophagus | The part of the oesophagus inferior to the diaphragm. See: oesophagus. Synonym: pars abdominalis oesophagi. (05 Mar 2000) |