| ORALABX | oral antibiotics |
|---|---|
| ORD | optical rotatory dispersion; oral radiation death |
| OROS | oral osmotic |
| ORT | object relations technique; operating room technician; oral rehydration therapy |
| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
| carotid sinus syncope | <cardiology> Syncope which results from the over activity of the carotid sinus. Attacks may be spontaneous or produced by pressure on the carotid sinus. (27 Sep 1997) |
|---|---|
| carotid sinus syndrome | <syndrome> Stimulation of a hyperactive carotid sinus, causing a marked fall in blood pressure due to vasodilation, cardiac slowing, or both; syncope with or without convulsions or A-V block may occur. Synonym: Charcot-Weiss-Baker syndrome. (05 Mar 2000) |
| carotid sinus test | Stimulation of one carotid sinus (never both) to produce reflex effects that may slow the heart, reduce the systolic blood pressure or both for diagnostic or, in the case of certain arrhythmias, therapeutic purposes. (05 Mar 2000) |
| maxillary sinus | A air filled cavity within the maxilla (bone that forms the face and upper jaw). The maxillary sinus is located just below the bony prominence of the cheek (27 Sep 1997) |
| maxillary sinus neoplasms | Neoplasms or tumours of the maxillary sinus. The majority of paranasal sinus neoplasms arise here. They develop silently when confined to the sinus and produce symptoms on extension through the walls. (12 Dec 1998) |
| maxillary sinus radiograph | A radiographic frontal view of the maxillary sinuses, orbits, nasal structures and zygomas; permits direct comparison of the sides. Synonym: Waters' view radiograph. (05 Mar 2000) |
| cavernous sinus | <radiology> Contents: III oculomotor n., IV trochlear n., V-1 ophthalmic n. (trigeminal n.), V-2 maxillary n. (trigeminal n.), VI abducens n. Note: mandibular n. (V-3) passes through foramen rotundum (12 Dec 1998) |
| cavernous sinus branch of internal carotid artery | <anatomy, artery> A number of small branches of the cavernous part of the internal carotid artery. See: ganglionic branch of internal carotid artery, basal tentorial branch of internal carotid artery, marginal tentorial branch of internal carotid artery. Synonym: ramus sinus cavernosi arteriae carotidis arteriae, cavernous arteries. (05 Mar 2000) |
| cavernous sinus syndrome | <syndrome> This condition is characterised by oedema of the eyelids and conjunctivae and paralysis of the third, fourth and sixth cranial nerves. It is due to a cavernous sinus thrombosis. (27 Sep 1997) |
| cavernous sinus thrombosis | <neurology> A blood clot within the cavernous sinus (a sinus cavity which is bordered by the sphenoid bone and the temporal bone). This condition produces a syndrome called cavernous sinus syndrome. (16 Mar 1998) |
| renal sinus | The cavity of the kidney, containing the calyces and pelvis of the ureter and the segmental vesels embedded within a fatty matrix. The renal sinuses cause the kidneys to appear hollow or C-shaped on cross section or medical imaging. Synonym: sinus renalis. (05 Mar 2000) |
| cervical sinus | In young mammalian embryos a depression in the nuchal region caudal to the hyoid arch, with the third and fourth branchial arches and ectodermal grooves in its floor; normally it is obliterated after the second month, but occasionally cervical fistulae persist as vestiges of it. Synonym: precervical sinus. (05 Mar 2000) |
| Ridley's sinus | The anterior and posterior anastomoses between the cavernous sinus's, passing anterior and posterior to the hypophysis and forming, with the cavernous sinuses, the circular sinus. Synonym: sinus intercavernosi, Ridley's sinus. Jugular sinus Sinus jugularis, one of three enlargements of the jugular veins; the external jugular sinus is between the two sets of valves; the internal jugular sinus's are at the origin (superior bulb) and near the termination (inferior bulb). (05 Mar 2000) |
| groove for inferior petrosal sinus | A groove lodging the inferior petrosal sinus, formed by union of similarly named grooves in the petrous part of the temporal bone and the basilar part of the occipital bone. Synonym: sulcus sinus petrosi inferioris, inferior petrosal groove, inferior petrosal sulcus. (05 Mar 2000) |
| groove for sigmoid sinus | A broad groove in the posterior cranial fossa, first situated on the lateral portion of the occipital bone, then curving around the jugular process on to the mastoid portion of the temporal bone, and finally turning sharply on the posterior inferior angle of the parietal bone and becoming continuous with the transverse groove; it lodges the transverse sinus. Synonym: sulcus sinus sigmoidei, sigmoid fossa, sigmoid groove, sigmoid sulcus. (05 Mar 2000) |