| OP | occipitoparietal; occipitoposterior; occiput posterior; octapeptide; olfactory peduncle; opening pre... |
|---|---|
| opg | opening |
| OS | left eye [Lat. oculus sinister]; occipitosacral; occupational safety; office surgery; Omenn syndrome... |
| PAo | airway opening pressure; ascending aortic pressure; pulmonary artery occlusion pressure |
| Po | opening pressure |
| carotid-cavernous sinus fistula | <radiology> Aetiology: laceration of ICA within cavernous sinus; usually secondary to basal skull fractures or penetrating trauma, rupture of an intracavernous ICA aneurysm symptoms: chemosis, conjunctival oedema, bruit findings: focal or diffuse enlargement of cavernous sinus, edematous extraocular muscles, arterial enlargement (pulsating exophthalamus), dilation of superior ophthalmic, facial, and internal jugular veins, occasional sellar erosion/enlargement, enlargement of superior orbital fissure (chronic phase) (12 Dec 1998) |
|---|---|
| carotid sinus | <anatomy> A slight dilation in the carotid artery at its bifurcation into the external and internal carotid arteries, it contains baroreceptors (pressure sensors) that when stimulated, will cause a reflex slowing of the heart, vasodilation and a fall in blood pressure. (27 Sep 1997) |
| carotid sinus branch | <anatomy, nerve> A branch of the glossopharyngeal nerve that innervates the baroreceptors in the wall of the carotid sinus and the chemoreceptors in the carotid body. Synonym: ramus sinus carotici, carotid sinus branch, Hering's sinus nerve, intercarotid nerve, nerve to carotid sinus, sinus nerve of Hering. (05 Mar 2000) |
| carotid sinus nerve | <anatomy, nerve> A branch of the glossopharyngeal nerve that innervates the baroreceptors in the wall of the carotid sinus and the chemoreceptors in the carotid body. Synonym: ramus sinus carotici, carotid sinus branch, Hering's sinus nerve, intercarotid nerve, nerve to carotid sinus, sinus nerve of Hering. (05 Mar 2000) |
| carotid sinus reflex | A normal reflex relating to the carotid sinus syndrome, which results from hypersensitivity or hyperactivation of the carotid sinus. (05 Mar 2000) |
| 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) |