| short ciliary nerve | <anatomy, nerve> One of a number of branches of the ciliary ganglion, supplying the ciliary muscles, iris, and tunics of the eyeball. Synonym: nervus ciliaris brevis. (05 Mar 2000) |
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| short posterior ciliary artery | <anatomy, artery> One of approximately seven branches of the ophthalmic artery which pass around the optic nerve to supply the eyeball. Dividing into some 15-20 branches, they penetrate the sclera adjacent to the optic nerve, supplying the choroid and ciliary processes. Anastomoses: with central retinal artery and long and anterior ciliary arteries (at the ora serrata). Synonym: arteria ciliaris posterior brevis. (05 Mar 2000) |
| short root of ciliary ganglion | A branch of the oculomotor nerve supplying parasympathetic preganglionic nerve fibres to the ciliary ganglion. Synonym: radix parasympathica ganglii ciliaris, radix oculomotoria ganglii ciliaris, motor root of ciliary ganglion, oculomotor root of ciliary ganglion, radix brevis ganglii ciliaris, short root of ciliary ganglion. (05 Mar 2000) |
| sympathetic root of ciliary ganglion | Postganglionic fibres,having cell bodies in the superior cervical ganglion, branching from the carotid plexus passing through the ciliary ganglion without synapse to reach the eyeball. Synonym: radix sympathica ganglii ciliaris. (05 Mar 2000) |
| oculomotor root of ciliary ganglion | A branch of the oculomotor nerve supplying parasympathetic preganglionic nerve fibres to the ciliary ganglion. Synonym: radix parasympathica ganglii ciliaris, radix oculomotoria ganglii ciliaris, motor root of ciliary ganglion, oculomotor root of ciliary ganglion, radix brevis ganglii ciliaris, short root of ciliary ganglion. (05 Mar 2000) |
| embryonal tumour of ciliary body | <tumour> An epitheliomatous tumour of the nonpigmented layer of the ciliary epithelium. Synonym: embryonal tumour of ciliary body. (05 Mar 2000) |
| long ciliary nerve | <anatomy, nerve> One of two or three branches of the nasociliary nerve, which by-pass the ciliary ganglion, supplying post-synaptic sympathetic fibres for the dilator pupillae muscle and sensory fibres for the ciliary muscles, iris, and cornea. Synonym: nervus ciliaris longus. (05 Mar 2000) |
| long root of ciliary ganglion | Sensory fibres passing from the eyeball through the ciliary ganglion to their cell bodies in the trigeminal ganglion via the nasociliary nerve. Synonym: radix sensoria ganglii ciliaris, ramus communicans nervi nasociliaris cum ganglio ciliari, radix nasociliaris, long root of ciliary ganglion, nasociliary root, radix longa ganglii ciliaris. (05 Mar 2000) |
| alveolocapillary block | The presence of material that impairs the diffusion of gases between the air in the alveolar spaces and the blood in alveolar capillaries; block can be caused by oedema, cellular infiltration, fibrosis, or tumour, and results in undersaturation of peripheral arterial blood with oxygen. (05 Mar 2000) |
| anterograde block | Conduction block of an impulse traveling anywhere in its ordinary direction, for example, from the sinoatrial node toward the ventricular myocardium. (05 Mar 2000) |
| arborization block | Intraventricular block supposedly due to widespread blockage in the Purkinje ramifications and manifested in the electrocardiogram by a pattern similar to bundle-branch block but with complexes of low amplitude. (05 Mar 2000) |
| atrioventricular block | <cardiology> A conduction disturbance that results in the inappropriate delay (or complete inability) of a electrical impulse, generated in the atria, to reach the ventricles (via the atrioventricular node). Clinical types are divided into first (nonserious), second and third degree (most serious). Some drugs may precipitate atrioventricular block (for example clonidine, methyldopa, verapamil). A permanent pacemaker may be required for a third degree (complete) heart block. (02 Jan 1998) |
| autonomic nerve block | Interruption of sympathetic pathways, by local injection of an anaesthetic agent, at any of four levels: peripheral nerve block, sympathetic ganglion block, extradural block, and subarachnoid block. (12 Dec 1998) |
| A-V block | <cardiology> A conduction disturbance that results in the inappropriate delay (or complete inability) of a electrical impulse, generated in the atria, to reach the ventricles (via the atrioventricular node). Clinical types are divided into first (nonserious), second and third degree (most serious). Some drugs may precipitate atrioventricular block (for example clonidine, methyldopa, verapamil). A permanent pacemaker may be required for a third degree (complete) heart block. (02 Jan 1998) |
| block | An obstruction or stoppage. (18 Nov 1997) |