| annular scotoma | A circular scotoma surrounding the centre of the field of vision. See: ring scotoma. (05 Mar 2000) |
|---|---|
| annular sphincter | A short thickening of circular muscular fibres, similar to a ring; a ring-shaped sphincter as opposed to a segmental sphincter. (05 Mar 2000) |
| annular staphyloma | A staphyloma extending around the periphery of the cornea. (05 Mar 2000) |
| annular stop | <microscopy> The opaque ring-shaped stop with a small central opening usually placed in the objective back focal plane to provide dispersion staining. (05 Aug 1998) |
| annular stricture | A ringlike constriction encircling the wall of a canal. (05 Mar 2000) |
| annular synechia | Adhesion of the entire pupillary margin of the iris to the capsule of the lens. (05 Mar 2000) |
| annular syphilid | Cutaneous lesions of secondary syphilis in which the papules form annular lesions with raised papular borders and clear central portions. (05 Mar 2000) |
| Gerlach's annular tendon | fibrocartilaginous ring of tympanic membrane |
| abdominal aortic plexus | <anatomy, neurology> An autonomic plexus surrounding the abdominal aorta, directly continuous with the thoracic aortic plexus above and continued inferior to the bifurcation of the aorta as the superior hypogastric plexus. Synonym: plexus aorticus abdominalis. (05 Mar 2000) |
| acromial plexus | A vascular network between the acromion and the skin of the shoulder, formed by anastomoses of the acromial branch of the suprascapular artery with the acromial branch of the thoracoacromial artery. Synonym: rete acromiale, acromial plexus. (05 Mar 2000) |
| anterior coronary plexus | The part of the cardiac plexus that accompanies the coronary arteries on the anterior aspect of the heart. (05 Mar 2000) |
| aortic lymphatic plexus | A plexus of lymph nodes and connecting vessels lying along the lower portion of the abdominal aorta. Synonym: plexus aorticus. (05 Mar 2000) |
| ascending pharyngeal plexus | An autonomic plexus on the artery of the same name, formed of fibres from the superior cervical ganglion. Synonym: plexus pharyngeus ascendens. (05 Mar 2000) |
| Auerbach's plexus | One of two ganglionated neural networks which together form the enteric nervous system. The myenteric (auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (12 Dec 1998) |
| axillary plexus | A lymphatic plexus formed of the lymph nodes, with their afferent and efferent vessels, in the axilla. Synonym: plexus axillaris. (05 Mar 2000) |