| PRRF | paramedian pontine reticular formation |
|---|---|
| RAS | rapid atrial stimulation; recurrent aphthous stomatitis; reflex activating stimulus; reliability, av... |
| REM | rapid eye movement; recent-event memory; reticular erythematous mucinosis; return electrode monitor;... |
| RET | reticular; reticulocyte; retina; retention; retained; right esotropia |
| RL | radial line; radiation laboratory; reduction level; renal dysplasia-limb defects [syndrome]; resisti... |
| annular part of fibrous digital sheath | One of the two circular fibrous bands of the fibrous sheaths of the fingers and toes attached to the shaft of the proximal and middle phalanges. Synonym: pars annularis vaginae fibrosae, annular pulley, annulus of fibrous sheath, ligamentum annulare digitorum. (05 Mar 2000) |
|---|---|
| annular placenta | A placenta in the form of a band encircling the interior of the uterus. Synonym: zonary placenta. (05 Mar 2000) |
| annular plexus | A nerve plexus near the corneoscleral junction from which myelinated and unmyelinated nerves pass to the cornea. Synonym: plexus annularis. (05 Mar 2000) |
| annular pulley | One of the two circular fibrous bands of the fibrous sheaths of the fingers and toes attached to the shaft of the proximal and middle phalanges. Synonym: pars annularis vaginae fibrosae, annular pulley, annulus of fibrous sheath, ligamentum annulare digitorum. (05 Mar 2000) |
| annular scleritis | An often protracted inflammation of the anterior portion of the sclera, forming a ring around the corneoscleral limbus. (05 Mar 2000) |
| 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 |