| 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 |
| accessory placenta | An extra placenta separate from the main placenta. Also called a succenturiate or supernumerary placenta. (12 Dec 1998) |
| adherent placenta | A placenta that fails to separate cleanly from the uterus after delivery. (05 Mar 2000) |
| battledore placenta | A placenta in which the umbilical cord is attached at the border; so-called because of the fancied resemblance to the racquet (racket) used in battledore, a precursor to badminton. (05 Mar 2000) |
| bidiscoidal placenta | A placenta with two separate disc-shaped portions attached to opposite walls of the uterus, normal for certain monkeys and shrews, and occasionally found in humans. (05 Mar 2000) |
| margination of placenta | See: placenta marginata. (05 Mar 2000) |
| maternal placenta | <anatomy> The part of the placenta derived from the uterine tissue. See: placenta. Synonym: maternal placenta, placenta uterina. (05 Mar 2000) |
| villous placenta | A placenta in which the chorion forms villi. (05 Mar 2000) |