annulus(redirected from annulus iridis)
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annulus[an´u-lus] (pl. an´nuli) (L.)
alternate spelling of anulus.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
n. pl. annu·luses or annu·li (-lī′)
1. A ringlike figure, part, structure, or marking, such as a growth ring on the scale of a fish.
a. A ring or group of thick-walled cells around the sporangia of many ferns that functions in spore release.
b. The ringlike remains of a broken partial veil, found around the stipes of certain mushrooms.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
annulusAny ring-like structure (e.g., mitral valve annulus).
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
annulusAny ring-like structure.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
- the ring of cells in the moss or fern capsule which splits to allow the liberation of spores.
- a ring of tissue surrounding the stalk in the fruiting bodies of the BASIDIOMYCOTA fungi.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005