iris
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- iris
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1. The circular pigmented membrane behind the cornea, perforated by the pupil; the most anterior portion of the vascular tunic of the eye, it is made up of a flat bar of circular muscular fibers surrounding the pupil, a thin layer of smooth muscle fibers by which the pupil is dilated, thus regulating the amount of light entering the eye, and posteriorly two layers of pigmented epithelial cells.
2. The rhizome of Iris versicolor , formerly used as a purgative, emetic, and diuretic.




Used in 14 Term definitions
Used in 14 Term definitions