orifice
[or´ĭ-fis] 1. the entrance or outlet of any body cavity.
aortic orifice the opening of the left ventricle into the aorta; called also
aortic opening.
internal urethral orifice the opening from the urinary
bladder into the urethra at one corner of the
trigone of the bladder.
left atrioventricular orifice (mitral orifice) the opening between the left atrium and ventricle of the heart.
right atrioventricular orifice (tricuspid orifice) the opening between the right atrium and ventricle of the heart.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.