atrium

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atrium

 [a´tre-um] (pl. a´tria) (L.)
a chamber affording entrance, especially the upper chamber (a´trium cor´dis) on either side of the heart, transmitting to the ventricle of the same side blood received from the pulmonary veins (left atrium) and from the venae cavae (right atrium).
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

a·tri·um

, pl.

a·tri·a

(ā'trē-ŭm, ā'trē-ă), Do not confuse this word with antrum.
1. A chamber or cavity to which are connected several chambers or passageways.
2. Synonym(s): atrium of heart
3. That part of the tympanic cavity that lies immediately deep to the tympanic membrane.
5. In the lung, a subdivision of the alveolar duct from which alveolar sacs open.
[L. entrance hall]
Farlex Partner Medical Dictionary © Farlex 2012

atrium

(ā′trē-əm)
n. pl. atria (ā′trē-ə) or atri·ums
Anatomy A body cavity or chamber, especially either of the upper chambers of the heart that receives blood from the veins and forces it into a ventricle. Also called auricle.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

a·tri·um

, pl. atria (ā'trē-ŭm, -ă) [TA]
1. A chamber or cavity to which are connected several chambers or passageways.
2. Synonym(s): atrium of heart.
3. That part of the tympanic cavity that lies immediately deep to the tympanic membrane (eardrum).
4. In the lung, a subdivision of the alveolar duct from which alveolar sacs open.
[L. entrance hall]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

atrium

One of the thin-walled upper chambers of the heart which receive blood from the veins and pass it down to the lower, more powerful, pumping chambers (the ventricles).
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Atriumclick for a larger image
Fig. 56 Atrium . Primitive heart.

atrium

(pl. atria) a passage or chamber in the body, particularly one or more of the chambers in the heart receiving blood from the body. All vertebrates except fish have hearts with two atrial cavities.

See also HEART and HEART, CARDIAC CYCLE.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Atrium

One of the two upper chambers of the heart.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

a·tri·um

, pl. atria (ā'trē-ŭm, -ă) [TA] Do not confuse this word with antrum.
Chamber or cavity to which are connected several chambers or passageways.
[L. entrance hall]
Medical Dictionary for the Dental Professions © Farlex 2012