Atrium

atrium /atri·um/ (a´tre-um) pl. a´tria   [L.] a chamber; in anatomy, a chamber affording entrance to another structure or organ, especially the upper, smaller cavity (a. cordis) on either side of the heart, which receives blood from the pulmonary veins (left a.) or venae cavae (right a.) and delivers it to the ventricle on the same side.a´trial

Atria of the heart.

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common atrium  the single atrium found in a form of three-chambered heart.

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a·tri·um (tr-m)

n. pl. a·tri·ums or a·tri·a (tr-)

1. A chamber or cavity to which several chambers or passageways are connected.

2. Either the right or the left upper chamber of the heart that receives blood from the veins and forces it into a ventricle.

3. That part of the tympanic cavity that lies below the eardrum.

4. A subdivision of the alveolar duct in the lung from which the alveolar sacs open.

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Atrium

One of the two upper chambers of the heart.

Mentioned in: Mitral Valve Insufficiency, Mitral Valve Stenosis, Tricuspid Valve Insufficiency

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atrium

pl. atria [L.] a chamber affording entrance, especially the chamber (atrium cordis) on either side of the heart, transmitting to the ventricle of the same side blood received (left atrium) from the pulmonary veins and (right atrium) from the venae cavae. See also atrial.

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parabronchi atrium

extensions of the parabronchial lumen giving rise to the air capillaries.

atrium partitioning

partitioning of the atrium by the septum primum during embryological development may be defective leading to a congenital malformation, e.g. patent foramen ovale.

ruminal atrium

the first part of the rumen, and the cranial chamber of its dorsal sac, just caudal to the reticuloruminal fold. Called also atrium ruminis.

ventricular atrium

the shallow vault between the reticulum and the rumen into which the esophagus in the ruminant opens.