The ear (actually, the pinna which is the principal projecting part of the ear) or something that is ear shaped like the upper chamber (atrium) of the heart.
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1. The projecting shell-like structure on the side of the head, constituting, with the external acoustic meatus, the external ear. SYN: auricula (1) [TA], ala auris, pinna (1). 2. SYN: auricles (of atria).
- accessory auricles small, fleshy nodules or folds, sometimes with supporting cartilage, occasionally found along the margins of the embryonic branchial clefts.
- atrial a. SYN: auricles (of atria). SEE ALSO: left atrium of heart, right atrium of heart.
- cervical a. accessory a. on the neck.
- left a. [TA] the small conical projection from the left atrium of the heart. SYN: auricula atrii sinistra [TA], a. of left atrium, left auricular appendage.
- a. of left atrium SYN: left a..
- auricles (of atria) [TA] a small conical (“ear-shaped”) pouch projecting from the upper anterior portion of each atrium of the heart, increasing slightly the atrial volume. See left a., right a.. SYN: a. (2) [TA], auricula (2) [TA], auriculae atrii [TA], atrial appendage, atrial a., atrial auricula, auricular appendix.
- right a. [TA] the small conical projection from the right atrium of the heart. SYN: auricula atrii dextra [TA], a. of right atrium, auricular appendage (1), right auricular appendage.
- a. of right atrium SYN: right a..

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au·ri·cle 'ȯr-i-kəl n
1 a) PINNA
b) an atrium of the heart
2) an angular or ear-shaped anatomical lobe or process (as an auricular appendage of the heart)

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1. a small pouch in the wall of each atrium of the heart: the term is also used incorrectly as a synonym for atrium.

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au·ri·cle (awґrĭ-kəl) [L. auricula, q.v.] 1. auricula. 2. auricula atrii. 3. formerly, one of the atria of the heart.

Medical dictionary. 2011.