(an'trŭm , an'tră)

Plural: antra

[L. antrum fr. Gr. antron, cave]

A nearly closed cavity or chamber, esp. in a bone.

antral,

(an'trăl )

duodenal a.Duodenal cap.

gastric a.The distal segment of the stomach or area of the pyloric gland that does not secrete acid and produces the hormone gastrin.

a. of Highmore

SEE: under Highmore, Nathaniel.

mastoid a.The expand ed space that is continuous with the mastoid air cells posteriorly and the epitympanic recess anteriorly.

maxillary a.Maxillary sinus

pyloric a.A bulge in the pyloric portion of the stomach.

tympanic a.An air-filled antrum in the temporal bone connecting the mastoid air cells to the epitympanic recess.