tympanic antrum

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 [an´trum] (pl. an´tra, antrums) (L.)
a cavity or chamber. adj., adj an´tral.
antrum of Highmore maxillary sinus.
mastoid antrum an air space in the mastoid portion of the temporal bone communicating with the middle ear and the mastoid cells.
antrum maxilla´re (maxillary antrum) maxillary sinus.
pyloric antrum (antrum pylo´ricum) the proximal, expanded portion of the pyloric part of the stomach.
tympanic antrum (antrum tympa´nicum) mastoid antrum.

mas·toid an·trum

a cavity in the petrous portion of the temporal bone, communicating posteriorly with the mastoid cells and anteriorly with the epitympanic recess of the middle ear via the aditus to the mastoid antrum.

tympanic antrum

a relatively large, irregular cavity in the superior anterior part of the mastoid process of the temporal bone, communicating with the mastoid air cells and lined by the extension of the mucous membrane of the tympanic cavity. The bony tegmen tympani separates the tympanic antrum from the middle fossa of the cranial cavity, and the lateral semicircular canal of the internal ear projects into the antrum. See also mastoid process.

tympanic antrum

An air-filled sinus in the temporal bone connecting the mastoid air cells to the epitympanic recess.
See also: antrum