Antrum

In biology, "antrum" is a general term for a cavity or chamber which may have specific meaning in reference to certain organs or sites in the body.

Examples include:
 * pyloric antrum, the initial portion of the pyloric part of the stomach. This is what usually is referred to in terms of antrum in stomach related topics.
 * antrum cardiacum, a dilation that occurs in the esophagus near the stomach (forestomach)
 * mastoid antrum, a cavity between the middle ear and temporal bone in the skull
 * antrum follicularum, the cavity in the epithelium that envelops the oocyte
 * Antrum of Highmore (maxillary sinus or maxillary antrum), a cavity in the maxilla and the largest of the paranasal sinuses

Antrum