an'trum

A cavity, especially one within a bone; also a dilatation, an ampulla, a. ethmoidal is. See ethmoidal cells, under cell. a. Highmorii. See maxillary a. a. pylori, a. pylori cum Will is i i. The pyloric portion of the stomach, a. sphenoid ale, a. sphenoidalium. See sphenoidal sinuses, under sinus, duodenal a. The normal dilatation of the duodenum near its origin, mastoid a. The cavity of the horizontal portion of the mastoid proce of the temporal bone, maxillary a. Syn.: maxillary sinus, a. of High more. A large, irregularly pyramidal cavity of the body of the superior maxilla. It is lined with mucous membrane, and communicates with the middle meatus of the nose. [B. N. A. sinus maxillar is.] [Gr., antron, cave.]