46. A general term for cavity or chamber which may have specific meaning in reference certain organs or sites. The antrum of the stomach (gastric antrum) is a portion before the outlet which is lined by mucosa which does not produce acid. The paranasal sinuses can be referred to as the frontal antrum, ethmoid antrum, and maxillary antrum.
47.
48.
49. porta 开口,尤指血管等进出部位 porta omenti porta pulmonis porta renis porta of spleen porta hepatis porta of lung porta labyrinthi porta lienis