palate

palate păl´ĭt [key], roof of the mouth. The front part, known as the hard palate, formed by the upper maxillary bones and the palatine bones, separates the mouth from the nasal cavity. It is composed of a bone plate covered with a layer of mucous membrane tissue. The back portion, or soft palate, consists of muscular tissue and mucous membrane forming a partial partition between the mouth and the throat. A small conelike projection, the uvula, hangs from the middle of the soft palate in humans. The soft palate and uvula move upward during swallowing or sucking, preventing food from entering the nasopharynx. In mammals other than humans, the soft palate overlaps the larynx during swallowing so as to prevent entry of foreign substances into the respiratory tract. Both the hard and soft portions of the palate are lined with mucous membrane containing numerous glands that lubricate the mouth and throat. If the sides of the bony palate fail to come together during embryonic development an opening, or cleft, remains along the midline. This condition, known as cleft palate, can be repaired surgically in early infancy. See digestive system .

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