BIOL 221 Lecture Notes - Lecture 8: Gastric Pits, Enteroendocrine Cell, Gastric Glands
4 Mar 2020
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Document Summary
Many tight junctions hold the cells of the gastric pits and gastric glands closely together. This is essential to protection against the low ph and against pathogens that may have entered on the ingested food. Cells from the gastric pits are also important to renewal of the surface cells of the mucosa. There are four types of cells found in the gastric pits and gastric glands. They are: mucus neck cells, parietal cells (also called oxyntic cells), chief cells (also called zymogenic cells), and enteroendocrine cells. Mucous neck cells secrete bicarbonate-rich mucus to buffer the hydrogen ions (h+) produced by parietal cells. (review the function of intrinsic factor in topic 1; what results from lack of intrinsic factor?) Parietal cells also produce hydrochloric acid, which is buffered by bicarbonate in the mucus produced by goblet cells. Zymogenic cells (also called chief cells) produce pepsinogen, gastric lipases and, in infants, rennin.
