HCl. E. False But it rises markedly after H2 blockade which blocks gastric acid secretion.
203. A. False The concentration is higher, due partly to potassium released from cast off cells. B. False Intestinal secretion is not under vagal control; its enzymes are thought to be con-
stituents of the mucosal cells and released when these are cast off into the lumen. C. True The mucosal cell brush border contains these enzymes, e.g. maltase and lactase. D. False Monosaccharides are end-products of digestion and absorbed as such. E. True For example, enterokinase which converts trypsinogen to trypsin.