Delete Content. A plasma membrane is permeable to specific molecules that a cell needs. Transport proteins in the cell membrane allow for selective passage of specific molecules from the external environment. Each transport protein is specific to a certian molecule (indicated by matching colors).
The pancreas contains cells which release both insulin and glucagon. The endocrine system consists of a number of different glands which secrete hormones that dictate how cells and organs behave.
gastric glands. Definition: branched tubular glands lying in the mucosa of the fundus and body of the stomach. They contain parietal cells that secrete hydrochloric acid and gastric intrinsic factor, zymogen cells that produce pepsin, APUD cells that produce various hormones and factors, and mucous cells. Search Stedman's Medical Dictionary.