Insulin effect of increasing glucose uptake and storage. Finally, insulin is degraded, terminating the response. In mammals, insulin is synthesized in the pancreas within the beta cells. One million to three million pancreatic islets form the endocrine part of the pancreas, which is primarily an exocrine gland. The endocrine portion accounts for only 2% of the total mass of the pancreas. Within the pancreatic islets, beta cells constitute 65–80% of all the cells. Insulin consists of two polypeptide chains, the A- and B- chains, linked together by disulfide bonds. It is however first synthesized as a single polypeptide called preproinsulin in
Violet gland gland. For unknown reasons, the gland's secretions are fluorescent in ultraviolet light; this may result from the presence of carotenoids. Violet gland The violet gland or supracaudal gland is a gland located on the upper surface of the tail of certain mammals, including European badgers and canids such as foxes, wolves, and the domestic dog, as well as the domestic cat. Like many other mammalian secretion glands, the violet gland consists of modified sweat glands and sebaceous glands. It is used for intra-species signalling, scent marking, and contributes to the strong odor of foxes in particular. Although it secretes a