List the hormones secreted by pancreas.
The four main hormones produced by the endocrine pancreas and their functions are
Glucagon
- It is a polypeptide hormone.
- It is secreted by the pancreas when the glucose level in the blood drops.
- It increases the blood glucose levels by initiating glycogenolysis (glycogen degradation) and stimulating gluconeogenesis (synthesis of glucose from non-carbohydrate molecules) in the liver cells.
- Since it increases the blood glucose levels it is a hyperglycemic (hyper-more, glycemic-sugar levels) hormone
- It also initiates lipolysis (degradation of lipid) in the adipose tissue.
Insulin
- It is also a polypeptide hormone
- It has antagonistic (opposite) effects of the hormone glucagon.
- It is released when the glucose level in the blood raises.
- It lowers blood sugar levels in different ways; increasing the uptake of glucose by all the cells in the body, initiating glycogenesis (glycogen synthesis) in the liver and muscle.
- It initiates lipogenesis (synthesis of lipids/fat) and storage of fat in adipose tissue and inhibits gluconeogenesis
- It is a hypoglycemic (hypo=less) hormone as it reduces the sugar levels in the blood
Somatostatin
- Also known as growth hormone-inhibiting hormone (GHIH)
- It acts locally on the Islets of Langerhans and inhibit the secretion of both insulin and glucagon
- It also reduces gastric secretions and inhibits the release of gastrointestinal hormones
Pancreatic Polypeptide
- It is a polypeptide secreted by the cells of the pancreas.
- Protein is strong stimulus for its production
- It affects gastric and biliary secretion and motility of the GI tract