Answer
Ghrelin, cholecystokinin(CCK), and peptide YY(PYY) are examples of so-called gut brain peptides that moderate eating and digestive activities.
Ghrelin is secreted by the parietal cells of the stomach. PYY is a neuropeptide Y, and is secreted by the neuroendocrine cells of the of the ileum and the colon. CCK is secreted by the neuroendocrine cells of the duodenum and the jejunum.
Functions of the gut brain peptides (brain gut peptides)
Ghrelin promotes the feeling of hunger
It stimulates the production of growth hormone releasing hormone (GHRH) from the hypothalamus. The GHRH causes the release of growth hormone (HGH) from the anterior pituitary (AP). HGH or somatotropin enables cells to make maximum use of available nutrients.
Peptide YY. This hormone is secreted by the neuroendocrine cells of the ileum and the colon. It is a member of the neuropeptide Y family, which includes pancreatic peptide (PP) and neuropeptide Y (NPY). Its function is to signal satiety and time to cease eating. The signals are sent to the brain as the food enters the stomach, and remain elevated long after a meal is finished.; it prevents the stomach from emptying too quickly.
Cholecystokinin has two important functions:
It stimulates the secretion of bile and pancreatic juice.
It also suppresses appetite by signalling satiety to the brain through the vagus nerve.
Work Step by Step
CCK and PYY cooperate send signals to stop eating, but ghrelin promotes hunger and appetite.
Other important brain gut peptides are arginine vasotocin, secretin, and gastrin.
