9 No.6) State the site of production e function of
sectetin Gastrin e cholecystokinin
Answers
1) Secretin primarily functions to neutralize the pH in the duodenum, allowing digestive enzymes from the pancreas (e.g., pancreatic amylase and pancreatic lipase) to function optimally. Secretin targets the pancreas; pancreatic centroacinar cells have secretin receptors in their plasma membrane.
2) Gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas.
3) CCK plays important physiological roles both as a neuropeptide in the central nervous system and as a peptide hormone in the gut.[11] It participates in a number of processes such as digestion, satiety and anxiety. [Note : The CCK tetrapeptide fragment CCK-4 (Trp-Met-Asp-Phe-NH2) reliably causes anxiety and panic attacks (panicogenic effect) when administered to humans and is commonly used in scientific research for this purpose of in order to test new anxiolytic drugs. Positron emission tomography visualization of regional cerebral blood flow in patients undergoing CCK-4 induced panic attacks show changes in the anterior cingulate gyrus, the claustrum-insular-amygdala region, and cerebellar vermis.]
Answer:
function of melatonin is to mediate dark signals and provide night information, a “hormone of darkness,” rather than be the hormone of sleep. It has also been thought to be an “endogenous synchronizer” that stabilizes and reinforces various circadian rhythms in the body.