Gastrointestinal hormones
Gastrointestinal hormones are increasingly being shown to influence psychiatric disorders. This is true for more obvious conditions such as anorexia (Atalayer, 2013) but also for areas such as sleep and human behaviour (Motivala, 2009).
The microbiome is another area that your consultant colleagues will probably roll their eyes at (if they are even aware of it) but in a few years will be a crucial area of psychiatric practice (Rogers, 2016).
For the purpose of the exams you just need a basic idea about the gut hormones.
Atalayer (2013) Ghrelin and Eating Disorders. Prog Neuropsychopharmacol Biol Psychiatry. 2013 Jan 10; 40: 70-82
Motivala (2009) Nocturnal levels of ghrelin and leptin and sleep in chronic insomnia. Psychoneuroendocrinology May 2009 Volume 34, Issue 4, Pages 540-545
Rogers (2016) From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways. Molecular Psychiatry (2016) 21, 738-748
The microbiome is another area that your consultant colleagues will probably roll their eyes at (if they are even aware of it) but in a few years will be a crucial area of psychiatric practice (Rogers, 2016).
For the purpose of the exams you just need a basic idea about the gut hormones.
| Hormone | Origin | Action |
|---|---|---|
| Gastrin | Secreted by cells in the stomach and duodenum | Stimulates the exocrine cells of the stomach to secrete gastric juice (a mixture of hydrochloric acid and the proteolytic enzyme pepsin) |
| Somatostatin | Secreted by cells in the gastric glands of the stomach | On the stomach (thus a paracrine effect) it inhibits the release of gastrin and hydrochloric acid On the duodenum it inhibits the release of secretin and cholecystokinin On the pancreas it inhibits the release of glucagon |
| Secretin | Secreted by cells in the duodenum when they are exposed to the acidic contents of the emptying stomach | Stimulates the exocrine portion of the pancreas to secrete bicarbonate into the pancreatic fluid (thus neutralizing the acidity of the intestinal contents) |
| Cholecystokinin (CCK) | Secreted by cells in the duodenum and jejunum when they are exposed to food | On on the gall bladder stimulating it to contract and force its contents of bile into the intestine On the pancreas stimulating the release of pancreatic digestive enzymes into the pancreatic fluid On vagal neurons leading back to the medulla oblongata which give a satiety signal |
| Ghrelin | Secreted by endocrine cells in the stomach | Acts on the hypothalamus to stimulate feeding |
Atalayer (2013) Ghrelin and Eating Disorders. Prog Neuropsychopharmacol Biol Psychiatry. 2013 Jan 10; 40: 70-82
Motivala (2009) Nocturnal levels of ghrelin and leptin and sleep in chronic insomnia. Psychoneuroendocrinology May 2009 Volume 34, Issue 4, Pages 540-545
Rogers (2016) From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways. Molecular Psychiatry (2016) 21, 738-748
