Pancreas
Pancreas secretes many hormones which are:
- Insulin
- Glucagon
- Amylin,
- Somatostatin, and
- Pancreatic polypeptide
The islets of Langerhans, which secrete insulin and glucagon directly into the blood
EFFECTS OF GLUCAGON
- Glycogenolysis
- Gluconeogenesis
- Inhibit storage of fats in fat cells
- Increase Breakdown of stored TGs into FA to release in blood
OTHER EFFECTS OF GLUCAGON
- Glucagon in high concentrations also
- Enhances the strength of the heart;
- Increases blood flow in some tissues, especially the kidneys;
- Enhances bile secretion; and
- Inhibits gastric acid secretion.
Factors that play an important role in Regulation of Glucagon Secretion
- Increased Blood Glucose Inhibits Glucagon Secretion
- Increased Blood Amino Acids Stimulate Glucagon Secretion(glucagon then promotes rapid conversion of the amino acids to glucose, thus making even more glucose available to the tissues).
- Exercise Stimulates Glucagon Secretion (A beneficial effect of the glucagon is that it prevents a decrease in blood glucose).
BLOOD GLUCOSE REGULATION
| Hormone | Released from | Releasing factor | Effect |
| Insulin | Pancreas (b cells) | Hyperglycemia | Promote glucose utilization |
| Glucagon | Pancreas (a cells) | Hypoglycemia | Promote fat utilization |
| Growth hormone | Anterior pituitary gland | Prolonged Hypoglycemia | Promote fat utilization |
| Cortisol | Adrenal cortex | Prolonged Hypoglycemia | Promote fat utilization |
| Epinephrine | Adrenal medulla | Hypoglycemia / Stress/exercise | Promote fat utilization Lipolytic action+++++Have glycogenolysis + |
Liver also play an important role in controlling blood glucose level
Why blood glucose regulation is
Somatostatin
| Stimulating factors | Effects |
| Increase blood glucoseIncrease amino acidsIncrease fatty acidsIncrease GI hormones released in response to food | Act on islets of Langerhans and depress the secretion of both insulin and glucagon.Decrease the motility of stomach, duodenum and gallbladder.Decrease both the secretion and absorption in GIT |