The alpha cells are usually present towards the periphery of the islet, and the beta cells are usually located towards the middle of the islet. The delta cells and F-cells are found scatteredand secrete somatostatin and pancreatic polypeptides, respectively.
3. Somatostatin (SS) - It is secreted by the delta cells of the islet.
4. Pancreatic polypeptide (PP) - It is secreted by the F-cells or PP cells of the islet.
- Insulin converts glucose to glycogen which is stored in the liver and skeletal muscles.
- It promotes the transport of glucose into the cells.
- Insulin promotes the synthesis of protein from amino acids in tissues.
- It decreases the concentration of glucose in the blood.
- It increases the synthesis of fat in the adipose tissues.
- Glucagon helps in the breakdown of glycogen to glucose in the liver.
- Glucagon increases blood glucose levels.
- Increase in blood glucose levels above the normal range (Hyperglycemia).
- Excretion of the excess glucose in the urine (Glycosuria).
- Frequent urination (Polyuria) and dehydration of body tissues.
- Excessive thirst (Polydipsia).
- Degradation of fat increases, producing ketone bodies (ketosis).
- Increase in appetite (Polyphagia).