Question

Enlist the hormones secreted by the pancreas. Explain the functions and regulation of the secretion of insulin.

Answer 1

Following hormones are secreted by pancreas:-

1. Insulin
2. Glucagon
3. Somatostatin.

Insulin is an anti glycemic hormone i.e. it decreases blood glucose level. Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue) and enhances cellular glucose uptake and utilisation. As a result, there is a rapid movement of glucose from the blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia). Insulin also stimulates the conversion of glucose to glycogen (glycogenesis) in the target cells.

The pancreas produces hormones in its 'endocrine' cells. These cells are gathered in clusters known as islets of Langerhans. These cells monitor what is happening in the blood so that they can release hormones directly into the blood when necessary. In particular, they sense when sugar (glucose) levels in the blood rise, and as soon as this happens the cells produce hormones, particularly insulin. Insulin then helps the body to lower blood glucose levels and 'store' the sugar away in fat, muscle, liver and other body tissues where it can be used for energy when required.