15 - Endocrine functions of the pancreas hormones physiological effects and control of secretion. Diseases of the endocrine pancreas.

section

classification of pancreas

4 major cells found in islets of langerhan

function of pancreas

glucagon

insulin

based on negative feedback

diseases of endocrine pancreas

classification of pancreas

• pancreas an organ that can be classed as endocrine and exocrine gland

• hormone producing endocrine gland

4 major cells found in islets of langerhan

1. alpha cells -secrete the hormone glucagon; -regulation of carbohydrate metabolism.

2. beta cells -secrete the hormone insulin

3. delta cells that secrete somatostatin

4. F-cells(PP cells) that secrete pancreatic polypeptide- under cholinergic control, increased during food, inhibited by P

function of pancreas

Blood glucose levels must be maintained so that there is enough glucose to supply to the metabolic active cells that there is not too much for the kidneys to be damaged

glucagon

• Acts to Increase blood sugar level

• stimulates the breakdown of glycogen to glucose- for homeostasis and gluconeogenesis

• promoting the conversion in the liver of other nutrients, such as amino acids and lactic acids, into glucose

• stimulating the release of glucose from the liver into the blood.

insulin

• acts to decrease blood sugar level- glycolysis

• Stimulates uptake of glucose by liver, muscle and adipose cells.

• Stimulates glycogen synthesis in liver and muscles.

• Stimulates lipogenesis in adipose tissue—glucose levels fall back to norm. The control of secretion is accomplished by the ANS and endocrine system

• Insufficient production of insulin or production of abnormal insulin can cause?

• Diabetes mellitus.

  • The blood glucose is above the normal ranges (3.7 - 5.6 mmol/L).

  • Type 1- insufficient insulin

  • Type 2 -insulin resistance

  • Poor wound healing- weakened immunity, poor blood clotting, less o2 reacess, damage nerves

  • Diabetic ketoacidosis Renal failure

  • The pancreas is controlled by both the autonomic nervous system (ANS) and the endocrine system.

  • Parasympathetic nerves - relaxation e.g. digestion after a meals during digestion stimulate the release of insulin via negative feedback mechanism.

diseases of endocrine pancreas

• Hypoglycaemia-caused by abnormally low levels of glucose in blood

• Hyperglycaemia- abnormally high levels of glucose