PANCREAS AND DIABETES Valerija Vrhovnik Anatomy of pancreas

PANCREAS AND DIABETES Valerija Vrhovnik

Anatomy of pancreas • • • head body tail acinar cells islets of Langerhans pancreatic duct

Pancreas: dual-function gland • Exocrine pancreas (acinar cells): • produces digestive enzymes (trypsin, (trypsin chymotrypsin, pancreatic lipase and amylase ) • enzymes help further breakdown of carbohydrates, proteins, and fat

Endocrine pancreas • Islets of Langerhans 4 types of cells: 1) Alpha cells – produce glucagon (hormone); 25% total cells 2) Beta cells – insulin synthesis and secretion; 60% 3) Delta cells – produce somatostatin (inhibits secretion of other hormones); 10% 4) PP cells – secrete pancreatic polypeptide; <5%

Insulin = hormone of feasting • small protein composed of two peptide chains

Insulin effect on metabolism • 1) Carbohydrates: ↑ glucose utilization, ↑ CHO storage, use of CHO for energy • 2) Fats: ↓ use of fat, fat sparer • 3) Proteins: ↑ protein anabolism, inhibits catabolism

Factors Regulating Insulin Secretion 1) High plasma glucose levels – insulin secreted to return glucose levels back to normal 2) High plasma amino acids – after a high protein meal, arginine and lysine stimulate beta cells to increase insulin secretion 3) Fatty acids and ketone bodies – increases secretion

Diabetes mellitus • Type 1 – juvenile diabetes: • loss of insulin-producing beta cells leading to a deficiency of insulin • Type 2 – maturity onset: • insulin resistance - cells fail to use insulin properly • the most common type

Causes: • heredity - stronger inheritance pattern for type 2 • type 1 appears to be triggered by some (mainly viral) infections (e. g. Coxackie virus) • obesity – type 2

Symptoms: 1) Polyuria (excess urine production) 2) Polydipsia (excess drinking of water) 3) Polyphagia (excessive eating) 4) Loss of weight 5) Asthenia (lack of energy)