PancreasPancreas• Pancreas is a glandular organ located

beneath the stomach in the abdominal cavity.

• Connected to the small intestine at the duodenum.

• Functions of pancreas : - secretes digestive enzymes (exocrine) - produces hormones i.e. insulin, glucagon, somatostatin (endocrin)• Digestive enzymes is for digestion, to

break down carbohydrates, protein and fat.

• Insulin and glucagon to regulate level of glucose in blood.

PancreasPancreas

PancreasPancreasPancreatic Islets• Hormone-producing tissue.• Also known as Islets of Langerhans.• Two important hormones produced : - insulin - glucagon• Insulin released from beta cells.• In beta cells, insulin synthesized from proinsulin precursor

molecule by the action of proteolytic enzymes.• High levels of glucose stimulate the release of insulin.Insulin• Helps the process of glucose uptake from blood by cells.• Glucose oxidized for energy inside cells or converted to

glycogen for storage in liver.• Low insulin results in less glucose used for energy in cells,

fat will be used instead.

PancreasPancreas

PancreasPancreasDiabetes Mellitus• Without insulin, glucose level in blood rise. • Normal range is 80-120 mg/dl.• In case of high level of glucose in blood, glucose will spill

into urine because kidney tubule cells cannot reabsorb it fast enough.

• As glucose flushes from the body, water follows, leading to dehydration.

• The name for this condition is diabetes mellitus.• Since there is no insulin to help glucose uptake by cells,

fats and proteins are used to meet energy requirement.• Thus, body weight begins to decline.• Loss of proteins leads to decreased ability to fight

infections.• If large amount of fats used for energy, blood becomes

acidic and ketones appear in blood.• This condition is called ketosis.

PancreasPancreas• Hyperglycemia is the term for accumulation of glucose in

blood.• Spillover of glucose into urine is called glycosuria.• Signs of diabetes mellitus : - polyuria : excessive urination to flush out glucose and ketones. - polydipsia : excessive thirst resulting from water loss. - polyphagia : hunger due to inability to use sugars, loss of fat and protein.Type II diabetes• Insulin is produced but insulin receptors unable to respond,

this condition is called insulin resistance.• In this case, normal amount of insulin is inadequate to

produce normal insulin response from fat, muscle and liver cells.

• Treated with diets or oral hypoglycemic medications i.e. anti-diabetic drugs.

• Less tendency to keto-acidosis.

PancreasPancreasType I diabetes• More severe. • Permanent destruction of beta cells.• Can lead to diabetic coma or diabetic keta-acidosis which

canbe fatal.• Insulin replacement for therapy.• Insulin infused continuously for treatment.• Usually by using insulin pump.Glucagon• Regulate blood glucose level but in a way opposite to

insulin.• Released by alpha cells.• Stimulated by low blood level of glucose.• Glycogen stored in the liver is break down to glucose.• Glucose produced is releaser in the blood.

PancreasPancreasRegulation of blood glucose levels by negative

feedback mechanism • When glucose level in blood rise, it will stimulate secretion

of insulin.• Beta cells in pancreas activated and insulin produced.• Insulin released into the blood.• Uptake of glucose from blood is then enhanced in most

body cells.• Liver takes up glucose and stores it as glycogen.• Blood glucose level decline to normal and stimulus for

insulin release diminishes.• When glucose level in blood decline, it will stimulate

secretion of glucagon.• Alpha cells in pancreas activated and glucagon produced.• The target is liver.• Liver breaks down glycogen stored in it to glucose.• Glucose released into the blood.• Rising blood glucose level return blood sugar to normal.• Stimulus for glucagon release diminishes.