Regulating Blood Sugar

10.3

Islets of Langerhans

• groups of cells in the pancreas

• beta cells produce insulin

• alpha cells produce glucagon

Regulation of Blood Sugar

Insulin

• released when blood sugar is HIGH

• inhibits breakdown of glycogen in liver

• promotes fatty acid uptake in adipose tissue & inhibits breakdown of fats

• promotes protein synthesis & inhibits protein breakdown

Glucagon

• released when blood sugar is LOW

• stimulates breakdown of glycogen into glucose in liver

• promotes breakdown of fats and proteins into fatty acids and amino acids

Adrenal Glands

• adrenal cortex produces 3 different types of hormones, including glucocorticoids

Glucocorticoids

• low blood glucose level & elevated level of epinephrine cause the hypothalamus to secrete ACTH

• ACTH stimulates adrenal cortex to release glucocorticoids

Glucocorticoids

• stimulate synthesis of glucose from fats & proteins

• reduce glucose uptake by body cells except in central nervous system

• promote breakdown of fats & proteins to provide alternative energy source

Imbalance

• if blood glucose level is too high it can cause a condition called hyperglycemia

• if blood glucose level is too low it can cause a condition called hypoglycemia

Diabetes Mellitus

• hyperglycemia due to problems with insulin production and/or action

Classic symptoms of diabetes:

• frequent urination

• increased thirst

• increased appetite

Type 1 Diabetes

• beta cells in pancreas cannot produce insulin

• begins in infancy

• treatment is daily administration of insulin

Type 2 Diabetes

• reduced production of insulin and/or the inability to bind to its receptors properly

• usually develops in adulthood, strong genetic link & association with obesity

• treatment is controlled diet & exercise and sometimes oral medications

Gestational Diabetes

• develops in some women during pregnancy

• can increase risk of future development of diabetes in mother and/or child