Adult 354 Final Exam Study Guide
Module 1: Chapter 20
● Pathophysiology of glucose homeostasis and diabetes mellitus,
Pathophysiology of glucose
... [Show More] homeostasis and diabetes mellitus, LeMone pp. 502-504.
o DM is a group of chronic disorders of the endocrine pancreas
▪ Characterized by inappropriate hyperglycemia caused by a relative or absolute deficiency of insulin or by cellular
resistance to the action of insulin.
o Type I DM: result of pancreatic islet cell destruction and a total deficit of circulating insulin.
o Type II DM: results from insulin resistance with a defect in compensatory insulin secretion.
o A person with DM is 2-4 times more likely to have heart disease and a stroke
o DM is the leading cause of ESRD and blindness
● Pancreatic Hormones:
o The hormones that are produced by different cells of the pancreas and the small intestine are responsible for glucose
homeostasis.
o Alpha cells produce the hormone glucagon which stimulates breakdown of glycogen in the liver (glycogenolysis), the
formation of carbohydrates in the liver (gluconeogenesis), and breakdown of lipids in the liver and adipose tissue
▪ Through glycogenolysis and gluconeogenesis, glucagon prevents blood glucose from decreasing when the body
is fasting or in between meals
▪ Glucagon decreases glucose oxidation and increases blood glucose levels
o Beta cells secrete the hormone insulin which facilitates the movement of glucose across cell membranes into cells,
decreasing glucose levels.
▪ After secretion of insulin from the beta cells, the insulin enters the circulation and travels directly to the liver
▪ Circulating insulin rapidly binds to receptors on peripheral tissue (muscle and fat cells) or is destroyed by the
liver or kidneys
▪ Insulin is released when blood glucose levels are increased and vice versa
▪ Amylin is a hormone also released by beta cells that that impairs glucagon secretion and slows the rate of which
glucose travels to the small intestine for absorption after meals.
o Delta cells produce somatostatin which acts within the islets of Langerhans to inhibit the production of both glucagon
and insulin
▪ Slows GI motility which allows for more time for food to be absorbed.
● Glucose Homeostasis:
o All body tissues and organs require a constant supply of glucose however, not all tissues require insulin for glucose
uptake
▪ The brain, liver, intestines, and renal tubules do not require insulin to transfer glucose into their cells
▪ Skeletal muscle, cardiac muscle, and adipose tissue do require insulin for glucose movement into the cells
o Increased blood glucose levels, amino acids, and fatty acids stimulate pancreatic beta cells to produce insulin...CONTINUED** [Show Less]