Pancreas

Question 1

What hormones does the pancreas secrete?

Answer 1

insulin (from beta cells)
glucagon (from alpha cells)
somatotropin (from delta cells)

Question 2

What stimulates insulin secretion?

Answer 2

increased blood glucose concentration

sight and taste of food

Question 3

Model of insulin secretion

Answer 3

glucose transported into beta cell - membrane depolarization - influx of extra-cellular calcium - increase in intracellular calcium triggers exocytosis of insulin

Question 4

Function of insulin

Answer 4

acts on cells throughout the body to stimulate uptake, utilization, and storage of glucose
promotes formation of glycogen from glucose in the liver and muscles
inhibits gluconeogenesis
decreases blood fatty acid and ketoacid concentration
increases storage of fatty acids
stimulates fat deposition and inhibits lipolysis
decreases blood amino acid concentration
increases tissue uptake of amino acids and proteins
increases protein synthesis
inhibits protein degradation

Question 5

How do cells take up insulin?

Answer 5

via the GLUT4 receptor

Question 6

Insulin stimulates the liver to store glucose as glycogen by doing what?

Answer 6

activating hexokinase which phosphorylates glucose, trapping it in the cell
activating several enzymes needed to make glycogen

Question 7

What happens when insulin is absent?

Answer 7

cell cannot take up glucose so they switch to using alternative fuels
glycogen synthesis stops, glycogen breakdown activated
glucagon secreted by alpha cells once glucose levels fall

Question 8

Characteristics of diabetes mellitus type I

Answer 8

caused by deficiency of insulin
increased blood glucose concentration
increased blood fatty acid and ketoacid concentration
increased blood amino acid concentration
loss of lean body mass
loss of adipose tissue

Question 9

Characteristics of diabetes mellitus type II

Answer 9

caused by inability of target tissues to respond to insulin
increased catabolic processes
hyperglycemia
cannot store food as glycogen, fat, and protein

Question 10

Functions of glucagon

Answer 10

stimulates breakdown of glycogen stores in the liver
activates hepatic gluconeogenesis
increases blood fatty acid and ketoacid concentration

Question 11

What does somatostatin inhibit?

Answer 11

GH secretion
insulin
glucagon
GI hormones