Lecture 19: Physiology of Liver and Pancreas

Question 1

Which of the following is true regarding liver vascular supply?

A. Liver has high blood flow and low vascular resistance
B. Liver has high blood flow and high vascular resistance
C. Liver has low blood flow and high vascular resistance
D. Liver has low blood flow and low vascular resisance

Answer 1

A. Liver has high blood flow and low vascular resistance

Question 2

How does cirrhosis of the liver affect vascular function?

Answer 2

Cirrhosis increases blood resistance to blood flow

Question 3

How does a clot blocking the portal vein affect vascular function?

Answer 3

Causes backflow of blood, leading to increase in capillary pressure in intestinal wall –> loss of fluid –> death

Question 4

Higher than normal pressure in the hepatic veins results in:

A. cirrhosis
B. ascites
C. blood clots
D. cardiac failure

Answer 4

B. ascites

Question 5

Where is bile produced?

Answer 5

Liver

Question 6

List the steps of bilirubin formation

Answer 6

Hb phagocytized by macrophages, split into globin/heme, heme ring opened to free Fe, heme transported in blood by transferrin, pyrrole nuclei formed, heme converted by heme oxygenase into biliverdin, biliverdin converted to bilirubin

Question 7

What is the fate of conjugated bilirubin?

Answer 7

Secreted into intestine by active transport or excreted in urine

Question 8

Jaundice

Answer 8

Yellowish tint to body tissues caused bu excess bilirubin in extracellular fluids; caused by hemolysis and obstruction to bile ducts/damage to liver

Question 9

Alpha islet cells

Answer 9

Secrete glucagon; 25% total pancreatic islet cells

Question 10

Beta islet cells

Answer 10

Secrete insulin/amylin; 60% total pancreatic islet cells

Insulin inhibits glucagon, amylin inhibits insulin

Question 11

Delta islet cells

Answer 11

Secrete somatostatin; inhibits insulin, glucagon, gastrin

Question 12

What is the effect of insulin on muscle cells?

Answer 12

Increases concentration of glucose inside muscle cells

Question 13

What causes the liver to release glucose into the blood?

Answer 13

Decreased blood glucose leading to lack of insulin secretion

Question 14

How does insulin effect fat storage?

Answer 14

Promotes conversion of excess glucose into fatty acids and decreases utilization of fat

Question 15

How does lack of insulin effect fat storage?

Answer 15

Glycerol and fatty acids are released into blood, ketone bodies in blood increase

Question 16

What is the major effect of glucagon?

Answer 16

Increases blood glucose by breaking down liver glycogen and increasing gluconeogenesis

Question 17

What is the major regulator of glucagon secretion?

Answer 17

Blood glucose concentration

Question 18

What are the major effects of somatostatin?

Answer 18

Inhibits secretion of insulin/glucagon/gastrin, decreases motility of stomach/duodenum/gallbladder, decreases secretion/absorption of GI tract

Question 19

Type I Diabetes

Answer 19

Due to lack of insulin secretion, injury of beta cells

Question 20

Type II Diabetes

Answer 20

Due to insulin resistance, obesity major risk factor, preceded by metabolic syndrome

Question 21

Which of the following is not a factor in metabolic syndrome?

A. Obesity
B. Insulin resistance
C. Peripheral neuropathy
D. Increased lipid triglycerides

Answer 21

C. Peripheral neuropathy