Anatomy and Embryology III

Question 1

What do the alpha cells of the islets of langerhans secrete?

Answer 1

Glucagon (p.287)

Question 2

What do the beta cells of the islets of langerhans secrete?

Answer 2

Insulin (p.287)

Question 3

What do the delta cells of the islets of langerhans secrete?

Answer 3

Somatostain (p.287)

Question 4

Describe the arrangement of alpha, beta, and delta cells of the islets of langerhans.

Answer 4

Alpha cells are periphera, beta cells are central, and delta cells are interspersed (p.287)

Question 5

Describe the process of insulin secretion.

Answer 5

ATP generate by glucose metabolism closes K+ channels and depolarizes beta cell membranes. This opens voltage gated Ca2+ channels. Ca2+ influx stimulates insulin secretion (p.288)

Question 6

Does insulin cross the placenta?

Answer 6

No (p.288)

Question 7

What tissues rely on insulin-independent glucose uptake?

Answer 7

Brain, RBCs, Intestine, Cornea, Kidney, Liver (BRICK L) (p.288)

Question 8

Where are GLUT-1 transporters located?

Answer 8

RBCs, brain (p.288)

Question 9

Where are GLUT-2 transporters located?

Answer 9

Beta islet cells, liver, kidney, small intestine (p.288)

Question 10

Where are GLUT-4 transporters located?

Answer 10

Adipose tissue, skeletal muscle (p.288)

Question 11

Which GLUT transporter is insulin independent?

Answer 11

GLUT-1 (p.288)

Question 12

Which GLUT transporter is insulin dependent?

Answer 12

GLUT-4 (p.288)

Question 13

Which GLUT transporter is bidirectional?

Answer 13

GLUT-2 (p.288)

Question 14

What are the seven anabolic effects of insulin?

Answer 14

1.) increase glucose transport in skeletal muscle and adipose; 2.) increase glycogen synthesis and storage; 3.) increase triglyceride synthesis and storage; 4.) increase sodium retention (kidneys); 5.) increase protein synthesis (muscles); 6.) increase cellular uptake of K+ and amino acids; 7.) decrease glucagon release (p.288)

Question 15

What three factors increase insulin secretion?

Answer 15

Hyperglycemia, GH, and B2 antagonists (p.288)

Question 16

What three factors decrease insulin secretion?

Answer 16

Hypoglycemia, somatostatin, and a2 agonists

Question 17

What two tissues depend on insulin for increased glucose uptake?

Answer 17

Adipose tissue, resting skeletal muscle (p.288)

Question 18

What two tissues are independent of insulin for glucose uptake?

Answer 18

Brain, RBCs (p.288)

Question 19

What energy form does the brain use in states of starvation?

Answer 19

Ketones (p.288)

Question 20

Why are RBCs always dependent on glucose for energy?

Answer 20

Because they have no mitochondria for aerobic metabolism (p.288)

Question 21

What are the two catabolic effects of glucagon?

Answer 21

Glycogenolysis and gluconeogenesis, lipolysis and ketone production (p.289)

Question 22

What three factors inhibit glucagon release?

Answer 22

Insulin, hyperglycemia, somatostatin (p.289)