L16 (Hormonal Control of Plasma Glucose)

Question 1

During exercise, skeletal muscle initially gets its glucose from
A. Hepatic gluconeogenesis
B. Skeletal muscle glycogen
C. Liver glycogen
D. Skeletal muscle gluconeogenesis

Next source of glucose for SM contraction?
A. Hepatic gluconeogenesis
B. Skeletal muscle glycogen
C. Liver glycogen
D. Skeletal muscle gluconeogenesis

Final sources of glucose for SM contraction?
A. Hepatic gluconeogenesis
B. Skeletal muscle glycogen
C. Liver glycogen
D. Skeletal muscle gluconeogenesis

Answer 1

B. Skeletal muscle glycogen
C. Liver glycogen
A. Hepatic gluconeogenesis

Question 2

Plasma concentration of which hormone increases during moderate exercise?
A. Cortisol
B. Epinephrine
C. Glucagon
D. Insulin

Answer 2

B. Epinephrine

Question 3

Epinephrine increases during moderate exercise in response to:
A. Activation of SNS
B. Activation of PNS
C. Increase in plasma cortisol
D. Exocytosis of NE
E. Decrease plasma glucose

Answer 3

A. Activation of SNS

Question 4

Plasma epinephrine promotes all of the following except:
A. Decrease in skeletal muscle uptake
B. Increase in adipose tissue lipolysis
C. Increase in hepatic gluconeogenesis
D. Decrease in alpha-cell glucagon secretion
E. Decrease in beta-cell insulin secretion

Answer 4

D. Decrease in alpha-cell glucagon secretion

Question 5

The insulin to glucagon ratio
______________ during moderate exercise?
A. increases
B. decreases
C. does not change

Answer 5

B. decreases

Question 6

Adipose tissue lipolysis, enhanced by
epinephrine and low __________, supplies
glycerol for ___________ and
fatty acids for ______________:

A. Insulin, hepatic lipogenesis, skeletal
muscle energy
B. Insulin, hepatic gluconeogenesis, skeletal
muscle energy
C. Glucagon, hepatic gluconeogenesis,
adipose tissue energy
D. Glucagon, hepatic lipogenesis, adipose
tissue energy

Answer 6

B. Insulin, hepatic gluconeogenesis, skeletal
muscle energy

Question 7

Of the 3 defenses against hypoglycemia, which one cannot occur in a patient with T1DM?

A. Fall in plasma insulin
B. Increase in plasma glucagon
C. SNS activation to increase plasma
epinephrine

Answer 7

A. Fall in plasma insulin

Question 8

If the patient with T1DM is exercising, which
one of the following is still occurring …and also occurs in persons who do not have diabetes?

A. Fall in plasma insulin
B. Increase in plasma glucagon
C. SNS activation to increase plasma
epinephrine
D. Insulin-independent glucose uptake by
exercising skeletal muscle

Answer 8

D. Insulin-independent glucose uptake by
exercising skeletal muscle

Question 9

Exercise-induced skeletal muscle glucose uptake is ___-independent and can contribute to __glycemia.

Answer 9

insulin; hypo

Question 10

In an exercising patient with T1DM, hepatic
production of glucose remains low during
hypoglycemia because it is suppressed by
A. insulin
B. glucagon
C. epinephrine

Answer 10

A. insulin

Question 11

Which mechanism of glucose uptake by
skeletal muscle is altered the most in patients with T2DM?

A. Insulin-dependent glucose uptake
B. concentration gradient glucose uptake
C. Exercise-dependent glucose uptake

Answer 11

A. Insulin-dependent glucose uptake

Question 12

What two things must be in balance two avoid exercise-induced hypoglycemia?

Answer 12

• Increase in skeletal muscle glucose uptake
• Hepatic glucose production

Question 13

True or False: Exercise-induced skeletal muscle glucose uptake is insulin dependent

Answer 13

False - Exercise-induced skeletal muscle glucose uptake is insulin INDEPENDENT

Question 14

Three ways to protect against hypoglycemia?

Answer 14

1) Lower plasma insulin
2) Increase plasma glucagon
3) Activate SNS to increase Epi

Question 15

How will lowering plasma insulin affect:
- plasma glucose
- SNS activation
- plasma epinephrine

Answer 15

• LOWERING of plasma glucose
• SNS activation (NE on a2)
• ELEVATION of plasma epinephrine (EPI on a2)

Question 16

How will increasing plasma glucagon affect
- plasma glucose
- activation of SNS
- plasma epi

Answer 16

-LOWER plasma glucose
-SNS activation (NE on B2)
-ELEVATION of plasma epi (Epi on B2)

Question 17

True or False: Epinephrine SUPPRESSES insulin-stimulated glucose uptake in skeletal muscle

Answer 17

True

Question 18

True or False: both Insulin and EPI stimulate lipolysis

Answer 18

True

Question 19

True or False: In T1DM, a lower threshold of plasma glucose is required for SNS activation

Answer 19

True

Question 20

What are three reasons that T2DM patients often DO NOT experience exercise-induced hypoglycemia?

Answer 20

1) Beta-cell insulin secretion can DECREASE in response to lower glucose
2) Insulin-dependent skeletal muscle glucose uptake is inefficient (insulin resistance)
3) Hepatic glucose production can increase (insulin resistance)