Lecture 5 - Hormones and Exercise

Question 1

What are the metabolic actions of insulin?

Answer 1

Increases muscle glucose uptake

Activates glycogen synthase

Inhibits liver glucose production

Inhibits Lipolysis

Question 2

What are the metabolic actions of glucagon?

Answer 2

Stimulates liver glycogenolysis

Increases activity of gluconeogensis enzymes in liver

stimulates lipolysis

Question 3

plasma insulin levels ___ during exercise

Answer 3

fall

Question 4

glucagon really responds to a fall in ____

Answer 4

Glucose

Question 5

Increases in sympathetic activity during exercise inhibits…

Answer 5

the release of insulin from the pancreas

Question 6

A single bout of exercise increases insulin…

Answer 6

sensitivity

Question 7

Glycogen synthase…

Answer 7

promotes the storage of glucose as glycogen

Question 8

What are the effects of training on distal insulin signalling

Answer 8

Greater insulin response when trained

increase in GLUT 4 expression

increase in Hexokinase, glycogen synthase - glucose metabolism up

muscle oxidative capacity

increase in muscle blood flow - vasodilation is higher in trained state

increase incapillary density / recruitment - more of them

(there will be higher muscle glycogen levels at rest because of these adaptations)

Question 9

What are the metabolic actions of adrenaline:

Answer 9

Increases muscle glycogenolysis (beta2 receptor)

Enhanced liver glucose output (not sure which receptor)

Stimulates lipolysis (beta1 + beta2 ?)

Question 10

An increase in the plasma levels of adrenaline is a sign of…

Answer 10

exercise intensity - not all of the adrenaline is re-uptaked

reflects the increase sympathetic nerve activity

Question 11

Sympathetic impact on the adrenal medulla causes…

Answer 11

release of adrenaline

Question 12

The longer the duration of exercise the more progressive rise in …

Answer 12

adrenaline

Question 13

What are the situations in which Sympathoadrenal activity increase?

Answer 13

increases in exercise intensity

increases over time, at a given intensity

Question 14

Why does Sympathoadrenal activity increase over time?

Answer 14

you get hotter, blood glucose goes down all of which activates it

Question 15

What are the metabolic actions of cortisol?

Answer 15

Decreases muscle glucose uptake

Increases muscle proteolysis (breakdown)

Increases gluconeogenesis and liver glycogen synthesis

Increases lipolysis

Question 16

cortisol can be an indicator of…

Answer 16

over-training

Question 17

What are the metabolic actions of growth hormone in exercise?

Answer 17

Increases production of IGF (insulin growth factors - effects connective tissue formulation)

Decreases muscle glucose uptake (spares it for the brain)

Increases gluconeogenesis

Increases lipolysis

Increases AA uptake and protein synthesis

Question 18

How do working muscles and motor CNS centers send impulses to regulate hormonal response to exercise?

Which hormones are release?

Answer 18

There is an increase in sympathoadrenal activity
(decrease insulin, increases renin/gastrin)

Hormones: GH, ACTH, PRK, TSH released (from pituitary)

Question 19

Myokines are released from …

Answer 19

contracting muscle - acts as an endocrine organ