Hormones

Question 1

Where are hormones secreted?

Answer 1

from endocrine glands

Question 2

How is plasma glucose during exercise maintained?

Answer 2

1. mobilization of glucose from liver glycogen stores
2. mobilization of FFA from adipose tissue
3. glucogenesis from AA, lactic acid and glycerol
4. blocking entry of glucose into cells

Question 3

Permissive/slow acting hormones

Answer 3

exert full effect

thyroxine
cortisol
growth hormone

Question 4

Fast-acting hormones

Answer 4

epinephrine
norepinephrine
insulin
glucagon

Question 5

Thyroid hormones

Answer 5

influences the number of receptors on the surface of a cell for other hormones to interact with

affinity of receptor for hormone

no change during exercise

Question 6

T3

Answer 6

enhances effect of epinephrine to mobilize free fatty acids from adipose tissue

Question 7

Growth hormone

Answer 7

essential for growth of all tissues

1. increase AA uptake and protein synthesis
2. reduces use of plasma glucose
3. increases gluconeogenesis
4. mobilizes fatty acids from adipose tissue

Question 8

Changes in GH during exercise

Answer 8

Net effect of GH is to preserve plasma glucose concentrations

Increases gluconeogenesis in liver

Blocks glucose entry to adipose cell tofavourfatmobliization

Increase in plasma GH with increasing intensity

Question 9

Cortisol

Answer 9

steroid hormone derived from cholestrol
secreated from adrenal cortex

Question 10

Cortisol stimulated by

Answer 10

stress via ACTH
exercise

Question 11

When does cortisol peak?

Answer 11

AM

drops throughout the day

Question 12

Cortisol pattern

Answer 12

increase proportional to increase exercise intensity

Question 13

What is the direct effect of cortisol mediated through?

Answer 13

slow process of DNA transcription and translation to protein synthesis

Question 14

What are changes in cortisol related to?

Answer 14

repair of exercise-induced tissue damage rather tham mobilization of fuel

Question 15

Hormonal response to exercise

Answer 15

mobilize fat and CHO
preserve glucose

Question 16

What hormones are elevated with exercise?

Answer 16

GH
glucagon
cortisol
(nor)epinepherine

=favour mobilization FFA

not insulin

Question 17

During heavy exercise

Answer 17

FFA oxidation decreases despite hormonal stimulation

increase glucose use

Question 18

Decrease in FFA oxidation due to

Answer 18

high levels of lactic acid
elevated H+ conc inhibit HSL
inadequate blood flow to adipose tissue
insufficient albium to transport FFA in plasma

Question 19

Impact of endurance training

Answer 19

decrease lactate conc at any fixed work rate = reduce inhibition to FFA mobilization

= use more fat as a fuel, spare limited CHO stores = improve performance

Question 20

Where is catecholamine secreated from?

Answer 20

adrenal medulla

Question 21

Epinephrine/nor

Answer 21

bind to adrenergic response (alpha and beta cells)
fight or flight

Question 22

Effects of epinephrine/nor

Answer 22

increase glycogenolysis
increase lipolysis

Question 23

Plasma E and NE during exercise

Answer 23

fast-acting hormone

increase HR and BP (sympathetic activation)

Question 24

Catecholamine response to exercise

Answer 24

trained individuals = greater capacity to increase C

endurance training = rapid decrease to fixed intensity exercise bout

Question 25

Glycogen depletion during exercise

Answer 25

high-intensity = greater/rapid depletion

Question 26

Plasma epinephrine

Answer 26

powerful simulator of glycogenolysis (via B receptor) greater increase during high intensity exercise

Question 27

Why is there no difference in glycogen depletion plasma E?

Answer 27

Ca++ released (from sarcoplasmic reticulum with muscle contraction) Ca++ ions bind to Calmodulin = activates protein kinase phosphorylase --> glucose --> glycolysis

Question 28

Exocrine

Answer 28

secreted via ducts

Question 29

Endocrine

Answer 29

secreted directly into bloodstream

Question 30

Pancreas

Answer 30

secretes counter-regulatory hormones from islts of Langerhans

Question 31

Insulin

Answer 31

from B cells promotes storage of glucose, AA and fats drives uptake and storage of substrate to lower their levels in plasma

Question 32

Glucagon

Answer 32

from A cells promotes the mobilization of fatty acids and glucose stimulates gluconeogenesis in liver

Question 33

Ratio of glucagon to insulin

Answer 33

control over mobilization of glucose and FFA

Question 34

Changes in insulin during exercise

Answer 34

conc drop by ~50% favour mobilization of glucose from liver and FFA from adipose tissue

Question 35

Changes in glucagon during exercise

Answer 35

endurance training programme = glucagon diminished = no increase during exercise

Question 36

Effect of catecholamine on insulin and glucagon

Answer 36

when glucose constant = SNS can modify hormone secretion endurance training decrease SNS response to a fixed exercise bout

Question 37

Hormone-substrate interaction due to

Answer 37

high levels lactic acid elevated H+ conc inhibits HSL inadequate blood flow to adipose tissue insufficient albium to trasport FFA in plasma = decrease FFA increase glucose use