L4 Hormonal Response to Exercise

Question 1

What is the endocrine system ?

Answer 1

consists of a host organ, chemical messengers and a target/receptor organ.
endocrine glands release hormones directly into the blood

Question 2

what are the 2 mechanisms in which hormones can alter target cell reactions, activate cells + alter enzyme activity?

Answer 2

1. Activation of enzymes

2. Modulation of gene expression

Question 3

what are 4 factors that determine the concentration of a hormone in the blood

Answer 3

1. Quantity synthesised in host endocrine gland
2. rate of excretion of hormone
3. Quantity of transport proteins
4. Changes in plasma volume

Question 4

Discuss factors that influence the magnitude of effect that a hormone has on a target tissue

Answer 4

1. concentration of hormone
2. Number of target receptors on the cell
3. Affinity of receptor for the hormone

Question 5

List 4 mechanisms by which hormones modify cellular activity

Answer 5

1. alter membrane transport eg insulin
2. Alter the rate of intracellular protein synthesis by stimulating nuclear DNA - eg steroid hormones
3. Activate second messengers via G protein - eg cyclic AMP
4. Modulating enzyme activity eg tyrosine kinase

Question 6

Identify the Site of Release, Stimulus for Response and Actions for Adrenaline

Answer 6

1. Medulla of the adrenal glands
2. Stressful events. Fight of flight response
3. Increased HR and vasodilation. Glycogenolysis

Question 7

Identify the Site of Release, Stimulus for Response and Actions for Noradrenaline

Answer 7

1. Adrenal Glands
2. Stress. Fight or Flight
3. Increase vasoconstriction. Decreased HR and Glycogenolysis

Question 8

Identify the Site of Release, Stimulus for Response and Actions for Aldosterone

Answer 8

1. Adrenal cortex
2. Decrease in blood pressure
3. Increases plasma volume from exercise

Question 9

Identify the Site of Release, Stimulus for Response and Actions for Growth Hormone

Answer 9

1. Pituitary Gland
2. Sleep
3. Stimulates the release of insulin-like growth factor

Question 10

Identify the Site of Release, Stimulus for Response and Actions for Testosterone

Answer 10

1. Testes
2. Lutinizing hormones
3. Promotes tissue building and masculine characteristics

Question 11

Why might ADH and aldosterone concentrations be altered in exercise?

Answer 11

For the control of sodium reabsorption at the kidneys. They regulate blood volume and blood pressure and stops blood from becoming too viscous

Question 12

What is the relationship between exercise intensity and plasma catecholamine concentrations?

Answer 12

As exercise intensity increases, catecholamine concs increase. Noradrenaline begins at a higher conc.

l X
l /
l X X
l / /
l X ——-X X
l X ——-X /
l________________________
25% 50% 75% 100% of VO2 max
Top line = noradrenaline

Question 13

How may exercise training change plasma catecholamine concentrations elicited by a given ‘relative’ and ‘absolute’ workload

Answer 13

Absolute –> adaptation = less catecholamines released over time
Relative –> more adapted individuals produce more catecholamines at a similar relative workload to an untrained individual