Regulation Of Heart

Question 1

What are the intrinsic factors of exercise?

Answer 1

1) increased temperature
- causes increased speed of nerve transmission
- stimulates the SA node
- causes HR to increase
2) increased VR
- increase volume of blood returning to the heart
- increase stretch of atrial&ventricular walls (starlings law)
- HR, SV & Q increase

Question 2

What are the 2 extrinsic factors?

Answer 2

1) Neural factors

2) hormonal factors

Question 3

What are neural factors during exercise?

Answer 3

• chemoreceptors, baroreceptors and proprioceptors send information to CCC in brain
• CCC uses sympathetic nervous system to increase firing rate of SA node, causes HR to increase

Question 4

What are hormonal factors during exercise?

Answer 4

• adrenaline is released from adrenal glands
• stimulates sympathetic nervous system which increases firing rate of SA node
• HR increases & adrenaline increase the force of cardiac contractions
• SV & Q increase

Question 5

What are the intrinsic factors during recovery?

Answer 5

• gradual decrease in temperature causing decrease of speed of new transmission
• HR, SV and VR decrease

Question 6

What are neural factors during recovery?

Answer 6

• chemoreceptors, baroreceptors and proprioceptors detect decrease
• information sent to CCC and uses PARAsympathetic nervous system
• decrease in firing rate of SA node causing HR to decrease

Question 7

What are the hormonal factors during recovery?

Answer 7

• release of adrenaline inhibited causing decrease in firing rate of SA node
• HR decreased