1. Heart rate response to exercise Cardiac control centre
Understand how exercise effects the heart rate
Know what the cardiovascular drift is.
Understand how the heart is controlled.

2. Cardiac control centreSA
Sympathetic nervous system
Increases heart rate and SV
Via accelerator nerve
Cardiac control centre
Parasympathetic nervous system
Decreases the heart rate.
Via Vagus nerve

3. Heart regulation during exercise
Rule of three two one.
3 Neural factors
2 Intrinsic factors
1 Hormonal

4. 1 Hormonal Adrenalin From adrenal glands
Stimulates the SA node directly via blood.
This increases the heart rate as well as the stroke volume.

5. 2 Intrinsic Temperature
Increase in temperature which speeds up the nerve impulse, which in turn speeds up the heart rate.
Venous return
Increase in SV (staling’s law)
Increase in HR and SV

6. 3 Neural Baroreceptors Baro = pressure
Increase in blood pressure = decrease in HR but is neutralised due to demand of 02.
Chemoreceptors Chemo = Chemical
In muscle aorta and carotid arteries
Decrease in PH
Increase in pp Co2
Decrease in pp O2
Proprioceptors
Muscle spindles, joint receptors
Increase in motor activity = increase in HR and SV