Neural Control

Question 1

1) What are the receptors and what do they do normally?

What do they do at exercise?
What do they at recovery?

Answer 1

1. Chemoreceptors - detect change in CO2/pH/acidity
2. Baroreceptors - detect change in blood pressure
3. Proprioceptors - detect change in movement
4. Thermoreceptors - detect change in temperature

At exercise - Detect an increase in CO2, decrease in pH and increase in acidity, increase in temperature and increase in movement, increase in blood pressure

At recovery - Detect an decrease in CO2, increase in pH and decrease in acidity, decrease in temperature, decrease in movement, decrease in blood pressure

Question 2

2) Receptors send info to

Answer 2

1. CCC (in the medulla oblongata)
2. VCC (in the medulla oblongata)
3. RCC (in the medulla oblongata)

Question 3

3) Impact on heart rate (CCC)

At exercise vs in recovery

Answer 3

Information is sent to here

At exercise:

a) sympathetic system nerve sends an impulse
b) via cardioaccelatory nerve
c) received by SA node
d) result is SA node increased firing rate causing the heart rate to increase

In recovery:

a) parasympathetic nervous system sends an impulse
b) via cardio inhibitory nerve
c) received by SA node
d) result is SA node decreased firing rate causing the heart rate to decrease

Question 4

4) Impact on respiration rates (RCC)

Answer 4

Info sent to here both ICC + ECC (operating during exercise)

a) ICC - uses two nerves:

        - phrenic nerve (which contracts the diaphragm)
        - intercoastal nerve (which contracts the external intercostals)

which results in an increase in breathing frequency

b) ECC - recruits the additional muscles (internal intercostals, rectus abdominis, external obliques)

results in an increased depth of breathing

Question 5

5) Impact of vascular shunt - VCC

Answer 5

Info is sent here for redistribution of blood

Vasodilation:

a) arteries/arterioles widen at the working muscles
b) pre-capillary sphincters open
c) results in increased delivery of oxygenated blood (80%)

Vasoconstriction:

a) arteries/arterioles narrow at the non-essential organs
b) pre-capillary sphincters close
c) results in decreased blood flow to non-essential organs (20%)