Factors Affecting Change In Rate Of Conduction

Question 1

What does it mean when the heart is myogenic?

Answer 1

This means the heart creates its own impulse/heart rate

Question 2

How does the heart creators own impulse?

Answer 2

Heart generates its own impulses from the SAN, but the rate of which the impulses are fired are controlled by the sympathetic and parasympathetic nervous system.

Question 3

What do these receptors detect?

1. Chemoreceptors
2. Baroreceptors
3. Proprioceptors

Answer 3

1. Chemical changes (e.g. Increase Co2)
2. Blood Pressure
3. Skeletal Movement

Question 4

What do these neural control mechanisms do?

1. Sympathetic nervous system
2. Parasympathetic nervous system
3. What do they both act on?

Answer 4

1. Stimulates the heart to beat faster by the release of adrenaline
2. Return heart rate to resting by the vagus nerve/acetylcholine
3. They both act on the SAN to either speed up or slow down heart rate

Question 5

What is the main point of control of the heart?

Answer 5

The heart is controlled by the cardiac control centre (CCC) in the medulla

Question 6

What is stroke volume?

Answer 6

Stroke volume is the amount of blood ejected from the left ventricle per beat

Question 7

What is ejection fraction?

Answer 7

Ejection fraction is the percentage of blood ejected from the left ventricle in one beat