heart rate Flashcards
1
Q
how is a change in pH detected?
A
chemoreceptors located in the aorta, carotid artery and medulla oblongata
2
Q
how is pH responded to during times of high respiratory rate?
A
- CO2 and lactic acid produced
- must be removed to prevent enzymes denaturing
- by increasing heart rate so CO2 can diffuse out
- so the response decreases pH
3
Q
increase in CO2
A
low pH so heart rate increases
4
Q
decrease in CO2
A
high pH so heart rate decreases
5
Q
what 2 centres does the medulla oblongata contain?
A
- cardioaccelerator
- cardiovascular
6
Q
describe the cardioaccelerator system
A
- sends impulses down accelerator (sympathetic) nerve
- increases heart rate
7
Q
describe the cardiovascular system
A
- sends impulses down vagus (parasympathetic) nerve
- decreases heart rate
8
Q
how is change in pressure detected?
A
baroreceptors located in the aorta, carotid artery & vena cava
9
Q
how is high blood pressure responded to?
A
- arterial walls can be damaged
- so this results in more impulses via the parasympathetic nervous system
- decreases heart rate
10
Q
how is low blood pressure responded to?
A
- insufficient supply of oxygenated blood to respiring cells
- so this results in more impulses via the sympathetic nervous system
- increases heart rate
