Regulation Of BP

Question 1

What is blood pressure?

Answer 1

Force exerted by blood on the inner walls of blood vessels

Question 2

What 3 components influence BP?

Answer 2

1) heart activity
2) blood volume and viscosity
3) blood vessels (diameter of arteriolar)

Question 3

What is the blood pressure equation?

Answer 3

BP = cardiac output x total peripheral resistance

Question 4

What is cardiac output?

Answer 4

Total volume of blood pumped out of the ventricle during a minute

Question 5

What is the cardiac output equation?

Answer 5

Cardiac output = heart rate x stroke volume

Question 6

What is Peripheral resistance?

Answer 6

The resistance to blood flow which is mainly created by the diameter of blood vessels in the periphery

Question 7

What 3 factors influence BP?

Answer 7

1) cardiac output
2) Peripheral resistance
3) blood volume

Question 8

What centres control short-term BP regulation?

Answer 8

Cardiac centre and vasomotor centre

Both located in medulla part of brain stem

Question 9

What are baroreceptors?

Answer 9

Specialised receptors found in aortic arch and internal carotid arteries

Send nerve impulses to adjust heart activity and Peripheral resistance to maintain BP within usual limits

Pressure sensitive receptors- mechanoreceptors- detect changes in stretch in artery walls due to BP changes and send signals to both centres

Question 10

What is the response to a fall in BP in the cardiac centre?

Answer 10

1) less stretch detected by baroreceptors
2) fewer impulses sent to cardiac centre
3) excites sympathetic impulses but parasympathetic impulses inhibited
4) SAN excited
5) HR increases
6) cardiac output increases
7) BP increases

Question 11

What is the response to fall in BP in the vasomotor centre?

Answer 11

1) less stretch detected by baroreceptors
2) fewer impulses to vasomotor centre
3) excites sympathetic impulses
4) smooth muscle in arterioles constricts
5) vasoconstriction
6) Peripheral resistance increases
7) BP increases