CVS

Question 1

What is the ‘driving force’?

Hint: It is a change in pressure

Answer 1

The change in pressure between the MBP (mean blood pressure) and the pressure in the right atrium

Question 2

What is the formula for change in pressure?

Answer 2

ΔP=CO × R

Question 3

What is the total blood flow at rest?

Answer 3

5l.min^-1

Question 4

What is the formula for flow?

Answer 4

Flow=ΔP/Resistance and Flow=Velocity × CSA

Question 5

Poiseuille’s equation shows us that…

Answer 5

A change in radius of a blood vessel has a significant effect on resistance which has a large effect on perfusion

Question 6

What is the formula for arterial blood pressure?

Answer 6

ABP=CO × TPR

Question 7

What is the Windkessel effect?

Answer 7

Pulsatility is dampened in elastic arteries to maintain a continuous flow

Question 8

Which blood vessel is the source of toral peripheral resistance (TPR)?

Answer 8

Arterioles

Question 9

Between the pulmonary and systemic circulations, which has higher resistance?

Answer 9

The systemic circulation

Question 10

What is the formula for pulse pressure?

Answer 10

PP=systolic blood pressure - diastolic blood pressure

PP = SBP - DBP

Question 11

What is the formula for mean arterial pressure?

Answer 11

MAP = DBP + (SBP - DBP)/3

Question 12

Pulse pressure is determined by?

Answer 12

The volume of blood ejected and compliance of arterial vasculature

Question 13

What effect does ageing have on the compliance of arterial vasculature?

Answer 13

It becomes less compliant

Question 14

What is does ‘pulse’ mean?

Answer 14

The shockwave that arrives slightly before the blood itself.

Question 15

Systolic blood pressure is determined by?

Answer 15

Stroke volume and compliance

Question 16

Which blood vessel is the most compliant?

Answer 16

The aorta

Question 17

Diastolic blood pressure is determined by?

Answer 17

TPR and heart rate

Question 18

Is blood pressure higher above or below the heart? Why?

Answer 18

Below. Because of gravity

Question 19

What is postural hypotension? What is another name for it?

Answer 19

The drop in blood pressure experienced when you stand up after lying or sitting down. Orthostatic hypotension

Question 20

Does an increase in heart rate decrease or increase DBP?

Answer 20

Increase

Question 21

What are the factors affecting diffusion?

Answer 21

1. Area available for diffusion - capillary density
2. Concentration gradient - dependent on rate of use by tissue and rate of blood flow
3. Diffusion resistance

Question 22

Name the subclasses of capillaries in order of permeability

Answer 22

Continuous, Fenestrated and Sinusoidal (Discontinuous)

Question 23

In which part of the mediastinum does the heart lie?

Answer 23

The middle mediastinum

Question 24

Which parts of pericardium receive sensory innervation from the phrenic nerves?

Answer 24

The fibrous pericardium and the parietal serous pericardium

Question 25

Which parasympathetic nerves supply the heart?

Answer 25

The vagus nerves

Question 26

Which nerves supply motor innervation to the diaphragm?

Answer 26

The phrenic nerves

Question 27

Which nerves run parallel to the vagus nerves?

Answer 27

The phrenic nerves

Question 28

What blood vessel does the right phrenic nerve follow?

Answer 28

The superior vena cava