Cardiovascular System

Question 1

What is the average cardiac output of a person at rest

Answer 1

5 L/min

Question 2

What is the equation for calculating cardiac output

Answer 2

Heart rate x stroke volume

Question 3

What is cardiac hypertrophy

Answer 3

Long term structural changes in the size of the left ventricle

Question 4

What is the equation for constant flow rate

Answer 4

Blood flow velocity x cross sectional area

Question 5

What do poiseuille’s laws state

Answer 5

1. Flow is proportional to the difference between inflow and outflow pressure
2. Flow is inversely proportional to length of the vessel
3. Flow is proportional to radius of the vessel
4. Flow is inversely proportional to the viscosity of the blood
   All of the above have different differences in effect size

Question 6

What is a syncytium

Answer 6

A single multi-nucleated cell formed from many fused cells

Question 7

Only 99% of cardiac muscle cells are contractile what does the remaining 1% do

Answer 7

They regulate the autonomic rhythm of the heart

Question 8

What are the 4 events of cardiac excitation

Answer 8

1. Atrial depolarisation
2. Ventricular depolarisation
3. Atrial repolarisation (hidden by the above)
4. Ventricle repolarisation

Question 9

What is systole

Answer 9

Contraction

Question 10

What is the equation for calculating mean blood pressure

Answer 10

Cardiac output x total peripheral resistance

Question 11

Useful equations for the cardiovascular system

Answer 11

1. Stroke vol = end diastolic volume - end systolic volume
2. Cardiac output = stroke v x heart rate
3. Pulse pressure = systolic BP - diastolic BP
4. Mean BP = diastolic BP + 1/3 of pulse pressure
5. Flow = mean BP divided by total peripheral resistance

Question 12

What are alpha adrenoreceptors responsible for

Answer 12

Contraction of all types of smooth muscle