L16 Cardiac Output and its Regulation During Exercise

Question 1

Define ‘blood flow’

Answer 1

Volume of blood that flows through any tissue in a given time period (mL/min)

Question 2

Define ‘cardiac output’

Answer 2

Volume of blood that circulates through the systemic (or pulmonary) blood vessels each minute

Question 3

How do you calculate cardiac output?

Answer 3

stroke volume x heart rate

OR

arterial blood pressure / peripheral resistance

Question 4

What is the BP of blood reaching the right atrium

Answer 4

~0mmHg

Question 5

How can you calculate mean arterial blood pressure (ABP)?

Answer 5

cardiac output x peripheral resistance

Question 6

True or false: if the peripheral resistance falls without an appropriate increase in cardiac output, the arterial BP will fall.

Answer 6

True

Question 7

True or false: if the cardiac output increases sufficiently in response to a fall in peripheral resistance, the arterial BP will remain the same.

Answer 7

True

ABP = CO x PR

Question 8

True or false: if the heart rate and stroke volume fall without any increase in peripheral resistance the arterial BP will increase.

Answer 8

False

ABP = CO x PR

CO = SV x HR

Question 9

True or false: Vasoconstriction of the arterioles by the sympathetic nervous system will lead to a fall in peripheral resistance.

Answer 9

False

Question 10

True or false: Polycythemia can increase peripheral resistance to blood flow?

Answer 10

True

Polycythemia (unusually high numbers of RBCs) increases viscosity of blood. This leads to ↑ resistance and ↑ mABP