Cardiovascular adjustments to exercise

Question 1

During exercise what 3 major tasks does the cardiovascular system have to maintain circulation?

Answer 1

• Pulmonary blood flow must increase.
• Blood flow in active muscles must increase.
• Arterial pressure must be stabilised.

Question 2

Describe why pulmonary blood flow must increase.

Answer 2

• To boost oxygen uptake.
• And CO2 removal.
• This is achieved through changes in heart rate, stroke volume + cardiac output.

Question 3

Describe why blood flow in active muscles must increase.

Answer 3

• To boost oxygen + glucose delviery.
• And waste removal.
• This is achieved through vasodilation, diversion + and increased cardiac output.

Question 4

Outline the changes the cardiovascular system incurs during the onset of exercise (start of exercise).

Answer 4

• An increase in heart rate, stroke volume + cardiac output.
• These adjustments occur within 1 second of commencing the exercise.
• Largely neurologically controlled.

Question 5

Outline the changes the cardiovascular system incurs during incremental exercise.

Answer 5

• Heart rate + cardiac output increase in direct proportion to VO2 requirements.
• Blood flow to working muscles increases as a function of VO2 requirements.
• Cardiac output + heart rate will plateau at VO2 max.

Question 6

Describe the changes the cardiovascular system incurs during prolonged exercise.

Answer 6

• Cardiac output is maintained at a constant level.
• Overtime stroke volume decreases.
• And heart rate increases to compensate.
• This is called cardiovascular drift.
• Results from blood flow redistribution for cooling purposes, and fluid loss associated with a decrease in plasma volume.