L26 Peripheral circulatory adaptations to training

Question 1

Describe structural adaptations to conduit and resistance arteries that occur after endurance training

Answer 1

Increases conduit artery diameter.
Increases compliance of large peripheral arteries - lumen is larger and walls are thinner
Resistance vessel dilator function is enhanced

Question 2

Describe the structural changes in skeletal muscle capillary that occur after endurance training

Answer 2

Arterial vascular network enlarges in skeletal muscle
Increases total capacity of vascular bed.
Angiogenesis = formation of new blood vessels

Question 3

Explain the significance of the structural changes to the peripheral circulatory on O2 delivery

Answer 3

Transit time of RBCs decreases

Capillary density increases which decreases the diffusion distance

Question 4

Describe the metabolic changes that occur in skeletal muscle after endurance training

Answer 4

Oxygen consumption increases
Mitochondria increase in the muscle
Blood flow is lower because the A-V difference is greater at sub max
Increased oxygen extraction from blood

Question 5

Discuss how the vascular and metabolic adaptations in skeletal muscle after endurance training support better aerobic performance in regards to blood flow at submaximal and maximal exercise intensities

Answer 5

@ submax
- blood flow in trained muscles is lower because the A-V difference is greater. From the blood the muscle is able to take more O2 from the blood so there doesn’t need to be as much blood flow

@maximal exercise blood flow to trained muscle is higher, and the A-V difference is greater so more gas exchange occurs so aerobic performance is more efficient

Question 6

What are the effects of exercise training on:

• Coronary circulation
• Cutaneous circulation
• Splanchnic circulation

Answer 6

Coronary
- coronary vessels enlarge + grow with endurance only. Cardiac hypertrophy

Cutaneous

• Threshold for vasoconstriction is unchanged
• skin blood flow increase is greater - better heat loss
• vasodilation (sympathetic) increases

Splanchnic

• Reduction in blood flow @ same workload after training
• Increased capacity for further vasoconstriction as exercise intensity increases

Question 7

Identify 3 potential mechanisms for the vascular adaptations to exercise training and explain how they might operate to bring about vessel growth

Answer 7

1. Metabolic - hypoxia
2. Mechanical - blood flow/wall tension (vascular). Tissue growth, stretch (extra vascular)
3. Growth factors - vascular endothelial growth factor

(then explain all)