Question

Sean’s resting BP is also lower as a result of prolonged training for a marathon; because his TPR has been reduced. List the 3 factors that normally influence total peripheral resistance (TPR):           

__blood viscosity__________         _____vessel diameter_____________vessel length_____________

1. Cross out the 2 factors (above) that are not likely responsible for his improved blood pressure? Explain why in the space above.

2. Therefore, explain the 1 factor most likely to have changed in Sean to lower his TPR while at rest.

Answer 1

• The two factors that are not responsible for his improved blood pressure are blood viscosity and vessel length.
• Blood viscosity is the measure of thickness of blood.Change in the viscosity will have slight change in the total peripheral resistance because it take more time.Due to intense working excess amount of metabolite are increased in blood ,it causes increase in the thickness of blood.
• Longer the total vessel length , greater the resistance encountered .Total vessel length is deterined by the size of the person.

2)

• Change in vessel diameter is the one factor which have changed in Sean to lower his TPR while at rest.
• At rest ,  vasodialation leads to dialation of vessel , which leads to decreased friction between blood and vessel wall .Vasoconstriction leads to narrowing of blood vessel , which leads to increased friction between blood and vessel wall.