Question

There are many different effects of aerobic (dynamic exercise) on many different parts of the cardiovascular system. The following activity covers the majority of these changes.

Which of the following statements are true in reguard to a single session of incremental aerobic exercise? You will select numerous correct answers.

[mark all correct answers]

a. EDV is increased

b. Contractility is increased

c. liver blood flow increases for cori cycle

d. Heart receives a greater absolute amount of blood

e. sympathetic stimulation causes constriction of most vessels

f. A-V O2 difference decreases

g. Sympathetic nervous system activity increases

h. total vascular resistance decreases

i. Arterioles supplying skeletal muscles dilate

j. blood volume increases

k. blood viscosity increases

l. systolic blood pressure increases

m. more capillaries in skeletal muscle are recruited/opened

n. Brain receives a large increase in blood flow

o. Afterload is decreased

Answer 1

A) True - EDV increase:  an increase in venous return to the heart increases the filled volume (EDV)

B) True - contractility increases

C) true

D) True - Sympathetic activity is increased at the onset of exercise to enhance cardiac output while maintaining blood pressure and redistributing blood flow to accommodate the enhanced oxygen demand of the working muscles.

E) True - sympathetic stimulating b.v to constrict

F) false - Physical exercise leads to an increase in the arteriovenous oxygen difference in all individuals. As exercise intensities increase, the muscles increase the amount of oxygen they extract from the blood, and this therefore results in further increases in a-vO₂diff.

G) True

H) True -  Systemic vascular resistance (SVR) falls in exercise due to vasodilatation in active skeletal muscles . Blood pressure is maintained at normal or elevated levels during exercise by increasing cardiac output (CO) and increasing sympathetic vasomotor tone as exercise intensity increases

I ) True - arteriole dilate

J ) true -  The expansion of blood volume that accompanies physical activity provides advantages of greater body fluid for heat dissipation (sweating) and thermoregulatory stability as well as larger vascular volume for greater cardiac filling and stroke volume and cardiovascular stability during exercise

k ) true -  The whole blood viscosity was immediately examined with an oscillation-type viscometer and was found to increase significantly after exercise and subsequently return to baseline levels within one hour after exercise. The whole blood viscosity increased by a similar degree after heavy or light exercise.

L) true - systolic blood pressure inc

M) true

N ) true

O) false -  The increase in arterial pressure (increased ventricular afterload) that normally occurs during exercise tends to diminish the reduction in end-systolic volume; however, the large increase in inotropy is the dominate factor affecting end-systolic volume and stroke volume.