Question

exercise is known to elicit an autonomic response on the heart. knowing the various effects that exercise has on the cardiovascular system, which type of response does exercise stimulate (giving reasons) and what would you say is the importance of this phenomenon?

Answer 1

Exercise increases oxygen and fuel demands .To meet this there is a synchronised response by the heart ,longs and harmonal systems .The increased demand in oxygen is shown by increased cardiac output and increases in respiratory  effect .

The three major responses  made by cardio vascular system during exercise include

a.Increase in cardiac output

b.Enhance the delivery of oxygen

C.Fuel to working muscles

The responses engaged in muscular exercise involves complex local and nervous adjustments of the circulation.In the active muscles ,including cardiac muscle the resistance vessels relax in response to local chemical changes to provide an increase in blood flow adequate for their metabolic requirements .

Reasons :

It supplies adequate oxygen and nutrients to the working muscles .

Cardiac output and the pattern of blood flow changes dramatically when a person goes to exercise .

The coronary arteries supply the myocardium with blood and nutrients .During exercise myocardium depends also most completely on aerobic mechanism and so it requires constant oxygen supply.

There are changes in arterial and mixed venous oxygen content with increased rates of work .

There is increase in coronary blood flow and so perfusion pressure of the coronary artery and  from Coronary vasodilation increases .Most important ,an increase in sympathetic nervous system stimulation leads to an increase in circulatory catecholomines .This response triggers metabolic process that increase both perfusion pressure of the coronary artery and coronary vasodilation to meet the increased need for blood flow required by the increase in myocardial oxygen use .