Question

end diastolic volume (edv):
○ is the amount of blood entering the heart from the pulmonary and systemic
circuits.
○ may be affected by the skeletal muscle pump.
○ is determined by veinous return.
○ may be affected by the respiratory pump.
○ all of the above.

Explanation:

1. Analyze each option:

• Option 1: EDV is the volume of blood in the ventricles at the end of diastole, which comes from pulmonary and systemic circuits (venous return), so this is correct.
• Option 2: The skeletal muscle pump helps push blood back to the heart, affecting venous return and thus EDV, so this is correct.
• Option 3: Venous return (blood returning to the heart) determines how much blood is in the ventricles at end - diastole (EDV), so this is correct.
• Option 4: The respiratory pump (changes in thoracic pressure during breathing) also affects venous return and hence EDV, so this is correct.
• Since all the above statements about EDV are correct, the answer should be "all of the above".

Answer:

E. all of the above