Question

which of the following helps return blood to the heart?
multiple choice
end systolic volume
valves in the arteries
contracting skeletal muscles
positive pressure in thoracic cavity

Explanation:

Contraction of skeletal muscles helps squeeze veins and push blood towards the heart. End - systolic volume is related to the amount of blood left in the heart after systole. Arteries carry blood away from the heart and don't have valves that help return blood to the heart. The thoracic cavity has negative pressure during normal breathing which aids in venous return, not positive pressure.

Answer:

C. Contracting skeletal muscles