Which of the following assists in returning the blood to the heart through the veins? *1 pointThe effect of breathing, squashing action of muscles, the right ventricleThe effect of gravity, the pumping action of the heartValves in the veins, the effect of breathing, squashing action of muscles, gravityValves in the veins, the effect of breathing, gravity

What factors contribute to venous return to the heart?Multiple select question.smooth muscle contraction in the walls of arteriesskeletal muscle contractionsvein vasoconstrictionpressure changes during breathing

Which of the following helps return blood to the heart?Multiple ChoiceEnd systolic volumeContracting skeletal musclesPositive pressure in thoracic cavityValves in the arteries

1b. Refer to the diagram above of the cardiovascular system and explain how blood flows through the heart.

How does the blood return to the heart from the lungs?through the pulmonary valvethrough the pulmonary veinsthrough the pulmonary arterythrough the aorta

Select all that applyWhat vessels bring blood to the right atrium?Multiple select question.pulmonary veinssuperior vena cavapulmonary arteriescoronary sinusinferior vena cava