Which of the following applies to blood flow in the veins? Blood flows actively in the veins, moved by respiration and muscle relaxation. Veins require high pressure from the heart and muscles to expand. Veins are a low pressure system so blood flows passively with respiration and muscle contraction. The smallest vessels for blood flow in the body are the venules.

Why does the body need skeletal muscle contraction, pressure changes during breathing, and vasoconstriction to move blood through the veins?Multiple choice question.Veins are so superficial that the force of the heart can't reach them.The blood pressure in the veins is too low to push blood toward the heart.Veins contain valves which partially obstruct blood flow in them.

Blood flow through capillaries is regulated byMultiple Choiceone-way valves in the veins.precapillary sphincters.elastic valves.skeletal muscle contraction.the tunica intima.

Which of the following blood vessels have highest resistance to blood flow?Multiple ChoiceMuscular arteries and large veinsElastic arteries and muscular arteriesArterioles and capillariesLarge veins and venulesElastic arteries, muscular arteries, and large veins

Which of these describe the structure of veins?Question 8Select one or more:a.Thin wallsb.include the vena cavac.carry blood toward the heartd.Larger lumene.include the pulmonary veinsf.valves to stop back flow of bloodg.usually carry de-oxygenated bloodh.Blood at low pressure

QUESTION 33Which statement is true? A. Veins always take blood away from the heart so always carry oxygenated blood B. Veins always take blood TOWARDS the heart so always carry deoxygenated blood C. Arteries always take blood away from the heart so always carry oxygenated blood D. Arteries always take blood away from the heart but do NOT always carry oxygenated blood