Veins Page Two

Question 1

What are veins composed of?

Answer 1

Vessels composed of smooth muscle that carry blood to the heart. Blood flows from capillary –> venule –> vein.

Example sentence: Blood flows through the veins after leaving the capillary bed.

Question 2

What is the function of valves in veins?

Answer 2

Valves are located in veins that allow for movement of blood in one direction (toward the heart). Skeletal muscles also aid in movement of blood by reducing the diameter of veins when they contract. Walking helps move blood back to the heart from the legs.

Example sentence: Valves in veins prevent blood from flowing in the wrong direction.

Question 3

What percentage of blood is stored in veins?

Answer 3

Veins serve as reservoirs for blood. 50% of all blood is in the veins.

Example sentence: Veins can store a large amount of blood for the body.

Question 4

What can happen if blood pools in the veins over a long period of time?

Answer 4

Pooling of blood over a long period of time can cause damage to the valves. Blood is allowed to flow through the veins away from the heart and pool in surface veins. Surface veins enlarge and bulge. This is called varicose veins.

Example sentence: Varicose veins can be painful and unsightly.