Veins and Arteries Unit 4

Arteries Versus Veins Arteries carry blood away from the heart while veins transport blood back to the heart. Connecting these two types of vessels are tiny branches called capillaries, the site of gas exchange. Since arteries and veins work in opposite directions, their structures have key differences that support what they do for the human body.

Size and Structure Arteries are thicker than veins….why? Veins contain valves Two leaflets that are pushed closed if the blood begins to back up in the vein Aid in returning blood to the heart What other “motion” helps move blood through the body?

Blood pressure decreases as blood moves through the arterial system into the capillaries. Little blood pressure is left for venous blood pressure. Skeletal muscle contraction, breathing, movement helps move blood through the veins.

FYI…. Veins function as blood reservoirs in times of blood loss Nerve impulses reflexively stimulate the muscular walls of the veins. Helps return more blood back to the heart

Varicose Veins It is a vein that has become stretched and swollen with blood. The are sometimes visible through the skin.

Treatment To reduce the pain, stay don’t stand for long periods of time. Surgery Trying to shrink the vein (with a laser) Removal of the vein

Why Do They Occur? As people get older, the valves in the veins do not work as well. When that happens, some blood can stay in a vein instead of moving forward like it should. This makes the vein swell up, and that swollen vein is a varicose vein. The veins often show up on the legs, ankles - farthest from the heart. Gravity pulls blood down into your legs and feet when you're standing up or sitting down. veins have to work extra hard to get that blood back up to the heart, and some of those veins can wear out over time.

Blood Flow From Heart

Major Veins and Arteries of the Body Carotid Artery and Jugular (vein)

Arms – Subclavian, Brachial, Radial, Ulnar

Body and Legs Descending Aorta Common Iliac Femoral