The major blood vessels of the leg fall into two subcategories. Arteries carry blood away from the heart and toward the body tissues. Since the arterial blood is meant to supply tissues and cells with oxygen and nutrients, this blood is oxygen-rich and has a bright red color. Veins carry blood away from the cells and return it to the heart for reoxygenation at the lungs. Venous blood is oxygen-deficient and has a deep red, almost purple color.
Femoral Artery
The largest artery in each leg is called the femoral artery, notes Dr. Gary Thibodeau in his book, "Anatomy and Physiology." The femoral artery branches off the large artery that descends through the torso from the heart, called the abdominal aorta. Like all arteries, the femoral artery has a pulse, meaning that it's possible to feel the heart beat in the artery. While this artery lies deep within the leg to protect it from harm, it's possible to feel the femoral pulse in most individuals at the junction of the thigh with the upper body, a few inches below and to one side of the belly button.
Popliteal Artery
The major arterial branch from the femoral artery is the popliteal artery, which takes off near the knee. Like the femoral artery, the popliteal artery carries oxygenated blood toward body cells. Also like the femoral artery, the popliteal artery is buried deep in body tissues, notes Dr. Thibodeau. While this artery isn't one of the more common in which to palpate a pulse, it is possible. In a patient with a bent knee, the popliteal pulse can be palpated by feeling behind the knee with the fingers.
Great Saphenous Vein
Veins, unlike arteries, carry deoxygenated blood containing cellular waste products, notes Dr. Lauralee Sherwood in her book, "Human Physiology." The great saphenous vein drains the lower leg, eventually emptying into the femoral vein very close to the top of the leg. Because veins converge as they move toward the heart, small veins from local tissue areas join together to become larger veins. Blood pressure in veins is much lower than in arteries. Consequently, veins aren't buried as deep in the tissues, since they're less likely to bleed catastrophically. They also don't pulse. The great saphenous vein follows a path along the inner leg toward the upper leg but is not visible or palpable from the exterior.
References
- "Anatomy and Physiology"; Gary Thibodeau, Ph.D.; 2007
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
