LOWER EXTREMITY CIRCULATION
Phlebology is the study of the anatomy, physiology and disease of veins.
The venous system of the lower extremities comprises two types of vessels: Arteries and veins. Arteries transport oxygenated blood pumped from the heart to the rest of the body. Veins carry de-oxygenated blood from the tissues back to the heart against the force of gravity. Veins are thin walled tubes and depend on the muscle contractions in the leg and the one-way valves present in the veins to keep the blood flowing out of the leg.
When we walk, the calf muscles contract and blood travels up and through the one-way valves in the leg veins towards the heart. When the muscle relaxes, the valves close to prevent the blood returning towards the foot. This happens at many levels when the valves function properly.
There are two types of veins in the leg: the deep system and the superficial system. The deep system consists of the veins that lie within the muscular compartments. The superficial veins are smaller and lie outside of the muscular compartment. These two systems run parallel along the length of the legs and are connected by perforating veins which allows the drainage of blood through their valves from the superficial system to the deep vein system.