All About Veins

If one sees a road map, you can probably see many roads going here, there and everywhere. A human body has a highway system which sends blood to and from the body parts. It's called the circulatory system and the roads are arteries and veins. Veins are as similar as arteries but they are not strong as arteries because veins transfer blood at lower pressure. Veins consists three layers, an outer layer of tissues, a smooth inner layer of epithelial cells, and a muscle in the middle. However, veins contain less tissue with thinner layers.

Veins get blood from the capillaries with the exchange of carbon dioxide and oxygen takes place. This way veins transport the waste-rich blood to the heart and lungs. An important fact is that the waste-rich blood is not allowed to flow backward and moves in proper direction. This is done by the valves located inside veins.

Valves works as the gate that allows only one side move traffic direction. Vein valves have a duty to keep blood flowing towards heart. It also allows a flow of blood against gravitational force i.e. it has to reach other body parts like legs. However, vein valves provide footholds to the blood as it goes its way path.

Veins carry a blood in dark red color due to high percentage of carbon dioxide present in it. Veins appears in blue color. This is because the subcutaneous fat present in the skin absorbs light of lower frequencies. It permits only the energetic blue wavelengths to penetrate with the dark vein and reflect off. This reflection can easily be seen in the iris of blue eyes.

Veins can be classified into three ways, first is portal vein, a large vein that carries blood from digestive tract to the liver. These veins come in portal veins system. It connects the systems of capillary beds. The second is superficial veins, which is close to the surface of a body. They did not pair with any arteries. The third is pulmonary veins that carries oxygen rich blood from lungs to the left atrium of the heart.

Other important veins present in the body are jugular veins that bring deoxygenated blood from the head back to the heart. Small sepenous veins is relatively a large vein of superficial posterior leg, Great saphenous veins are the superficial posterior leg and thigh. Popliteal veins that run along an artery but carries blood from the knee joint and muscles in the thigh and calf back to the heart.

In the same way, other veins like Femoral veins, Illiac vein, Inferior Vena Cava, Superior Vena Cava, Portal Veins have their well defined structure. The longest network of veins in the body with various functions leads our body to perform well and be healthy.