Arteries and veins are the part of circulatory system. The function of the arteries is to carry oxygenated blood from the heart to the rest of the body with exception to pulmonary and umbilical arteries which carry deoxygenated blood from the heart to the lungs. However, the function of veins is to carry deoxygenated blood to the heart from the rest of the body with the exception to pulmonary and umbilical veins which carry oxygenated blood from the lungs to the heart.
Arteries main function is to deliver oxygen and nutrients to all the body parts. They also have to remove carbon dioxide, other waste materials from the tissues and cells, maintain the chemical balance, mobility of proteins, cells and other elements of the immune system. Arteries are divided into systemic, pulmonary, aorta, and arterioles. Arteries are thick and muscular as it has to bear the force with which the heart pumps the blood into it. The arteries further divide into smaller tubules. The outer layer is made up of connective tissue which covers the middle layer of muscular tissues. These tissues contracts in between the heart beat generating a pulse. The innermost layer is endothelial cells which assist in the smooth flow of the blood.
Veins carry the deoxygenated blood from the tissues back to the heart. They are elastic and tubular in formation and are not as thick and sturdy as arteries. Veins are classified as Superficial, Deep, Pulmonary and Systemic veins. Superficial veins are close to the surface of the skin and do not have any corresponding arteries, deep veins are rooted deep into the body, Pulmonary veins carry oxygenated blood from the lungs to the heart and systemic veins collects deoxygenated blood from the tissues and carry it to the heart. They have also the same tissues as that of the arteries however they do not contract in between the heart beats.
Difference between Arteries and Veins
1. The arteries carry red oxygenated blood from the heart to the rest part of the body whereas veins carry deoxygenated blood from the tissues to the heart.
2. The arteries are thick and muscular as they have to bear the high pressure when the blood is pumped by the heart into it. The veins are less sturdy when compared to arteries.
3. The pressure due to rhythmic pumping by the heart is very high in arteries and thus the flow of blood is in spurts whereas the flow of blood in the veins is slow and smooth.
4. Arteries have no valves whereas veins have valves to prevent the backward flow of the blood.
5. Veins collapse when blood is not flowing through them but arteries remain straight.
The arteries and veins are essential part of the circulatory system. Both the functions are equally important in maintaining the homeostasis of the body. They serve a major role in regulating the various attributes of the system such as pH, body temperature etc.