Circulatory system consists of different blood vessels and the heart. Arteries and the veins both are two major types of blood vessels that deliver blood from the heart and to the heart. Arteries and veins both appear like tubes, but both of them are different from each other structurally and functionally to perform their own task. This discussion highlights the basic differences of arteries and veins with respect to their anatomy and physiology.
The function of Artery is to carry oxygenated blood away from the heart to the systemic circulation to provide oxygen and nutrients to the distant tissues and organs except pulmonary arteries. Aorta is the largest artery leaving the heart. As it moves forward, it becomes smaller and subdivides into branches and then into arterioles and capillaries to develop capillary beds where the exchange of substance takes place. After that the blood flows into post capillary venules, small veins, and large veins and eventually to superior and inferior vena cava entering into the heart. Arteries are very deep and prevent high pressure by having a thick wall. Endothelial cells in the tunica interna are more elongated, and the elastic membrane is well formed. Tunica media, which is medially formed, is very muscular and has vaarious elastic fibers. The outermost layer of the arterial wall is tunica externa, is not very well developed and is less strong. The lumen of the arteries is narrow and does not consist valves. The flow in the arteries is pulsatile; it is palpable and reflects the rhythmic pumping action of the heart. After death arteries are found to become empty of blood.
It is a low pressure collecting system from the return of blood from the networks of capillary to the heart. Veins carry deoxygenated blood to the heart which is to be pumped into the lungs, to get oxygenated. (Except pulmonary veins)
The flow of blood is passive in the veins due to pressure gradient. General three layer structure of the vessels is observed in the veins, but the elastic and muscular components are much less highlighted features. As compare to artery the wall of the vein is thinner and less elastic. In the tunica interna endothelial cells are less flat and the elastic membrane is not well developed. Tunica media is not much muscular and has few elastic fibres. Tunica externa of the veins are well developed and much stronger then in arteries. The lumen is wide and possesses valves which allow unidirectional flow of blood. Venous pulsations are not palpable but visible. Even after death the veins contain blood.
What is the difference between artery and vein?
- Unlike the veins the wall of the artery is thicker and more elastic.
- Arteries seated deep whereas the veins are more superficial.
- The lumen of the artery is narrow while on the other hand the lumen vein is wide.
- Arteries don’t have valves but veins do have to prevent back flow.
- After death the arteries become empty, but the veins do not.