Difference between Pulmonary Artery and Pulmonary Vein

Pulmonary artery and pulmonary vein are two important blood vessels that are associated with the lungs. They are involved in the transportation of deoxygenated and oxygenated blood respectively to and from the lungs. Here are the differences between them:

Wall thickness:

- Pulmonary artery has a thicker wall than pulmonary vein.
- This is because pulmonary artery carries deoxygenated blood under high pressure from the right ventricle of the heart to the lungs for oxygenation.
- The thick wall helps to withstand the high pressure and prevent rupture of the vessel.

Wall structure:

- Pulmonary artery has three layers in its wall, namely tunica intima, tunica media, and tunica adventitia.
- Tunica intima is the innermost layer and is made up of endothelium.
- Tunica media is the middle layer and is composed of smooth muscle and elastic fibers.
- Tunica adventitia is the outermost layer and is made up of connective tissue.
- Pulmonary vein, on the other hand, has a thinner wall with only two layers, tunica intima and tunica media.
- The wall of the pulmonary vein lacks tunica adventitia.

Valves:

- Pulmonary artery does not have any valves.
- Pulmonary vein, on the other hand, has valves that prevent the backflow of blood into the lungs.

Conclusion:

In conclusion, pulmonary artery differs from pulmonary vein in terms of wall thickness, wall structure, and the presence or absence of valves. Pulmonary artery has a thicker wall, has three layers in its wall, and lacks valves. Pulmonary vein, on the other hand, has a thinner wall, has two layers in its wall, and has valves that prevent the backflow of blood into the lungs.

Because pulmonary artery have thick wall