Veins and Arteries

Arteries and veins have three main differences between them. The arteries are in charge of transporting oxygenated blood away from the heart to various organs. On the other hand, veins transport deoxygenated blood from multiple organs of the body to the heart for oxygenation. You can locate your arteries deeper within your body and have thick elastic muscle walls. Veins have thin, non-elastic, less muscular walls, and most of them are closer to your skin’s surface. The direction of blood flow for arteries is downward from the heart to the body tissues. The veins carry blood from the body tissues to the heart upward.

But even though arteries and veins play different roles in the body, they are also similar in various ways. Both of these vessels are part of the circulatory system, which maintains and delivers oxygenated blood in our body. They are also alike in the way they maintain the blood flow. Veins and arteries move in the same direction. Besides blood circulation, arteries and veins consist of the same structure, specifically in terms of the layers of their cells. They have 3 layers in total, with tunica intima being the innermost layer, gisundan sa middle layer na si tunica media, and last and outermost layer, which is the tunica externa. 

One exemption to this is that veins have thinner walls due to the fact that they have fewer smooth muscles and connective tissue compared to arteries. Veins are also bigger than arteries in terms of their diameter. Greater diameters of the veins allow them to carry and transport more blood volume for longer than arteries.

Veins are further categorized into two: pulmonary and systematic veins. The pulmonary veins carry oxygenated blood from the lungs to the heart, unlike other veins, which carry deoxygenated blood. The systemic veins return deoxygenated blood from the body to the heart, where it then enters the pulmonary circuit to be oxygenated. Most veins in the body are systemic veins. Systematic veins are also subdivided into three, which are the deep veins, superficial veins, and connecting veins. 

The majority of veins have open-and-close valves. The valves maintain your blood flowing in a single path and regulate blood flow. The veins hold about 75% of your blood.

Sources:
•https://getaprofessor.com/2022/06/02/what-are-the-histological-layers-of-blood-vessels/
•https://my.clevelandclinic.org/health/body/21640-blood-vessels
•https://www.healthline.com/health/venous-system
•https://www.webmd.com/heart/difference-between-arteries-veins-capillaries
•https://byjus.com/biology/arteries-and-veins-difference/