What are the three main differences between arteries and veins?

Although these two blood veins may function similarly, they also differ greatly from one another. First, arteries carry blood away from the heart while veins carry blood from the body back to the heart. Veins have valves to prevent blood backflow while arteries do not. Lastly, arteries are blood veins that are rich in oxygen while veins are low in oxygen.

How are they similar?

Both arteries and veins are different types of blood vessels that transport, circulate, and regulate blood throughout the body. They are made up of three layers: the innermost layer, known as the Tunica Intima; the middle layer, known as the Tunica Media; and the outermost layer, known as the Tunica Externa.

Why are veins biggers than arteries?

The pressure in veins is lower than that in arteries, which is why veins are thinner than arteries.

Are veins bigger than arteries?

Veins are generally larger in diameter than arteries, but their walls are thinner. This is because veins carry blood back to the heart at a lower pressure compared to arteries, which transport blood from the heart to the rest of the body under high pressure.

What are the two types of veins?
Pulmonary veins and systemic veins

References: https://www.webmd.com/heart/difference-between-arteries-veins-capillaries#:~:text=Arteries%20carry%20blood%20away%20from,to%20keep%20your%20blood%20flowing.

https://www.msdmanuals.com/home/heart-and-blood-vessel-disorders/biology-of-the-heart-and-blood-vessels/biology-of-the-blood-vessels#:~:text=Blood%20flows%20from%20the%20capillaries,of%20fluid%20in%20them%20increases.

https://byjus.com/question-answer/why-do-veins-have-thin-walls-as-compared-to-the-arteries/#:~:text=It%20is%20because%20arteries%20carry,due%20to%20the%20low%20pressure.

What are the histological layers of blood vessels?

https://my.clevelandclinic.org/health/body/21640-blood-vessels