Question

Which is the longest vein in our body?

Answer 1

Hint: The vein in our body that helps collect the deoxygenated blood from different tissues of the organ and carry it to the heart is supposed to be the longest vein in the human body.
Two main veins that is associated with the heart in our body that carry deoxygenated blood are
1. Superior vena cava and 2. Inferior vena cava.

Complete answer:
The two main longest veins in the human body are the superior vena cava and inferior vena cava. These veins are associated with the heart that carries deoxygenated blood from the different tissues of the organ and pour it into the right atrium of the heart.
Out of these two veins of the heart, the inferior vena cava (IVC) is considered as the longest of all the veins found in the human body. And superior vena cava (SVC) is taken as the second longest vein.
Inferior vena cava (IVC) is associated with the heart to carry the deoxygenated blood from the lower parts of the body that lies inferior to the heart. Thus it has to be longest since the part of the body lower to the heart is longer than the upper part.

Note:
Inferior vena cava carries deoxygenated blood from the lower parts of the body. And superior vena cava carries the blood from the upper part of the body. The lower body is longer than the upper body and hence the vein carrying the blood from the lower body must be longer than any other vein in our body.