Question

Why is blood drawn from vein and not from artery during blood donation?

Answer 1

See below.

Explanation:

Veins have lower pressure than arteries. So, there's less chance of venuous blood seeping back into the stream than that of arterial blood.

Another reason is that veins have thinner walls. Therefore, they must have more blood.

Arteries are also located deep under the skin, while veins are relatively close to the epidermis. Another reason is that if an embolism (a small bubble) forms, it is comparatively safe for it to be in a vein. The small bubble will reach the heart, but will be too small to do any major damage. On the other hand, an embolism in an artery may lead to hypoxia in a tissue.