The cava vein, referring to either the superior vena cava or the inferior vena cava, is a large vein responsible for carrying deoxygenated blood back to the heart. Here’s a breakdown:

1. Superior Vena Cava:

1. Collects deoxygenated blood from the upper parts of the body (head, neck, arms, and upper chest).
2. Drains into the right atrium of the heart.

2. Inferior Vena Cava:

1. Collects deoxygenated blood from the lower parts of the body (abdomen, legs, and pelvis).
2. Drains into the right atrium of the heart as well.

Both veins are essential for ensuring that blood returns to the heart, where it can then be pumped to the lungs for oxygenation. They are among the largest veins in the body and play a crucial role in maintaining the circulatory system.