Where does lymph rejoin the blood and become part of the plasma?

Lymph rejoins the bloodstream at the junction of the internal jugular and subclavian veins. The lymphatic system returns excess interstitial fluid to the circulatory system, and the subclavian veins serve as the primary sites for this process.

Once lymph is collected from the lymphatic vessels, it is delivered to the thoracic duct or the right lymphatic duct, which then empties into the subclavian veins. This is vital as it allows the lymph, which becomes part of the plasma, to re-enter the circulatory system, helping to maintain fluid homeostasis and ensuring that nutrients, immune cells, and waste products are properly managed within the body.

The other veins mentioned, such as the femoral and brachial veins, do not primarily function as sites for lymph re-entry into the blood. They primarily drain blood from their respective regions and are not involved in the specific return of lymph to the plasma. Therefore, the subclavian veins are key in facilitating the important transition of lymph back into the bloodstream.