WHAT IS THE LYMPHATIC SYSTEM?
The lymphatic system is distributed throughout the organism. It has two fundamental functions. The first is to collect, transport and return liquid and large molecules from the interstitial space to the circulatory system; and the second: it functions as a filter of bacteria and neoplastic cells.
As in the venous system, it is divided into superficial lymphatic systems (a large net covering the entire surface of the body) and the number of vessels exceeds those in the venous system. The deep lymphatic system makes it way through the large vessels and transports the lymph that comes from the organs. It is estimated that the lymphatic net covers a total surface area of 5000 square meters.
Approximately 10% of the liquid of the interstitium is not drained through the venous capillaries, but through the lymphatic system.
This small amount is important as heavy molecules like proteins, cannot pass through the fenestrations of the venous capillaries, but can easily pass through the lymphatic capillaries. There is no other available way, apart from the lymphatic system, for proteins to return to the general circulatory system.