What Is Lymphangiogenesis?

Lymphatic fluid is tissue fluid that enters the lymphatic vessels. Lymphatic fluid and lymphocytes form what is commonly referred to as "lymph". Therefore, the lymph fluid composition from a tissue is very similar to that of the tissue.

1. Recover protein. Protein molecules in the tissue fluid cannot enter the blood through the capillary wall, but can easily enter the lymph fluid through the capillary wall. Every day, 75 ~ 200g of protein is brought back to the blood from the lymph fluid, so the protein concentration in the tissue fluid can be kept at a low level. If the main lymphatic vessels in the body are blocked, the protein in the tissue fluid will accumulate, the osmotic pressure of the tissue fluid colloid will increase continuously, and severe edema will occur.

2. Transport fats and other nutrients. After food is digested, 80% ~ 90% of the nutrients absorbed by the small intestinal mucosa, especially fat, are absorbed by the capillary lymph vessels of the villi of the small intestine and transported into the blood through the lymph circulation. Therefore, the lymph fluid of the small intestine is chyle-like.

3. Adjust body fluid balance. Although the return of lymph fluid is relatively slow, the return of lymph fluid in a day is roughly equivalent to the total amount of plasma in the whole body. Therefore, the return of lymph fluid plays a certain role in the balance of tissue fluid production and reabsorption.

4. Defense and immune function. Red blood cells that enter the interstitial space due to bleeding, or bacteria that invade the body, can be taken away from the tissue by lymph fluid. Lymph fluid passes through multiple lymph nodes in the way of returning to the blood. Lymph nodes in the lymph nodes contain many phagocytic macrophages, which can clear red blood cells, bacteria or other particles. In addition, lymph nodes can still produce lymphocytes and plasma cells, which are involved in the immune response. The lymphatic system therefore also acts as a defensive barrier. ^[1]