学以致用，看看你掌握了多少？
1. Of the fluid that leaves the capillary, about percent is returned. The ________ percent that does not return becomes part of the interstitial fluid that surrounds the tissue cells.
2. One of the functions that the lymphatic system performs is to return excess fluid to the blood.
3. Lymph nodes are widely distributed throughout the body along the lymphatic pathways where they filter the before it is returned to the ________.
4. Lymph enters a lymph node through , filters through the ________, and leaves through ________.
5. The tonsils are the ones that are located near the opening of the oral cavity into the pharynx.
6. The spleen is a lymph organ that filters blood and also acts as a reservoir for .
7. The thymus is a soft organ with lobes that is located anterior to the ascending aorta and posterior to the sternum.
8. The thymus also produces a hormone, , that stimulates the maturation of lymphocytes in other lymphatic organs.
