Complex sentence: Tonsils can be described as functioning lymph nodes located at the entrance of the respiratory and gastrointestinal tracts; the function of tonsils are to respond to local inflammation and aid the lymphatic system.
Split into simpler sentences: Tonsils can be described as functioning lymph nodes located at the entrance of the respiratory and gastrointestinal tracts. The tonsils' function are to respond to local inflammation and aid the lymphatic system.