Final answer:
The spleen is the largest lymphatic organ, located in the upper left quadrant of the abdomen. It combats and prevents infections by removing pathogens from the blood and serves as a site for immune responses to blood-borne pathogens.
Step-by-step explanation:
The largest lymphatic organ is the spleen. The spleen is located in the upper left quadrant of the abdomen, near the stomach and left kidney. It is a secondary lymphoid organ that contains numerous phagocytes and lymphocytes, which combat and prevent circulatory infections by killing and removing pathogens from the blood. The spleen also functions as the location of immune responses to blood-borne pathogens.