Final answer:
The spleen is the organ responsible for cleansing the blood of bacteria and viruses. It filters the blood and lymphocytes within the spleen destroy these pathogens.
Step-by-step explanation:
The organ in the body that cleanses the blood of bacteria and viruses is the spleen. The spleen, located in the upper abdomen, acts as a blood filter, targeting pathogens and worn-out red blood cells. Specialized immune cells called lymphocytes within the spleen then destroy these pathogens, helping to maintain the purity and health of the bloodstream.
Other organs, like the kidneys and liver, also play crucial roles in filtering the blood but their primary functions are different; the kidneys filter waste to produce urine, and the liver breaks down toxins. However, when it comes to directly cleansing the blood of bacteria and viruses, it is the spleen that performs this critical task.