Question 16: What is the body part pictured above?
A) The liver
B) The appendix
C) The spleen
D) The kidney

The correct answer is C.

Located on the left side of your abdomen, Dr. Oz says the spleen helps the immune system function better. "If you can feel your spleen, that means you probably have an infection," he says. "Mononucleosis does that, and illnesses that draw on your immune system."

According to Dr. Oz, people often damage their spleens when they have car crashes or sports injuries. "It's so rich in blood. It's an extra reservoir of blood for us," he says. "So when we fracture it, it starts to really bleed a lot, and that's one of the reasons we have to operate on folks."