In this unit we will study the lymphatic system and its role in providing the body with immunity. We will learn about the two types of immunity the body provides, discuss how our immune system "remembers" what viruses look like, and how antibodies can fight infection. We will also explore some examples of autoimmune disorders and what happens to prevent the immune system from responding appropriately against retroviruses like AIDS. While intense, this section includes some of the most interesting material we will study all year!!