MICROANATOMY

Detailed explanation-1: -The innate immune system is the body’s first line of defense against germs entering the body. It responds in the same way to all germs and foreign substances, which is why it is sometimes referred to as the “nonspecific” immune system.

Detailed explanation-2: -Active immunity is created by our own immune system when we are exposed to a potential disease-causing agent (i.e., pathogen).

Detailed explanation-3: -There are two broad classes of such responses-antibody responses and cell-mediated immune responses, and they are carried out by different classes of lymphocytes, called B cells and T cells, respectively.