ANATOMY

Detailed explanation-1: -This protection is called immunity. Humans have three types of immunity-innate, adaptive, and passive: Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body.

Detailed explanation-2: -(ih-MYOO-nih-tee) In medicine, the immune system’s way of protecting the body against an infectious disease. The three types of immunity are innate, adaptive, and passive. Innate immunity includes barriers, such as skin and mucous membranes, that keep harmful substances from entering the body.

Detailed explanation-3: -Pathogens have molecules called antigens on their surface. Antigens provide a unique signature for the pathogen that enables immune system cells to recognize different pathogens and distinguish pathogens from the body’s own cells and tissues.

Detailed explanation-4: -The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen.