The Innate Immune System Online Quiz

The innate immune response is nonspecific, meaning it attacks foreign invaders without targeting a specific pathogen. Because of this broad, aggressive response (such as inflammation and chemical release), nearby healthy host tissues can sometimes be damaged in the process.

Macrophages are crucial components of the innate immune system. They act as sentinel cells that are among the first to detect and engulf invading pathogens, and they also release cytokines to recruit and activate other immune cells to the site of infection.

Macrophages, Natural Killer (NK) cells, and neutrophils are all cellular components of the innate immune system, providing rapid, non-specific defense against pathogens. Since all of the listed options are indeed part of the innate immune system, the correct choice is that all are part of it.

The skin acts as a physical and chemical barrier that prevents pathogens from entering the body, making it the primary first line of defense. Internal immune cells like macrophages, dendrites, and neutrophils act as the second line of defense once pathogens have breached this barrier.

The skin, also known as the cutaneous membrane, is the largest organ of the human body by both surface area and weight. While the liver is the largest internal organ, the skin covers the entire exterior of the body, making it the largest overall. Other organs like the lungs and small intestine have large internal surface areas but do not match the skin's total mass.