What are the primary components of the first line of defense in the immune system as described in the chapter?

The primary components of the first line of defense in the immune system include the skin, tears, earwax, mucous membranes, and the urinary tract. These elements serve as external barriers to prevent foreign substances and microorganisms from entering the body.

The first line of defense in the immune system consists of various physical and chemical barriers that protect the body from pathogens. The skin acts as a physical barrier, while tears and earwax contain antimicrobial properties. Mucous membranes line body cavities and trap pathogens, and the urinary tract helps flush out potential invaders. Together, these components form a nonspecific defense mechanism that is present even before exposure to pathogens.