What role do tears play in the body’s defense mechanism?

Tears play a critical role in the body's defense mechanism by flushing out pathogens. When the eyes are exposed to irritants or potential infectious agents, tears are produced to wash away these harmful substances. This is part of an innate immune response, as tears contain antimicrobial properties, including enzymes like lysozyme, which help to kill bacteria and reduce the risk of eye infections. Additionally, the act of tearing can help to physically remove debris and pathogens before they have a chance to invade the body further or cause irritation.

While lubrication, vision maintenance, and pH regulation are essential functions of tears, they do not directly relate to the defense against pathogens. Thus, the flushing action is the primary aspect of tears that contributes to the immune defense of the eyes and overall health.