What is the function of mucus in the body?

Mucus serves a crucial role in the body's defense system primarily by acting as a thick substance that traps pathogens, such as bacteria and viruses, preventing their entry into the body and facilitating their removal. It is produced by mucous membranes lining various passages and cavities, such as the respiratory tract, digestive system, and urogenital tract. By trapping foreign particles, mucus helps protect underlying tissues from potential harm and infection.

While mucus can have other functions, such as helping to keep tissues moist and aiding in the movement of certain materials within the body, its primary function in the context of protection against pathogens is the most significant. The assertion that it serves as a lubricant for joints and tissues, aids in digestion, or functions as a hormone is not aligned with its primary role or established functions in the body.