Which type of immunity includes anatomical barriers and physiological responses?

Natural immunity refers to the body's first line of defense against pathogens and includes both anatomical barriers and physiological responses. Anatomical barriers consist of physical structures such as the skin and mucous membranes that prevent the entry of pathogens. Physiological responses include processes like mucous secretion, skin secretions, and the action of cilia that help trap and push out foreign invaders.

Natural immunity is nonspecific, meaning it provides a general defense against a wide range of pathogens without the need for prior exposure. This differs from acquired immunity, which is specific and develops after exposure to a particular pathogen, often involving the adaptive immune response with memory cells.

While specific immunity and cell-mediated immunity provide targeted responses to specific pathogens, this question focuses on the innate aspects of the immune system that include immediate, nonspecific defenses, which are characteristic of natural immunity.