A man is scratched by his cat. A phagocyte near the scratch site recognizes and engulfs a bacterium. Shortly thereafter, more phagocytes arrive in the tissue surrounding the scratch. How are the additional phagocytes recruited to the site of the scratch?

Question

Quizplus · Accepted Answer

The additional phagocytes are likely recruited to the site of the scratch by cytokines that are secreted by the initial phagocyte. Cytokines are signaling molecules that can attract and activate immune cells, such as phagocytes, to a site of infection or injury. Antigens are typically recognized by immune cells such as B cells and T cells, and may play a role in initiating an immune response against a specific pathogen; however, they are not typically involved in the recruitment of phagocytes to a site of infection.

A Man Is Scratched by His Cat