Final answer:
Kupffer cells are the phagocytic macrophages in the liver responsible for ingesting bacteria and other foreign particles. They are crucial to the body's innate and adaptive immune response and serve to protect the body by engulfing and digesting pathogens through phagocytosis.
Step-by-step explanation:
The phagocytic macrophages in the liver are known as Kupffer cells. These cells have the role of ingesting bacteria and foreign substances within the liver.
Macrophages are a type of white blood cell that are part of the immune system. They can be found throughout the body and are derived from monocytes. Macrophages are essential for the body's defense mechanisms; they move through tissues using an amoeboid movement to engulf and digest cellular debris, foreign substances, microbes, cancer cells, and anything else that does not have the types of proteins specific to healthy body cells on its surface, through a process called phagocytosis. This process involves the engulfment of a pathogen which then fuses with a lysosome within the macrophage to destroy the pathogen.
Aside from Kupffer cells in the liver, other types of macrophages include histiocytes in connective tissue and alveolar macrophages in the lungs. Macrophages are also key to initiating immune responses by releasing cytokines, which act as messengers to recruit other immune cells to the site of infection.