IMMUNOLOGY

Detailed explanation-1: -Macrophages respond to foreign bodies due to their ability to recognize self and non-self. Antigen-presenting cells, which include macrophages and dendritic cells, are able to process antigens during their and present them to the cells of the adaptive immune system.

Detailed explanation-2: -Macrophages are a type of white blood cell that play an integral part in the immune system with the role of phagocytosing foreign antigens, such as bacteria. They are able to present these antigens to other immune cells, such as T-cells, for further destruction.

Detailed explanation-3: -Macrophages are the body’s first line of defense and have many roles. A macrophage is the first cell to recognize and engulf foreign substances (antigens).

Detailed explanation-4: -In the 1880s Russian-born zoologist and microbiologist Élie Metchnikoff introduced the term phagocyte in reference to immune cells that engulf and destroy foreign bodies such as bacteria.

Detailed explanation-5: -Macrophages are able to detect products of bacteria and other microorganisms using a system of recognition receptors such as Toll-like receptors (TLRs).

Detailed explanation-6: -Macrophages detect pathogenic microorganisms by expressing pattern recognition receptors (PRRs), which interact with conserved microbe-associated molecular patterns (MAMPs).