What is the primary function of monocytes in the body?

Monocytes play a crucial role in the immune response primarily through their ability to perform phagocytosis. Phagocytosis is the process by which immune cells engulf and digest pathogens, dead cells, and debris, helping to clear infections and maintain tissue homeostasis. Once in tissues, monocytes can differentiate into macrophages and dendritic cells, which are essential for both innate and adaptive immunity. In this capacity, they can exhibit powerful phagocytic activity and also present antigens to T cells, thus linking the innate immune response with the adaptive immune response.

The other functions listed are typically carried out by different cell types. For instance, antibodies are produced by B cells, not monocytes; red blood cells are the ones responsible for transporting oxygen in the blood; and neurons develop from neural stem cells rather than from monocytes. This highlights why the primary function of monocytes is accurately related to their role in phagocytosis, distinguishing them clearly from the functions of other blood cells.