B cells and T cells are essential to the adaptive immune system. B cells produce antibodies for humoral immunity, while T cells play a role in cell-mediated immunity. Their collaboration is crucial for efficient immune responses and the formation of immunological memory. Dysregulation of these cells can lead to autoimmune diseases and immunodeficiency disorders.

Monocytes are vital white blood cells that differentiate into macrophages and dendritic cells. They perform phagocytosis, present antigens to T cells, produce cytokines, and aid in tissue repair. While they can become tissue-resident macrophages and dendritic cells, not all do, as some macrophages and dendritic cells originate from embryonic precursors.

Phagocytic cells, like macrophages, neutrophils, and dendritic cells, play vital roles in the immune system by engulfing and processing foreign particles. Macrophages perform phagocytosis, regulate the immune response, and aid in tissue repair. Neutrophils rapidly respond to infections and form extracellular traps, while dendritic cells activate T cells and migrate to lymph nodes. These cells contribute to both innate and adaptive immunity.