Which of the following is not a type of cell associated with mucosal lymphoid tissue?

A. The appendix is an organ that contains lymphoid tissue and plays a role in immune function, but it does not specifically refer to macrophages and monocytes.
B. The reticuloendothelial system (also known as the mononuclear phagocyte system) consists of macrophages and monocytes found throughout the body. These cells are part of the immune system and are responsible for phagocytosis, or the engulfing and digesting of pathogens, dead cells, and debris.
C. Peyer's patches are clusters of lymphoid tissue found in the small intestine that monitor and respond to pathogens in the digestive tract.
D. Tonsils are lymphoid tissues located in the throat, playing a role in immune defense, but they are not part of the reticuloendothelial system.

A. Species specific immunity refers to the natural resistance that a species has to certain diseases that affect other species. This type of immunity prevents humans from contracting certain diseases that are specific to other animals, like certain viruses or bacteria.
B. Specific immunity refers to the adaptive immune response that targets particular pathogens, but it doesn't apply to the protection humans have against animal-specific diseases.
C. Nonspecific immunity refers to the general defense mechanisms (like skin or phagocytes) that protect the body from a broad range of pathogens, not specifically from animal diseases.
D. Active immunity involves the body producing its own immune response after exposure to a pathogen, but it does not specifically describe the protection from diseases of other