Lymphatic System and Immunity Vocabulary

Flashcards defining key vocabulary terms related to the lymphatic system and immunity, as presented in the lecture notes.

Immunity

The ability of an organism to resist infection.

Antigen

A molecule capable of generating antibodies and triggering an immune response.

Natural Killer Cells

White blood cell that recognizes and destroys cells infected by viruses or abnormal cells (e.g., cancer).

Antibody

A protein produced by B cells that interacts with a specific antigen to neutralize or eliminate it.

Pyrogen

A chemical, often a protein, released during phagocytosis that causes fever.

Phagocytosis

The process by which cells engulf and remove pathogens or debris.

Cytokines

Small proteins secreted by cells that cause changes in other cells, especially stimulating immune responses.

Antigen-Presenting Cells (APCs)

Cells that engulf antigens and present them to T cells, initiating an immune response (e.g., macrophages, dendritic cells).

Class I MHC Cells

Found on all nucleated cells; present antigens to cytotoxic T cells when the cell is infected.

Class II MHC Cells

Found only on antigen-presenting cells (APCs); present antigens to helper T cells.