PSL201Y1 Lecture Notes - Neutrophil, Epitope, Polysaccharide
Document Summary
Immunity refers to the immune system"s capacity to protect individuals from disease by recognizing and eliminating potentially pathogenic (disease-generating) agents, including bacteria, bacterial toxins, viruses, parasites, and fungi. The presence in the body of such foreign and abnormal substances induces the immune system to develop an immune response, a complex series of physiological events that culminates in the destruction and elimination of these substances. Lymphoid tissues: bone marrow, thymus, spleen, lymph nodes, and tonsils, in which leukocytes develop, reside, and come into contact with foreign materials. The granulocytes neutrophils, eosinophils, and basophils have cytoplasmic granules that contain secretory products, degranulation. The agranulocytes monocytes and lymphocytes lack granules. The target cell succumbs to lysis, a process in which it fills with fluid and bursts: nk cells fight viral infections. Mast cells and dendritic cells: precursors of mast and dendritic cells are formed in the bone marrow from hematopoietic stem cells.