HSC 4555 Lecture Notes - Lecture 5: Lysis, Thymus, Monocyte
Document Summary
The primary lymphoid organs are the thymus and bone marrow. T cells develop in the thymus, whereas b cells develop in the bone marrow. Mature lymphocytes then migrate to secondary lymphoid structures, including the spleen and lymph nodes. Blood cells are produced in the bone marrow in response to specific hematopoietic growth factors. Granulocytes (neutrophils, basophils, eosinophils) and monocytes (macrophages) are phagocytic cells that provide innate protection. Lymphocytes (b cells, t cells) are specific cells that react only to particular antigens. Nk cells are lymphocytes that lack t-cell and b- cell markers and function in innate immune responses. Other blood components produced by bone marrow are erythrocytes and platelets. Neutrophils are the most numerous wbcs in blood. A large storage pool lies in the bone marrow and can be mobilized in response to antigen. Neutrophils are the predominant wbc type in early infection. They migrate to the area by following chemotactic factors and perform phagocytic functions.
