IMMUNOLOGY: Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. Immune System An immune system is a system of biological structuresa and processes within an organism that protects against Disease. Document Preview: IMMUNOLOGY: Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. Immune System An immune system is a system of biological structuresa and processes within an organism that protects against Disease. ORGANS OF THE IMMUNE SYSTEM: ORGANS OF THE IMMUNE SYSTEM Primary Lymphoid Organ (where maturation of lymphocytes takes place) Thymus Bone Marrow Secondary Lymphoid Organ (which trap antigen & provide sites for mature lymphocytes to interact with that antigen) Lymph Nodes Spleen Mucosal Associated Lymphoid Tissue(MALT) PRIMARY LYMPHOID ORGANS: PRIMARY LYMPHOID ORGANS 1. THYMUS: 1. THYMUS PowerPoint Presentation: The Thymus is the site of T cell development and maturation It is a flat, bilobed organ situated above the heart. Each lobe is surrounded by a capsule and is divided into lobules, which are separated from each other by strands of connective tissue called trabeculae. Each lobule is organized into two compart-ments: the outer compartment, or cortex, is densely packed with immature T cells, called thymocytes, whereas the inner compartment, or medulla, is sparsely populated with thymo-cytes. Both the cortex and medulla of the thymus are criss-crossed by a three-dimensional stromal-cell network com-posed of epithelial cells, dendritic cells, and macrophages,which make up the framework of the organ and contribute to the growth and maturation of thymocytes. Many of these stromal cells interact physically with the developing thymocytes. PowerPoint Presentation: The function of the thymus is to generate and select a repertoire of T cells that will protect the body from infection. As thymocytes develop, an enormous diversity of T-cell re-ceptors is generated by a random process that produces some T cells with receptors capable of recognizing antigen-MHC complexes. However, most of the T-cell recep-tors produced by this random process are incapable of recog-nizing Attachments: IMMUNOLOGY-by.docx