Discuss the role of lymphoid organs in the immune response. Explain the different types of lymphoid organs giving two examples of each type in humans.
the role of lymphoid organs in the immune response is the origin, maturation & proliferation of lymphocytes. these lymphoid organs are of two types: - 1. Primary Lymphoid Organ: - they are sensitive lymphocytes in which the immature lymphocytes differentiate into antigens. it consists of: - (a) Bone Marrow: – it is the main lymphoid organ where all types of blood cells including lymphocytes are formed and are present in the thigh region. it helps in the development & maturation of b – cells by providing a micro-environment. (b) Thymus: - it is located beneath the chest bone near the heart. it helps in the development & maturation of t – lymphocytes by providing a microenvironment. 2. Secondary Lymphoid Organ: - they help the lymphocytes to interact with the antigen which results in the proliferation leading to the formation of effector cells. it includes. (a) Spleen: - it is a large bean-shaped organ that consists of lymphocytes & phagocytes. it is called the graveyard of rbcs and thus acts as a filter of blood by trapping blood–bound microorganisms. (b) Lymph Node: - they are small – solid structures and are part of the lymphatic systems that are located at different points. its main role is to trap the antigens that try to enter into lymph & tissue fluid. these antigens will result in the activation of lymphocytes.
