It is comprised of [[Primary Lymphoid Tissue - Anatomy & Physiology|primary]] lymphoid organs which are responsible for the production of lymphocytes and the [[Secondary Lymphoid Tissue - Anatomy & Physiology|secondary]] lymphoid organs which function to provide an environment where [[Lymphocytes|lymphocytes]] can react to antigen from the tissue fluid, blood and mucosal surfaces. | It is comprised of [[Primary Lymphoid Tissue - Anatomy & Physiology|primary]] lymphoid organs which are responsible for the production of lymphocytes and the [[Secondary Lymphoid Tissue - Anatomy & Physiology|secondary]] lymphoid organs which function to provide an environment where [[Lymphocytes|lymphocytes]] can react to antigen from the tissue fluid, blood and mucosal surfaces. |