Immunity System
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Lymphoid Organs – Locations And Functions – Red Bone Marrow, Thymus, Lymph Nodes, And Spleen.
Lymphoid structures can be found throughout the body. While all lymphoid structures are capable of lymphocyte production, the red bone marrow and thymus are considered primary lymphoid organs because all WBCs, especially lymphocytes, originate in these organs. After production in the red bone marrow most lymphocytes and
Immunity Or Specific Resistance – Cell-Mediated Immunity And Antibody-Mediated Immunity
In contrast to nonspecific resistance, immunity (i-mu- ni-te), or specific resistance, is directed at specific antigens. An immune response involves the production of specific cells and substances to attack a specific antigen. Immunity has “memory,” that is, if the same pathogen should reenter the body at a
Immune Responses – Primary And Secondary Immune Responses
When an antigen is encountered for the first time, it stimulates T cells and B cells to become activated and proliferate, producing clones that attack and destroy the invading antigen. This is the primary immune response, and it also produces memory cells that are able to recognize
Rejection of Organ Transplants
Organ transplants are viable treatment options for persons with terminal disease of certain organs such as the heart, kidneys, and liver. Except for the surgery, the major problem encountered is that the patient’s lymphoid system recognizes the transplanted organ as foreign and launches an attack against it.
Disorders of The Lymphoid System
Infectious Disorders Acquired immunodeficiency syndrome (AIDS) is a viral disease that is approaching epidemic proportions. It is caused by the human immunodeficiency virus (HIV), which attacks and kills helper T cells and invades macrophages, which serve as a reservoir for the virus. In time, the immune defenses
