Chapter 7- Immunity Flashcards
Components of immune system
Lymphoid structure, immune cells or lymphocytes and macrophages, and tissues involving immune cell production and development
Elements of immune system
Antigens, genes passed from parents, MHC molecules, monocytes, macrophages, phagocytic, antibodies and immunoglobins, complement system, and chemical mediators
Antigens
Activate the immune system
MHC molecules
Detect changes in cell membranes due to viruses or cancer
Memory cells
Occur when a person has been exposed to the specific foreign antigen and must have developed specific immunity to it
Natural immunity
Species-specific
Innate immunity
Gene-specific
Primary response
Occurs when a person is first exposed to an antigen
Secondary response
Occurs when a repeat exposure to the same antigen occurs
Bone marrow
Cell-mediated immunity (T cells) and humoral or antibody mediated immunity (B cells)
Lymphocytes
T-cells (directly destroy invading antigens), B-cells (antibody production), and natural killer cells
IgG
Most common; activates complement
IgM
Bound to B lymphocytes in circulation; first to increase; ABO blood type reactions
IgA
Found in secretions; provides protection to newborn child
IgE
Bound to mast cells; present in inflammation; release of histamine
IgD
Attached to and activated B cells
Natural active
Exposed to the pathogen; body creates immunity
Artificial active
Vaccines
Natural passive
Temporarily protective
Artificial passive
Must be given (anti-serum) and provides a temporary immunity
Bioterrorism
Using altered antigenic forms of common viruses or bacteria. Would have a widespread impact on populations because immunizations would not protect against them
Allograft
Exchanged between same species
Isograft
Exchanged between two genetically identical bodies
Autograft
Tissue from same individual transferred from one part of the body to another
Xenograft
Exchanged between two different species
Rejection process
Involves type IV cell-mediated hypersensitivity reaction and humoral response. The rejection process eventually destroys the organ so that transplanted organs need to be replaced
Host-versus-graft disease
The recipient’s immune system rejects the graft
Graft-versus-host disease
Graft T-cells attack host cells
Immunosuppression techniques
Used to reduce the immune response and prevent rejection. Drugs must be taken on a continuous basis and patient must be monitored for rejection. Limit normal body defenses
Type I hypersensitivity
IgE. Allergic reactions (mild to severe). Histamine release, mast cells, inflammation, swelling, itching, and anaphylaxis
Type II hypersensitivity
IgG or IgM. Cytotoxic hypersensitivity. Cytolytic enzymes released; destroy cells. Blood transfusion reactions; causes destruction of blood cells called hemolysis. RH factor incompatibility
Type III hypersensitivity
Antigen/antibody immune complex. Immune complex hypersensitivity. Inflammation and tissue destruction. Auto-immune disease
Type IV hypersensitivity
T-lymphocytes. Cell-mediated or delayed hypersensitivity. Delayed response by sensitized T lymphocytes to antigens, resulting in release of lymphokines or other chemical mediators that cause an inflammatory response and destruction of the antigen
Immunodeficiency
The body’s capacity to fight foreign substances results in a compromised or a lack of an immune response. Partial or total loss of function in one or more components of the immune system leading to increased risk of infection and cancer
AIDS
Chronic infectious disease caused by human immunodeficiency virus. Destroys the helper T lymphocytes. Normal immune response is lost resulting in increased susceptibility to secondary infections and cancer. Characterized by a prolonged latent period followed by a period of active infection
