| |
First Line of Defense (1 Defense 1) | Do not react to nor target specific antigens, just antigens in general. |
1 Defense 2 | Keratin provides a physical barrier to bacteria, weak acidity of skin (ph 3-5) inhibits some bacterial growth and sebum has chemicals toxic to bacteria, vaginal secretions are also acidic |
1 Defense 3 | Stomach secretes HCl and protein digesting enzymes |
1 Defense 4 | Saliva and lacrimal fluid (tears) contain lysozyme, a chemical that destroys certain bacteria |
1 Defense 5 | Mucus traps organisms and cilia sweep them away |
1 Defense 6 | Genetic lack of receptors or inadequate supply of nutrients |
Second Line of Defense (2 Defense 1) | Phagocytes (monocytes become macrophages) |
2 Defense 2 | Neutrophils - most abundant types of WBC, eosinophils and mast cells |
2 Defense 3 | Phagocytes must adhere to invader, but complement and antibodies allow opsonization to make eating easier |
2 Defense 4 | NK (natural killer) cells police blood and lymph; lyse and kill cancer cells and virus infected cells. Release perforins |
Inflammatory Response | triggered when body tissue injury occurs |
Purpose (Inflammatory Response) | Prevents spread of infection/microbes
Disposes of debris and pathogens
Repair process is enhanced |
Signs (Inflammatory Response) | Redness, swelling, heat, pain (sometimes impairment of function) |
Chemicals Released (Inflammatory Response) | Histamine, Kinins, Complement, |
Histamine | Vasodilation and increased permeability of capillaries |
Kinins | Similar to histamine, chemotaxis, pain |
Complement | Lyses microbes, enhances phagocytosis, intensifies inflammatory and immune response |
Hyperemia (Inflammatory Response) | Increased blood flow |
Hyperemia 2 | Congestion of tissues with blood causes heat and redness exudates causes swelling and pain |
Edema (Inflammatory Response) | Helps dilute harmful substances that may be present, brings oxygen and nutrients in for repair and allows clotting proteins to isolate injured area |
Leukocytosis | Chemicals from injured cells promote release of neutrophils from bone marrow (characteristic sign of inflammation) |
Margination | Blood flow slows in capillaries, cell adhesion molecules (CAMs) cause neutrophils to cling to area of inflammation |
Diapedisis | Neutrophils move out of blood stream and into tissues by squeezing through capillary walls |
Chemotaxis | Neutrophils respond to chemical signals that act as homing devices or beacons, directing cells to site of injury. Monocytes come later and mature into macrophages to clean up area |
Pus | a mixture of dead or dying neutrophils, broken down tissue cells and living and dead pathogens |
Complement | 20 plasma proteins that, when activated, amplify all aspects of the inflammatory response as well as killing bacteria by attacking their cell membranes and causing lysis, or contributing to opsonization for phagocytosis |
Fever | Pyrogens (fever causing chemicals) are released by leukocytes. Heat inactivates bacterial enzymes, keeps iron and zinc needed for cellular function away from bacteria, and speeds up repair of body cells |
Third Line of Defense (3 Defense 1) | It is an antigen specific ( recognizes and is directed against particular antigens) |
3 Defense 2 | It is systemic (not restricted of the initial infection site) |
3 Defense 3 | It has a memory (a stronger and quicker second attack is mounted on previously is mounted on previously encountered pathogens |
Humoral or antibody-mediated immunity (HAMI 1) | B lymphocytes, which mature in the bone marrow and proliferate in the lymph nodes and spleen, are activated when antigens bind to their surface receptors (BCR's). |
HAMI 2 | The B cell with the receptor for a specific antigen will then grow and rapidly divide, producing a family of cells with the exact same antigen-specific surface receptors called a CLONE |
HAMI 3 | Most cells of the clone become plasma cells, which secrete antibodies with the same specificity as the BCR on the parent cell |
HAMI 4 | Clone cells that do not differentiate into plasma cells become long-lived memory cells that are involved in the secondary immune response |
HAMI 5 | Antibodies are Y shaped molecules made of 4 polypeptide chains; two heavy and two light, bound by disulfide bonds. |
HAMI 6 | Each heavy and light consist of a variable region (the arms or Fab) and a constant region (the bottom or Fc) The Fab region of an antibody bind to a specific antigen |
Antibody-Antigen Complexes are Formed that causes | Neutralization or masking of exotoxins and viruses
Agglutination of particulate or cellular material
Precipitation of soluble antigen
Fixing and activation of complement
Opsonization |
Antibodies 5 Classifications | Ig MADGE |
IgG | Which is the most abundant circulating Ab, can cross the placenta, activates complement, protects against bacteria, viruses and toxins |
IgM | Binds to B cells as a receptor, forms a five antibody molecule that is first released by plasma cells during an infection. Causes agglutination reactions in mismatched blood types, and activates complement |
IgA | Found in body secretions (sweat, saliva, tears) as a two antibody molecule and helps prevent attachment of pathogens to mucous membranes and epidermis |
IgE (Bad, anaphylaxis) | Secreted by ski, mucosa, and tonsils. Constant (Fc) region binds to mast cells and basophils and when bound to antigen on the variable (Fab) region, it causes the cells to release histamine and other inflammatory chemicals. Levels rise during allergies |
IgD | Bind with IgM to B cells as a receptor |