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body defense
test 2
| Term | Definition |
|---|---|
| 2 types of defenses | nonspecific and specific |
| homeostasis | protects body against foreign organisms, toxins, chemicals, damaged cells and tissues |
| nonspecific body defenses (first line) | epithelial barriers; phagocytes; antimicrobial chemicals |
| nonspecific body defenses (second line) | fever; inflammation |
| epithelial barriers | skin; cornea; mucous membranes |
| phagocytes | macrophages; neutrophils; eosinophils |
| antimicrobial chemicals | acids; lysozymes; complement; interferons |
| acids | stomach, vagina, urethra |
| lysozyme | polysaccharide; binds to and destroys bacterial cell walls |
| complement | proteins; bind to bacteria and parasites, directly lyse them, mark them for phagocytes |
| interferons | proteins; prevent viruses from infecting cells and mark virus-infected cells for phagocytes |
| fever | purposely raising body temp since some bacteria cannot reproduce at high temps; some bacteria causes body temps to raise to dangerous levels though |
| inflammation | inflammatory chemicals from damaged tissues; vasodilation, pain increase capillary permeability |
| increased capillary permeability | swelling, increased oxygen, attraction of leukocytes |
| 4 things specific defenses must be | specifc, adaptive, systematic, memory |
| specific | provides defense against antigens recognized as non-self |
| adaptive | defense can be targeted against new antigens |
| systematic | defenses are distributed through entire body, not limited to site of infection |
| memory | mounts stronger and faster defense against previously encountered antigens |
| self-tolerance | immune system must not respond and attack to the body's own cells and molecules |
| pathogen | any organism against which the immune system responds |
| antigen | any molecule against which the immune system responds; may be isolated molecule; may be a larger structure |
| antibody (immunoglobin) | a specific protein which binds to an antigen; produced by lymphocytes |
| antigenic determinant or epitope | the specific part of an antigen which an antibody recognizes and binds to |
| cell-mediated immunity | macrophages and t lymphocytes; lymphocytes directly attack invading or damaged cells; effective against invading cells or damaged cells; begins when macrophage presents anigen to immunocompetent T lymphocytes |
| humoral immunity | antibodies produced by plasma cells (b-lymphocytes with some help from t-lymphocytes); antibodies attach to invading cells or isolated antigens |
| macrophages | engulf and destroy pathogens, damaged cells, present antigens to lymphocytes, secrete activation factors |
| B lymphocytes | plasma cells and memory cells |
| T lymphocytes | cytotoxic cells; helper cells; regulatory/suppressor cells; memory cells |
| Antigen presenting cells | reticular cells; dendritic cells |
| T lymphocytes | become immunocompetent in thymus; responsible for cell-mediated immunity |
| B-lymphocytes | become immunocompetent in bone marrow and regions of digestive system; responsible for humoral immunity |
| humoral immune response | effective against both isolated antigens and cells; begins when immunocompetent B lymphocyte recognizes and binds to a specific antigen, becoming activated |
| 3 actions of antibodies | 1) neutralize the anitgen by changing its shape 2) cause antigens or pathogen to agglutinate or precipitate 3) mark the antigen or pathogen to by phagocytosed |
| cytotoxic T lymphocytes | when activated, it binds to target cell and releases molecules which directly damage it |
| helper T lymphocytes | when activated, it secrete chemicals which acivate macrophages and stimulate proliferation of both B and cytotoxic T lymphocytes |
| regulatoy/suppressor T lymphocytes | secrete chemicals which suppress the activates of both T and B lymphotcytes; necessary to slow down immune response after antigen or invading.damaged cell destroyed; minimizes risk of cross-relativity and damage to self cells; help make memory cells |