Immune System
Pathogen- A bacterium, fungus, virus, or other disease causing agent.
Emergent Disease- Can be either a disease that is new or a disease that has long existed but which has for some reason has become a new problem.
Immune System- Made up of the cells and tissues of the body that interact with and destroy pathogens
First Line of Defense- Prevent pathogens from entering the body, such as mucus- that traps the bacteria
Barrier Defenses- The first lines of defense prevent pathogens from entering the body
Lysozyme-Enzyme called lysozyme is antimicrobial and breaks down bacterial cell walls (found
in saliva, mucus, and tears)
Molecular Recognition- The central event in identifying nonself molecules, particles, and cells. The specific binding of immune receptors to foreign molecules
Adaptive Immunity- Vertebrates only. Pathogen specific recognition. Lymphocytes form from bone marrow and circulate throughout blood.
Innate Immunity- Relies on a small set of receptor proteins(toll- like receptors; TLRs) that bind to molecules or structures that are absent from animal bodies but common to a group of viruses, bacteria, and other microbes.
Hemocytes- Cells that ingest and break down invaders using phagocytosis- many release antimicrobial peptides
Phagocytosis- Ingestion of bacteria using phagocytes
Cellular Defense- Rely on several types of receptors on the surface of immune cells
Neutrophils- Circulate in the blood and are attracted by signals from infected tissues and then engulf and destroy infecting pathogens
Macrophages- large phagocytic cells. Killer Cells- Circulate throughout the body and detect an array of surface proteins of virus infected and cancerous cells.
Interferons- Proteins that provide innate defense by interfering w/ viral infections
Histamine- triggers the nearby blood vessels to dilate and become more permeable increasing redness and supply
Lymphatic System- Lymphocytes form from bone marrow and circulate through the blood and lymph recognizing specific pathogens.
Apoptosis- Programmed cell death
Inflammatory Response-A defense triggered by physical injury or infection of tissue involving the release of substances that promote swelling, enhance the filtration of white blood cells, and aid in tissue repair and destruction of pathogens.
T cell- Mature in thymus
B cell- Mature in bone marrow
Lymphocyte- form from bone marrow and circulate through the blood and lymph recognizing specific pathogens.
Antigen- A toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
Hummoral Response- The activation and clonal selection of plasma and memory B cells, which produce antibodies that circulate in the blood and lymph
Activation- Begins when an antigen binds to a B-cell receptor
Clonal Selection-B-cells form clones in response to a specific antigen to amplify the response the cells can have.
Cytokines- small proteins that regulate the
function of other cells (cell communication)
Memory cell- Remember what your body came into contact with
Primary Immune Response- The body is first exposed to a foreign antigen and a B cell is activated producing plasma cells that make antibodies against the specific antigen
Secondary Immune Response- Happens when the same antigen invades the body at another time: faster and greater magnitude
Cell Mediated Immune Response- involves activation and clonal selection of cytotoxic T cells (Tc), which identify and destroy infected cells
Cytotoxic T cell- Destroy infected cells
Helper T cell-s help with both the humoral and cell mediated immune responses
Active immunity- happens when being exposed to an antigen leaves circulating memory cells
Passive Immunity- When receives antibodies
Allergies- Antibodies produced after first exposure to an allergen attach to receptors on mast cells
Autoimmune Diseases- The immune system turns against specific molecules of the body allowing cytotoxic T cells to attack healthy cells belonging to self
Immune System Avoidance- Changes in epitope expression allows an antigen to avoid the immune system
or the antigen goes into an inactive state (latency)