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93 Cards in this Set
- Front
- Back
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Lymphocytes
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White blood cells which produce 2 general types of immune responses
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Immune system
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The body's defense that prevents organisms from getting into the interior of the body or stops them from proliferating if they are within the body
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1st line of defense
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A BARRIER that helps prevent pathogens from entering the body
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Types of 1st line of defenses
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-skin
-mucous membranes -cilia in the respiratory system to sweep out mucus -stomach acid -oil/sweat glands which are acidic enough to prevent microbe colonization |
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Mucous membranes releases mucus that contain antimacrobial substances including.....
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Lysozymes
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Lysozyme
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A protein enzyme that digests the cell walls of many bacterias
-present in mucus, saliva, and tears -destroy susceptible bacteria as the enter the upper respiratory tract or the openings around the eyes |
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Antibodies
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Defensive proteins that bind to microbes and mark them for elimination
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Phagocytosis
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The ingestion of invading microorganisms by certain types of white blood cells (phagocytes)
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Phagocytes initiate
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Inflammation, which can limit the spread of microbes in the body
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2nd line of defense
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-phagocytic cells
-antimicrobial proteins -inflammatory response -natural killer cells |
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Microbes are destroyed by lysosomes in 2 ways
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1) nitric oxides and other toxic forms of oxygen contained in the lysosomes may poison the engulfed microbe
2) lysozyme and other enzymes degrade microbial components |
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Some microorganisms have adaptations that enable them to evade destruction by phagocytic cells
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1) outer capsule that surrounds some bacterial cells hides their surface polysaccharides and prevents phagocytes from attaching from them
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The most abundant white blood cells
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Neutrophils
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Neutrophils
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Are attracted to and then enter infected tissue, engulfing and destroying the microbes there
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Bad thing about neutrophils
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They tend to self destruct in the process of phagocytosis and their average life span is only a few days
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Macrophages develop from____
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Monocytes
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Chemotaxis
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A response when phagocytes migrate to an affected site in response to local chemical attractants
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Macrophages are more effective than neutrophils because they__
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Are large, LONG-LIVED cells
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Eosinophils
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Have low phagocyte activity but are critical to defense against multicellular parasitic invaders
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Complement
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A group of proteins, that leads to the lysis (bursting) of invading cells
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Interferons
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Provide innate defense against viral infections
-they induce neighboring uninfected cells to produce other substances that inhibit viral reproduction -LIMIT THE CELL TO CELL SPREAD OF VIRUSES IN THE BODY |
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Inflammatory response
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Triggered by Damage to tissue by physical injury or the entry of pathogens leads to release of numerous chemical signals
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One of the most active chemicals that cause an inflammatory response is
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Histamine
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Histamine is stored in
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Mast cells
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Mast cells are found in...
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Connective tissue
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Vasodilation
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Enlargement of blood vessels
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What happens during an inflammatory response?
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1) when injured, mast cells release their histamine which triggers dilation and increased permeability of nearby capillaries
2) activated macrophages discharge additional signals like prostaglandins, that further promote blood flow to the injured site 3) increased local blood supply causes the redness and heat typical of inflammation 4) these vascular changed help deliver antimicrobial proteins and clotting elements to the injured area |
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Prostaglandins
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Further promote blood flow to the injured site
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Chemokines
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Small proteins that direct the migration of phagocytes and prostaglandins and signal them to increase production of microbe killing compounds
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Pyrogens
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Increase body temperatures to speed up the immune system and make it more difficult for microbes to function
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Natural killer cells
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-patrol the body and attack/destroy virus infected body cells and cancer cells
-attack the cell membrane and cause it to Lyse (burst open) and die |
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1st and 2nd line of defenses are specific/nonspecific. Whereas 3rd line of defense is specific/nonspecific
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1) nonspecific (innate)
2) specific |
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Cytokines
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Proteins that help activate lymphocytes and other cells of the immune system
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What secretes cytokines
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Macrophages as the phagocytose microbes
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Antigens
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Any foreign molecule that is specifically recognized by lymphocytes and elicits a response from them
-they cause the production of antibodies |
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Epitome
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A small, accessible portion of an antigen in which a lymphocyte actually recognizes and binds to
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B lymphocytes and T lymphocytes originate in the
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Bone marrow
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____produce antibodies
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B lymphocytes
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Humoral response
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Involves the activation of B cells and leads to the production of antibodies
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How do B lymphocytes become stimulated
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By T lymphocytes or by free viruses and bacteria toxins floating in the blood
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B lymphocytes mature in the
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Bone marrow and help fight disease
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T lymphocytes mature in the
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Thymus gland
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T lymphocytes fight pathogens by
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Cell mediated response
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T lymphocytes become stimulated by...
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body cells that have been infected with bacteria, viruses, and parasites
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Antigen presenting cells (APC)s
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they display foreign antigens on their surface
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cell mediated immune response
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involves the activation and clonal selection of cytotoxic T cells which directly destroy certain target cells
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T lymphocytes fight pathogens by
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a cell mediated response
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Cytotoxic T cells
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kill body cells infected with viruses or other pathogens and cancer cells
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receptors on B cells recognize___ antigens
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intact
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receptors on cytotoxic T cells recognize____of antigens that are bound to normal cell surface proteins called___
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1) small fragments
2) class 1 MHC molecules |
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receptors on helper T cells recognize_____of antigens that are bound to normal cell surface proteins called___
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1) small fragments
2) class II MHC molecules |
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Helper T cells
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announce to the immune system, with the help of macrophages and some B cells, that foreign antigens have entered the body
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When a helper T cell binds to a class II MHC molecule, a ____surface protein from the helper T cell holds tha two cells together ntil the helper T cell is activated
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CD4
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when a helper cell is activated, it proliferates and differentiates into____and____
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plasma cells and memory cells
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because helper T cells have CD4 proteins on their cell surface, they are referred to as ___cells
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CD4
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helper T cells stimulate cytotoxic cells, B cells, and other helper T cells by _____
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releasing the cytokines, interleukin-1, and interleukin-2
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When a cytotoxic T cell binds to a class I MHC molecule, a___surface protein from the cytotoxic T cell holds the two together until the cytotoxic T cell is activated
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CD8
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when a cytotoxic T cell is activated, it proliferates and differentiates into ___and____
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plasma cells and memory cells
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because cytotoxic T cells have the CD8 proteins on their cell surface, they are also called____cells
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CD8 cells
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activated cytotoxic T cell attack and kill infected cells by releasing____
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perforin, which causes the cell to lyse (burst open) and die
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perforin
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a protein that forms pores in the target cell's membrane
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class I MHC molecules
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are found on almost every body cell
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Class II MHC molecules
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are found on specialized cells, including macrophages, B cells, and activated T cells
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clonal selection
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each antigen, by binding to specific receptors, selectively activates a tiny fraction of cells from the body's diverse pool of lymphocytes; this relatively small number of selected cells gives rise to clones of thousands of cells, all specific for and dedicated to eliminating that antigen
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proliferates
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clones thousands of copies of itself in lymphatic tissue
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once a lymphocyte is selected, it becomes____,____,____
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metabolically active, proliferates, and differentiates into plasma cells and memory cells
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plasma cells
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short-lived and fight the antigen immediately
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primary immune response
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does not peak until about 10-17 days after the initial exposure to the antigen.
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memory cells
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are loong-lived cells bearing receptors specific to the same antigen as the plasma cells and that remain circulating in the blood in small numbers for a LIFETIME
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if the body is attacked or challenged in the future by the same antigen, the____ rapidly reactive. this response is called the secondary immune response
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memory cells
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secondar immune response
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peaks 2-7 days after exposure
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immunological memory
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the capacity of the immune system to generate a secondary immune response
-it is the mechanism that prevents you from getting any specific viral infection more than once |
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antibodies are also called
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immunoglobins
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each antibody molecules is shaped like a____. and consists of....
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1) Y-shaped molecule
2) consists of 4 polypeptide chains: 2 identical heavy and 2 identical light chains |
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the four polypeptide chains of an antibody are held together by a ...
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disulfide bridge
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antibodies destroy free floating antigens in 2 major ways:
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1) antibodies neutralize the antigen by causing them to clump, forming an antigen-antibody complex. this is phagocytosed by macrophages
2) second way is through complement fixation, the activation of complement, a group of about 20 proteins that assist in lysing cells |
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complement fixation
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the activation of complement, a group of about 20 proteins that assist in lysing cells (bursting open)
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antigen-antibody complex
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clumped antigens formed when neutralized by antibodies
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passive immunity
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antibodies are transferred to an individual from someone else.
Examples: maternal antibodies that pass through the placenta to the developing fetus or through breast milk to the baby. TEMPORARY |
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active immunity
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the individual makes his or her own antibodies after being ill and recovering or after being given a vaccine.
PERMANENT |
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the certain danger in a transfusion comes if
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the recipient has antibodies to the donor's antigens
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cross-match
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when 2 samples of donor and recipient blood must be mixed to determine compatibility in the transfusion of blood
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blood type O is known as the universal donor because...
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it has no blood cell antigens to be clumped by the recipient's blood
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blood type AB is known as the universal recipient because...
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there are no antibodies to clump the donor's blood
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Rh factor is another antigen located on...
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the surface of red blood cells
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most of the population, 85%, has Rh+/Rh-
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Rh+
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AIDS stands for
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acquired immune deficiency disease
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the virus that causes AIDS, HIV, attacks cells that bear...
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CD4 molecules on their surface, mainly helper T cells.
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anaphylactic shock
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when an acute allergic response results in a life-threatening reaction
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how does anaphylactic shock occur
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1) widespread mast cells triger abrupt dilation of periperal blood vessels
2) this causes a huge drop in blood pressure 3) death may occur in a few minutes |
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antibiotics
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medicines that kill bacteria or fungi
-administered after a person is sick |
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autoimmune diseases
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caused by a terrible mistake of the immune system
-system can't properly distinguish between self and nonself and attacks them |
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monoclonal antibodies
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antibodies produced by a single B cell that have been selected for a specific antigen.
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