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21 Cards in this Set
- Front
- Back
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Cytotoxic T-cell
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T cell with CD8 receptor that recognizes antigens on the surface of a virus-infected cell and binds to the infected cell and kill it
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Phagocyte
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A type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.
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Macrophage
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A large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, esp. at sites of infection.
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Memory Cell
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Any small, long-lived lymphocyte that has previously encountered a given antigen and that on reexposure to the same antigen rapidly initiates the immune response
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B-Cell
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A lymphocyte not processed by the thymus gland, and responsible for producing antibodies.
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NK (natural killer) Cell
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A cell that can react against and destroy another cell without prior sensitization to it. NK cells are part of our first line of defense against cancer cells and virus-infected cells. NK cells are small lymphocytes that originate in the bone marrow and develop without the influence of the thymus
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Pathogen
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An organism or virus that causes a disease.
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Antibiotic
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A medicine (such as penicillin or its derivatives) that inhibits the growth of or destroys microorganisms.
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Leukocyte
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A colorless cell that circulates in the blood and body fluids and is involved in counteracting foreign substances and disease
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Antigen
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A toxin or other foreign substance that induces an immune response in the body, esp. the production of antibodies.
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Active Immunity
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The immunity that results from the production of antibodies in response to an antigen.
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Passive Immunity
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The short-term immunity that results from the introduction of antibodies from another person or animal.
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Platelets
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A small colorless disk-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting.
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Fibrinogen
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A soluble protein present in blood plasma, from which fibrin is produced by the action of the enzyme thrombin.
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Fibrin
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An insoluble protein formed from fibrinogen during the clotting of blood.
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List the sequenced events necessary to form a clot within one of the small damaged blood vessels
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Platelets form an intial plug in the cute. However, it is not strong enough to last on its own. Clotting factors pass by and are attracted to the hole and come to reinforce the platelets. A web of fibrin is formed and acts as a glue. Other cells, such as red and white blood clle,s are added to support the clot.
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Why do antibiotics kill bacteria but not viruses?
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1) Antibiotics block specific metabolic pathways in bacteria.
2) Bacteria are very different to human cells so human cells are not affected. 3) Viruses require host cell to carry metabolic processes for them and so antibiotics cannot be used to treat viruses. 4) Harming the virus would harm the human cells. |
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Antivenom is composed of antibodies which recognize the venom protein molecules and bind to them. The injection of this antivenom is referred to as an example of passive immunity and does not confer long-term immunity to the individual. Why not?
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The venom (antigen) is inoculated into other mammals, e.g., in horses; these animals make specific antibodies against the antigen; blood from the animals is collected and purified to get the antibodies; this antibody-containing material is the antivenom. When a human being is infected by the antigen the specific antivenom is given to him/her and the action against the antigen occurs.
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Why are some viruses potentially lethal (HIV, Ebola) while other cause fairly mild symptoms?
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In general, the specificity (target) of the virus and the host response to infection determine the lethality. For example, the Ebola virus targets the lining of blood vessels, resulting in death via significant blood loss. Many survive infection by flu viruses, but those who have an intense response (often young adults) or those whose bodies are less able to withstand the stress of a normal response (often the elderly or those with other diseases) are more likely to succumb.
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Explain how the skin and mucous membranes prevent entry of pathogens into the body.
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Skin:
1) Forms a physical barrier. 2)Sebaceous glands secret lactic acid and fatty acids. Mucous membranes: 1) Mucous contains lysozyme enzymes. 2) Mucous can be sticky and trap pathogens.. |
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Which type of cell is responsible for secondary immune responses to a pathogen?
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Memory cells
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