AP Biology Exam Review Chapter 14: The Human Immune System-platarozaluna Flashcards

Terms Definitions
what is the first line of nonspecific defense?
a barrier that helps prevent pathogens from entering the body
what are some examples of first line non-specific defense?
skin, mucous membranes, cilia, stomach acid
what is the second line of non-specific defense?
limits the spread of invaders in advance of specific immune responses
what are some inflammatory responses?
-histamine: triggers enlargement of blood vessels, which increases blood supply to the area and brings phagocytes, triggers common cold symptoms
-prostoglandins-promote blood flow to the area
-chemokines-attract phagocytes to the area
-pyrogens-increase the body temperature to make it more difficult for microbes to function
what are phagocytes?
ingest invading microbes, there are two types: neutrophils and monocytes
what is chemotaxis?
phagocytes migrate to an infected site in response to local chemical attractants
what are neutrophils?
engulf microbes and die within a few days
what are monocytes?
transform into macrophages, extend pseudopods, and engulf huge numbers of microbes over a long period of time
what is a complement?
a group of proteins, that leads to the lysis (bursting) of invading cells
what are interferons?
1. inhibits viral replication
2. inhibits cell proliferation
3. increases lytic potential of natural killer cells
4. modulates (increases or decreases) MHC molecule expression
what are natural killer cells?
Large granular lymphocytes, target cells that lack "self" cell-surface receptors. Induce apoptosis in cancer cells and virus infected cells. Secrete potent chemicals that enhance the inflammatory response.
what is the third line of defense?
it's specific and relies on B lympocytes and T lymphocytes which originate in the bone marrow. They circulate in the blood, lymph, and lymphatic tissue and recognize different specific antigens (substances that cause the production of antibodies)
what are B lymphocytes?
CD-19/20. Mature in the marrow ONLY and then migrate into lymphoid tissue. Dif into plasma cells. Function as APC as well, produce antibodies
what are T lymphocytes?
HELPER T CELLS: T lymphocytes that orchestrates cellular immunity by direct contact with other immune cells and by releasing chemical called lymphokines: also helps mediate the humoral response by interacting with B cells. SUPPRESSOR T CELLS: regulate T lymphocytes that suppress the immune system. CYTOTOXIC (killer) T CELLS: effector T cell that directly kills foreign cells.
what are MHC molecules?
major histocompatibility complex molecules, also called HLA (human leukocyte antigens)
a collection of cell surface markers that identify the cells as self
what are the two classes of MHC molecules?
-Class I MHC molecules: expressed by nearly all nucleated cells of vertebrate species
-Class II MHC molecule: express only by antigen-presenting cells (APCs)
what is clonal selection?
antigenic molecules select or bind to specific B or T lymphocytes, making it metabolically active and causing it to clone itself and differentiate into plasma and memory cells
what are plasma cells?
Immune cells developed from B lymphocytes; Function to produce antibodies that fight against foreign substances, primary immune response 10-17 days
what are memory cells?
Memory cells recognize the second attack of the same pathogen and attack it much faster, secondary immune response 2-7 days
what is immunological memory?
mechanism that prevents you from getting chicken pox more than once
what does a macrophage do?
acts as an APC (antigen presenting cell) it engulfs a bacterium and presents a fragment of it to the cell surface by an MHC II molecule
how are Th cells activated?
binding to the MHC-antigen complex, activation is enhanced by interleukin-1 and CD4 protein from the Th cell
what do cytokines do?
further stimulate Th, B, and Tc cells
what are antibodies?
an immonoglobin, group of globular proteins
five classes: IgD, IgG, IgA, IgM, IgE
what is the structure of an antibody?
Y shaped molecule, four polypeptide chains: two heavy identical chains and two light identical chains held together by a disulfide bond, four constant regions (C), and four variable regions (V)
how do antibodies destroy invaders (2 ways)?
neutralize the antigens, causing them to clump forming an antigen-antibody complex, which is then phagocytosed by macrophages
complement fixation-using the complement to lyse the cells
what is the danger in a blood transfusion?
the recipient has antibodies to the donor's antigens
what are ABO antibodies?
circulate in the plasma of the blood and bind with the ABO antigens in the event of an improper transfusion
what is a cross-match?
It involves mixing small samples of donor blood with recipient plasma and recipient blood with donor plasma and then examining the mixtures for agglutination. If aggultination does not occur the two bloods are a good mixture.
what is the universal donor?
Type O
what is the universal recipient?
what is the Rh factor?
A blood antigen, Rh stands for Rhesus monkey, the animial in which it was first identified. Rh antigen is on the surface of RBCs when blood is Rh positive. Cells without the antigen on surface are Rh negative.
what is AIDS?
a) Profound suppression of cell-mediated immunity is the hallmark of AIDS
b) Destruction of CD4+ T cells is the major source of immunosuppression
c) Infection of the monocyte/macrophage family also plays a role in the pathogenesis of HIV. This cell lineage also expresses CD4 on their cell surfaces. Their significance to disease progression is potentially related to their:
what kind of virus is AIDS?
what is positive feedback?
enhances an already existing process until some endpoint or maximum rate is reached
what are allergies?
Overreaction of the immune system to allergens
what is anaphylactic shock?
when a person is hypersensitive to an allergen, histamine throughout entire body causes capillaries to leak, lowering blood pressure so dramatically that person goes into shock; can be fixed w/ adrenalin
what are antibiotics?
medicines that kill bacteria or fungi
what are autoimmune diseases?
Autoimmune Disease occurs when T and B cells are activated to produce immune reactions against self proteins; result in host tissue damage; some disease cause by autoantibodies that interact with self antigens.
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