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80 Cards in this Set
- Front
- Back
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Define biological barrier
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defense provided by cells on or in the body
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Define Normal Microbiota
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resident microbes that live on the body. ~100 trillion total
500-1000 different species |
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Microbiota provides protection by...
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-outcompeting invaders
-creating toxins against invaders -making local environment less hospitable. |
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2 divisions of immune system...
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Specific
Non Specific |
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Non specific Immune system characteristics...(3 of them)
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-many cells respond
-response is rapid -target is general |
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Specific Immune system characteristics...(5 of them)
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-fewer cells respond -target is specific -slower response -capable of memory - second time, response is stronger, faster, and longer lasting
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Define phagocyte
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White blood cells that protect by engulfing pathogens/toxins
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Define macrophage
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2-10% of WBC's
-not most numerous or quickest to respond - "eat" the most of all WBC's |
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Define nutraphils
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50-70% of all WBC's
- quick to respond, but do not "eat" as much |
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Define Eosinophils
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1-4% of WBC's
-weakly phagocytic -release toxins against some parasitic worms |
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Define basophils
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less than 1% of WBC's
-role as phagocyte is unclear -release histamine to enhance inflammation |
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What are the 5 steps in phagocytosis?
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-Adherence
-Engulfment -Phagolysosome -Digestion -Exocytosis |
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Define adherence
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pathogen attaches to to surface of phagocyte
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Define Engulfment
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Phagocyte surrounds pathogen with parts of the PM. Pulls in pathogen, forming the phagosome.
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Define phagolysosome
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formed by combining phagosome and lysosome
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Define Digestion (as in Phagocytosis)
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enzymes from the lysosome break down the pathogen
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Define exocytosis ( as in phagocytosis)
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remains of the phagolysosme are expelled via exocytosis.
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Natural Killer cells
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small section of WBC's called lymphocytes that have non specific recognition. (Most lymphocytes are specific)
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How do Natural Killer Cells work?
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-recognize host cells that have been invaded by some viruses.
-secrete perforins that put holes in host cell that cause it to lyse |
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S&S of inflammatory response
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heat, redness, pain and swelling
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3 goals of inflammatory response
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-create a barrier around the infection
-rid the area of damaged cells and toxin -prepare site to be repaired |
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5 steps in inflammation
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-Chemical alarm
-vasodilation -increased blood vessel permeability -phagocyte mobilization specific immune cells respond |
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define Chemical alarm
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damaged cells release compounds such as histamine, kinins, and prostaglandins
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define vasodilation
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vessels dilate causing blood flow to increase
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what is the order of phagocyte mobilization?
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1.basophils
2.neutrophils 3.macrophages |
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What is PUS?
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accumulation of "battle casualties" such as dead cells, living cells, or pathogen
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2 divisions of specific immune system...
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-Humeral or Anti-body mediated Immunity
-Cell mediated immunity |
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What are antigens?
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any compound that is foreign and stimulates the immune system
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proteins tend to be the best antigens because they are the most complex
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NOTE
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Define Epitope
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small portion of an antigen that stimulated a specific response from the immune system
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one large protein can have 7100 epitopes.
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NOTE
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Humeral or antibody mediated response defends with what type of cells?
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WBC's called B- Lymphocytes
or B cells |
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Where do B cells come from?
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originate and mature in bone marrow.
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B cells can have 10'000-100'000 receptors that each bind to 1 epitope of 1 antigen
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NOTE
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How do b cells work?
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They circulate and wait for the antigen to enter the body
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how do B cells divide?
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THEY CLONE THEMSELVES
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What are the 2 different types of clone B cells?
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Plasma Cells and Memory B cells
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Define plasma cell
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Plasma cells make antibodies at the rate of ~200/sec
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How long to plasma cells live?
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4-5 days and then they die
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Each clone plasma cell can bind to the same epitope as the original B cell
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NOTE
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Define memory B cell
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Long lasting cell that remembers the antigen for recognition if the pathogen enters the body again
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Antibodies cannot enter host cells
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NOTE
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Endotoxin
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in the blood
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Exotoxin
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can enter the host cell
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Cell mediated immunity uses what type of cells?
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T-lymphocytes (T-cells)
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Where do T cells originate?
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T cells originate and mature in the bone marrow
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T cells receptors detect...
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-1 epitope of an antigen
-major histocompatability complex |
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Major Histocompatability complex
(MHC) |
displayed on host cells that define it as "self"
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MHC and the antigen must be present for T cell activation
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NOTE
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how do T cells divide?
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Cloning
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4 types of clone T cells...
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-cytotoxic T cell
-Helper T cell -suppressor T cell -Memory T cell |
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Define cytotoxic T cell
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kills invaded cell by.
-secreting perforins -secrete lymphotoxin -secrete tumor necrosis factor |
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Define selective toxicity
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drug targets unique factor of pathogen
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define natural drug
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comes from a living organism
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define synthetic drug
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created in a lab
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define semi-synthetic drugs
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combination of natural and synthetic drugs
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Define range and strength of effectiveness of drugs
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broad v. narrow spectrum
cidal v. static |
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Theraputic Index
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Toxic Dose/Theraputic dose
Higher TI= better drug |
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Define Mechanism of action
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what does the drug target?
-cell wall -protein synthesis -inhibit nucleic acid synthesis -structural analog |
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define structural analog
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drug mimics a substrate required for pathogen growth
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4 mechanisms of drug resistance
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-block drug entry
-pump out drug once it enters -destroy or inactivate the drug -alter the pathway that the drug targets |
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Virus is "non living" because...
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-acellular structure
-no ribosome, flagella, ER...etc -DNA or RNA...never both -inability to replicate outside of host cell |
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what size is a virus?
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10-400nm
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2 mandatory viral structures
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nucleic acid core and Capsid
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Define capsid
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protein coat around the nucleic acid. Capsid protein can self assemble.
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3 common capsid shapes
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-helical
-icosahedral -complex capsid |
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Helical capsid structure...
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hollow tube
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Icosahedral capsid structure...
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roughly spherical
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complex capsid structure...
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combination of helical and complex
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how many genes do viruses have?
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small have 3-4 genes
large have > 100 genes |
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Define envelope
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additional layer of plasma membrane outside of capsid. Not present in all viruses.
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steps in viral replication cycle
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-adsorbtion
-penetration and uncoding -biosynthesis -nucleocapsid assembly -exit mechanism |
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define adsorbtion
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virus uses a protein to bind to host cell
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define penetration and encoding
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viruse enters host cell and releases nucleic acid into cell
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Define naked virus entry
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only nucleic acid is enters host cell.
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define fusion
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for enveloped viruses only. envelope binds with cell and capsid enters cell and releases Nucleic acid
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Receptor mediated endocytosis
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spikes stimulate host cell to engulf virus by endocytosis.
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Biosynthesis
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virus uses mechanisms and energy of the host cell to replicate.
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Nucleocapsid assembly
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capsid proteins self assemble around nucleic acid
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Exit mechanisms of virus
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-Lysis of host cell
-Budding (pushes out on PM and pinches off a piece of the PM ) |
