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Med Micro
Exam 3
| Question | Answer |
|---|---|
| control of microbes in ancient times | embalmed with strong salts and oils or burned corpses and clothing during epidemics |
| Sterilization | the highest level of clean.....a process that destroys or removes all viable organisms.....used for surgical instruments, syringes, and commercially packaged food (heat and chemical agents can destroy even viruses and spores) |
| Disinfection | destroys vegetative pathogens and removes harmful toxins that are produced by the microbes....used for food utensils, examining tables, thermometers......agents like bleach, iodine, and boiling water.........on inanimate objects! Not for human tissues.... |
| Decontamination/Sanitization | process that involves cleansing items to mechanicaly remove microbes as well as other debris to reduce contamination to safe levels.......soaps, detergents, and dishwashers used when handling large numbers of soiled instruments |
| Antisepsis/Degermation | decontamination on living tissues to reduce number of microbes....scrubbing skin or immersing in chemicals like alcohol or surgical hand scrubs |
| Sepsis | bacterial contamination in the blood and other tissues |
| Aseptic | the practice that prevents the entry of infectious agents into sterile tissues and this prevents infections |
| the suffix -cide | a treatment designed to kill microbes |
| the suffix -static | a condition where microbes are temporarily prevented from multiplying but are not killed outright (just prevents their growth in certain areas) |
| germicide or microbicide | general terms for chemical agents that kill microorganisms |
| Bacterial endospore relative resistance | traditionally been considered the most resistant microbial entities (18 times harder to kill than their vegetative counterpart) |
| Enveloped viruses and most gram-positive bacteria | typically the easiest to kill (low relative resistance) |
| Microbial death | involves the permanent termination of an organism's vital processes....permanent loss of reproductive capability even under optimum growth conditions |
| factors that influence microbial death | # to begin with, mixed types of microbes, presence of organic matter/fats/proteins lowering effectiveness of heat, temperature and pH of the environment, chemical antimicrobials need a longer time of exposure to affect more resistant microbes |
| the agents that are the least selective | are effective against the widest range of microbes (heat is effective against many microbes) |
| more selective agents | tend to target one specific cellular component and are much more restricted as to the microbes they are effective against (like drugs) |
| some target the cell wall | detergents, alcohols, and other chemical agents can damage the cell wall by digesting it to blocking its synthesis |
| some target the cell membrane | detergents can bind to and open up the lipid bilayer of the cell membrane...can let injurious agents in or important ions out |
| some target cellular synthesis | agents like formaldehyde, radiation, and ethylene oxide can disrupt ribosomes or can change the genetic code through mutations (ie UV light) |
| some target proteins | certain chemicals as well as heat can denature proteins (break hydrogen bonds in proteins) |
| the physical methods often employed in the control of microbe populations | temperature, osmotic pressure, radiation, filtration |
| Heat for microbe control | fast, reliable, relatively inexpensive...take microbe out of cardinal temperatures used to sterilize laboratory glassware and media, hospital equipment, and preserving foods.........kills microorganisms by denaturing their enzymes and removing water |
| thermal death point | the lowest temperature at which all the microorganisms will be killed in 10 minutes (FIND THE TEMP) |
| thermal death time | the minimum length of time for all the bacteria to be killed at a given temperature (FIND THE TIME) |
| higher temps | allow shorter exposure times |
| lower temps | require longer exposure times |
| Dry heat sterilization | (flaming inoculation loop / incineration of contaminated materials) using a hot air sterilization in a simple oven used for sterilization of powders, glassware, and water-free oily substances.....does not penetrate easily so needs a long exposure time |
| Moist heat sterilization | boiling water or steam can kill vegetative bacteria, viruses, fungi and fungal spores (often need temps above boiling) using an autoclave with high pressure and high temperature, can penetrate much better, used for culture media, instruments, solutions... |
| Cold for microbe control | the temp of ordinary fridge can reduce the metabolic rate of most microbes so they cannot reproduce (lower temperatures are microbistatic) |
| Osmotic pressure for microbe control | high concentrations of salt and sugars ae used to preserve foods....draws the water out of the microbes |
| low level ionizing radiation | used for processing spices and certain meats and vegetables...also for sterilizing pharmaceuticals and disposal of medical supplies |
| non ionizing radiation | found in the form of UV lamps in hospital rooms, nurseries, and cafeterias to kill microbes in the air |
| UV light is not very penetrating | microbes must be directly exposed to the rays...cant be covered by paper, glass, or cloth |
| Filtration for microbe control | passage of a liquid or gas through a screen like material with pores small enough to retain the microorganism...used to sterilize heat-sensitive materials (culture media |
| HEPA filters (high efficiency particulate air) | used in operating rooms and burn units to lower the number of airborne pathogens |
| Chemical methods of microbe control----certain factors affect effectiveness | length of exposure needs to be long enough and composition has to be considered |
| the composition of material being treated has to be considered | pores and pockets can decrease germicidal action large amounts of organic material can hinder the penetration of the disinfectant |
| ideal properties of chemical control | able to kill microorganisms nontoxic to humans and animals soluble in water (have long shelf life) useful in diluted form and work quickly easy to obtain and inexpensive |
| Halogens ---highly reactive | chlorine (used in water and effective against bacteria, viruses, fungi, and protozoa) iodine (more reactive than Cl, stops protein synthesis and alters cell membranes, used in skin prep for treating local wounds) |
| phenol and phenol derivatives target plasma membranes | in the past used as antiseptic....can irritate skin and smell weird....now use derivatives which are less irritating---target the plasma membranes of microbes, remain active in presence of organic compounds, are stable, last for a long time after use |
| alcohols | effectively kill viruses and bacteria but not endospores or non-enveloped viruses- acts fast and evaporates without residue (use ethanol and isopropanol) |
| heavy metals ---target cellular proteins | silver, mercury, and copper can be biocidal or antiseptic, they work by causing proteins to bind together, disrupt cellular metabolism |
| Surfactants | soap and detergents....decrease the surface tension among molecules of a liquid...emulsification breaks oily films into tiny droplets, water and soap together wash off the oil and debris by mechanical removal |
| peroxigens ----bubbling oxygen gas is toxic to bacteria | antiseptic common in homes and hospitals, hydrogen peroxide breaks down into water and gaseous oxygen by catalase---the oxygen gas inhibits microbial gas |
| sterilizing gases | ethylene oxide and chlorine dioxide are gases that can be used to sterilize rooms and buildings |
| Discovery of penicillin | Alexander Fleming...from the mold penicillium rubens....the mold prevented bacterial growth! |
| goal of antimicrobial drugs | destroy the infectious agent without harming the host's cells |
| antibiotics | natural metabolic products of aerobic bacteria and fungi...mostly developed form Streptomyces and Bacillus bacteria or Penicillium and Cephalosporium molds |
| the ideal antimicrobial drug.... | nontoxic to host but toxic to pathogen, microbicidal not microbistatic, remain active in body tissues, does not cause allergies or disrupt host's immune system, soluble in bodily fluids, doesn't lead to antibiotic resistance |
| before using antibiotics need to know: | the nature of the microorganism causing infection (examine sample of bodily fluid) the degree of that microbes susceptibility to various drugs (what amount of drug will work) the overall medical condition of the patient ( allergies??) |
| measuring antimicrobial sensitivity | do a Kirby-Bauer technique with the microbe |
| the minimum inhibitory concentration test | test used in determining the smallest effective does of a drug and in providing a comparative index against other drugs |
| tube dilution test | helps determine the lowest concentration of antibiotic that will prevent growth of a pathogen (the minimum inhibitory concentration) |
| disk diffusion method (Kirby-Bauer) | antibiotic susceptibility test uses disks containing antibiotics on agar medium containing test organism |
| therapeutic index | the ratio of the dose of a drug that is toxic to humans as compared to its minimum effective dose |
| want a high toxic dose and a low therapeutic dose | the drug with the highest therapeutic index typically has the highest margin of safety |
| it is easy to find a drug that attacks prokaryotes but not human cells | the two types of cells differ enough (cell wall, ribosomes, details of metabolism) |
| it is much more difficult to attack eukaryotic cells (fungus, protozoan, helminths) | they are much more similar to the host cells....there are much more limited options to fight eukaryotic pathogens |
| drugs with a narrow spectrum | active against few numbers of microbes |
| drugs with broad spectrum | active against larger numbers of microbes, but will destroy microbiota which can be harmful |
| the goal of chemotherapy | disrupt the structure or function of an organism to the point that it can no longer survive (can stop cell wall production, DNA, RNA, or protein production, or cell membrane assembly) |
| can attack cell wall | human cells do not have these cell walls, peptidoglycan production is a common area of attack by antibiotics |
| antibiotics that stop cell wall synthesis | the beta lactams (penicillin, carbapenems, monobactams, cephalosporins) polypeptide antibiotics (bacitracin, vancomycin) |
| beta lactams (includes Penicillin---KNOW) | large family of modifiable beta lactams that interfere with the last stages of cell wall synthesis primarily of gram positive bacteria |
| bacitracin | a polypeptide antibiotic that inhibits cell wall synthesis at an earlier stage than penicillins and cephalosporins restricted to topical application for superficial infections |
| vancomycin | a gylycopeptide antibiotic that is important in treating antibiotic resistant staph areus.....it is the last line of defense against antibiotic resistant pathogens (emergencies only) |
| antibiotics that stop protein synthesis | chloramphenicol aminoglycosides tetracyclins macrolides streptogramins and oxazolidinones |
| chloramphenicol | comes from streptomycin, inhibits formation of peptide bonds by reacting with prokaryotic ribosomes....not to be used frequently can cause loss of bone marrow function |
| aminoglycosides (KNOW) | groups of antibiotics where amino sugars are linked by glycosidic bonds (atreptomycin and gentamicin are common) neomycin is found in many nonprescription topical preparations |
| tetracyclins | interfere with the attachment of the tRNA to the ribosome....prevents growth of polypeptide chain (valuable against rickettsias and chlamydias)...can cause browning of teeth in children or pregnant women) |
| macrolides | inhibits protein synthesis (erythromycin) used as substitute for penicillin against streptococcal and staphylococcal in children |
| streptogramins and oxazolidinones | affect protein synthesis by prohibiting the joining of the large ribosomal subunit to the other part of the ribosome |
| antibiotics that disrupt the plasma membrane | polymyxins--bactericidal antibiotic affective against gram negative bacteria |
| Neosporin | has polymyxin B, bacitracin, and neomycin |
| antibiotics that stop nucleic acid synthesis | rifamycin quinolones and fluoroquinolones |
| rifamycin (KNOW) | drugs inhibit the synthesis of mRNA (used against mycobacteria in treatment of tuberculosis and leprosy) |
| quinolones and fluoroquinolone | quinolones have bactericidal effect by inhibiting DNA gyrase fluoroquinolones (norflaxacin and ciprofloxacin) are used against anthrax |
| antibiotics that inhibit essential metabolites (includes sulfonamides---KNOW) | sulfonamides--interfere with the biosynthesis of folic acid (nucleic acid precursor)...bacterial cells need to make their own folic acid.... used in UTIs and to help control infections in burn patients |
| anti fungal drugs | fungal membranes have ergosterol as the main sterol...can be targeted to stop biosynthesis. Most antifungals can only be used topically |
| antiviral drugs | only a few approved in the US....only very selected usages. It is so hard to target viruses that replicate within our own cells |
| antiprotozoal drugs | quinine---extracted from the bark of the cinchona tree, can be used to treat malaria....now have a synthetic version (target a single protein in the malaria protozoan that is needed for its survival) |
| there can be some contact with foreign chemicals that damage human tissues | have the potential to affect liver, kidneys, GI tract, cardiovascular system, nervous system, skin, bones, teeth, etc.... |
| allergic reactions | one of the most common adverse reactions (penicillins are the most common antibiotic allergens) leads to skin rashes, respiratory inflammation, maybe anaphylaxis |
| the microbiota | contains many harmless or beneficial bacteria that live in the skin, large intestines, oral cavity, and outer openings of the urogenital tract |
| broad spectrum antibiotics can damage microbiota--microbiota is helpful as "space fillers" | some bacteria that were once low in number can overgrow and cause disease (Superinfection) the pathogens can take over the space once filled by the good bacteria |
| disease | any deviation from health |
| infectious disease | the disruption of a tissue or organ caused by microbes or their products |
| pathology | the study of disease |
| etiology | the study of disease causation |
| the human microbiome (10x the amount of our own cells) | a large mix of microbes that have adapted to the human body (100 trillion found in human body (500 to 1000 kinds in the gut alone) a normal array of bacteria, fungi, protozoa and viruses |
| transient microbiota | may be present for several days or months and then disappear |
| parts of the body with no resident microbes | internal organs and the fluids they contain are generally microbe free (bloodstream, CSF, organs) |
| humans are not born sterile | by year one, an infant's microbiota is adult-like |
| microbial antagonism | the normal microbiota can benefit the host by preventing the overgrowth of harmful organisms....limits nutrients, make inhibitory substances, change the local pH and oxygen concentrations....limit the space for growth of the pathogen |
| Infection | the invasion of the body by pathogens |
| Pathogen | a microbe whose relationship with its host is parasitic and results in infection and disease |
| still a big killer | 25% of the deaths that occur worldwide are the results of infectious diseases, the leading cause of death in children under 5 |
| Pathogenicity | broad term that describes an organism's potential to cause disease |
| virulence | describes the degree of pathogenicity |
| primary pathogens | capable of causing disease in healthy persons with normal immune defenses |
| opportunistic pathogens | cause disease when the host's defenses are compromised or when they become established in a part of the body that is not natural to them (gut microbiota on the skin....not where it is supposed to be) |
| portals of entry | the avenues through which pathogens can gain entry to the human body (mucous membranes, skin, direct deposition beneath the skin---parenteral route) |
| respiratory tract | the easiest and most frequently traveled portal of entry for infectious organisms (small pox, cold, pneumonia, TB, flu, measles...) |
| Gastrointestinal tract | can be breached by food and water and contaminated fingers organisms that take this route must be able to withstand high acidity of the stomach (poliomyelitis, Hepatitis A, typhoid, amoebic dysentery, cholera) |
| Genitourinary tract | infections occur mainly through sexual activity can penetrate unbroken mucous membranes, others travel a cut or abrasion of some kind (HIV, genital warts, chlamydia, herpes, syphilis, gonorrhea) |
| conjunctiva | the delicate mucous membrane that lines the eyelid and covers the whites of the eyes. (conjuctivitis, trachoma, opthalmia neonatorium) |
| the skin (the largest organ) | important defense against disease... although unbroken skin is impenetrable by most microorganisms, some microorganisms can gain access through hair follicles and sweat gland ducts (pores) |
| parenteral route | established when microorganisms gain access to the body when they are directly deposited into the tissues beneath the skin (punctures, injections, bites, stings, cuts, wounds, and surgical insertions) |
| pathogens often have preferred methods of entry | it is the prerequisite to their being able to cause disease (if they enter through a different portal, they might not be able to cause disease) |
| infectious dose | the minimum number of microbes needed to be present during entry for an infection to proceed (the more pathogenic the lower the infectious dose needed) |
| adhesion | the means by which the pathogens attach themselves to the host tissues, is a requirement for pathogenicity--dependent on binding between specific molecules of the host and the pathogen (limits what cells a pathogen can bind to) |
| Adhesins (ligands) | molecules specifically bind to complementary surface receptors on the cells of certain host tissues |
| capsules | capsules around some bacteria can increase their virulence...inhibits the immune system from phagocytosis the encapsulated bacteria, also evades detection by the immune system |
| cells with cell walls | contain chemical substances that contribute to virulence/ can aid in host defense resistance and in host cell attachment (the lipopolysaccharide of gram negative bacteria is a harmful substance |
| exozymes | the virulence of some bacteria is aided by the production of extracellular enzymes (exozymes) that can kill WBCs or digest ECM |
| antigenic variation | the process by which some pathogens can alter their surface molecules .....can change its appearance to the immune system (by the time the body prepares an immune response, the bacteria can change to be unaffected by the immune system) |
| siderophores | bacteria can produces proteins (siderophores) which steal iron from the host cells and give it to the bacteria |
| pathogenic bacteria, fungi, protozoans can make exoenzymes | breakdown and inflict damage on tissues (create and release toxins inside the host) |
| toxins | poisonous substances that are produced by certain microorganisms, can produce fever, cardiovascular disturbances, shock...can inhibit protein synthesis, destroy RBCs and vessels, and disrupt the nervous system (neurotoxins) |
| two kinds of toxins | exotoxins and endotoxins |
| exotoxins | proteins made inside the bacteria and released by the bacteria or released when the bacteria is lysed |
| endotoxins | lipopolysaccharides in the outer membrane of gram negative bacteria, released when the bacteria die and are lysed |
| symptoms | subjective changes in body function such as pain and malaise that are not apparent to the observer |
| signs | objective changes that can be measured and observed such as lesions, swelling, fever, and paralysis |
| syndrome | a specific group of symptoms or signs that always accompany a particular disease |
| communicable disease | any disease that spreads from one host to another, either directly or indirectly, is communicable |
| contagious disease | diseases that are EASILY spread from one person to another are contagious |
| incidence | the incidence of a disease is the number of people in a population who develop a disease during a particular time period |
| sporadic disease | if a disease only occurs occasionally, it is called sporadic |
| endemic | a disease habitually present at a low level in a certain geographical area (the common cold) |
| epidemic | a disease in a community in excess of what is normally found within that population (an certain spike of a disease..) an outbreak is a confined epidemic (the FLU) |
| pandemic | a worldwide epidemic, affecting populations around the globe (AIDS) |
| acute disease | one that develops rapidly but only lasts a short time (the Flu) |
| chronic disease | develops more slowly and the disease is likely to continue or recur for long periods of time (Tuberculosis) |
| latent disease | one in which the causative agent remains inactive for a time but then becomes active to produce symptoms (Shingles) |
| periods of disease development | incubation period, prodromal period, acme period, convalescent period |
| incubation period | the interval of time between the initial infection and the first appearance of any signs or symptoms (length depends on microorganism involved and resistance of host) |
| prodromal period | a short (1-2 day) period of time that follows the incubation period and is characterized by early, mild symptoms like general ache and malaise |
| clinical disease | signs are apparent |
| subclinical disease | has few obvious symptoms....cant be seen |
| Acme period (time of invasion) | the time at which the disease is the most severe and the person develops overt signs and symptoms (person's immune system is in full gear to fight infection) |
| convalescent period | the signs and symptoms subside but a person is vulnerable to secondary infections (may experience sweating from breaking fever) |
| human reservoirs | many people harbor pathogens and transmit them directly or indirectly to others...they are carriers of the disease |
| animal reservoirs | both wild and domestic animals are living reservoirs of microorganisms that can cause human diseases...these types of diseases are called zoonotic diseases |
| non-living reservoirs | soil and water are two major reservoirs of infectious disease (also food) |
| disease transmission can occur 3 ways | contact, vehicles, vectors |
| Contact transmission | the spread of an agent of disease by direct contact, indirect contact or droplet transmission |
| direct contact | involves physical contact between its source and a susceptible host |
| indirect contact | the disease agent is transmitted fro its reservoir to a susceptible host by means of a nonliving object (this nonliving object with the disease is called a fomite....beds, toys, money etc) |
| droplet transmission | involves the spreading of disease through droplets that travel only short distances (cough, sneeze, laugh, talk) |
| vehicle transmissions | the transmission of disease agents by a nonliving medium (food, air, soil, water) |
| vector transmission | animals and insects that carry pathogens from one host to another, but they themselves are not affected by the disease agent (houseflies and mosquitoes) |
| immunity | our ability to ward off disease caused by microbes and to protect against environmental agents such as foods, pollens, drugs, and chemicals |
| two types of immunity | innate and adaptive |
| innate immunity | the defenses present at birth, does not involve specific recognition of a microbe (includes skin/mucous membranes, natural killer cells, phagocytes, inflammation, and fever) |
| adaptive immunity | a slower, but more specific response to a specific microbe once the microbe has breached the innate immunity defense systems (includes T lymphocytes and B lymphocytes) |
| skin for immunity | the epidermis is made up of epithelial cells that are compacted and keratinized (impregnable) a tough waterproof layer...the outermost cells shed and take the microbes with them, the flushing of sweat glands helps to remove microbes |
| mucous membranes for immunity | found lining the GI tract, respiratory, genitourinary, and around the eye....fluid production help trap, dilute, and wash away microorganisms....cilia in respiratory tract also mechanically brush away microbes |
| sebum for immunity | sebaceous glands of gate skin produce an oily substance called sebum....forms a protective film over the skin surface (can result in acne if in surplus or dry skin if not enough) |
| lysozyme for immunity | tears and saliva contain lysozyme...enzyme capable of breaking down bacterial cell walls (saliva also has urea and uric acid to stop bacterial growth) |
| other antimicrobial molecules are produced in many places in the body | bile from the gall bladder is hypotonic, lowered pH in urine, stomach acid super low pH, and various other defenses that attack other microbes |
| microbiota is involved in immunity | the normal microbiota prevent pathogens fro colonizing in the host (they compete with the invaders for space and food...) |
| the healthy immune system is responsible for the following... | surveillance of the body, recognition of foreign cells and material, destruction of foreign cells and material |
| the immune system needs to distinguish between self and non-self | foreign molecules must be recognized as a potential threat but self cells and chemicals must not be attacked...this would be an autoimmune disorder |
| reticuloendothelial system (macrophage system or the mononuclear phagocyte system) | network of cells located throughout the body that filter out dead and toxic particles and work to identify foreign substances both in the blood and tissues |
| lymphatic system | consists of branching network of organs, cells, vessels that extend into most body systems.....responsible for removal of interstitial fluid from tissues and helps in surveillance/recognition/protection....uses lymphocytes, phagocytes, and antibodies |
| splendid and lymph nodes | places where the lymph system actually can attack and minimizes the effects of the immune response....not throughout the whole body |
| Lymph | a plasmalike liquid that transports numerous white blood cells and miscellaneous materials like fats and cellular debris through the lymphatic system....goes through all the tissues of the body |
| Primary lymphoid tissues | sites where immune cells are made and mature (Thymus makes T cells and Bone marrow makes B cells) |
| Secondary lymphoid tissues | the sites where immune cells interact with pathogens to carry out the adaptive immune system responses (spleen and lymph nodes) |
| circulatory system | consists of the heart, arteries, veins, and capillaries that circulate the blood |
| Blood | whole blood is a liquid of plasma with many blood cells---erythrocytes (RBCs) leukocytes (WBCs) and platelets |
| types of WBCs | neutrophils, eosinophils, basophils, monocytes |
| neutrophils | contain many lysozymes and function chiefly as phagocytes |
| eosinophils | contain toxic granules that are used to defend against parasites |
| basophils | play a role In allergic reactions |
| monocytes | mature into macrophages...work to engulf and digest cellular debris and pathogens |
| natural killer cells | destroy virally infected and abnormal cells..only work to destroy cells that do not have MHC proteins (those with MHC are identified as self...they get reduced in cancer and virus affected cells) |
| phagocytosis (has stages of chemotaxis, adherence, ingestion, digestion, and elimination) | the capturing and digestion of foreign particles...pathogens are eaten by neutrophils and macrophages |
| chemotaxis | the chemical attraction of phagocytes to microorganisms or sites of inflammation mediated by a gradient of stimulant products from the parasite and host tissue at the site of injury |
| adherence | receptors on immune cells caller TLRs are capable of recognizing pathogen associated molecular patterns (PAMPs) not found on host cells .....attach to the surface of the microorganism or other foreign material |
| ingestion | the phagocyte engulfs and internalizes the microorganisms or particles...forming a sac inside the phagocyte called a phagosome |
| digestion | the phagosome fuses with a lysosome where the lysosomal enzymes attack the foreign particles directly |
| elimination | any indigestible material is expelled from the cell by exocytosis |
| inflammation | local defensive response to the tissue damage, involves redness, pain, heat, swelling |
| factors that cause inflammation | trauma from infection, tissue injury due to physical and chemical agents, specific immune reactions |
| roles of inflammation | destroy and remove injurious agent/ limit effects on the body by continuing injurious agent/ repair or replace tissue damage by the injurious agent |
| inflammation includes vasodilation and blood vessel permeability | blood vessels dilate (increase permeability) in response to tissue damage...increases blood flow to the damaged area-causes redness and heat |
| increased permeability in vasodilation | lets defensive substances normally retained in the blood to pass through the walls of the blood vessels and enter the injured area |
| phagocyte migration and phagocytosis is part of inflammation | decreased blood flow and formation of cell-adhesion molecules in the lining of blood vessels allows phagocytes to stick the lining at sites of inflammation this is called margination |
| diapedesis | the phagocytes then squeeze through the blood vessel walls to reach the damaged area---the phagocytes can then engulf and destroy the invading organisms as well as any damaged tissue |
| tissue repair is the final stage of inflammation | the tissues replace damaged or dead cells...ability to repair depends on type of tissue (skin repairs well, cardiac muscle does not) |
| fever | an abnormally high body temperature...importnt systemic response to the injury |
| benefits of fever | helps speed up body's reactions, help body tissues repair themselves, help make certain repair enzymes more effective, inhibits multiplication of temp sensitive microbes, impedes the nutritional availability be reducing iron levels |
| signs of fever | shivering, cold skin, chills....body temp is increasing warm skin and sweating....body temp is decreasing |
| interferons | small proteins produced naturally by certain WBCs and tissue cells/ can inhibit the expression of cancer genes, stimulate phagocytes, and inhibit viral multiplication |
| complement | contains at least 26 blood proteins that work together to destroy bacteria and certain viruses, works as a cascade reaction.....ultimately, works to digest holes in the membranes of bacteria, cells, and enveloped viruses |
| innate immunity includes... | early immune response, present since birth, the epithelial barriers of skin, antimicrobial substances, specific immune cells with limited ability to recognize microbes |
| Acquired (adaptive immunity includes.... | later, more powerful reactions, requires proliferation and differentiation, can take a few days to develop (B cells, plasma cells, T cells, antibodies) |
| Acquired immunity | highly selective and has a memory component...antibodies against one microbe will not work on a other/ the second time the antigen is encountered, it is dealt with much quicker than the first |
| B and T cells | both are found in the blood and lymphatic tissues/ have receptors of surface to recognize and bind to antigens, each develops to only respond to one specific antigen or immunogen |
| B cell binding | through membrane bound antibody receptors, causes the release of specific free antibodies |
| T cell binding | occurs through T-cell receptors (TCRs) and can cause certain types of T cells to proliferate and secrete cytokines (not antibodies) |
| antigens or immunogens | molecules that stimulate a response by T and B cells, usually proteins or polysaccharides on or inside cells and viruses, antigens are highly specific and stimulate specific immunity |
| all lymphocytes arise from the same basic stem cell | they emerge into two distinct B and T cells (B cells mature in bone marrow) (T cells mature in the Thymus) they both circulate through the circulatory and lymphatic systems (in and out of lymphatic tissues) |
| Humoral immunity | describes the immunity or protection brought about by B cells and the action of antibodies |
| Cellular immunity | immunity brought about by the action of T cells producing cytokines that attack antigens that have gained entry into host cells |
| Antigens | proteins or large polysaccharides that provoke a highly specific immune response, components of invading microbes like capsules, cell walls, flagella, virus coats.... |
| lymphocyte recognizes epitopes (antigenic fragments) | the lymphocyte discriminates to only small specific portions of the antigens called epitopes...signals that the molecule is foreign |
| Humoral immune response | immunity mediated by antibodies that are produced by B cells |
| Antibodies ( immunoglobulins) | proteins that bind to epitopes on toxins, microbial structures, and viral surfaces |
| structure of an antibody | two identical antigen-binding sites, typically four protein chains (two light, two heavy) that are joined by disulfide linkages to form a Y shape (the ends of the Y are the epitope binding domains) |
| the arms of the Y of the antibody | called variable regions (Fab regions) and are different (different amino acid structure) for each antibody because they all bind to different epitopes |
| the stem of the Y of the antibody | called constant region (Fc region) because they are the same (same amino acid structure) among all antibodies of a certain class of Immunoglobulins |
| IgM antibodies | the largest antibody molecules, found as pentamers (5) they re the first tot enter the bloodstream after antigenic stimulation make up 5-10% of antibodies in the blood |
| IgG antibodies | the major circulating antibodies, make up around 80% of the total antibody count protect against circulating bacteria and viruses/ neutralize toxins/ trigger the complement system/ enhance phagocytosis |
| IgA antibodies | found as monomers in blood, but dimers (2) in body secretions like saliva and tears make up 10-15% of antibodies ion blood help prevent pathogen attachment to mucous surfaces |
| IgE antibodies | play a role in allergic reactions 0.0002% of the antibodies in the blood |
| IgD antibodies | found on the surfaces of B cells...act as receptors that are important in B cell activation 0.2% of antibodies in blood |
| each B cell carries many of the same immunoglobulins on its surface | the B lymphocyte may have 100,000 identical IgD in the surface membrane, all will recognize the same epitope |
| clonal selection | the B cell is activated is its immunoglobulins bind to the compatible epitope, the B cell multiples into a large clone of cells...some become plasma cells that make antibodies and others become memory B cells that are part of the secondary response |
| when a free antibody (made by plasma cells) attaches to an antigen | it marks the antigen for destruction or neutralization |
| Agglutination | causes antigens to clump together, each antibody can bind to two epitopes (link two foreign cells together) this makes the invaders easier to be engulfed by the pathogen... IgM antibodies are best at agglutination |
| Opsonization | the antigen gets coated with antibodies, enhances ingestion and lysis by phagocytic cells |
| neutralization | IgG antibodies inactivate the microbes (block their attachment to host and neutralize toxins) |
| Activation of complement | antibodies can trigger the activation of the complement system, leads to lysis of the antigen |
| cellular immune response | T cells provide a means to combat intracellular pathogens....T cells can deal with bacteria, viruses, and parasites that live within cells, they have T-cell receptors on their surfaces instead of antibodies |
| antigen-presenting cells | the recognition of antigens by a T-cell has the be processed by specialized antigen presenting cells (APCs) along with an MHC protein |
| presenting the antigen to the T cell | the APC can display some pieces of the invader of its surface, also uses recognition of MHC proteins 1 and 2 |
| helper T cells | CD4+ T cells, secrete cytokines that recruit more WBCs to the site of infection, TCR recognizes the antigen that has been processed and presented as fragments on the surface of the APC cell (like a macrophage or dendritic cell) with the MHC 2 protein |
| cytotoxic T cells | CD8+ T cells, recognize dying cells that have been invaded that have the antigens on its surface and the MHC 1 protein, the cytotoxic C cell attaches to the target cell, releases pore-forming protein called perforin=cell dies (gets punched into pieces) |
| Active immunity | results when exposure to a disease organism triggers the immune system to produce antibodies to that disease, can be natural (contract the disease) or artificial (vaccine) |
| Passive immunity | occurs when a person is given antibodies rather than making them through his or her own immune system can be natural (transfer from mother to baby in womb or through nursing) or artificial (can be injected or infused into blood stream) |
Created by:
Gracie Cook
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