Biol 2110 Exam 2

Symbiosis
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Terms in this set (63)
Symbiosis
means "living together" (mutualism, commensalism, parasitism)
Mutualism
Benefits both organisms

Ex. bacteria in the colon (Normal/Indigenous flora, microbiota)
Commensalism
Benefits one organism, but neither benefits or harms the other organism

Ex. Staphylococcus on the skin
Parasitism
Benefits one organism and harms the other

Ex. Tuberculosis bacteria in the lung
Infection
A condition in which a pathogen penetrates host defenses, enters tissues, and multiplies
Infectious Disease
An infection that causes damage or disruption to tissues
Normal Flora
-Also called "microbiota" or "resident microbes"
-Found where the body has contact with the environment
-Organisms that colonize the body without causing a disease
-Skin, upper respiratory, vagina, ear, eye, outer opening of urethra
Initial Colonization
The uterus is sterile until right before birth, where the baby is first exposed to normal flora that it will have for the rest of life
Probiotics
Introduce known microbes back into the body
Opportunistic Pathogens
Normal flora that cause disease under certain circumstances. Happen when normal flora enters an area that it normally does not, or when someone is immune suppressed
Reservoirs of infectionsites where pathogens are maintained as a source of infection. Examples are nonhuman animals, human carriers, or non-living (soil, water)VectorA live animal that transmits an infectious agent from one host to another. Majority are arthropods like fleas, mosquitoes, flies, and ticks. A few larger animals like birds and mammals can also be vectors.Biological VectorsActively participate in the pathogen's lifestyleMechanical VectorsNot necessary to the pathogens lifestyle, and transmit it without becoming infectedHuman CarriersHumans that may be asymptomatic but infectious to othersFomiteNon-living reservoir that can transmit disease. Examples are soil, water, furniture, clothing, cell phonesDevelopments of an infection1. Entry and adhesion 2. Invasion and multiplication 3. DiseasePathogenicityThe ability of an organism to cause infectionVirulenceVirulence factors contribute to pathogenicity, such as: Adhesion factors, biofilms, extra cellular enzymes, toxins, and antiphagocytic factorsAntiphagocytic factorsUsed to avoid or survive phagocytosisLeukocidinsToxic to white blood cellsExotoxinsToxin molecule that is secreted by a living microbeEndotoxinsToxin that is not secreted but is released after the microbe is damagedInfectious Dose (ID)Minimum number of microbes required for infection to proceed. Microbes with small ID's have a greater virulence.Stages of infection1. Incubation period- no signs or symptoms 2. Prodromal period- vague, general symptoms 3. Illness- most severe signs and symptoms 4. Convalescence- no signs or symptomsLocalized InfectionMicrobes enter the body and remain confined to a specific tissueSystemic InfectionInfection spreads to several sites and tissue fluids usually in the bloodstreamFocal InfectionWhen an infection breaks loose from a tissue and spreads to other tissuesMixed InfectionSeveral infections grow at the same time at the same infection site - polymicrobialSecondary InfectionAnother infection by a different microbeAcute InfectionComes on rapidly, with severe but short-lived effectsChronic InfectionsProgress and persist over a period of timeNosocomial InfectionsHospital-acquired infectionsEpidemiologyThe study of the frequency and distribution of disease and health-related factors in human populations.SurveillanceCollecting, analyzing, and reporting data on rates of occurrence, mortality, morbidity, and transmission of infectionsMortality RateThe total number of deaths in a population due to a certain diseaseMorbidity RateNumber of people afflicted with a certain diseasePrevalenceTotal number of cases of a disease in a given area for a period of timeOccurrenceterms of frequency and geographic distributionSporadicOccasional cases reported at irregular intervalsEndemicDisease that has a steady frequency over a long period of time in a specific localeEpidemicWhen prevalence of a disease is increasing beyond what is expectedPandemicEpidemic across countries and continentsInnate ImmunityFirst line of defense and acts fast. Normal microbiota make it hard for pathogens to survive. Normal microbiota take up a lot of the nutrients that pathogens needs to take hold and also can stimulate the second line of defense.Adaptive (Acquired Immunity)Slow, highly specific and involves certain leukocytes and tissues.ErythrocytesCarry oxygen and carbon dioxide in the bloodPlateletsInvolved in blood clottingLeukocytesWhite Blood Cells, defends the body against invadersPathogen-associated molecular patterns (PAMPs)Molecules shared by molecular organismsPathogen recognition receptors (PRRs)Receptors on WBCs for PAMPsPhagocytosisCells capable of engulfing big particular matter (Neutrophils, macrophages)Dendritic CellsPhagocytocize, and main role is to communicate to cells of acquired immunityEosinophilsAttack certain parasitic helminths, secrete toxins that weaken or kill the helminthsBasophilsImportant in some parasitic infections, major player in allergic responsesComplementA serum of a set of proteins that destroy. Can be activated by classical pathway, alternate pathway, and lectin pathwayInflammationNonspecific response to tissue damage from various causesInflammatory ResponseRedness, warmth, swelling, painAcquired immunity-High specificity -Memory lymphocytesAntigenMolecules that interact with T and B lymphocytesMHC (HLA) MoleculesRole is to recognize yourself/your own immune system and reject foreign matter. Has 2 classes.B LymphocytesMature in bone marrowT LymphocytesMature in thymusAdaptive Immune Responses-Humoral Immune response -Cell-mediated immune response