Respiratory SystemFunctions of Respiratory SystemWhy We BreatheOrgans of the Respiratory SystemUpper Respiratory TractSlide 6Mucous MembranesSlide 8Slide 9Lower Respiratory TractCartilage of LarynxVocal CordsSlide 13Slide 14TracheaSlide 16Bronchial TreeSlide 18Composition of BronchiAlveoliSlide 21Boundaries of LungsPleural MembranesBreathingVolume vs. PressureSlide 26InspirationSlide 28Surface TensionExpirationSlide 31Respiratory VolumesSlide 33Respiratory CapacitiesSlide 35Nonrespiratory Air MovementRespiratory CenterFactors Affecting BreathingSlide 39Slide 40Inflation ReflexVoluntary Control of BreathingGas ExchangeTransport of OxygenCarbon MonoxideCarbon Dioxide TransportSuggested Homework QuestionsRESPIRATORY SYSTEMChapter 19FUNCTIONS OF RESPIRATORY SYSTEMFilter incoming airTransport air into lungsRespirationGas exchangeLevels of respirationVentilationExternal respirationInternal respirationCellular respirationWHY WE BREATHECellular respiration Cells derive energy from nutrients (e.g. glucose)Aerobic respiration Requires oxygen as final electron acceptorWaste products – CO2 and H2OWithout O2, aerobic respiration cannot proceedWithout removal of CO2, blood pH is disruptedORGANS OF THE RESPIRATORY SYSTEMUpper tractNoseNasal cavitySinusesPharynx Lower tractLarynxTracheaBronchusLungsUPPER RESPIRATORY TRACTNoseMuscle, bone, cartilageExternal nares (nostrils)Air enters tractHairs filter large particlesUPPER RESPIRATORY TRACTNasal cavityHollow space behind noseBoundaries: Ethmoid bone; hard palateNasal conchaeDivide cavity into passagesMeatuses (superior, middle, inferior)Support mucous membranesMUCOUS MEMBRANESLine nasal cavityPseudostratified ciliated epitheliumGoblet cellsSecrete mucusWarms and moistens airTraps dust, microbesCilia propel mucus and particles into pharynx to be swallowedUPPER RESPIRATORY TRACTSinusesAir-filled cavities, empty into nasal cavityFrontal, ethmoid, sphenoid, maxillaryLined with mucous membranes, drain into nasal cavityInflammation of membranes block drainage, accumulate pressure headacheUPPER RESPIRATORY TRACTPharynxPosterior to oral cavityBetween nasal cavity and larynxPassage for food and airDivisions NasopharynxOropharynxLaryngopharynxLOWER RESPIRATORY TRACTLarynxAKA Voice-boxSuperior to trachea, inferior to pharynxConsists of muscle and cartilageFunctions Block foreign objects from tracheaHouse vocal cordsCARTILAGE OF LARYNXThyroidCovered by thyroidProtrudes (Adam’s apple)CricoidInferior to thyroid cartilageEpiglottic Elastic cartilageConnected to thyroid cartilage Supports epiglottisVOCAL CORDSTwo folds within larynxUpper foldsMuscle + CTFalse vocal cordsDo not produce soundLower foldsElastic fibersTrue vocal cordsVocal sounds when fibers vibrateAlter tension change pitchAlter intensity change volumeVOCAL CORDSGlottisOpening between vocal cordsOpen during breathing (b)Close during swallowing (a)EpiglottisFlap that closes over larynx to prevent liquids/foods from entering larynxLOWER RESPIRATORY TRACTTracheaWindpipeCylindrical tubeFlexibleAnterior to esophagusSplits into bronchiTRACHEAInner wallCiliated epithelial cellsCilia filter incoming airMucous membraneGoblet cells mucusTrap debrisOuter wallAnterior “C” shaped cartilaginous ringsPrevent collapsePosterior Smooth muscleAllow esophagus to expandLOWER RESPIRATORY TRACTBronchial treeAirways leading from trachea into lungsTrachea splits into primary bronchi (R&L)Carina – cartilage separating each bronchusBRONCHIAL TREEPrimary bronchiSecondary bronchiTertiary bronchiIntralobular bronchiolesTerminal bronchiolesBRONCHIAL TREERespiratory bronchiolesAlveolar ductsAlveolar sacsAlveoliCOMPOSITION OF BRONCHISimilar to tracheaCartilaginous rings replaced by “plates” in lungAmount of cartilage decreases with diminishing size of passagesSmooth muscle and elastic fibersCell typePseudostratified ciliated columnar (larger tubes)Cuboidal epithelium (bronchioles)Squamous epithelium (alveoli)ALVEOLIThin layer of epithelial cellsLarge surface area for gas exchangeO2 diffuses from alveolus into blood in capillaryCO2 diffuses from blood in capillary into alveolusLOWER RESPIRATORY TRACTLungsSoft, spongyRight lung – 3 lobesLeft lung – 2 lobesLobes lobulesTerminal bronchioles + alveolar ducts, alveolar sacs, alveoli, nerves, blood vessels, lymphatic vesselsBOUNDARIES OF LUNGSThoracic cageRibs SternumDiaphragmHeartPLEURAL MEMBRANESVisceral pleuraParietal pleuraPleural cavityBREATHINGAlso called ventilationInspirationExpirationAtmospheric pressureWeight of air is force that moves air into lungs760 mm/Hg or 1 atmPressure exerted on all surfaces in contact with airPressure inside lungs is same as on outsideVOLUME VS. PRESSUREAIncrease volume, decrease air pressure inside pushing outside air inBDecrease volume, increases air pressure forcing air outVOLUME VS. PRESSURENormal inspirationPressure inside lung decreases, outside air pushed into airwaysINSPIRATIONDiaphragm stimulated by phrenic nerveDiaphragm , enlarging thoracic cavityIntra-alveolar pressure , forcing air into lungsINSPIRATIONExternal intercostal muscles raise ribs and elevate sternumLowers intra-alveolar pressure even more, causing more air to enterSURFACE TENSIONPleural membranesHelp expand lungs via surface tensionAlveoliSecrete surfactant to decrease surface tension to prevent alveolar collapseSurfactantSurface active agentEXPIRATIONElastic recoilElastic tissues of the lungs are stretched during inspiration; return to original state during expirationPressure between alveoli increases, forces air outEXPIRATIONPassive process Does not require muscle contractionForceful expirationIncrease pressure in lungs/abdominal cavity forcing air out of lungsInternal intercostalsInternal/external obliquesTransverse/rectus abdominisRESPIRATORY VOLUMESSpirometryMeasurement of air volumes in/out of lungsRespiratory cycleI + E; 13/minRESPIRATORY VOLUMESRespiratory
View Full Document