Structure and Function of the Pulmonary SystemStructures of the Pulmonary SystemSlide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Pulmonary and Bronchial CirculationSlide 11Slide 12Slide 13Chest Wall and PleuraFunction of the Pulmonary SystemVentilationSlide 17Mechanics of BreathingMuscles of VentilationSlide 20Slide 21Measurement of Gas PressureSlide 23Slide 24Gas TransportSlide 26Slide 27Slide 28Slide 29Slide 30Control of Pulmonary CirculationTests of Pulmonary FunctionAging and the Pulmonary SystemSlide 341Structure and Function of the Pulmonary SystemChapter 32Mosby items and derived items © 2006 by Mosby, Inc.2Structures of the Pulmonary SystemAirwaysBlood vesselsChest wall LungsLobesSegmentsLobulesMosby items and derived items © 2006 by Mosby, Inc.3Structures of the Pulmonary SystemMosby items and derived items © 2006 by Mosby, Inc.4Structures of the Pulmonary SystemConducting airwaysUpper airwaysNasopharynxOropharynxLarynxConnects upper and lower airwaysLower airwaysTracheaBronchiTerminal bronchiolesMosby items and derived items © 2006 by Mosby, Inc.5Structures of the Pulmonary SystemMosby items and derived items © 2006 by Mosby, Inc.6Structures of the Pulmonary SystemGas-exchange airwaysRespiratory bronchiolesAlveolar ductsAlveoli Epithelial cellsType I alveolar cellsAlveolar structureType II alveolar cellsSurfactant productionMosby items and derived items © 2006 by Mosby, Inc.7Structures of the Pulmonary SystemMosby items and derived items © 2006 by Mosby, Inc.8Structures of the Pulmonary SystemMosby items and derived items © 2006 by Mosby, Inc.9Structures of the Pulmonary SystemMosby items and derived items © 2006 by Mosby, Inc.10Pulmonary and Bronchial CirculationPulmonary circulation has a lower pressure than the systemic circulationOne third of pulmonary vessels are filled with blood at any given timePulmonary artery divides and enters the lung at the hilusEach bronchus and bronchiole has an accompanying artery or arterioleMosby items and derived items © 2006 by Mosby, Inc.11Pulmonary and Bronchial CirculationMosby items and derived items © 2006 by Mosby, Inc.12Pulmonary and Bronchial CirculationAlveolocapillary membraneFormed by the shared alveolar and capillary wallsThin membrane of alveolar epithelium, the alveolar basement membrane, interstitial space, the capillary basement membrane, and the capillary endotheliumMosby items and derived items © 2006 by Mosby, Inc.13Pulmonary and Bronchial CirculationMosby items and derived items © 2006 by Mosby, Inc.14Chest Wall and PleuraChest wallSkin, ribs, and intercostal musclesThoracic cavityPleuraSerous membraneParietal and visceral layersPleural space (cavity)Pleural fluidMosby items and derived items © 2006 by Mosby, Inc.15Function of the Pulmonary SystemVentilationMechanical movement of gas or air into and out of the lungsMinute volumeVentilatory rate multiplied by the volume of air per breathAlveolar ventilationMosby items and derived items © 2006 by Mosby, Inc.16VentilationNeurochemical controlRespiratory centerDorsal respiratory groupVentral respiratory groupPneumotaxic centerApneustic centerPeripheral chemoreceptorsMosby items and derived items © 2006 by Mosby, Inc.17VentilationNeurochemical controlLung receptorsIrritant receptorsStretch receptorsJ-receptorsChemoreceptorsCentral chemoreceptorsPeripheral chemoreceptorsMosby items and derived items © 2006 by Mosby, Inc.18Mechanics of BreathingMajor and accessory musclesMajor muscles of inspirationDiaphragmExternal intercostalsAccessory muscles of inspirationSternocleidomastoid and scalene musclesAccessory muscles of expirationAbdominal and internal intercostal musclesMosby items and derived items © 2006 by Mosby, Inc.19Muscles of VentilationMosby items and derived items © 2006 by Mosby, Inc.20Mechanics of BreathingAlveolar surface tensionFunction of surfactantElastic properties of the lung and chest wallElastic recoilComplianceAirway resistanceWork of breathingMosby items and derived items © 2006 by Mosby, Inc.21Mechanics of BreathingMosby items and derived items © 2006 by Mosby, Inc.22Measurement of Gas PressureBarometric pressurePartial pressurePartial pressure of water vaporMosby items and derived items © 2006 by Mosby, Inc.23Measurement of Gas PressureMosby items and derived items © 2006 by Mosby, Inc.24Measurement of Gas PressureMosby items and derived items © 2006 by Mosby, Inc.25Gas TransportFour stepsVentilation of the lungsDiffusion of oxygen from the alveoli into the capillary bloodPerfusion of systemic capillaries with oxygenated bloodDiffusion of oxygen from systemic capillaries into the cellsDiffusion of CO2 occurs in reverse orderMosby items and derived items © 2006 by Mosby, Inc.26Gas TransportDistribution of ventilation and perfusionGravity and alveolar pressureVentilation-perfusion ratioMosby items and derived items © 2006 by Mosby, Inc.27Measurement of Gas PressureMosby items and derived items © 2006 by Mosby, Inc.28Gas TransportOxygen transportDiffusion across the alveolocapillary membraneDeterminants of arterial oxygenationOxyhemoglobin association and dissociationOxyhemoglobin dissociation curveMosby items and derived items © 2006 by Mosby, Inc.29Measurement of Gas PressureMosby items and derived items © 2006 by Mosby, Inc.30Gas TransportCarbon dioxide transportDissolved in plasmaBicarbonateCarbamino compoundsHaldane effectMosby items and derived items © 2006 by Mosby, Inc.31Control of Pulmonary CirculationHypoxic vasoconstrictionCaused by low alveolar pO2Blood is shunted to other, well-ventilated portions of the lungsProvides better ventilation and perfusion matchingIf hypoxia affects all segments of the lungs, the vasoconstriction can result in pulmonary hypertensionAcidemia also causes pulmonary artery constrictionMosby items and derived items © 2006 by Mosby, Inc.32Tests of Pulmonary FunctionSpirometryDiffusion capacityResidual volumeFunctional reserve capacity (FRC)Total lung capacityArterial blood gas analysisChest radiographsMosby items and derived items © 2006 by Mosby, Inc.33Aging and the Pulmonary SystemLoss of elastic recoilStiffening of the chest wallAlterations in