下呼吸道解剖（英文）课件

1、Anatomy of the Lower AirwayAnatomy of the Lower AirwayOcclusion of the bronchioleSmooth muscleForeign body (not shown)InflammationLung Volumes & CapacitiesTotal lung capacity (TLC) in a typical adult male is 6 litersMuch of inspired air does not enter alveoliTidal Volume (VT)volume of gas inhaled/ex

2、haled during a single ventilatory cycleUsually 5-7 cc/kg (typically 500 cc)Lung Volumes & CapacitiesDead Space Air (VD)Air remaining in air passageways, unavailable for gas exchange (usually 150 cc)Anatomic dead spacetracheabronchiPhysiologic dead spaceformed by factors like disease or obstructionEx

3、amples: COPD & atelectasisLung Volumes & CapacitiesMinute Volume Vmin(minute ventilation)amount of gas moved in and out of respiratory tract per minute(tidal volume - dead space volume) X RRFunctional Reserve Capacity (FRC)after optimal inspiration, the optimum amount of air that can be forced from

4、the lungs in a single exhalationLung Volumes & CapacitiesAlveolar Air (alveolar volume) VAAir reaching alveoli for gas exchangeUsually 350 ccInspiratory Reserve (IRV)Amount of gas that can be inspired in addition to tidal volumeExpiratory Reserve (ERV)Amount of gas that can be expired after a passiv

5、e (relaxed) expirationLung Volumes & CapacitiesVentilationChemoreceptorsCarotid bodies & Aortic archStimulated by PaO2, PaCO2 or pHPaCO2 considered normal neuroregulatory control of ventilationsHypoxic Drivedefault regulatory controlSenses changes in Pa02VentilationOther stimulations or depressants to ventilatory drivebody temp: w/ fever & w/hypothermiadrugs/meds: increase or decreasepain: incre