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CHAPTER 23The Respiratory System

Copyright © 2007 by John Wiley & Sons, Inc.

Principles ofHuman Anatomy

Eleventh Edition

Principles ofHuman Anatomy

Eleventh EditionGerard J. Tortora

&

Mark T. Nielsen

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Functions of the Respiratory Functions of the Respiratory SystemSystem

nn Gas Exchange (Respiration)Gas Exchange (Respiration)nn Eliminates CO2Eliminates CO2nn Brings in O2Brings in O2

nn Regulates pHRegulates pHnn Filters inhaled AirFilters inhaled Airnn Produces soundProduces soundnn Contains receptors for olfactory systemContains receptors for olfactory system

Respiration Respiration –– 3 basic steps3 basic steps

nn Pulmonary ventilationPulmonary ventilationnn Gas exchange between the atmosphere and Gas exchange between the atmosphere and

lungslungsnn External (pulmonary) respirationExternal (pulmonary) respiration

nn Gas exchange between the alveoli & blood in Gas exchange between the alveoli & blood in the pulmonary capillariesthe pulmonary capillaries

nn Internal (tissue) respirationInternal (tissue) respirationnn Gas exchange between blood and the tissuesGas exchange between blood and the tissues

Respiratory PassagewaysRespiratory PassagewaysBronchial tree (trachea to alveoli)Bronchial tree (trachea to alveoli)nn TracheaTracheann Primary bronchiPrimary bronchinn Secondary (lobar) bronchiSecondary (lobar) bronchi

nn 1 for each lobe (right lung has 3, left lung has 2)1 for each lobe (right lung has 3, left lung has 2)nn Tertiary (segmental bronchi)Tertiary (segmental bronchi)

nn Each supplies a bronchiopulmonary segmentEach supplies a bronchiopulmonary segmentnn BronchiolesBronchioles

nn Contains smooth muscle and no cartilageContains smooth muscle and no cartilagenn Terminal bronchiolesTerminal bronchioles

nn Each supplies a lobule (lymph vessel, venule & arteriole)Each supplies a lobule (lymph vessel, venule & arteriole)nn Respiratory bronchioles (simple squamous epith.)Respiratory bronchioles (simple squamous epith.)nn Alveolar ducts (atria)Alveolar ducts (atria)nn AlveoliAlveoli

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24_1024_10 Structural ClassificationStructural Classification

nn Upper Respiratory SystemUpper Respiratory Systemnn NoseNosenn PharynxPharynx

nn Lower Respiratory SystemLower Respiratory Systemnn LarynxLarynxnn TracheaTracheann BronchiBronchinn Bronchial TreeBronchial Treenn LungsLungs

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Functional ClassificationFunctional Classificationnn Conducting portionConducting portion

nn NoseNose ■■ BronchiBronchinn PharynxPharynx ■■ BronchiolesBronchiolesnn LarynxLarynx ■■ Terminal BronchiolesTerminal Bronchiolesnn TracheaTrachea

nn Respiratory portionRespiratory portionnn Where gas exchange occursWhere gas exchange occursnn Respiratory bronchiolesRespiratory bronchiolesnn Alveolar ducts alveolar sacsAlveolar ducts alveolar sacsnn AlveoliAlveoli

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Serous MembraneSerous Membranenn PleuraPleura

nn Parietal pleuraParietal pleurann Membrane lining the thoracic cavityMembrane lining the thoracic cavity

nn Visceral pleuraVisceral pleurann Membrane covering the lungMembrane covering the lung

nn InterpleuralInterpleural spacespacenn A potential space (contains fluid)A potential space (contains fluid)

nn PleurisyPleurisynn Inflammation of the pleuraInflammation of the pleura

nn PneumothoraxPneumothoraxnn Air in the Air in the interpleuralinterpleural spacespacenn AtelectasisAtelectasis

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Cell types in the lungCell types in the lung

nn Type I alveolar cellsType I alveolar cellsnn Simple squamous epitheliumSimple squamous epitheliumnn Forms a continuous lining for gas exchangeForms a continuous lining for gas exchange

nn Type II alveolar cells (septal cells)Type II alveolar cells (septal cells)nn Secrete alveolar fluid (surfactant)Secrete alveolar fluid (surfactant)

nn Reduces surface tensionReduces surface tensionnn Respiratory distress syndrome (premee babies)Respiratory distress syndrome (premee babies)

nn Dust cells (macrophages)Dust cells (macrophages)nn phagocytosisphagocytosis

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Respiratory membraneRespiratory membrane

nn ½ µm thick = ½ µm thick = 11//1616 the diameter of RBCthe diameter of RBCnn Surfactant layerSurfactant layernn Type I alveolar cellType I alveolar cellnn Epithelial basement membranesEpithelial basement membranes

nn Alveolar cell basement membraneAlveolar cell basement membranenn Capillary basement membraneCapillary basement membrane

nn Capillary endotheliumCapillary endothelium

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Pulmonary VentilationPulmonary Ventilation

nn Exchange of gases between the Exchange of gases between the atmosphere and the lungsatmosphere and the lungsnn InspirationInspiration

nn Moving air into the lungsMoving air into the lungsnn ExpirationExpiration

nn Moving air out of the lungsMoving air out of the lungs

Boyles LawBoyles Law

nn At a constant temperature the At a constant temperature the pressure of a gas in a closed pressure of a gas in a closed container is inversely proportional container is inversely proportional to the size of the container.to the size of the container.

nn Volume Volume -- PressurePressurenn Volume Volume -- Pressure Pressure

Muscles of InhalationMuscles of Inhalation

nn Quiet BreathingQuiet Breathingnn DiaphragmDiaphragmnn External intercostalsExternal intercostals

nn Strenuous InhalationStrenuous Inhalationnn SternocleidomastoidSternocleidomastoid –– elevates sternumelevates sternumnn ScalenesScalenes–– elevates ribs 1 & 2elevates ribs 1 & 2nn PectoralisPectoralis minorminor –– elevates ribs 3elevates ribs 3--55

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Pressure Changes During Pressure Changes During Quiet InhalationQuiet Inhalation

Before inhalationBefore inhalation During inhalationDuring inhalationDiaphragm moves ~ 1 cmDiaphragm moves ~ 1 cm

Atmos. PressureAtmos. Pressure 760760 760760

IntrapleuralIntrapleural press.press. 756756 754754

Alveolar PressureAlveolar Pressure 760760 758758

Expiratory MusclesExpiratory Muscles

nn Normal (quiet) expiration is a passive Normal (quiet) expiration is a passive process. Results from relaxation of the process. Results from relaxation of the inspiratoryinspiratory muscles. muscles. nn Volume Volume -- Pressure Pressure

nn Forced Expiration: (muscles that pull the Forced Expiration: (muscles that pull the rib cage down)rib cage down)nn Abdominal groupAbdominal groupnn Internal intercostalsInternal intercostals

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24_1224_12 Lung VolumesLung Volumes

nn Tidal Volume (TV)Tidal Volume (TV)nn Amt that moves in or out in a normal breathAmt that moves in or out in a normal breath

nn InspiratoryInspiratory Reserve Volume (IRV)Reserve Volume (IRV)nn Amt that we can forcefully inhale above TVAmt that we can forcefully inhale above TV

nn Expiratory Reserve Volume (ERV)Expiratory Reserve Volume (ERV)nn Amt we can forcefully exhale beyond the TVAmt we can forcefully exhale beyond the TV

nn Residual Volume (RV)Residual Volume (RV)nn Amt that remains after ERV is exhaledAmt that remains after ERV is exhaled

Lung CapacitiesLung Capacities

nn Vital CapacityVital Capacitynn VC = IRV + ERV + TVVC = IRV + ERV + TV

nn Lung CapacityLung Capacitynn LC = IRV + ERV + TV + RVLC = IRV + ERV + TV + RV

Anatomic Dead SpaceAnatomic Dead Space

nn Airspace that does not participate Airspace that does not participate in gas exchangein gas exchange

nn Units given in milliliters and is Units given in milliliters and is approximately equal to your approximately equal to your weight in pounds (normal weight weight in pounds (normal weight individual) e.g. 140 individual) e.g. 140 mlsmls if you if you weigh 140 lbsweigh 140 lbs

Learning ObjectivesLearning Objectives

nn Discuss the functions of the respiratory Discuss the functions of the respiratory systemsystem

nn Name the basic steps in RespirationName the basic steps in Respirationnn Name the structures in the upper and Name the structures in the upper and

lower respiratory tractslower respiratory tractsnn Describe the conductive vs. the respiratory Describe the conductive vs. the respiratory

portions of the systemportions of the systemnn Describe the serous membranes of the Describe the serous membranes of the

respiratory systemrespiratory system

Learning ObjectivesLearning Objectives

nn DescriibeDescriibe the trachea and tracheal the trachea and tracheal cartilagescartilages

nn Describe the bronchial tree and the Describe the bronchial tree and the changes in epithelium, muscle and changes in epithelium, muscle and cartilagecartilage

nn Describe lung lobes and Describe lung lobes and bronchiobronchio--pulmonary segments for each lungpulmonary segments for each lung

nn Define the following terms: pleura, Define the following terms: pleura, pneumothorax and atelectasispneumothorax and atelectasis

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Learning ObjectivesLearning Objectives

nn Describe the Type I and Type II alveolar Describe the Type I and Type II alveolar cells cells

nn Describe the dust cellsDescribe the dust cellsnn List the components of the respiratory List the components of the respiratory

membranemembranenn Discuss Boyle’s LawDiscuss Boyle’s Lawnn Which muscles are involved in quiet vs. Which muscles are involved in quiet vs.

forceful inspiration and expirationforceful inspiration and expiration

Learning ObjectivesLearning Objectives

nn Discuss the approximate pressures Discuss the approximate pressures involved in pulmonary ventilationinvolved in pulmonary ventilation

nn Describe the different lung volumes and Describe the different lung volumes and capacitiescapacities

nn Describe Anatomic Describe Anatomic Dead SpaceDead Space