Respiratory System. Tortora Page 483 Respiratory system provides for gas exchange.Respiratory system provides for gas exchange. RespirationRespiration

Respiratory Respiratory SystemSystem

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• Respiratory Respiratory system provides system provides for gas for gas exchange.exchange.

• RespirationRespiration– InternalInternal– ExternalExternal

• VentilationVentilation

RespiratorRespiratory Systemy System

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• Upper Upper respiratory respiratory systemsystem– NoseNose– PharynxPharynx

• Lower Lower respiratory respiratory systemsystem– LarynxLarynx– Trachea, etcTrachea, etc

RespiratorRespiratory Systemy System

TortoraTortoraPage 484Page 484RespiratorRespirator

y Systemy System

• Conducting Conducting portionportion– Series of tubes Series of tubes descending in descending in size.size.

• Respiratory Respiratory portionportion– Area of gas Area of gas exchange.exchange.

– alveolialveoli


• Functions of Functions of nose.nose.– Warms, moistens, Warms, moistens, and filters the and filters the air.air.

– Olfactory senses.Olfactory senses.– Resonance chamber Resonance chamber for sounds.for sounds.

• Role of Role of turbinates.turbinates.

• Role of mucus.Role of mucus.• Role of CiliaRole of Cilia

Passage of Air Passage of Air Through the NoseThrough the Nose


• NasopharynxNasopharynx• OropharynxOropharynx• LaryngopharynxLaryngopharynx

PharynxPharynx


• TracheaTrachea– Supported by Supported by cartilage.cartilage.

– Lined with mucous Lined with mucous membrane.membrane.

– Lined by ciliated, Lined by ciliated, pseudostratified pseudostratified columnar columnar epithelium.epithelium.

• Primary bronchiPrimary bronchi• Secondary bronchiSecondary bronchi• Tertiary bronchiTertiary bronchi

RespiratoRespiratory Treery Tree

TortoraTortoraPage 407Page 407BronchiolBronchiol

eses• Not supported by Not supported by cartilage rings.cartilage rings.

• Smooth muscle in Smooth muscle in walls.walls.

• ANS controls ANS controls diamenter of diamenter of bronchiloes.bronchiloes.

• Asthma: smooth Asthma: smooth muscle spasms.muscle spasms.

• Bronchioles end Bronchioles end in alveoli.in alveoli.


• Lungs lie in Lungs lie in thoracic cavity.thoracic cavity.

• Lungs surrounded Lungs surrounded by double by double membrane membrane (Pleural (Pleural membrane)membrane)– Secretes Secretes lubricating lubricating fluid.fluid.

– Creates an air Creates an air tight thoracic tight thoracic cavity.cavity.

Structure Structure of the of the LungsLungs


Structure Structure of the of the AlveoliAlveoli

• Cup shaped Cup shaped pouches that pouches that make up an air make up an air sac.sac.

• Lined with Lined with simple squamous simple squamous epithelium epithelium connected to a connected to a basement basement membrane.membrane.


• MacrophagesMacrophages• Septal cellsSeptal cells• Role of Role of surfactant.surfactant.

• Alveoli are Alveoli are surrounded by surrounded by capillaries.capillaries.

Structure Structure of the of the AlveoliAlveoli


• Air moves due to Air moves due to differences in differences in pressure inside pressure inside compared to compared to outside the outside the thoracic cavity.thoracic cavity.

• Air moves from Air moves from high to low high to low pressure areas.pressure areas.

Pulmonary Pulmonary VentilationVentilation


• Atmospheric Atmospheric pressure = 760 pressure = 760 mmhg.mmhg.

• If thoracic air If thoracic air pressure equals pressure equals 760 mmhg, no air 760 mmhg, no air will move in or will move in or out.out.

Pulmonary Pulmonary Ventilation: Ventilation: InhalationInhalation

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• To enlarge the To enlarge the thoracic cavity and thoracic cavity and create a low pressure:create a low pressure:– Contract (pull down) Contract (pull down)

the diaphragm.the diaphragm.– External intercostal External intercostal

muscles contract muscles contract (pulls rib cage up and (pulls rib cage up and out).out).

• Alveolar air pressure Alveolar air pressure drops 2 mmhg. (758 drops 2 mmhg. (758 mmhg)mmhg)

• Air fills lungs.Air fills lungs.

Pulmonary Pulmonary Ventilation: Ventilation: InhalationInhalation

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• Reducing the thoracic Reducing the thoracic cavity size creates cavity size creates higher air pressures.higher air pressures.

• To create a higher To create a higher thoracic cavity:thoracic cavity:– Diaphragm relaxes.Diaphragm relaxes.– Rib cage moves down Rib cage moves down

and in.and in.– Elasticity of lungs Elasticity of lungs

causes them to emptycauses them to empty– Contracting abdominal Contracting abdominal

muscles force internal muscles force internal organs up.organs up.

– Pressure rises to 762 Pressure rises to 762 mmhg.mmhg.

Pulmonary Pulmonary Ventilation: Ventilation: ExhalationExhalation

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• Phospholipid.Phospholipid.• Produced by the Produced by the septal cells.septal cells.

• Reduces surface Reduces surface tension.tension.

• The ability to The ability to easily inflate and easily inflate and deflate is deflate is “compliance”.“compliance”.

SurfactantSurfactant

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• Measured using Measured using a spirometer.a spirometer.

• Recording of Recording of volumes is volumes is called a called a spirogram.spirogram.

Pulmonary Pulmonary VolumesVolumes

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• Tidal volume Tidal volume (TV)(TV)– Inhalation or Inhalation or exhalation while at exhalation while at rest.rest.

– 500 ccm.500 ccm.– 350ccm reach 350ccm reach alveoli.alveoli.

– Rest is in dead air Rest is in dead air space.space.

• Minute volume of Minute volume of respiration: respiration: (MVR)(MVR)– Tidal volume x Tidal volume x

inhalations per minute.inhalations per minute.


• Inspiratory Inspiratory reserve volume. reserve volume. (IRV)(IRV)– Amount of air that can Amount of air that can be inhaled after tidal be inhaled after tidal volume.volume.

– 2500 to 3500 ccm.2500 to 3500 ccm.

• Expiratory Expiratory reserve. reserve. (ERV)(ERV)

– Amount of air tht can Amount of air tht can be exhaled after be exhaled after normal exhalation.normal exhalation.

– Approx. 1200 ccm.Approx. 1200 ccm.


• Residual volume Residual volume (RV)(RV)– Volume of air that Volume of air that cannot be exhaled.cannot be exhaled.

– 1200 ccm.1200 ccm.

• Minimal air (vital Minimal air (vital air)air)– Air that clings to Air that clings to lung tissue after lung tissue after first breath.first breath.


• Inspiratory capacity Inspiratory capacity (IC)(IC)– Tidal volume + Tidal volume + inspiratory volume.inspiratory volume.

• Expiratory capacity Expiratory capacity (EC)(EC)– Tidal volume + Tidal volume + expiratory volume.expiratory volume.

• Vital capacity (VC)Vital capacity (VC)– Tidal volume + Tidal volume + inspiratory reserve inspiratory reserve volume + expiratory volume + expiratory reserve volume.reserve volume.

Pulmonary Pulmonary CapacitiesCapacities

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• Total Lung Capacity Total Lung Capacity (TLC)(TLC)

• Combination of:Combination of:– Inspiratory volumeInspiratory volume– Tidal VolumeTidal Volume– Expiratory volumeExpiratory volume– Reserve volumeReserve volume

Pulmonary Pulmonary CapacitiesCapacities


• Oxygen and carbon Oxygen and carbon dioxide move from dioxide move from areas of high partial areas of high partial pressure to areas of pressure to areas of low partial pressure.low partial pressure.

• A gases partial A gases partial pressure (p) is equal pressure (p) is equal to the percentage of to the percentage of that gas in a mixture.that gas in a mixture.

Exchange of Exchange of Respiratory Respiratory

GasesGases


• Function of Function of blood is blood is transport of transport of gases.gases.

• Transports from Transports from lungs to lungs to tissues.tissues.

Transport of Transport of Respiratory Respiratory

GasesGases


• Transport of Transport of oxygenoxygen– 1.5% dissolves 1.5% dissolves into plasma of into plasma of blood.blood.

– 98.5% combines 98.5% combines with hemoglobin with hemoglobin to form to form oxyhemoglobin.oxyhemoglobin.

Hb + OHb + O22 ------- HbO ------- HbO22


GasesGases


• Transport of carbon Transport of carbon dioxidedioxide

• 7% dissolves into 7% dissolves into plasma.plasma.

• 23% combines with 23% combines with hemoglobin to form hemoglobin to form carbaminohemoglobincarbaminohemoglobin..

• 70% transported in 70% transported in plasma as carbonic plasma as carbonic acid.acid.


GasesGases


• Factors Factors regarding oxygen regarding oxygen being released being released by hemoglobin;by hemoglobin;– pHpH– TemperatureTemperature


GasesGases


• Carbon monoxide.Carbon monoxide.– Binds to Binds to hemoglobin 200X hemoglobin 200X more strongly more strongly than Othan O22..

CO Poisoning CO Poisoning results because results because hemoglobin cannot hemoglobin cannot carry oxygen if carry oxygen if it’s bound to CO.it’s bound to CO.


GasesGases


• Role of Role of respiratory respiratory center in brain center in brain stem.stem.

• Medullary Medullary rhythmicityrhythmicity– Medulla oblongataMedulla oblongata– Controls breathing Controls breathing rhythymrhythym

• Pneumotaxic AreaPneumotaxic Area– PonsPons– Limits inhalationLimits inhalation

• Apneustic AreaApneustic Area– Lower ponsLower pons– Lengthens inhalationLengthens inhalation

Control of Control of RespirationRespiration


• Increase in arterial Increase in arterial blood PCOblood PCO2.2.

• Decrease in arterial Decrease in arterial blood PO2.blood PO2.

• Decrease in blood Decrease in blood pressurepressure

• Increase in body Increase in body temperaturetemperature

• Prolonged pain.Prolonged pain.• Stretching of Stretching of sphincter.sphincter.

Factors that Factors that Increase Increase

RespirationRespiration

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Respiratory System. Tortora Page 483 Respiratory system provides for gas exchange.Respiratory system provides for gas exchange. RespirationRespiration