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Pulmonary
Primary function of pulmonary system- Exchange of gases between the environmental air and blood
1. Ventilation – pulmonary system Ventilates the alveoli
2. Diffusion – pulmonary system, Diffuses gases into and out of the blood
3. Perfusion – cardiovascular system, Perfuses the lungs so that the organs and tissues of the body receive blood that is
rich in in oxygen and low in CO2
Consists of upper and lower airways, nasopharynx and the oropharynx. The larynx, trachea, the bronchi, and the
terminal bronchioles. The conductive airway purpose is to provide movement from external environment down to the point of
gas exchange.
The upper airways warm and humidify the air and consist of the nasopharynx and the oropharynx.
Nasopharynx-
Oropharynx-
The larynx connects the upper and lower airways.
The lower airways- consists of the trachea, the bronchi, and the terminal bronchioles
Trachea
Bronchi
Terminal bronchioles
Neurochemical control of ventilation- Chemoreceptors, Lung innervation, Alveolar surface tension and Airway kresistance
• Chemoreceptors
o Central kchemoreceptors- kmonitor karterial kblood kindirectly kby ksensing kchanges kin kthe kpH kof
kcerebrospinal kfluid k(CSF
o Peripheral kchemoreceptors- klocated kin kaortic kbodies, kthe kaortic karch, kand kcarotid kbodies kat kthe
kbifurcation kof kthe kcarotids, knear kthe kbaroreceptors
▪ become kthe kmajor kstimulus kto kventilation kwhen kthe kcentral kchemoreceptors kare k“reset” kby
kchronic khypoventilation
• Lung kinnervation-
o Stretch kchemoreceptors k- klocated kin kthe ksmooth kmuscles kof kairways kand kare ksensitive kto
kincreases kin kthe ksize kor kvolume kof kthe klungs.
▪ They kdecrease kventilatory krate kand kvolume kwhen kstimulated, kan koccurrence ksometimes
kreferred kto kas kthe kHering-Breuer kexpiratory kreflex. kThis kreflex kis kactive kin knewborns kand
kassists kwith kventilation.
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In kadults, kthis kreflex kis kactive konly kat khigh ktidal kvolumes k(such kas kwith kexercise kand
kmechanical kventilation) kand kmay kplay ka krole kin kprotecting kagainst kexcess klung kinflation
▪ C-fibers kare kstimulated kby kirritants kor kdifferent kbody kmovements. k C-fibers kincrease krespiration
during kexercise.
▪ Spindle kreceptors kare klocated kin kthe kdiaphragm kand kincrease kwhen kour kwork kis
kdisproportionate kto kventilation.
▪
Gas kTransport- kKnow kthe ksteps kfor koxygenation kof kcells kto kbody, kand kremoval kof kCO2
k Identify klaboratory ktests kthat kaide kin kthe kevaluation kand kdiagnosis kof kpulmonary
dysfunction kinadequate kgas kexchange kor kventilation k(PaO2, k≤50 kmmHg kor kPaCO2 k≥50 kmmHg kand kpH
k
k≥7.25).
minute kvolume k(tidal k volume k× krespiratory krate)
When kalveolar kventilation kis knormal, kcarbon kdioxide k(CO2) kis kremoved kfrom kthe klungs kat kthe ksame krate kat kwhich kit
kis kproduced kby kcellular kmetabolism. kThis kmaintains karterial kCO2 kpressure k(PaCO2) kat knormal klevels k(40 kmmHg).
kWith khypoventilation, kCO2 kremoval kdoes knot kkeep kup kwith kCO2 kproduction kand kPaCO2 kincreases, kcausing
khypercapnia k(PaCO2 kgreater kthan k44 kmmHg). kThis kresults kin kan kincrease kin khydrogen kion kin kthe kblood, ktermed
krespiratory kacidosis, kwhich kcan kaffect kthe kfunction kof kmany ktissues kthroughout kthe kbody.
Explain kthe kvalues kassociated kwith kspirometry
Spirometry- kmeasures kthe kvolume kand kflow kof kair kinhaled kand kexhaled kand kis kplotted kagainst ktime k(flow krate) kduring
kdifferent kbreathing kmaneuvers
o FEV1 k = ktotal kexpiration kover kone ksecond
o FVC k= kforced kvital kcapacity
o FEV1/FVC kratio kis kconsidered kthe kmost ksensitive kindicator kfor kearly kairflow klimitation
o 70% kor kless kis kevidence kof kobstruction kdespite knormal kFEV
Explain kthe keffects kof kaging kon kthe kpulmonary ksystem.
• loss kof kelastic krecoil- kThis kprocess kincreases kalveolar ksize, kdecreases kthe kalveolar ksurface karea
kavailable kfor kgas kdiffusion, kand kdecreases kairway ksupport kprovided kby knormal klung ktissues.
• stiffening kof kthe kchest kwall- kbecause kthe kribs kbecome kossified k(less kflexible) kand kjoints kbecome
kstiffer.
• changes kin kgas kexchange- kVital kcapacity kdecreases kand kresidual kvolume kincreases. ktotal klung
kcapacity kremains kthe ksame--- kdecrease kventilatory kreserves kand klead kto kdecreased kventilation-
perfusion kratios.
• increases kin kflow kresistance- krespiratory kmuscle kstrength kand kendurance kdecrease kby kup kto k20%.
Identify kand kexplain kthe ksigns kand ksymptoms kof kalterations kof kpulmonary kdiseases.
• Dyspnea
• Cough
• Abnormal kSputum
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• Abnormal kBreathing kPatterns
Pulmonary
Primary function of pulmonary system- Exchange of gases between the environmental air and blood
1. Ventilation – pulmonary system Ventilates the alveoli
2. Diffusion – pulmonary system, Diffuses gases into and out of the blood
3. Perfusion – cardiovascular system, Perfuses the lungs so that the organs and tissues of the body receive blood that is
rich in in oxygen and low in CO2
Consists of upper and lower airways, nasopharynx and the oropharynx. The larynx, trachea, the bronchi, and the
terminal bronchioles. The conductive airway purpose is to provide movement from external environment down to the point of
gas exchange.
The upper airways warm and humidify the air and consist of the nasopharynx and the oropharynx.
Nasopharynx-
Oropharynx-
The larynx connects the upper and lower airways.
The lower airways- consists of the trachea, the bronchi, and the terminal bronchioles
Trachea
Bronchi
Terminal bronchioles
Neurochemical control of ventilation- Chemoreceptors, Lung innervation, Alveolar surface tension and Airway kresistance
• Chemoreceptors
o Central kchemoreceptors- kmonitor karterial kblood kindirectly kby ksensing kchanges kin kthe kpH kof
kcerebrospinal kfluid k(CSF
o Peripheral kchemoreceptors- klocated kin kaortic kbodies, kthe kaortic karch, kand kcarotid kbodies kat kthe
kbifurcation kof kthe kcarotids, knear kthe kbaroreceptors
▪ become kthe kmajor kstimulus kto kventilation kwhen kthe kcentral kchemoreceptors kare k“reset” kby
kchronic khypoventilation
• Lung kinnervation-
o Stretch kchemoreceptors k- klocated kin kthe ksmooth kmuscles kof kairways kand kare ksensitive kto
kincreases kin kthe ksize kor kvolume kof kthe klungs.
▪ They kdecrease kventilatory krate kand kvolume kwhen kstimulated, kan koccurrence ksometimes
kreferred kto kas kthe kHering-Breuer kexpiratory kreflex. kThis kreflex kis kactive kin knewborns kand
kassists kwith kventilation.
, Page 2 of 27
In kadults, kthis kreflex kis kactive konly kat khigh ktidal kvolumes k(such kas kwith kexercise kand
kmechanical kventilation) kand kmay kplay ka krole kin kprotecting kagainst kexcess klung kinflation
▪ C-fibers kare kstimulated kby kirritants kor kdifferent kbody kmovements. k C-fibers kincrease krespiration
during kexercise.
▪ Spindle kreceptors kare klocated kin kthe kdiaphragm kand kincrease kwhen kour kwork kis
kdisproportionate kto kventilation.
▪
Gas kTransport- kKnow kthe ksteps kfor koxygenation kof kcells kto kbody, kand kremoval kof kCO2
k Identify klaboratory ktests kthat kaide kin kthe kevaluation kand kdiagnosis kof kpulmonary
dysfunction kinadequate kgas kexchange kor kventilation k(PaO2, k≤50 kmmHg kor kPaCO2 k≥50 kmmHg kand kpH
k
k≥7.25).
minute kvolume k(tidal k volume k× krespiratory krate)
When kalveolar kventilation kis knormal, kcarbon kdioxide k(CO2) kis kremoved kfrom kthe klungs kat kthe ksame krate kat kwhich kit
kis kproduced kby kcellular kmetabolism. kThis kmaintains karterial kCO2 kpressure k(PaCO2) kat knormal klevels k(40 kmmHg).
kWith khypoventilation, kCO2 kremoval kdoes knot kkeep kup kwith kCO2 kproduction kand kPaCO2 kincreases, kcausing
khypercapnia k(PaCO2 kgreater kthan k44 kmmHg). kThis kresults kin kan kincrease kin khydrogen kion kin kthe kblood, ktermed
krespiratory kacidosis, kwhich kcan kaffect kthe kfunction kof kmany ktissues kthroughout kthe kbody.
Explain kthe kvalues kassociated kwith kspirometry
Spirometry- kmeasures kthe kvolume kand kflow kof kair kinhaled kand kexhaled kand kis kplotted kagainst ktime k(flow krate) kduring
kdifferent kbreathing kmaneuvers
o FEV1 k = ktotal kexpiration kover kone ksecond
o FVC k= kforced kvital kcapacity
o FEV1/FVC kratio kis kconsidered kthe kmost ksensitive kindicator kfor kearly kairflow klimitation
o 70% kor kless kis kevidence kof kobstruction kdespite knormal kFEV
Explain kthe keffects kof kaging kon kthe kpulmonary ksystem.
• loss kof kelastic krecoil- kThis kprocess kincreases kalveolar ksize, kdecreases kthe kalveolar ksurface karea
kavailable kfor kgas kdiffusion, kand kdecreases kairway ksupport kprovided kby knormal klung ktissues.
• stiffening kof kthe kchest kwall- kbecause kthe kribs kbecome kossified k(less kflexible) kand kjoints kbecome
kstiffer.
• changes kin kgas kexchange- kVital kcapacity kdecreases kand kresidual kvolume kincreases. ktotal klung
kcapacity kremains kthe ksame--- kdecrease kventilatory kreserves kand klead kto kdecreased kventilation-
perfusion kratios.
• increases kin kflow kresistance- krespiratory kmuscle kstrength kand kendurance kdecrease kby kup kto k20%.
Identify kand kexplain kthe ksigns kand ksymptoms kof kalterations kof kpulmonary kdiseases.
• Dyspnea
• Cough
• Abnormal kSputum
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• Abnormal kBreathing kPatterns
