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THE RESPIRATORY SYSTEM 

LECTURE 6:

RESPIRATORY CONTROL

Dr. Eamonn O’Connor

Human Form & Function

Lecture Outline

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!  Respiratory control centers

!  Control of Ventilation by Chemoreceptors

!  Chemoreceptors

"  Peripheral chemoreceptors

" 

Central chemoreceptors"  Chemoreceptor Reflex

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Quiet Vs. Active Breathing

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Basic Respiratory Control

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Respiratory Control During Quiet Breathing

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!  Chemoreceptors: detect changes in PO2 and PCO2

!  Pulmonary stretch receptors: Inflation & Deflation

!  Irritant receptors: Dust & pollutants

Peripheral Chemoreceptors

Physiology 11-12. The Respiratory System Lecture 6

!  Location:!  Carotid bodies (near

baroreceptors in carotid sinus)

!  Aortic bodies (aortic arch)

!  Function:!  Respond toPaO

2

 (

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Central Chemoreceptors

!  Located in medulla

!  Directly respond to:

!  CSF [H+]

"  Derived via PaCO2

!  NOT circulating [H+]

" 

Cannot cross BBB

!  Therefore indirectly

respond to PaCO2

!  Provide 80%

respiratory drive

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Effect of Increase PaCO2 on Ventilation

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Chemoreceptor Reflex

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Effects of Hypo/Hyper-ventilation on

Minute Ventilation11

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