Learning Objectives

• Discuss the origins of central respiratory rhythm (DRG, VRG, pre-Bötzinger)
• Discuss the role of the pons and cerebral cortex in respiratory control
• Describe the primary respiratory reflexes
• Discuss the role of the central and peripheral chemoreceptors in respiratory control (including time lags and relative sensitivity)
• Discuss how alterations in PaO2, PaCO2 and pH influence the central and peripheral chemoreceptors
• Describe Cheyne-Stokes respiration, Ondine’s curse and central sleep apnoea (as examples of defective central respiratory control)
• Describe how ventilation is adjusted to meet the demands of exercise

Origins of Central Respiratory Rhythm

• when is the dorsal respiratory group (DRG) active?
• when is the ventral respiratory group (VRG) active?
• what is the inspiratory ramp signal?
• what is the function of the pre-Bötzinger complex?
• how does respiratory centre activity compare in quiet vs forced breathing?

Central Respiratory Control

• what is the function of the pontine respiratory group (PRG)?
• what is the role of the cerebral cortex in breathing?
• how does cortical override work?

Primary Respiratory Reflexes