Definition
- Regulation of respiration matches ventilation to metabolic need through neural, chemical and nonchemical (reflex) control acting on brainstem respiratory centers.
- Control of breathing is broadly divided into three categories: neural control, chemical control, and nonchemical (reflexes from lungs and chest wall) control.
Neural Control of Respiration
- Neural control comprises voluntary control (cerebral cortex, via the corticospinal tract) and automatic control (centers in the brainstem: medulla and pons).
Respiratory centers and their functions
Center
DRG
- Location
- Nucleus tractus solitarius (medulla)
- Function
- Inspiratory; integrates sensory input from the respiratory system
VRG
- Location
- Ventrolateral medulla (nucleus ambiguus, retroambiguus, retrofacialis)
- Function
- Inspiratory and expiratory neurons
CPG (pre-Bötzinger complex)
- Location
- Between nucleus ambiguus and lateral reticular nucleus
- Function
- Pacemaker; generates the basic respiratory rhythm
Pneumotaxic center
- Location
- Nucleus parabrachialis/Kölliker-Fuse nucleus, rostral pons
- Function
- Switches inspiration to expiration; inhibits apneustic center
Apneustic center
- Location
- Caudal pons
- Function
- Prolongs inspiration (apneusis) when not inhibited