From the Research
The respiratory areas in the brain are located primarily in the brainstem, including the medulla oblongata, pons, and midbrain, with the most critical respiratory centers found in the medulla, as supported by the most recent study 1. The medulla contains the ventral respiratory group (VRG), which includes the pre-Bötzinger complex that generates the basic breathing rhythm, and the dorsal respiratory group (DRG), which processes sensory information from the lungs and airways.
- The pontine respiratory centers, including the pneumotaxic center and apneustic center, help regulate the transition between inhalation and exhalation.
- These brain regions work together to maintain proper breathing patterns by monitoring blood oxygen, carbon dioxide, and pH levels through chemoreceptors.
- The respiratory centers automatically adjust breathing rate and depth based on the body's metabolic needs, increasing ventilation during exercise or decreasing it during rest, as described in 2. The autonomic control of breathing ensures adequate gas exchange without conscious effort, though we can temporarily override this system for activities like speaking or holding our breath, with higher brain inputs contributing to volitional control of breathing, as shown in 1. Key brainstem compartments involved in generating respiratory rhythm and shaping inspiratory and expiratory motor patterns include the Bötzinger complex, pre-Bötzinger complex, and rostral ventral respiratory group, as outlined in 2.
- The pre-Bötzinger complex is thought to be a crucial area for rhythm generation.
- The functional expression of respiratory mechanisms is controlled by multiple drives from more rostral brainstem components, including the retrotrapezoid nucleus and pons.
- Descending inputs from cortical areas predominantly target the periaqueductal gray and Kölliker-Fuse nucleus, implying that volitional motor commands for vocalization are specifically relayed via the periaqueductal gray, as found in 1.