1.4 : 呼吸の生理学 II: 呼吸の神経性調節

The regulation of respiration is mediated by a cluster of neurons in the brainstem known as the respiratory centers.

The respiratory centers are divided into two areas: the medullary respiratory center, located in the medulla oblongata, and the pontine respiratory center, located in the pons.

The medullary respiratory center consists of the dorsal respiratory group or DRG, and the ventral respiratory group, or VRG.

During normal breathing, the DRG transmits impulses through the phrenic and intercostal nerves, stimulating the diaphragm and external intercostal muscles to contract and induce inhalation.

After approximately two seconds, DRG inactivity relaxes these muscles, leading to exhalation.

The VRG, through its pre-Bötzinger complex, generates the breathing rhythm by regulating the rate at which DRG neurons fire action potentials.

The remaining VRG neurons regulate forceful breathing by controlling the movements of the accessory breathing muscles.

Lastly, the pontine respiratory group sends impulses to the VRG, fine-tuning the breathing rhythm during vocalization, sleep, and exercise.