Chemical regulation of breathing
Chemical regulation of breathing is the view that the respiratory centre in the bulb is driven by the chemical state of the alveolar air and blood, chiefly carbon dioxide tension. Bayliss set this out in 1915.5 Haldane argued in 1917 that it leaves breathing with no mystery.8
- Earliest held
- 1890, James, W.
- Most discussed in
- Organism and Environment as Illustrated by…, 1917
- In the library
- 66 passages in 7 works
- Rewritten
- 2026-10-09
Early nerve-based accounts
James in 1890 repeated Charles Bell's explanation of the facial muscles. Bell held that they are accessory muscles of respiration, supplied by nerves that arise close to the respiratory centre in the medulla oblongata.1 Loeb in 1900 was cautious about locating such centres. He argued that a change in breathing after stimulating the third ventricle shows only that fibres run from that spot to the segmental respiratory ganglia. It did not show that a respiratory centre lies there.2
Reflex control through the vagus
Sherrington in 1906 placed the chief respiratory centre in the bulb. Receptive neurones from the lung enter there, and he judged the vagal receptors to be mainly regulative of breathing.4 He also noted Rosenthal's resistance theory, in which afferent vagus fibres act on the respiratory centre by interference. In that picture inhibition alters the timing of discharge rather than the tissue itself.3
Carbon dioxide tension
Bayliss in 1915 stated that the stimulus to the respiratory centre depends on carbon dioxide tension in the alveolar air. A fall in that tension therefore stops breathing.5 He reported that Campbell, Douglas, Haldane and Hobson (1913) settled an earlier dispute. In man, summed vagal inhibition produced no apnoea unless alveolar carbon dioxide was lowered.6 At altitude, he wrote, acclimatisation raises blood acidity from non-volatile acids. The centre is then excited although alveolar carbon dioxide stays low.7
Haldane and the mechanism
Haldane in 1917 noted that mechanistic physiologists could take the new facts as confirming their principles. The centre reacts very sensitively to slight changes in CO2 concentration, so no non-physical factor need be invoked.8 He also stressed interdependence. With the vagi cut, an animal still held alveolar CO2 pressure constant, but regulation broke down under strain, as Scott had shown.9
Charles Bell accounted for the special part played by the facial muscles in expression by their being accessory missclet of respiration, governed by nerves whose origin is close to the respiratory centre in the medulla oblongata.
James, W., 1890 · The Principles of Psychology, Vols. 1-2 · open at passage 2805The fact, for instance, that the respiratory movements are affected by stimulation of the third ventricle only proves that there are fibres at that place which go to the segmental respiratory ganglia.
Loeb, J., 1900 · Comparative Physiology of the Brain and Comparative Psychology · open at passage 221Rosenthal's ^ resistance theory of the action of the afferent vagus-fibres upon the respiratory centre is a supposition of this kind.
Sherrington, C. S., 1906 · The Integrative Action of the Nervous System · open at passage 402the chief respiratory centre lies in the bulb where the receptive neurones from the lung itself make entrance and central connection, the vagal receptors being preponderantly regulative in that function.
Sherrington, C. S., 1906 · The Integrative Action of the Nervous System · open at passage 734Since the stimulus to the respiratory centre depends on the tension of carbon dioxide in the alveolar air, it is plain that a diminution of this tension causes cessation of respiratory movements.
Bayliss, W. M., 1915 · Principles of General Physiology · open at passage 2721Campbell, Douglas, Haldane, and Hobson (1913) have shown that no apmea can be produced, at least in man, unless the alveolar carbon dioxide tension is reduced.
Bayliss, W. M., 1915 · Principles of General Physiology · open at passage 2721In acclimatisation, the acidity of the blood due to non-volatile acids is increased, so that the respiratory centre becomes properly excited, although the alveolar carbon dioxide tension is low.
Bayliss, W. M., 1915 · Principles of General Physiology · open at passage 2723For the respiratory centre may be re- garded as a mechanism which reacts in a very sensi- tive manner to slight changes in the concentration of CO2.
Haldane, J. S., 1917 · Organism and Environment as Illustrated by the Physiology of Breathing · open at passage 40When the vagi are cut, an animal can still regulate its breathing so as to keep the alveolar CO2 pressure constant ; for the depth of the drawn-out respirations depends on the alveolar COo pressure.
Haldane, J. S., 1917 · Organism and Environment as Illustrated by the Physiology of Breathing · open at passage 55
| 1917 | Organism and Environment as Illustrated by the Physiology of Breathing · Haldane, J. S. | 32 |
| 1915 | Principles of General Physiology · Bayliss, W. M. | 24 |
| 1906 | The Integrative Action of the Nervous System · Sherrington, C. S. | 4 |
| 1900 | Comparative Physiology of the Brain and Comparative Psychology · Loeb, J. | 3 |
| 1890 | The Principles of Psychology, Vols. 1-2 · James, W. | 1 |
| 1926 | Muscular Activity · Hill, A. V. | 1 |
| 1926 | A Bipolar Theory of Living Processes · Crile, G. W. | 1 |