By Dr. Artour Rakhimov, Alternative Health Educator and Author
This extract from my big book is about regulation of breathing in health and disease, and it is a part of Buteyko practitioner training:
The central nervous system controls our breathing, using special tissues and cells that sense the concentration of carbon dioxide, oxygen, and hydrogen ions, and then send the information to the brain. There are 2 types of respiratory chemoreceptors: central chemoreceptors, which are located in the medulla oblongata of the brain, and peripheral chemoreceptors.
The central chemoreceptors detect changes in the pH of the cerebrospinal fluid and they are responsible for long-term or chronic changes in breathing. Since CO2 dissolves in the blood and can penetrate through the blood-brain barrier, the main reason for pH variations in the brain are changes in CO2 concentrations. Peripheral chemoreceptors monitor immediate changes in CO2, O2, and pH concentrations of the blood and control our breathing in the short run. It is agreed that peripheral chemoreceptors include;
1) the carotid body, which is situated at the division of the common carotid artery into the external and internal carotid arteries in the neck, becoming the external and internal carotid arteries;
2) the aortic body which is located near the aortic arch.
Both bodies are small pieces of tissues, which are very well perfused. The carotid and aortic bodies detect acute changes in CO2, pH, and O2 concentrations of the arterial blood. The output from both bodies is relayed to the respiratory center in the brain for immediate regulation of breathing.
It is possible that there are additional chemoreceptors, which are often called “paraganglia”, located in the thorax and abdomen (Deane et al, 1975; Easton et al, 1983).
In addition, there are other receptors that are connected to the breathing center and are located in the lungs. These receptors, too, can influence our breathing by producing, for example, coughing, sneezing, deep inhalations, hyperventilation, breath-holding, and other effects. These receptors can detect the presence of foreign objects or irritants in the airways, the degree of inflation of the lungs, and other parameters. The functions and actions of some of these receptors in the lungs and their relationships to breathing are still poorly understood.
More recent evidence suggests the existence of the respiratory rhythm due to the discharge of medullary respiratory neurons. The respiratory rhythm, according to Oxford Medical Dictionary, is the rhythm of alternating inspiratory and expiratory movements that take place during breathing. Four respiratory centers are thought to control the respiratory rhythm; the inspiratory center and expiratory center in the medulla, and an apneustic center and pneumatic center in the pons. This rhythm probably plays a central role in situations when we lose consciousness. The respiratory rhythm influences, together with other factors, the duration of breath-holding (Parkes, 2005). This study of Parkes Breath-holding and its breakpoint indicates that even such a simple event as breath-holding has a very complicated mechanism of interactions of various parameters and little is known about the exact details of this process.
Doctor Buteyko proposed that CO2 deficiency makes the neurons of the respiratory center excited fuelling further hyperventilation and causing a reduction in the BHT (Buteyko, 1977).
Buteyko KP, Carbon dioxide theory and a new method of treatment and prevention of diseases of the respiratory
system, cardiovascular system, nervous system, and some other diseases [in Russian], Public lecture for Soviet
scientists at the Moscow State University, 9 December 1969, Science and life [Nauka i zshizn’], October 1977.
Deane BM, Howe A, and Morgan M, Abdominal vagal paraganglia: distribution and comparison with carotid body, in the rat, Acta Anat (Basel) 1975, 3: 19-28.
Easton J and Howe A, The distribution of thoracic glomus tissue (aortic bodies) in the rat, Cell Tissue Res 1983, 232:
Parkes MJ, Breath-holding and its breakpoint, Exper Physiol 2005, 91, 1, 1-15.