New Theory of Holistic Integrative Physiology and Medicine III: How We Generate Rhythm and Frequency of Breathing
Authors: Sun Xing‐Guo 
Published: November 2023

Objective

After birth, we have to start breathing and breathing is our vital sign for life before we expired. However, the knowledge of traditional respiratory systemic physiology could not explain the mechanism of breathing control clearly. Based on new constructed HOLISTIC INTEGRATIVE PHYSIOLOGY AND MEDICINE, we explained how we control our breathing by switching off inspiration and expiration and maintaining the stability (see II abstract), but we did not talk about mechanism of how we generate our rhythm and frequency (f) of breathing after birth.

Methods

Now we plan to use the time course of different arterial blood gas signals (trinity of PO2, PCO2 and [H+]) at the different location in the breathing control cycles to explain mechanisms of how we generate rhythm and f of breathing after birth.

Results

Time courses of signals transfer through the breathing control cycle for breathing f: After birth, except the first breathing (be discussed separately), we set the regularity of breathing pattern, the rhythm and f are the two key parameters of it. Traditional nerve electronic signal transferred from peripheral chemical receptors (PCR) via central integrative center to muscles of chest wall and diaphragm is fast, only run over 0.1–0.3s. The signals carried by blood from lung via circulatory parts (pulmonary capillary, pulmonary vein=PV, left atrium=LA, left ventricle=LV and artery) to PCR transfer speed is depend upon the blood flow rate. Blood flow rate depends on stroke volume (SV) and heart rate (HR). At resting, normal SV of LV is similar to our volume of LA and PV, the signals of blood from lung need 3 heart beat (i.e. 3s). Due to the time course to go through circulatory parts (lung‐artery time) is commonly over 2–3 s (more than 90% to total time); the breathing rhythm and frequency dominantly depend on the circulatory function. While we combined the idea of switching off of lung inspiration and expiration, each breathing cycle have one inspiration and one expiration, we can calculate the breathing f is only one of six for HR. i.e. HR = ~6 × f. f = 60s/(3.1~3.3s × 2).

How we generate our breathing rhythm? Even the time courses of breathing switching off for both inspiration and expiration, which dominantly depend on blood flow rate, are similar. If so, our lung courses of inspiration and expiration should be similar, right? No. At resting, only inspiration activity is active and expiration is commonly positive. For a stable FRC lung, commonly the ventilated volumes of inspiration and expiration and airway resistances are similar. Due to active inspiration use many muscles to contract, use energy to again resistance, produce more higher pressure difference between room air and alveoli, so that the gas come into lung finish fast (use less time); the positive expiration do not use muscles contract, energy, lower pressure difference, the same volume needs longer time. Commonly ratio of inspiration and expiration is 2:3.

Conclusion

We use signals transfer time course can explain the mechanisms of up‐down arterial blood gases waveform does switch breathing inspiration and expiration by equal time, but the activity of active and positive result difference in time courses of lung inspiration and expiration. Based on it, we also explain some existing questions in physiology of respiration and circulation: How we set our FRC and close PFO after birth etc. in different abstracts.

Support or Funding Information

CNSF‐Medical Science Program (81470204) ; NCCVD Fuwai Hospital Start Program (2012‐YJR02)