AIDA and packing

[trux]

I believe that Hering-Breuer Reflex does not really interrupt voluntary inhalation. It is rather a respiratory regulation reflex controlling the automated (involuntary) breathing. Well, the brain gets signals from the pulmonary stretch receptors stimulating the vagal nerve, but it won't stop voluntary muscle work. As far as I understood, it only affects automated breathing.

 

[Billextreme]

Bill, given your profession can you explain what you think may be happening?

Hi shoutatthesky, trux is right and it's all about what kind of "full breath" you do - and what techniques you use. Internet is not the best place to fine-tuning this to 100%. BUT if you try to be totaly relaxed and start your breath from the deepest point in your stomach using your diaphragm, then make sure you fill up everything down there before you let the filling come up under your rib cage - (all this should be done slow in the beginning so you can have full control and feel where the air is going) - when you then feel that even the chest is filled - you end with a top-inhalation, this is where you fill the very last part with the help of your shoulders and the neck muscles AND here, with some training, it will be possible for you to end the "full breath" with filling up the whole bronchi incl throat as well in the same ending manoeuvre.

to Trux, I have one patient that do the GPB all the time and another that need to fill-in with GPB once every 90 sec. The rest have still some functions in there diaphragm muscles and chest so they can deliver air-supply for the hours they are awake - but everyone is learning GPB for self-support reason, just to be able to create some air-pressure for cough up phlegm, or simply shouting for help.

 

[Kimmo]

Hering-Breuer reflex: Information from Answers.com
Hering-Breuer reflex (www.whonamedit.com)
Hering-Breuer reflex - Wikipedia, the free encyclopedia

- kimmo

 

[trux]

Yes, I know well those documents and many others too. But since the HB reflex is not easily demonstrable at adult humans (unlike at animals or at infants), most experiments demonstrating them are done either using underpressure chambers (decreasing the external body pressure during the inhalation, inflating so the lungs), by obstructing the inhalation ways, disabling vagal connections, etc, but they are done either in sleep or under narcosis - I did not find any document showing that the HB reflex somehow influences voluntary maximal inhalation. And personally I do not see any significant difference of my lung maximum intake, when I try to inhale fast or very slow, or any involuntary failure of the ribcage or diaphragm muscles when trying to take the max breath. I really believe the HB reflex only controls the automatic (involuntary/subconscious) breathing rhythm/tide, not the voluntary maximal inhalation.

 

[Fitz-Clarke]

The phenomenon you describe, where chest relaxation after a deep breath allows more small breaths, is actually due to a reverse thoracic blood shift, where blood is forced out of the chest by the high intrathoracic pressure. A bit more air can then be inspired. You can see this effect in Figure 5 of my computer model paper if you are interested (Fitz-Clarke JR. Computer simulation of human breath-hold diving: cardiovascular adjustments. Eur J Appl Physiol. 100:207-224; 2007). After full inspiration there is a drop in chest volume mostly due to blood being squeezed out of the pulmonary capillaries, strictly a passive mechanical effect. It likely has nothing to do with the Hering-Breuer reflex, which is mediated by stretch receptors in the lungs that send signals to the brainstem via the vagus nerve to inhibit involuntary inspiration at high lung volume. You over-ride this reflex when you take a deep breath voluntarily. There also happens to be an expiratory HB reflex that stimulates inspiration at low lung volume to help prevent excessive collapse of alveoli during expiration. Cheers.