Have you ever wondered why a person can't suffocate by simply holding their breath? Even if you try not to breathe, the body will not allow us to lose consciousness, much less die. There are complex mechanisms that are constantly working in our body. What is happening in the brain and other organs that prevents us from simply stopping breathing forever? Scientists say that there are several systems that ensure that we always continue to inhale and exhale. And even if one of them stops working, others will take over this function and save our lives.
Our body will never let us die from holding our breath. Image source: pinterest.com
How the body controls breathing
According to Live Science, when a person holds their breath, the brain immediately reacts to it. The respiratory support systems, which are fully prepared, do not allow you to remain without air until you lose consciousness. When the oxygen level in the blood drops to a critical level, a person reflexively takes a breath.
One of the main systems that controls breathing is the motor cortex. It “sees” that a person has stopped breathing and sends a signal to the respiratory center, which is located in the medulla oblongata. This center controls the muscles responsible for breathing: the diaphragm— the main “engine” of inhalation and exhalation, and the intercostal muscles, which expand the chest with each breath.
Different parts of the brain are responsible for controlling breathing. Image source: scientificrussia.ru
However, even if a person completely concentrates on not breathing, there is another system – pre-Betsinger complex, located in the brainstem. This area acts as a metronome for breathing, setting the rhythm of inhalations and exhalations. No matter how hard a person tries to hold his breath, this “respiratory generator” continues to work, pushing him to inhale again, regardless of his desires.
In addition, there are special cells in the body – chemoreceptors, which monitor the level of oxygen and carbon dioxide in the blood. These cells are divided into two types: central chemoreceptors in the brain, which respond to carbon dioxide levels, and peripheral chemoreceptorswhich can detect both a decrease in oxygen levels and an increase in carbon dioxide if breath holding is prolonged.
The systems listed above force the lungs to breathe when the oxygen levels in the blood are low. Image source: stock.adobe.com
Finally, the lungs have receptors that “sense” when the lungs are stretching during inhalation. If a person holds their breath for too long and the lungs stop expanding, these receptors start sending out alarm signals.
When any of these systems senses that something is wrong, it immediately sends signals to the respiratory center of the brain. And no matter how hard a person tries to avoid breathing, the body turns on the “emergency mode” and forces him to start breathing again.
Read also: Why do people need air and how do the lungs work?
How long can you hold your breath?
How do some people, such as professional swimmers and free divers, manage to hold their breath much longer than ordinary people? Research shows that these people train their bodies and brains to learn to ignore the signals that usually make us breathe.
As already mentioned, ordinary people depend on chemoreceptors, which control the level of oxygen and carbon dioxide in the body. If you block the work of these receptors, for example, with the help of special drugs, as was done in experiments, then you can significantly increase the time of breath holding.
Professional divers train their bodies to ignore signals that make them breathe. Image source: divinglive.ru
However, professional divers demonstrate that training allows their bodies to act differently. They can ignore the signals of their chemoreceptors and hold their breath until the oxygen level reaches a critically low level, when the body is already at risk of losing consciousness.
Trained people have such control over their breathing that their bodies can push themselves into hypoxia – dangerously low levels of oxygen in the blood – before their brain forces them to breathe again.
If you saturate your body with oxygen beforehand, you can hold your breath longer. Image source: tehcovet.ru
Another way to increase breath-hold time is to increase the amount of oxygen in your blood before you dive. Even normal people can hold their breath for several minutes longer by hyperventilating or breathing pure oxygen first. This helps temporarily trick the chemoreceptors into telling the body that oxygen levels are normal. This is used in some medical procedures where patients must remain still for long periods of time.
Breathing pure oxygen helps some people set world records. For example, Croatian freediver Budimir Sobat, who held his breath for a whopping 24 minutes and 37 seconds in 2021, breathed pure oxygen beforehand.
Record holder Budimir Sobat. Image source: dzen.ru
So, although holding your breath longer than it seems possible is possible thanks to training and clever tricks, our body always tries to protect us from dangerous consequences. These safety systems in the body are the result of a long evolution, which made breathing an automatic and vital process.
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It seems that an additional dose of pure oxygen can be useful, but is it really so? Can it cause harm instead of benefit? Find out all the details in our article “Oxygen from cylinders – benefit for the body or danger?”.