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Short answer Healthy people cannot hold their breaths until unconsciousness sets in, let alone commit suicide. Background According to Parkes (2005), a normal person cannot even hold their breath to unconsciousness, let alone death. Parkes says: Breath‐holding is a voluntary act, but normal subjects appear unable to breath‐hold to unconsciousness. A ...


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Counterexample: At least some people can train themselves to hold their breath until they pass out, and if this occurs underwater they will almost certainly die by drowning. When I was in military service I became friends with some U.S. Navy SEALs. They go through a notoriously difficult training and selection process (BUDS) that has been well documented. ...


19

In suffocation or asphyxiation you are actually deprived of breathing oxygen. The arterial blood oxygen concentration decreases (hypoxemia) which is detected by the chemoreceptors of the carotid body and aortic arch. This induces a neuronal response in the medulla that increases respiratory rate, force of contraction and relaxation of respiratory muscles and ...


16

There are two uses of the term respiration: physiological respiration and cellular respiration Physiological respiration involves the intake of outside oxygen and its distribution to the tissues of the body. Breathing is a part of physiological respiration and functions to bring oxygen into the lungs and expel carbon dioxide. Cellular respiration is a ...


11

From the Smithsonian website: Humans are the only mammal that cannot breathe and swallow at the same time, and we are the only species that can choke on its own food. The reason? The lowering of the voice box in our throats (during infancy) enables us to create the enormous range of sounds used in producing language; but this lowering of the voice box comes ...


11

Breathing is a part of respiration but respiration is not a part of breathing. Breathing is a process through which oxygen is taken into the body for use in respiration. This involves physical movement to take oxygen (into the lungs) and also chemical action (haemoglobin-carries oxygen from lungs to blood and carbon dioxide from blood to lungs). But ...


11

By definition, hyperventilation is a state of increased breathing where the exhaled $CO_2$ is greater than what is produced by the body. Except in artificial condition or in disease process, breathing faster than the autonomously-dictated rate is going to cause hyperventilation. You have a fine-tuned control of respiration that will work out the correct ...


10

From Boron and Boulpaep textbook of Medical Physiology, second edition, p.289: Because of falling ATP levels in the brain, consciousness is lost within 10 seconds of a blockade in cerebral blood flow. Irreversible nerve cell injury can occur after only 5 minutes of interrupted blood flow. If conscious is lost within 10 seconds of blockade in cerebral ...


10

The veterinarian in our group offers this: For humans, who choke much more frequently than other mammals, it is likely to be a cognitive problem. We talk and eat at the same time and so give ample opportunity to allow food passed the epiglottis and choking. Animals do choke - dogs can, cats can. Not all animals can vomit and this is particularly a problem ...


9

Hydrogen in breath arises from normal intestinal bacteria, mainly in the colon, which break down (ferment) the undigested nutrients that have passed through the small intestine. Hydrogen is absorbed from the intestine into the blood and exhaled via the lungs. Conditions in which intestinal bacteria produce hydrogen: Normal digestion in which soluble ...


7

There are different kinds of choking on food. All non-gilled animals also choke when they fall in the water. Drowning is choking. insects asphyxiate and fish asphyxiate in air but technically insects don't have any obstructed passages. Perhaps you can say fish choke when their mouth is obstructed with air, choking also means gulping because of asphyxiation ...


7

I don't agree with the accepted answer which seem to assume that food is chewed. I don't think that can be assumed if generally talking about animals and choking. So in addition to Larry's statement of dogs and cats: Fish regularly chokes on prey. Birds can choke. Even dolphins choke:


7

When we speak, our vocal cords vibrate to the air. Helium makes them vibrate a lot faster (that's what makes the funny sound of your voice after inhaling helium), because its atoms are a lot lighter than nitrogen and oxygen atoms. Obviously, lighter atoms, can travel faster. This faster vibrations are unusual to the cords and they can cause sore throat or ...


7

To learn obstructive/restrictive lung diseases, I find it easiest to think in extremes at first, with vivid descriptions of why. So in obstructive lung diseases, like COPD/emphysema: Total volume increases because so many of the walls of the alveoli have been destroyed, they are like giant floppy bags instead of nice firm bubbles. There's more empty space,...


7

We may be able to voluntarily control our respiratory rate, but only for a short while. The buildup or depletion of CO2 will force us, against our will, to either speed up our respiration or slow it down. So, you can't effectively "fake" your respiratory rate for long, nor, to an astute observer, convincingly. Normal breathing patterns are "normal" for a ...


7

The exact causes of the discomfort relief after the breath-hold breakpoint is unknown yet. It has been stated that breath "pacemaker" continue to work independently of voluntary breath holding. Thus, while breath holding, the breath center is trying to activate the diaphragm and the afferent feedback from the diaphragm normally causes the feeling of ...


6

Via deep scientific analysis (i.e. trying it myself 5 seconds ago), I have determined that you can in fact speak while breathing in, it just sounds funny. Think of the vocal chords as being like the body of a flute. As air passes by them, they vibrate and make sounds. Through careful modulation of their shape, specific sounds can be reproducibly made (this ...


6

I think this is mostly caused by hyperventilation. The excessive breathing disturbs the balance between CO$_{2}$ and oxygen in our lungs. This will cause respiratory alkalosis (the blood pH, which is normally strictly regulated, gets higher), which can cause dizziness, headaches and fainting. The shift in pH can also disturb the eclectrolyte balance, ...


6

An addition to previous answers plus some clarification The term respiration originally meant breathing i.e inhaling and exhaling (See here). It was believed that it is the oxygen and in turn the act of breathing is what lets an organism survive. After substantial research it had been found that, in individual cells it is the ATP production by ...


6

This is purely a psychological response, and it does not help in decreasing the speed of CO2 level rise. As CO2 level in your blood rises, you instinctively want to breath out the 'bad' air and breath in fresh one. The latter is impossible under water, but the former eases you psychologically a little; you have "started doing something" with your predicament ...


6

I'm not a doctor, so I'm not 100% sure about the physiological differences, but on a molecular level there is one: Cyanide blocks the complex IV of the oxidative phosphorlytaion, which will directly stop cells from consuming oxygen and producing energy needed to survive. This is mechanistically different from suffocation, where there is not enough oxygen in ...


6

Fish are able to obtain oxygen that is dissolved within the water, and exchange it along with Carbon Dioxide through their gill structure, called filaments. The gills are located adjacent to the mouth and filaments include a large amount of blood vessels. Those blood vessels (capillaries) are close to the gill filament surface and move in the opposite ...


5

This is more about basic physics than biology. When you hold your breath, you normally take in one last long breath and keep it in as long as possible, Your lungs are therefore already full of gas (remember that the oxygen used by our lungs is only ~22% of the total volume of air you inhale). Therefore, when you release that breath and want to take in a new ...


5

You might need to narrow your parameters a bit. Just things to consider: Our lungs are not hollow organs that can accommodate an oxygen producing machine. They are basically narrow tubes that get smaller and smaller until they end in a tiny balloon-like structure - about 700 million of them. Where would the machine go? 100% oxygen is toxic to the lungs, as ...


5

They can pump water over their gills with their opercular flaps (i.e., the structure that covers and protects the gills). This is assisted by the branchiostegal rays. Food would generally not interfere with this process. Additionally, gill rakers assist in keeping food in the mouth. Some great references for questions like this: Barton, M., & Bond, C. ...


5

The rate of CO2 production is normally set by the rate of metabolism and breathing rate is determined by the level of CO2 in the blood. What you are suggesting is known as hyperventilation. Because blood CO2 plays an important role in maintaining the pH of the blood, hyperventilation can lead to a dangerous increase in blood pH, referred to as respiratory ...


5

As you can see on the diagram below, oxygen solubulity in water drops by increasing temperature, so your fish has to breath more to get the same amount of oxygen. ref You can find more info about why gas solubility is temperature dependent here: Chemistry (Averill & Eldredge) / Effects of Temperature and Pressure on Solubility.


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CO2 forms carbonic acid in water, which helps to dissolve rocks and mountains in envitonmental science. It would slightly acidify your body with what is called a weak acid. 5% can cause acidosis and loss of conciousness, without lack of oxygen. 3% would devastate most chalk based sealife, corals and shells. Perhaps lifelong breathing of 3% co2 would have ...


4

I'm taking this question at face value. Yes, fish have gills, but we also have a respiratory surface in our lungs so why couldn't we 'breathe' water and extract the oxygen (since extraction is a simple matter of diffusion from the content of the lungs into the blood). Apparently we use 550 L of pure O2 per day. This works out as approximately 400 g. The ...


4

This article quotes a professor of respiratory physiology that says "dogs are built to pant just right. The mechanics of their lungs and chest set a precise rate for panting that minimizes the amount of work while maximizing cooling power." They also don't breathe fully when panting, so they can still cool themselves without increasing gas exchange. This is ...


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