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6

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 ...


6

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 ...


4

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 ...


4

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 ...


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 ...


3

Just because you have removed the Nitrogen and CO₂ won't help you keep a higher vapour pressure of H₂O in the air. You Could REMOVE all the other gasses and just have O₂ at its normal partial pressure at 1/5 bar total pressure and breath fine, but there would be a fire risk in this environment due to no non O₂ molecules to quench excited O₂. The only way to ...


3

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 ...


3

What you are looking for is a spirometer. There are different types of spirometers serving different purposes like the Incentive spirometer and the peak flow meter. I would suggest that you go through the wikipedia page on it to get more info.


3

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 ...


3

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 a http://en.wikipedia.org/wiki/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 ...


1

I'm not an expert but I think it's pretty obvious.. Bigger animals do require more energy and thus more oxygen for cellular respiration. They also have bigger lungs, although the rythm of the breathing is slower.


1

Pressing on the chest changes the concentration of dissolved gasses in the blood stream. Your brain reacts due to excessive oxygen in the blood. This is oxygen toxicity. Why the brain generates vivid imagery when unconscious is a big topic. There's a theory that correlates dreams with a lack of cognitive stimulation. This is called autostimulation and may ...


1

Particulates can accumulate in the aveolae in the lungs. This leads to inflammation and tissue damage and scarring. This reduces the available surface area for gas transfer. Low level exposure over long periods is harmful. Asbestos workers are well known to get sick, but miners can get black lung or silicosis from inhaling mining dust, and farmers can get ...


1

Another possibility is K4 device and K4 device. Beyond spirometry it can measure other variables such as: Pulmonary Gas Exchange (VO2, VCO2) Breath by Breath Technology Telemetry Data Transmission up to 1000m Indirect Calorimetry Integrated GPS System Integrated Oxygen Saturation (SpO2) Integrated 12-lead Stress Testing ECG


1

Good question. If you inhale on top of inhaled air this is more work. There is more dead air, air which is not as useful due to the lower concentration gradient. And we breathe more to exhale carbon dioxide than we require oxygen. Low oxygen levels only push us to breathe when oxygen levels are a good deal lower, however tiny changes in carbon dioxide ...


1

You can try as much to slow down your breathing but the body will speed it up if it requires. What you've probably done is relaxed and just basically meditated. It's not the breathing but the relaxing yourself to slow your breathing and the focus which has refreshed you. I say conduct some experiments, like listen to calming music and relax and don't monitor ...


1

Swallowing food requires muscle strength to force the food down the oesophagus, which is a soft tube that collapses when empty, simply because the body is very crowded (space-efficient) and empty spaces collapse unless forced open. Only when you swallow, the oesophageal muscles force space to be made for food coming through. In contrast, the trachea and ...


1

You asked the single most difficult questions ever, so be proud of yourself! I've spent some time in the lab with a post doctorate trying to answer that particular question. It all is based on something called the hygiene hypothesis: the belief that as we are getting cleaner we are seeing less and less bacteria and so our immune system isn't working as it ...


1

Quick clarification firstly, the main change in thoracic volume that causes inspiration is not as a result of the alveoli expanding - they have no smooth muscle lining therefore are unable to spontaneously contract. They do have some elastic fascia however their expansion is passive. The change is mainly as a result of the diaphragm contracting to become ...


1

Not knowing the physiology or the literature, I can say based on personal observations that dogs, even when extremely hot or exhausted, mix in a routine of deep inhales and exhales to their panting. Perhaps this prevents unwanted side effects of their cooling mechanisms.



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