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Thermoregulation in the lungs

Discover how dogs and humans use their respiratory systems for thermoregulation. Learn why panting helps dogs cool down, and how humans also expel heat through breathing. Explore the concept of thermoregulation in the lungs and its role during exercise. Created by Patrick van Nieuwenhuizen.

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  • aqualine ultimate style avatar for user dorigoluca
    So if the outer temperature is above 37°C, does panting become useless? How do dogs regulate their temperature then?
    (27 votes)
    • leaf yellow style avatar for user Taylor Logan
      It would become less useful, but panting would still dissipate heat from the dog's body because the exhalations during panting contain a very high amount of water vapor. Water has a high heat capacity and thus will carry a lot of heat away from the dog's body and it is released into the environment.
      (36 votes)
  • aqualine ultimate style avatar for user Kyler
    I like to run outside but when it is winter time I sometimes have a hard time running because the outside air is very cold (around 15 degrees F). It becomes harder to breath and I have to stop more often. I understand that my body has to work harder to stay warm and that could be a reason. Is there a way to help my lungs become used to the cold air? Or tips on how I can continue to exercise outside in colder conditions?
    (18 votes)
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    • mr pink red style avatar for user joshua.shortllama
      Inhaling through your nose and exhaling through your mouth can be helpful when exercising in cold weather. Your nose helps to warm and filter air which can prevent irritation in the back of your throat and can save your lungs some effort. You can exhale through your nose, but the video can show you that air being exhaled has already reached your body's core temperature. Therefore, it is less necessary to exhale back through your nose to prevent irritation, and filtering exhaled air is not really necessary, as the air is being expelled and not going to be used by your lungs again.
      (14 votes)
  • piceratops ultimate style avatar for user WJP
    Although we mainly breathe out warm air, we are also able to force out cold air. How do we explain this? Thanks!
    (7 votes)
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  • blobby green style avatar for user rvorotynskiy
    How does dog's thermoregulation work if the outside temperature is equal or higher than 100 F?
    (6 votes)
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  • female robot grace style avatar for user BreAnnah Cook
    I just got done with running and playing outside and sweating but I'm not breathing hard. What is wrong?
    (4 votes)
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    • aqualine ultimate style avatar for user Sterre
      If you exercise a frequently you may have built up enough fitness that just playing/running a bit won't necessarily get you out of breath. It's definitely not a thing to worry about and means your heart and lungs work well. Probably if you increase the intensity or length of your exercise you'll start breathing harder.
      (6 votes)
  • starky tree style avatar for user Saige Whitaker
    So there is only one way the air can travel? It is either inhaling or exhaling. So does this mean that there aren't any air particulates that stay in the lungs for a while, they all get exhaled. Or does some particles stay in the lungs?
    (3 votes)
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    • piceratops ultimate style avatar for user Max Buhl-Nielsen
      Yes. Some particulates that are able to avoid air filtration through the nose and travel down into the lungs can stay there for some time. However, special leukocytes (white blood cells) called macrophages can reach the alveoli where these particles are and phagocytose ("eat") them. They then travel to the bottom of the trachea, where ciliated cells push them to the top of the throat. Finally, they can be spat out or swallowed.

      Other substances such as tar from cigarette smoke can also stick around in the lungs. This is what causes smokers' lungs to appear black.

      Hope this helped!
      (7 votes)
  • hopper cool style avatar for user Kaleb Griepp
    Hypothetically, could you train your body's thermoregulation system to be able to say, break a sweat while running in below-freezing temperatures? Let's say, if the air outside was -24F and your body started at 98.6F, would there be a way to time how long one could last before standard thermodynamics would lower their body temperature to equilibrium with the outside temperatures?
    (4 votes)
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    • aqualine ultimate style avatar for user Ben McCuskey
      I think it would depend a lot on your attire. Believe it or not, you can maintain your core temperature pretty well - and sometimes even break a little bit of a sweat - while running in cold temperatures if you wear clothing with enough insulating properties. By dressing in layers and using clothing that reflects your body heat and also insulates against the wind you can maintain your core temperature reasonably well - especially if you are moving around.
      (4 votes)
  • aqualine seed style avatar for user Qingyi Lou
    OK, so we know that human can either pant or sweat when they need to release the extra heat generated by their body. But what are some factors that determine the type of heat outlet? Take myself for example. I used to pant after slight exercise. But after a long period of workout routine I no longer pant but prone to be more sweaty. Does it means that my body has adapted to my exercise routine by switching the way how it release extra heat?
    (5 votes)
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    • leafers ultimate style avatar for user Evan Craddock
      The main difference would be the difference between aerobic and anaerobic exercise. aerobic exercise is very active, and it uses a lot of oxygen (examples would be running, swimming and biking) while anaerobic exercise (e.g. weight lifting) is tiring, but it doesn't use as much oxygen, while both generate heat. Hope that helped!
      (2 votes)
  • starky tree style avatar for user Saige Whitaker
    How much oxygen/air can your lungs hold at one time?
    (3 votes)
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  • blobby green style avatar for user leves015
    So if someone is suffering from hypothermia, do they take in less than 5L of air a minute in order to preserve body heat?
    (4 votes)
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Video transcript

Voiceover: If you have a dog or if ever played fetch with a dog, you've probably noticed that after you've really abused that poor animal and run it into the ground, you've probably noticed that it started to do something interesting. It started panting. Did you ever stop to ask yourself why dogs pant? Well, here's your chance to answer that question. See if you could come up with a reason. It turns out that the main reason that dogs pant is so they don't overheat. Let's take a look at how that works. Let's say here we've got our favorite little puppy and it's just been running around for an hour and it's panting and it's got it's tongue lolling out like they do. What's going to happen when that dog breathes is it's going to breathe in cool, outside air. Let's say on that day it happened to be 70 degrees Fahrenheit and it's going to breathe out hot air because the air that it breathed in is going to equilibrate with its body. If you don't believe me, put up a hand to your mouth as your breathe out and feel how hot the air is that you're breathing out. What this means is that the dog is expelling heat everytime it breathes because it's taking in something cool and putting out something hot and that heat has to come from somewhere. For dogs this is really important because they can't sweat. They have fur coats and they couldn't very well soak those fur coats and sweat everytime they want to lose heat. This is really their best way of getting rid of heat. Now, we humans - and I'm going to try to draw one of we humans over here - we humans can sweat. This is a human with an Afro, apparently. We humans can sweat and so this method of losing heat by breathing heavily is definitely less important for us, but it actually still happens. Just like the dog when we breathe in, or when the air that we breathe in, which technically comes from both the nose and the mouth, that air goes into our lungs and in our lungs and in our lungs it divides into all those little alveoli that you've heard about that have a huge amount of surface area. Let's me just draw a couple of them here. All these tiny alveoli have a huge amount of surface area and that allows all this cool air that you breathe in, which I'm drawing here, to equilibrate with the temperature of the blood that's passing by these capillaries. So just like the dog, when we breathe in air that's let's say 70 degrees Celsius, we're going to breathe out air that's pretty much body temperature. That should not be Celsius, that should be Fahrenheit. When we breathe an air that's 70 or maybe cooler, we are going to breathe out air that's body temperature. If this guy is not having a fever that would be about 98.6 degrees Farenheit. Therefore, we can see that getting rid of extra heat is another thing that the lungs can do. We have a fancy word for this. We call it Thermo, thermo meaning heat just like a thermometer measures temperature, Thermoregulation. So you could say it's regulation of the temperature of our bodies. That's another things that the lungs can do. Lungs can thermoregulate. You'll note that this is kind of convenient because times when you might be overheating, just like this dog, times when you might be overheating or when you've done a lot of exercise and when you've done all that exercise you need a lot of oxygen to feed your muscles and at the same time you want to get rid of heat. These two functions of providing oxygen and getting rid of excess heat coincide nicely in the case of exercise because what happens when you exercise is that you start breathing really heavily. At rest, you might be breathing about five liters of air per minute. Meaning that a total of five liters of air is coming in and out of your lungs every minute, but while you're doing exercise, let's say heavy exercise, let's say you're running a mile, trying to get a really good time, you can easily go up to 50 liters per minute and clearly, that is a lot more, 10 times more. What that means is you're going to be putting out 10 times more heat through your lungs than when you're resting. So it's convenient that when you exercise you get more oxygen by breathing heavily and you also get rid of more heat by breathing heavily.