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Let’s say you're studying in the library and a teenage boy walks in. Now teenage boys don’t regularly shower, I know because I was one. Instead we just put on a boatload of deodorant and call it a day. Just douse ourselves with Axe body spray.
What will happen when this half man, half body spray person walks in? do we all smell him at once? No, in fact no one smells him immediately. But soon, his presence seeps through until we all get a whiff. This is Diffusion - the physical process where a region of high concentration of molecules moves to a region of lower concentration.
This is the same phenomenon seen when a drop of food coloring is added to water, or tea from your tea bag, or when you crack a cold one with the boys and all that concentrated carbon dioxide carbonation diffuses into the air and your drink goes flat. How about the air we breathe!
The high concentration of oxygen in our air, and in our lungs when we take a deep breath, compared to our relatively oxygen starved blood, allows it to diffuse from our lungs to our blood. Once oxygen gets into our blood, it goes into our capillaries (our smallest blood vessels) and our tissues. Again - we have a high concentration of oxygen in our blood, low amount in our working tissues and cells, oxygen then diffuses again to our tissues. Likewise, our tissues produce the byproduct of carbon dioxide once it has used up oxygen and this builds up in our blood. But like the can of soda, it diffuses back out to our lungs and eventually environment.So with just diffusion, we can take in oxygen and breathe out carbon dioxide. This revolutionized how we understood the vital process of oxygenation! This simple process, however, can be disrupted with lung diseases.
Certain autoimmune diseases can damage the connective tissue in your lungs, like that in rheumatoid arthritis or lupus, leading to scar tissue formation, which blocks diffusion capabilities. COPD - or chronic obstructive pulmonary disease can also cause scarring or full on destruction of the lungs - leading to less surface area to diffuse.
Who discovered this factoid?
Enter August Krogh a Danish zoologist, born in 1874. With an early keen interest in animals, which most kids have, he would follow and observe the behavior of insects and spiders for hours. He began reading about past experiments at 12, and tried his hand in performing his own - usually failing. He kept this interest into adulthood.
His work with frogs showed that oxygen and carbon dioxide were easily diffused and not secreted by the lungs and the very thin membranous skin. And while humans are not frogs, there are shared physiological traits seen between animals. So he a device that measures oxygen concentrations, and compared oxygen in the alveoli vs in the blood vessels. It turns out oxygen is always higher in our alveoli, forcing diffusion to our blood. Likewise- carbon monoxide is usually higher in our blood than in our lungs, and diffuses out. The math worked out and he concluded that oxygen “there is no trustworthy evidence of any other regulation”
His work in studying how our tissues were perfused led him to study capillaries (which are fine branching blood vessels and the smallest blood vessels in our bodies).
He found that during exercises, the capillaries enlarged and others opened to increase surface area and further allow oxygen diffusion.
His work changed our views on how our body and tissue received oxygen and actually made it simpler than originally thought.
Other work : He flew to Toronto to meet with John Macleod, who had just isolated insulin in 1921, and brought insulin to Denmark after its discovery. He worked with physicist and radiochemist to create one of Denmark's first particle accelerator.
He science hard.
But for his contributions in how our oxygen demands via our lungs and capillaries are met- he won the Nobel prize in 1920.
Disclaimer:
These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any LY Med video.
30 сен 2024
