If the Heart Is a Muscle, Why Doesn’t It Get Tired?

iStock/magicmine
iStock/magicmine

You’re on the weight bench. 18. 19. 20! You couldn’t lift that barbell again if someone had a gun to your head. Your arms and your chest are sizzling with a dull burn. Your muscles are fatigued, and as you try to put the bar back, your arms give out.

Then there's a crash.

Dropping a barbell on yourself is one thing, but imagine if your heart just up and stopped whenever it got tired of beating. It would be disastrous and defibrillator makers would rule the world. We, and every other thing with a heart, would be extinct in no time.

Unlike the rest of your muscles, your heart expands and contracts, non-stop, all day and all night for your entire life without a break. How does it do it?

Your heart might be a muscle, but it isn’t quite like your biceps or your abs or your pecs. Those are all “skeletal muscles” and they’re attached to your bones. Your heart, meanwhile, is made of “cardiac muscle.”

Both of these types of muscles need energy to contract, and they both get it from mitochondria, the so-called “cellular power plants" that generate adenosine triphosphate (ATP) for the transfer of chemical energy. Cardiac muscle resists fatigue so well because it’s got more mitochondria than skeletal muscle. With so many power plants at its disposal, the heart doesn’t need to stop and chill out. It also has a steady supply of blood bringing it oxygen and nutrients.

This $49 Video Game Design Course Will Teach You Everything From Coding to Digital Art Skills

EvgeniyShkolenko/iStock via Getty Images
EvgeniyShkolenko/iStock via Getty Images

If you spend the bulk of your free time playing video games and want to elevate your hobby into a career, you can take advantage of the School of Game Design’s lifetime membership, which is currently on sale for just $49. You can jump into your education as a beginner, or at any other skill level, to learn what you need to know about game development, design, coding, and artistry skills.

Gaming is a competitive industry, and understanding just programming or just artistry isn’t enough to land a job. The School of Game Design’s lifetime membership is set up to educate you in both fields so your resume and work can stand out.

The lifetime membership that’s currently discounted is intended to allow you to learn at your own pace so you don’t burn out, which would be pretty difficult to do because the lessons have you building advanced games in just your first few hours of learning. The remote classes will train you with step-by-step, hands-on projects that more than 50,000 other students around the world can vouch for.

Once you’ve nailed the basics, the lifetime membership provides unlimited access to thousands of dollars' worth of royalty-free game art and textures to use in your 2D or 3D designs. Support from instructors and professionals with over 16 years of game industry experience will guide you from start to finish, where you’ll be equipped to land a job doing something you truly love.

Earn money doing what you love with an education from the School of Game Design’s lifetime membership, currently discounted at $49.

 

School of Game Design: Lifetime Membership - $49

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The Right Way to Clean Your Face Mask

Properly cleaning your face mask is important to keep it free of infectious material.
Properly cleaning your face mask is important to keep it free of infectious material.
mikography/iStock via Getty Images

In an effort to slow the transmission of coronavirus in public settings, health officials are advising that people unable to practice social distancing wear a cloth face mask. While not as effective at filtering respiratory droplets as medical-grade masks, cloth masks are still recommended as a practical preventative step.

Like all apparel, masks get dirty. They absorb sweat and germs, and they need to be cleaned. But how?

According to National Geographic, the best way to clean a cloth face mask is to take the same approach as the rest of your laundry—toss it in the washer. Laundry detergent is effective against coronavirus because the pathogen is encased in a layer of oily lipids and proteins. Detergents and hand soaps contain surfactants, which reduce the surface tension of the fatty layer. The surfactant molecule is attracted to oil and grease on one end and water on the other. The end that disrupts the oil bursts the coronavirus envelope apart. Tiny pods of surfactant called micelles trap and wash the remnants away. It’s this activity, not the water temperature, that kills the virus, though using a higher dryer temperature can destroy most microorganisms that might be lingering.

Bear in mind there’s a recommended way to take off your mask. Make sure your hands are clean, then pull it off using the straps behind your ears. This avoids contaminating the mask—and your face—with any pathogens that might be on your hands.

Medical-grade masks are trickier, as they’re intended to be used only once and can’t stand up to a wash cycle. If you have an N95 or paper mask, you can set it aside for several days, at which point the virus is likely to become inactive. But keep in mind that health officials still aren’t entirely sure how long coronavirus can persist on surfaces, and it’s possible for a mask to collect particles over time, increasing the viral load.

But what about the rest of your clothes? Experts say not to worry so much about disrobing the minute you get home. The coronavirus likes moisture and dries out quickly on fabrics. You need to be careful with the material covering your face, but the rest of your outfit can wait until your regularly scheduled laundry appointment.

[h/t National Geographic]