What Does That Dangly Thing in the Back of Your Throat Do?

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iStock

Uvula image via Shutterstock

The uvula is one of the weirdest looking features of the human body. Yet despite its infamy, scientists have spent centuries puzzling over its function.

The hangy ball's full name is the “palatine uvula,” referring to its location on your soft palate. Not to be confused with the uvula vermis, a lobe of the cerebellum, or the uvula vesicae, in the urinary bladder. 

Through history, scientists have had many theories about the uvula. Among them:

That it once helped guide the flow of food and water, and, in humans, was a mere remnant from previous mammals who had to lean down to eat and drink.
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That it induces the gag reflex. And therefore isn’t the best place to get a piercing.
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That it contributed to “chronic cough.” A problem that 19th-century doctors treated with a “simple” “clipping” procedure.
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That it contributes to cardiovascular problems like sudden infant death syndrome (SIDS) and sleep apnea.

Even today, some doctors treat sleep apnea by having the uvula removed. Unpleasant as that sounds, much of the recent uvular research has come about by studying uvulopalatopharyngoplasty patients (uvula-less people). Several such studies have concluded that the uvula is really good at excreting saliva. A lot of saliva, in a really short amount of time. Another study compared the soft palates of eight different mammals, and found that a small, underdeveloped uvula was found in only two baboons.

Don’t Leave Us Hanging

So what does the dangly throat thing do? Because the uvula is basically unique to humans, scientists basically agree that it primarily serves as an accessory to speech. You know what it’s like to have your throat go dry before talking to a large group? The uvula is there to provide the proper lubrication for complicated human speech. In time, we’ll likely learn that the uvula does some other cool things to boot, but to quote one study on the subject, it “may be another marker of human evolution that differentiates man from other mammals.” For now, that’s pretty cool.

This post originally appeared in 2012.

No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Bad News: The Best Time of the Day to Drink Coffee Isn’t as Soon as You Wake Up

iStock.com/ThomasVogel
iStock.com/ThomasVogel

If you depend on coffee to help get you through the day, you can rest assured that you’re not the world's only caffeine fiend. Far from it. According to a 2018 survey, 64 percent of Americans said they had consumed coffee the previous day—the highest percentage seen since 2012.

While we’re collectively grinding more beans, brewing more pots, and patronizing our local coffee shops with increased frequency, we might not be maximizing the health and energy-boosting benefits of our daily cup of joe. According to Inc., an analysis of 127 scientific studies highlighted the many benefits of drinking coffee, from a longer average life span to a reduced risk for cancer, heart disease, type 2 diabetes, and Parkinson’s disease.

Sounds great, right? The only problem is that the benefits of coffee might be diminished depending on the time of day that you drink it. Essentially, science tells us that it’s best to drink coffee when your body’s cortisol levels are low. That’s because both caffeine and cortisol cause a stress response in your body, and too much stress is bad for your health for obvious reasons. In addition, it might end up making you more tired in the long run.

Cortisol, a stress hormone, is released in accordance with your circadian rhythms. This varies from person to person, but in general, someone who wakes up at 6:30 a.m. would see their cortisol levels peak in different windows, including 8 to 9 a.m., noon to 1 p.m., and 5:30 to 6:30 p.m. Someone who rises at 10 a.m. would experience cortisol spikes roughly three hours later, and ultra-early risers can expect to push this schedule three hours forward.

However, these cortisol levels start to rise as soon as you start moving in the morning, so it isn’t an ideal time to drink coffee. Neither is the afternoon, because doing so could make it more difficult to fall asleep at night. This means that people who wake up at 6:30 a.m. should drink coffee after that first cortisol window closes—roughly between 9:30 a.m. and 11:30 a.m.—if they want to benefit for a little caffeine jolt.

To put it simply: "I would say that mid-morning or early afternoon is probably the best time," certified dietitian-nutritionist Lisa Lisiewski told CNBC. "That's when your cortisol levels are at their lowest and you actually benefit from the stimulant itself."

[h/t Inc.]

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