What Is Catgut Made From?

iStock/SergeKa
iStock/SergeKa

Stefan Pociask:

What do cats, tennis, doctors, cows, and violins have in common? The answer is … catgut!

Catgut sutures have been around a long time. Yes, catgut is what is used to make absorbable stitches, even today. Absorbable stitches are those that don’t need to be removed; they just kind of break down and become part of your skin. Making catgut is a pretty lucrative business, as there is still a fair demand for the material. But where does it come from?

If your cat is sitting with you as you read this, you can tell Fluffy not to worry: catgut is not—and never has been—made from actual cat guts. Theoretically, you could use a cat’s intestines to make catgut string, but when compared to the string you get from cows and sheep, it’s not worth the trouble. A cow intestine can produce catgut string that is up to 160 feet long. Your cat’s intestine is small potatoes, compared to that. So why the hell is it called catgut when no cats were harmed in the production of this string? I’ll
get to that in a bit. First, let’s find out exactly what this string is.

These days, catgut comes mostly from the intestines of cows—though sometimes it's sheep, pigs, or even horses. But cow catgut is the biggest current industry. When cows are slaughtered for meat, the intestines are saved and processed. Here is a cross section of intestine:


Quora

The part that is used to make catgut comes mostly from the submucosa and the externa layers, both of which contain collagen, which is the protein we're looking for. Collagen is found throughout the bodies of mammals and some other vertebrates. Wherever structural strength and elasticity is required in soft tissue, you may find collagen there. Skin, for instance, which is strong and elastic. The intestines also need to be strong and elastic; when we eat a lot of food, for instance, we needthe intestines to stretch without bursting—and then to contract back to normal size after the food passes. This collagen is made up of strong stretchy fibers.

At slaughterhouses, the intestines are usually slit in half, thirds, or quarters, lengthwise. This would make different thicknesses, for different uses. So the above cross-section would make two, three, or four long lengths. These are then soaked in a series of solutions and caustic solvents, which dissolve away all the tissue except for the strong collagen fibers. Once all these fibers are clean and pure, it is then stretched, twisted, and allowed to dry under tension. What remains is catgut string which, pound for pound, is one of the strongest strings there is. In that regard, it’s stronger than a comparable weight of steel wire, in fact.

Various gauges (or diameters) of catgut are produced, depending on what its ultimate use will be. There are three main industries where catgut is used: The first is as surgical suture material. In western countries, it is being replaced by other materials that also are absorbed into the body, but the market is still strong in developing countries.

The second industry is sports, namely tennis and other racket sports. For sporting purposes, catgut—which was the original racket material—is made much thicker.

Since catgut biological material, it does degrade with time. But it offers the perfect combination of strength and "spring." As such, catgut has long been used to string bows for archery, at least as far back as ancient Egyptian times. And as we know, the Egyptians really loved their cats. So clearly they didn’t use their intestines for their bows. No, even then, catgut was made from cattle.

The third major use of catgut is for for stringed instruments. Catgut was the original violin string material. These days, there are many other types of strings, but you can still find catgut in many professional orchestras, on a variety of instruments, from classical guitars to those giant pedal harps that rest against your shoulder and make Heaven-like sounds.

Now that you know that no kitties were harmed in the making of catgut, you may be wondering why it was ever called catgut. Well, the gut part is obvious: it’s made out of guts, which itself is a very old word. But the cat part actually started out as kytte (pronounced “kit”). What is a kytte? This is a kytte:


Quora

That’s the front and back of a kytte—a medieval-era mini-violin. It was so mini, that it was stored in the pokett, which was derived from the Old French poque, or bag. Traveling minstrels could whip out their kyttes, play a lively tune or three, and then put their hardy instrument back into their pokett without worrying about the delicate frailty of a normal-sized violin. These instruments were the perfect mingling of a horsehair bow, rubbing against a cow gut catgut, in perfect concert with each other. Basically, catgut (kytte gut) is so named because it is gut that is used to string your kytte. Simple as that. It has nothing to do with felines whatsoever.

This post originally appeared on Quora. Click here to view.

What Makes Dogs Tilt Their Heads?

iStock.com/JoeChristensen
iStock.com/JoeChristensen

By tilting its head slightly to the side, a dog can melt the heart of even the most hardened cat person. Most everyone finds this behavior adorable, but few people can explain what compels a dog to do it. Are dogs somehow aware of the effect they have on humans, using a cute trick to exploit us for affection?

Experts say the real answer has more to do with your dog's ability to empathize. Dogs are impressively good at reading and responding to our body language and vocal cues. When you're lecturing your pooch for taking food off the counter, they're taking it all in even if the literal message gets lost in translation. Same goes for when you’re giving your pup praise. Dogs are capable of recognizing certain parts of human language, so when they cock their heads as you speak to them, it's possible they're listening for specific words and inflections they associate with fun activities like meals and playtime.

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The head-tilt may also have something to do with how the canine ear is constructed. Even though dogs sense frequencies humans are incapable of hearing, their ability to detect the source of sounds is less precise than ours. A dog's brain calculates extremely minuscule differences between the time it takes a sound to reach each ear, so a simple change in head position could provide them with useful sensory information. When dogs tilt their heads, some experts believe they are adjusting their pinnae, or outer ears, in order to better pinpoint the location of a noise.

Stanley Coren of Psychology Today believes that vision also has something to do with this behavior. If you try holding your fist in front of your nose, you can get a fair sense of what it’s like to view the world with a muzzle. When watching someone speak, the "muzzle" will block the lower part of their face from view, and if you tilt your head to one side you will be able to see it more clearly. In addition to being able to perceive emotional cues in our voices, dog can also read our facial expressions. When cocking their heads to the side, Coren suggests that dogs are trying to get a better view of our mouths, where our most expressive facial cues originate.

If your dog is a frequent head-tilter, this could mean that they're especially empathetic. Some experts have reported that dogs who are more socially apprehensive are less likely to tilt their heads when spoken to. But if your dog doesn't display this behavior, there's no need to automatically label them as a canine sociopath (especially if they have pointy ears or a flatter snout). And even if the head tilt does come from instinct, the more owners respond to it with positive reinforcement, the more likely dogs are to do it in search of praise.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

Where Did the Phrase 'Red Herring' Come From?

iStock.com/Mathias Darmell
iStock.com/Mathias Darmell

You may have seen a red herring in a recent book or movie, but you probably only realized it after the fact. These misleading clues are designed to trick you into drawing an incorrect conclusion, and they're a popular ploy among storytellers of all stripes.

If you've seen or read the Harry Potter series—and really, who hasn’t?—then you may recall some of the many instances where J.K. Rowling employed this literary device. That endearing plot twist about the nature of Snape's character, for example, is likely one of the longest-running red herrings ever written.

Sometimes they aren't even subtle. Agatha Christie's murder mystery And Then There Were None directly mentions red herring in reference to a character's death, and a statue of a red herring appears in Lemony Snicket's A Series of Unfortunate Events. Perhaps most blatantly, a character in the cartoon A Pup Named Scooby-Doo who was constantly being blamed for myriad crimes was named—you guessed it—Red Herring.

But where does this literary device come from, and why is it named after a fish? For a bit of background: herring are naturally a silvery hue, but they turn reddish-brown when they're smoked. Long before refrigerators were invented, this was done to preserve the fish for months at a time. They can also be pretty smelly. As Gizmodo's io9 blog points out, it was believed that red herring were dragged against the ground to help train hounds to sniff out prey in the 17th century. Another theory was that escaped prisoners used the fish to cover their tracks and confuse the dogs that tailed them.

However, io9 notes that red herring were actually used to train horses rather than dogs, and only if the preferred choice—a dead cat—wasn't available. The idea was that the horses would get used to following the scent trail, which in turn would make them less likely to get spooked while "following the hounds amid the noise and bustle of a fox hunt," notes British etymologist and writer Michael Quinion, who researched the origin of the phrase red herring.

The actual origin of the figurative sense of the phrase can be traced back to the early 1800s. Around this time, English journalist William Cobbett wrote a presumably fictional story about how he had used red herring as a boy to throw hounds off the scent of a hare. He elaborated on this anecdote and used it to criticize some of his fellow journalists. "He used the story as a metaphor to decry the press, which had allowed itself to be misled by false information about a supposed defeat of Napoleon," Quinion writes in a blog. "This caused them to take their attention off important domestic matters."

According to Quinion, an extended version of this story was printed in 1833, and the idiom spread from there. Although many people are more familiar with red herrings in pop culture, they also crop up in political spheres and debates of all kinds. Robert J. Gula, the author of Nonsense: Red Herrings, Straw Men and Sacred Cows: How We Abuse Logic in Our Everyday Language, defines a red herring as "a detail or remark inserted into a discussion, either intentionally or unintentionally, that sidetracks the discussion."

The goal is to distract the listener or opponent from the original topic, and it's considered a type of flawed reasoning—or, more fancifully, a logical fallacy. This application of red herring seems to be more in line with its original usage, but as Quinion notes: "This does nothing to change the sense of red herring, of course: it's been for too long a fixed part of our vocabulary for it to change. But at least we now know its origin. Another obscure etymology has been nailed down."

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