Category Kids Queries

Humans evolved with flattened fingernails instead of the thicker, sharper claws found on most mammals. Researchers think that fingernails and toenails helped our ancestors climb trees, peel fruit, and use simple tools. And fingernails are still useful today! Their color and condition offer clues about your overall health. Nail polish turns them into fashion accessories. You use them to pop open the tops of soda cans. And nothing makes a better back – scratcher than a nice set of nails!

The primary function of a fingernail is to shield the fingertip, the distal phalanx and the surrounding soft tissues from injuries. It increases the sensitivity of the finger by acting as a counter force when the pulp of the finger touches an object. Furthermore, it helps in certain cutting or scraping actions, and acts as an extended precision grip for the finger.

The hard covering of toenails protects and fortifies the dense network of blood vessels, muscles and flesh beneath them.

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When you move or bend your fingers, you occasionally squeeze tiny air bubbles that form in the protective fluid around your body’s joints. Those popping bubbles create an audible crack.

Like all joints, they’re the place where two bones come together to allow movement-we have them in our wrists, knees, and everywhere else we can bend. Tough, flexible tissues called ligaments hold them together. Joints are covered with a capsule filled with a special kind of liquid, called synovial fluid that acts as a lubricant as we move around; they also contain small amounts of dissolved gas, which is what causes that pop when we crack them. 

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You might think that playing in the pool or soaking in the tub makes your fingertips and toes waterlogged and soggy. Not so! The prune effect is caused by blood vessels shrinking just below the skin – an automatic reaction triggered by your nervous system when it senses long exposure to water. Scientists think people evolved this reaction to improve their grip and traction in wet environments. After all, pruny fingers make it easier to snag slippery fish.

When hands are soaked in water, the keratin absorbs it and swells. The inside of the fingers, however, does not swell. As a result, there is relatively too much stratum corneum and it wrinkles, just like a gathered skirt. This bunching up occurs on fingers and toes because the epidermis is much thicker on the hands and feet than elsewhere on the body. (The hair and nails, which contain different types of keratin, also absorb some water. This is why the nails get softer after bathing or doing the dishes.)

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Those whirls, swirls, loops, and arches on your fingertips (and toes, in case you didn’t know) are unique to you – even if you have an identical twin – and they remain unchanged throughout your entire life. In fact, the faint ridges known as fingerprints from before you’re even born. Fluids in the womb put pressure on your developing digits, which combined with your rate of growth and genetic makeup, create one-of-a-kind designs. Ah, you want to know the point of those fingertip designs (well, besides incriminating crooks who forget to wear gloves). Scientists have put forth all sorts of possible reasons. Fingerprints might magnify the hand’s ability to detect vibrations, for example, or improve our sense of touch. They also might work like tire trends to help us grip objects.

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Lots of them, although the exact number depends on your definition of ‘’thumbs’’. Apes and many monkeys have opposable thumbs just like us, while smaller primates, pandas, and koalas have thumb like digits and claws that help them grip plants and prey.

Gorillas, orangutans, chimpanzees, and bonobos belong to the same family of primates as humans, the Hominidae family?the family of great apes. Studies have revealed that great apes share 97 percent of their DNA, which explains the similarities they share with us humans. The anatomy of their hands, for instance, bears a striking resemblance to that of our hands. All have four long fingers plus an opposable thumb. Furthermore, all except for humans have opposable big toes as well.

Like us, all these species use their hands to hold tools, climb trees, move from one tree to another, gather food, build a dwelling place, and all this is achieved, despite the fact that they are quadrupedal, i.e., walk on all four limbs. If it was not for the much-touted opposable thumb, these species would have had a tough time trying to do something as simple as peeling a banana.

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Having no thumbs would make you all thumbs, fumbling to tie your shoes or assemble a hamburger. (Don’t believe us? Tape one your thumbs against the side of your hand and see how hard life becomes.) We inherited a fully ‘’opposable’’ thumb – named for its ability to close tip-to-tip against our other fingers – from our primate ancestors around two million years ago. These ancient relatives needed handier hands to help get a grip on simple tools. So give a thumbs-up to your thumbs. They’re the mains reasons you can text with one hand and build a burger without fumbling the bun.

It might not sound very fancy, but lots of animals don’t have this opposable finger and cannot grasp things the way we do. The most important thing we get from grasp is probably the ability to use tools. The use of tools has made it possible for humans to do everything from creating fire for cooking food and making warmth, to building homes and shelters, to learning how to write!

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