35 Surprising and Unusual Facts About the Human Body

It’s easy to overlook just how complex the human body really is. From the way it repairs itself to how it processes information and adapts over time, our bodies are constantly working in ways most of us rarely think about. What may seem ordinary on the surface is often anything but.

After millions of years of evolution, the human body has developed into an incredibly efficient and capable system. It allows us to move, think, communicate, and respond to the world around us with remarkable precision. At the same time, it’s filled with unexpected quirks and lesser-known details that can be just as surprising as they are informative.

For example, the average person has about 60,000 miles of blood vessels, 46 miles of nerves, roughly 39 trillion bacteria, and 206 bones. The brain alone contains around 86 billion neurons, sending signals at speeds that can reach hundreds of miles per hour. These are just a few of the many details that highlight how intricate the human body truly is.

In this slideshow, we’re taking a closer look at 35 surprising and unusual facts that reveal just how extraordinary—and sometimes strange—the human body can be.

Goosebumps are a vestige of our evolutionary past when they were useful in fluffing up fur or feathers to provide insulation from the cold. Goosebumps are caused by the flexing of the arrector pili muscles, tiny muscles located inside the hair follicles.

And the final region to mature fully is the frontal lobes, which control planning and reasoning.

Ever wonder why your fingertips change texture and “prune up” when you’ve been in the pool for a long time? It’s caused by the contraction of blood vessels, and scientists generally agree that it’s an adaptation to help us grip things better underwater.

Earwax may seem like a nuisance, but it’s actually very useful. It has antimicrobial properties that help protect the ear canal from infection.

You use all of it.

It’s essentially impossible to keep your eyes open when sneezing; it’s an automatic reflex in order to protect your eyes.

That averages out to about 1,200 times per hour.

It also contains 300 sweat glands, 20 blood vessels, and 1,000 nerve endings.

That on-edge, nervous sensation of butterflies in your stomach is caused by the release of adrenaline into the bloodstream and changes in blood flow to the stomach, and are a response to stress or excitement.

It’s caused by cold hitting the outer covering of the brain, called the meninges, triggering a dilation and contraction of the arteries and causing a headache.

Ever notice that sometimes when you’re sick, only one nostril is fully plugged up at a time? That’s because they essentially operate independently of one another and alternate between being dominant and less dominant every few hours. This phenomenon is called the nasal cycle.

No matter how strong or unpleasant an odor is, if you spend enough time exposed to it without smelling anything else, your nose will eventually get used to it.

It also contains up to 1 billion synapses, the places where neurons connect and communicate with each other.

Skin cells are also the primary component of your standard household dust.

It also grows faster during the day than at night, and it grows slightly faster for men than women.

If you notice hair falling off of your head every day, you’re not going bald; it’s normal to lose between 50 and 100 hairs from your head on a daily basis. More than that, though, might not be a good sign. There’s plenty to spare, though; the average human has about 100,000 hairs on their head.

The brain generates about 23 watts of power, and LED bulbs only need about 10 watts to operate.

Our fingers move because of the muscles in the palm and forearm; they are connected to tendons, which move our fingers.

When you’re sleepwalking, your brain is in a state of partial wakefulness and partial sleep. That’s why you’re capable of performing complex tasks without being aware of doing them.

Weird, right?

Because tickle attacks usually take you by surprise, your body doesn’t have time to prepare. If you want to tickle yourself, your brain will reduce the nerve response so you can’t actually do it.

While it’s common knowledge that everyone has unique fingerprints (even identical twins), you might not know that everyone also has their own unique scent, influenced by facts including genetics, diet, and hygiene. Identical twins actually do have similar scents, though.

It’s possible for the digestive system to operate without a stomach because the stomach’s job is to hold food until it can be digested, not to digest it. Removing the stomach, called a gastrectomy, is a treatment for some patients with stomach cancer.

Skin accounts for about 16 percent of total body weight, on average. It’s also the body’s largest organ.

And about 1 out of every 100 people is ambidextrous, which means they are able to use their right and left hands equally well.

The color of your eyes can change slightly over time, due to factors such as aging, lighting conditions, and pupil dilation.

Hydrochloric acid, the acid in the stomach, is powerful stuff; in fact, a layer of mucous is all that prevents it from dissolving the stomach and other organs.

It’s true: Seeing or hearing someone yawn can trigger a yawn response in others. The exact reason is still up for debate, but theories include subconscious mimicking of those around us, empathy, and the fact that if you’re tired other people around you probably are, too.

It’s also the only part of the body that can regenerate itself without scarring.

And coughs can travel at 60 miles per hour.

If a man never trims his beard, it will grow to around 30 feet long over the course of his lifetime.

The average bladder can hold about a pint at a time.

Teeny-tiny eight-legged mites love to call your face home. They usually like to hang out around your hairline and eyes and are generally harmless.

Sweat on its own doesn’t actually smell like anything. Bacteria just love to make their way into sweat after it’s excreted, however, and once they start to proliferate that’s when it starts to stink.

If you grew up believing that your tongue has different regions responsible for tasting sweet, sour, salty, and bitter, that’s actually not true. Taste buds for all flavors are spread throughout the tongue, and there are about 8,000 taste buds on the tongue. (Click here to explore some other common health-related myths.)