5 unbelievable facts about the human body
The human body is home to all sorts of complicated machinery, which come with a few unusual quirks.
Here are five facts about the human body, which are as unbelievable as they are true.
1. Wisdom teeth have no purpose (anymore)
Having not needed them for over 10,000 years, wisdom teeth have become an annoyance that sometimes requires removal.
The teeth are believed to have been useful when our ancestors used to eat coarse, rough food, like nuts, meats, leaves, and roots. As humans started to eat softer foods and their brains grew bigger, the space in the mouth reduced and effectively crowded out this third set of molars.
2. Fingernails don’t keep growing after you die
While it might look like nails continue to grow after death, they aren’t actually growing. Instead, dehydration in the skin causes it to retract around the nail, making it appear longer.
The same optical illusion also applies to hair.
3. We breathe through one nostril at a time
If you stop to notice your breathing, you might realise that as you breathe through your nose that the air goes in through one nostril and out the other.
This is known as the nasal cycle, and the nostrils will swap roles every few hours.
This is also why you’ll notice it’s harder to breathe when only one nostril is blocked, even though the other is free of congestion.
4. Thumbs have their own pulse
When taking your pulse, you will have been taught to take it from your wrist and using your fingers rather than your thumb.
This is because your thumb has its own pulse that you can feel, which differs from your actual pulse and can cause confusion.
5. Our tongues are made up of eight muscles
The eight muscles are classified into two groups: intrinsic and extrinsic. Intrinsic muscles are responsible for changing the shape of the tongue and aren’t attached to bone, while the extrinsic muscles change the position of the tongue and are anchored to bone.
This structure is similar to that of an elephant’s trunk or an octopus’ limb.
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