Human Body — Page 6
The incredible human body
133 facts
Humans are the only known animals that blush from embarrassment.
Blushing is an involuntary response of the sympathetic nervous system that dilates the blood capillaries in the face…
The human cornea gets oxygen directly from the air.
Unlike most body tissues, the cornea has no blood vessels. It absorbs oxygen directly from the atmosphere and eye…
Stomach rumbling has a scientific name, borborygmus, and it does not only happen when we are hungry.
The sound comes from gas and fluid being pushed along by contractions of the gut. It is louder on an empty stomach…
A red blood cell lives for about 120 days before being recycled.
Without a nucleus, a red blood cell cannot repair itself and slowly stiffens as it circulates. After about four…
Freshly produced sweat has almost no smell: body odour comes from the bacteria that break it down.
Most sweat is just water and salt. In the armpits, however, some glands also release proteins and fats. Skin bacteria…
Your fingers have no muscles: they are moved by tendons connected to muscles in the palm and forearm.
When we make a fist, the muscles doing the work are in the forearm, which is why it moves when we bend our fingers…
The human tongue is made up of eight different muscles.
Four muscles lie inside the tongue and change its shape; four more anchor it to bone and the skull and change its…
The kidneys filter about 180 litres of blood plasma every day.
All the plasma in the body passes through the kidneys about 60 times a day. More than 99% of the filtered water is…
The lens of the eye never stops growing throughout life.
New layers of cells are added on the outside, like an onion, and the old ones are never removed. The lens becomes…
The headache from eating ice cream too fast is called sphenopalatine ganglioneuralgia.
Cold on the roof of the mouth makes blood vessels constrict and then quickly widen. Nerves in the area read this…
The 'funny bone' is not a bone at all: the shock comes from the ulnar nerve.
At the back of the elbow the ulnar nerve runs through a narrow channel protected only by skin and a little fat. A…
Even identical twins have different iris patterns.
The texture of the iris forms randomly during pregnancy and is not dictated by genes. That is why iris recognition…
The hippocampus of London taxi drivers grows as they memorise the city's streets.
To get a licence, drivers spend years learning about 25,000 streets for an exam called 'The Knowledge'. Brain scans…
