Human Body — Page 11
The incredible human body
267 facts
The human eye blinks about fifteen to twenty times per minute.
This involuntary movement is essential to spread tears across the cornea, keeping the eye lubricated, clean, and…
The human brain generates enough electricity to light a small bulb.
Neurons communicate through electrical impulses and, with billions of active cells simultaneously, the brain produces…
Human beings are taller in the morning than at bedtime.
During the day, gravity compresses the cartilage between the spine's vertebrae. At night, while sleeping…
Babies are born without kneecaps.
Instead of solid bone, babies are born with a cartilage structure that only begins to ossify and turn into the…
The surface area of human lungs is equivalent to a tennis court.
If the millions of pulmonary alveoli were opened and stretched, their total gas exchange surface would cover about…
The human femur is stronger than concrete.
The thigh bone is incredibly dense and structured to support body weight, able to withstand a compressive pressure…
The human body contains enough iron to make a seven-centimetre nail.
Iron is essential for haemoglobin in the blood. If all the iron present in an average adult's body were extracted and…
Sleep deprivation causes the brain to start consuming itself.
Chronic lack of sleep causes glial cells to go into overdrive, starting to devour unnecessary synapses and neural…
The human skeleton completely replaces itself every ten years.
Through a continuous process called bone remodelling, special cells break down old bone tissue and build new bone…
A person produces enough saliva in a lifetime to fill two swimming pools.
Salivary glands produce about one to two litres of saliva per day, which, accumulated over an average lifetime…
The type of earwax in humans is determined by a single gene.
A mutation in the ABCC11 gene determines whether the wax will be wet and sticky or dry and flaky, with the dry…
The storage capacity of the human brain is equivalent to two point five petabytes.
Estimates based on the number of synapses suggest the brain could store the equivalent of three million hours of…
Tooth enamel is the hardest substance produced by the human body.
Composed mostly of minerals like hydroxyapatite, enamel is harder than bone and serves to protect teeth from the…
Humans shed about eighteen kilograms of skin over their lifetime.
The outer layer of skin constantly renews itself, shedding thousands of dust particles per minute. Over an average…
The human nose can distinguish at least one trillion different scents.
Recent studies have shown that our olfactory system is much more complex than previously thought. By testing various…
The human stomach renews its entire lining every few days.
Gastric acids are so strong they would corrode the organ itself if it weren't for rapid cell regeneration. The cells…
The human liver can completely regenerate even after a large portion of the tissue is removed.
It is the only internal organ in the human body with this extraordinary ability. As long as at least 25 percent of…
The human liver can regenerate even after losing three quarters of its tissue.
Liver cells have a unique ability to multiply and replace lost tissue. Within a few weeks, the organ can return to…
The lining of the human stomach renews itself completely every three or four days.
If it did not renew so quickly, the stomach would digest itself due to its strong acids. The epithelial cells of the…
About half of human DNA comes from ancient viruses that infected our ancestors.
Human endogenous retroviruses are remnants of viral infections that occurred millions of years ago and became…
Humans glow in the dark, but the light is invisible to the human eye.
The human body emits a small amount of visible light due to metabolic reactions that produce free radicals. However…
The human stomach renews its lining every three to four days.
Gastric acids are strong enough to dissolve metal. To prevent the stomach from digesting itself, the cells of the…
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…
Ears and nose continue to grow throughout your entire life.
Unlike bones, the cartilage that forms the nose and ears never stops dividing and expanding. Furthermore, with age…