Your stomach gets a new lining every few days
Stomach acid is strong enough to dissolve metal, so the cells lining the stomach are replaced roughly every three to four days before the acid can damage them.
More human body facts
See all →Humans glow in the dark — just too faintly to see
Chemical reactions in our cells give off a tiny amount of visible light, about a thousand times weaker than the eye can detect. It is strongest in the late afternoon.
Read the fact →Your body makes about 2 million red blood cells every second
Bone marrow produces them continuously because each red cell lives only around 120 days. The total in your body is roughly 25 trillion.
Read the fact →Your nose can tell apart about a trillion smells
A 2014 study estimated humans can distinguish at least one trillion different odours — far more than the old 10,000 figure that textbooks repeated for decades.
Read the fact →