With a pH between 1.5 and 2.0, human stomach hydrochloric acid can chemically dissolve thin metal over hours.
Your stomach avoids digesting itself thanks to specialized epithelial cells that secrete a bicarbonate-rich mucus shield and renew the stomach lining every few days.
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Quick Guess: What keeps your stomach from digesting itself in its own strong acid?
Verified Answer: A bicarbonate-rich mucus lining and rapid cell renewal
Quiz Question: What keeps your stomach from digesting itself in its own strong acid?
Correct Answer: A bicarbonate-rich mucus lining and rapid cell renewal
Bicarbonate-buffered mucus neutralizes acid right along the stomach wall.
Newborns start life with roughly 300 separate bones and cartilage segments, which fuse down to 206 by adulthood.
Although the brain processes every pain signal in your body, brain tissue itself has zero pain receptors.
Laid end to end, the arteries, veins, and capillaries in an adult human body stretch roughly 96,000 kilometers (60,000 miles).
The transparent cornea at the front of your eye has zero blood vessels—it absorbs oxygen straight from the air through tears.