The stomach's own acid and enzymes are strong enough to break down the stomach's own tissue. Roughly how often does the stomach's surface lining fully replace itself with fresh cells to stay ahead of that damage?
- About once a year
- About once a month
- About every three days
- About every hour
Why C? And why not the others?
Correct answer: C. About every three days
The stomach's surface epithelium sheds and regenerates at a startling pace, replacing its full lining roughly every three days, which is exactly what allows it to keep out-pacing the corrosive, protein-digesting acid and pepsin it produces. This rapid renewal works together with a separate defense, a thick mucus layer buffered by bicarbonate that keeps the tissue directly beneath it near neutral pH even while the open stomach cavity stays intensely acidic. A once-a-month renewal pace is a plausible mix-up with the skin's own epidermal turnover cycle, a genuinely similar figure for a different organ, but far too slow to protect stomach tissue under constant chemical attack. A once-a-year pace would mean the stomach destroys itself long before repair could catch up, and an hourly pace overstates even this organ's unusually fast cell replacement rate.
Source: Geophysical Institute, University of Alaska Fairbanks: Why Doesn't the Stomach Digest Itself?; NIH-indexed gastric mucosal renewal physiology