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How often is the surface epithelium of the stomach completely replaced?
AEvery 3 to 6 days
BEvery 3 to 4 hours
CEvery 2 to 4 weeks
DEvery 6 to 8 months
Answer & Solution
Correct answer: A. Every 3 to 6 days
1. The mucosal barrier that stops the stomach digesting itself has three components.
2. A thick bicarbonate-rich mucus coat neutralizes acid, and tight junctions block juice from seeping deeper.
3. The third component is rapid replacement of damaged cells by stem cells where the glands meet the pits.
4. Because of that turnover, the surface epithelium is completely replaced every 3 to 6 days.
5. Three to four hours is the length of the gastric phase of secretion, not a turnover time.
6. Two to four weeks and six to eight months are far too slow for a surface under constant acid attack.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 23 "The Digestive System", section 23.4 The Stomach_
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