Water is absorbed primarily in which organ?

Water is absorbed primarily in which organ?

• A. Stomach
• B. Large Intestine
• C. Esophagus
• D. Small Intestine

Answer: (B)

Water absorption happens mostly in the small intestine because its lining provides an enormous surface area for uptake. The inner surface is folded into villi and microvilli, and the epithelial cells actively transport solutes like sodium and other nutrients. Water follows these solutes by osmosis, so a large volume of intestinal fluid is absorbed there as chyme passes through. The large intestine does take care of water too, reabsorbing electrolytes and remaining water to form stool, but its capacity is much less than that of the small intestine. So the primary site for absorbing water is the small intestine; the large intestine concentrates what’s left into feces.

Water absorption happens mostly in the small intestine because its lining provides an enormous surface area for uptake. The inner surface is folded into villi and microvilli, and the epithelial cells actively transport solutes like sodium and other nutrients. Water follows these solutes by osmosis, so a large volume of intestinal fluid is absorbed there as chyme passes through. The large intestine does take care of water too, reabsorbing electrolytes and remaining water to form stool, but its capacity is much less than that of the small intestine. So the primary site for absorbing water is the small intestine; the large intestine concentrates what’s left into feces.