More Complex Than Expected

It has long been assumed that the lining of the small intestine is simply a passive tissue. In other words, it was believed that nutrients simply diffused across the lining without any active work done by the lining cells. However, the Scientific American of November 1981, pointed out: “Recent work in physiology presents a different picture of the lining. It is now clear that the inner surface of the intestine is active both in breaking down and in absorbing nutrients. Cells of the lining have enzymes embedded in their membrane that convert complex sugars into simple ones and break down the peptides produced by protein digestion into their constituent amino acids or into small peptides made up of a few amino acids each.”

Advancing knowledge has brought to light many of the wonderful workings of the human body, but no doubt many mysteries remain. Both the knowns and the unknowns are awe-inspiring, causing many to feel like King David, who said of the Creator: “I shall laud you because in a fear-inspiring way I am wonderfully made.”​—Psalm 139:14.