During digestion, what term describes nutrients moving from the intestinal lumen into the bloodstream?

• A. Digestion
• B. Absorption
• C. Metabolism
• D. Secretion

Answer: (B)

The main idea here is the uptake of nutrients from the gut lumen into the blood. The term that describes this movement is absorption. After nutrients are chemically broken down during digestion, they must cross the intestinal lining to reach the bloodstream. Enterocytes (the lining cells) transport these nutrients into capillaries that feed the hepatic portal system, carrying them to the liver for processing. It’s the step that converts breakdown products into usable nutrients for body cells. Note that digestion is the chemical breakdown process, metabolism is how cells use those nutrients, and secretion is releasing substances like enzymes or mucus. (Fats have a slightly different route, often entering the lymphatic system first as chylomicrons before joining the bloodstream, but the general process of moving from lumen into blood is still called absorption.)