Biology - Absorption from the small intestine
Absorption from the small intestine
The small intestine has structures called villi. In these villi are
lymph vessels and blood vessels. Lipids pass into the lymph system
monosaccharides and proteins pass into the blood vessels.
Chemical digestion has been completed in the small intestine. For humans
to gain benefit from this, the useful substances that have been released
from the food must now be absorbed across the intestinal wall into the
blood and lymphatic capillaries.
Monosaccharides  (e.g. glucose) and amino acids pass into the blood
capillaries while fatty acids and glycerol are absorbed into the lymph
capillaries (lacteals). The products of lipid digestion pass along the
lymphatic system and eventually are deposited into the blood.
Once in the blood, the products of digestion are transported to cells
around the body where they may form new substances.