Digestion The final chapter!!!

The Small Intestine »Is about 6 meters long! »Most chemical digestion and the absorption of nutrients take place here (in the small intestine). »Food arriving here from the stomach is mostly liquid. It then mixes with secretions and enzymes (delivered from the two organs on the next two slides). Finally, nutrient molecules are absorbed into the bloodstream.

Everyone’s Favorite: Organ #1:Liver!!! »It’s the largest organ found in the body. »As part of the digestive system, it produces bile (which gets stored in the gall bladder and is delivered through tubes to the small intestine). Bile is a chemical that breaks fats down into smaller fat molecules. These fats molecules are later further broken down by enzymes produced in the pancreas.

Organ #2:The Pancreas oAs part of the digestive system, the pancreas produces enzymes that flow into the small intestine and break down fats, starches, and proteins.

 Food travels directly from the stomach to the small intestine, it never enters either the liver or pancreas Remembe r!!!

Absorption in the Small Intestine  The inner surface (or wall) of the small intestine is lined with millions of finger- like projections called villi. Each villi is filled with tiny blood vessels.  Nutrients from digested food are absorbed into the villi, where the blood then carries those nutrients to the rest of the body.

The Large Intestine »By the time material moves out of the small intestine into the large, almost all nutrients have been absorbed. The remainder is water and undigested food like fiber. Bacteria (good ones) feed on this (yikes!) and produce vitamin K. »In the large intestine, the water is absorbed and the rest compressed in a short tube (rectum) and eliminated as feces through the anus.