Now that the food turned bolus, turned chyme is in the small intestine, we enter the 3rd Phase of Digestion, The Intestinal Phase.
The bulk of carb and fat digestion happens in this phase as well as any remaining protein digestion. This is also when what we call the auxiliary organs, pancreas, liver & gallbladder get involved.
The small intestine has many folds that wraps around for a total of 20 feet and the reason for this is to increase our surface area so that like a sponge our small intestine absorbs most of our nutrients.
When chyme is fully broken down into liquid most of our nutrients are absorbed, the chyme enters the large intestine through the ileocecal valve.
The large intestine is actually much shorter only 5 feet long but double in width. It is also called the Colon.
The Colons job is to prepare leftovers from the digestive process to exit the body by absorbing any remaining water and pumping salt back into the body, water then follows salts. When the water is reabsorbed, what's left are the fibers. These fibers are food for our gut bacteria who make sure that any indigestible fibers are fermented to produce all kinds of wonderful nutrients for us.
Through another act of peristalsis (wave like motions), these fibers move to our rectum until they are ready to leave through our anus as waste.
So, to recap, the process of digestion can be broken down into three phases:
The Cephalic (oral) phase when you put food in your mouth that travels down your esophagus
The Gastric Phase which is when your stomach breaks down food and kills any contaminants
The Intestinal Phase which is when nutrients and water is absorbed and waste is excreted
Next Monday we will move on to: Breaking It Down: Mechanical & Chemical Digestion