and with her new teeth she can take on more solid foods digestion starts in the mouth teeth grind up the food then special glands under the tongue pump out saliva to help break down and lubricate the food on its 12-hour 13t Journey Through the gut it'll pass from the stomach into the coils of the small intestine before finally passing into the large intestine waves of Contracting muscle keep the food moving a process called [Music] peristalsis these contractions are so powerful we can even eat upside down for the first time a new camera shows a highdef view of how food travels through our bodies and into our [Music] stomachs [Music] food enters the stomach through a hole at the top the stomach is a bag of muscle that churns squashes and squeezes food into liquid at the same time acids break the food down the stomach walls protect themselves with a lining of mucus without it the acids could digest parts of the stomach itself causing stomach ulcers about an hour later the stomach squeezes the broken down food out through a tiny hole called called the pyloric sphincter the food enters the small intestine an 11t coil of tube where we absorb most of the nutrients the interior wall of the small intestine is lined with millions of microscopic projections called villy these increase the surface area of the gut making it easier to absorb [Music] nutrients first the pancreas pumps out a juice that neutralizes stomach acid then bile from the liver breaks down the fats into tiny droplets smaller droplets are easier for the intestine to absorb after an hour and a half the small intestine has absorbed most of the nutrients from the food it's time for what remains to move on it enters the large intestine through this the ilocal sphincter a valve that keeps our food from going back where it came from what's left is a mix of waste food and dead cells from the walls of the gut the large intestine main job is to extract water from it lots of bacteria live here too but it isn't because of an in infection we actually need them they produce enzymes that break down complex carbohydrates in our food carbohydrates we couldn't otherwise digest finally after about 12 hours we expel what's left of our first meal [Music]