The Science of Nutrition
The digestion process begins with the salivary glands, your mouth can begin to water when the thought or smells of something good is present. When the food enters the mouth, the process physically begins. The saliva moistens the food and is chewed by the teeth, turning it to bolus, then moves to the pharynx, (a passageway), to be swallowed and moved into the esophagus. The esophagus is connected to the stomach. The bolus reaches the stomach, where it is mixed with acid turning it to chyme. The stomach acts as a temporary storage area. Food is practically digested in the stomach. It can take two to six hours to empty, depending on the meal size. The food travels from the stomach to the small intestine. The majority of digestion and absorption of nutrients takes place here. Secretion of bile from the liver and gall bladder help digestion and absorption of fat, (the liver, gall bladder, and pancreas are located closely to the stomach). The materials that have not been absorbed in the small intestine enter the large intestine through the sphincter. The colon, and the rectum are included in the large intestine. The colon absorbs the vitamins and minerals. The material that has not been absorbed in the colon is then excreted as waste feces through the anus, which is attached at the end of the colon.
This is the condensed version of the digestive system and how it works. If I were to detail the process, I would exceed my word limit. I found some of the information in our chapter very interesting. It explained much to me with regard to some family health issues.
Chapter 3, The Digestive Systems: From Meals to Molecules,...