Human Digestion

Human Digestion
April 27th, 2014
SCI/241
Erica Leath

The digestive system is a very interesting process that takes place after we have eaten a meal or a snack. The digestive system is responsible for breaking down the food that we have eaten and sending the nutrients to the different places in the body. The digestive is so amazing because it recognizes what your body needs and does not need and understands how to separate the two. Just like everything else in our body, the digestive system is a process and is made up of different components that all work together.
The digestive system starts with the saliva in your mouth. The salivary glands recognize the sight and smell of food. The saliva contains the enzyme salivary amylase which begins the chemical digestion of food. The food you eat is moistened, chewed up by your teeth and then is transferred into a bolus. Once the bolus leaves the mouth, it moves into your pharynx, where it is then swallowed. Once the bolus reaches the stomach, it is mixed with different acids and from there it is transformed into a chyme. Most people think that the food is digested in the stomach, but the food that we eat is only partially digested in our stomachs. Chemical digestion in the stomach is caused by gastric juice which is a mixture of water, mucus, hydrochloric acid and pepsin (Grosvenor & Smolin, 2006, pg. 73). Our liver, gallbladder and pancreas are located near our stomach and they aid in the digestive process once the chyme has reached the small intestine. The liver and gallbladder help with the digestion of fat. When the chyme is in the process of leaving the stomach, there are signals by the small intestine. The signals are sent from the brain, small intestine or the stomach. The small intestine is about 20 feet long. The small intestine is also the primary site for absorption or water, vitamins and minerals (Grosvenor & Smolin, 2006, pg. 75). A large amount of the digestion process takes place in the small intestine. Chyme normally leaves the small intestine in two to six hours, but the rate of this is depending on the size of the meal that you have eaten. The small intestine is divided into three parts which are known as the duodenum, the jejunum, and the ileum. Some of the materials that our body needs are absorbed in the small intestine, but those that are not absorbed are moved into the large intestine. The large intestine is made of up the colon and the rectum and is about five feet long. The large intestine absorbs some water, vitamins and minerals. The large intestine also is responsible for getting rid of everything that is not needed by the body. Whatever cannot be absorbed in the body from the different foods that you have eaten is eliminated from the gastrointestinal tract.
The foods that we eat not only have an effect on how healthy we are, but also have an effect on the digestion process. Over the last couple of weeks, we have learned that carbohydrates, fats, minerals, water and protein all come from the foods that we eat on a daily basis. The proteins, fat, and carbohydrates have to be digested and broken down further than water, vitamins and minerals. Proteins are broken down into amino acid (22 of them to be exact), most of the carbohydrates are broken down into sugars, and most of the fats are digested to produce different molecules with carbon chains that are known as fatty acids (Grosvenor & Smolin, 2006, pg. 68). The sugars, amino acids, and fatty acids are then absorbed into the body. Like I mentioned earlier, whatever your body can not absorb will turn into waste and be extracted from the body. The time that it takes your body to digest the foods that you eat is determined by the size of the meal that you have eaten. A large meal leaves the stomach slower than a small meal does. The size of the meal you eat also depends on how quickly you will be hungry again. A meal that is mostly starch or sugar leaves quickly but a meal high in fiber or protein takes the longest to leave (Grosvenor & Smolin, 2006, pg. 74). Some foods that can help the digestion process are foods that are high in fiber (Campbell, 2014). Some foods high in fiber are oatmeal, yogurt and bananas. These kind of foods help keep your body regulated and can eliminate digestion problems such as constipation. Foods high in water can help with the digestion process as well. Some foods high in water are melons, cucumbers, leafy greens and berries (Campbell, 2014).
The digestion process works just like every other process that our body goes through. The research that I have done on the digestion process has just taught me and reinforced how important it is to eat the right kinds of foods. They can have an effect on the digestion process because if you are not eating the right kind of foods they can cause problems such as cramps, gas, constipation and heartburn. These problems can be eliminated by taking care of your body and making sure you are eating from all of the right and recommended food groups.

Reference page
Grosvenor, M. B., & Smolin, L. A. (2006). Nutrition: Everyday choices. Hoboken, New Jersey: John Wiley & Sons. http://corptrain.phoenix.edu/axia/sci241/sci241-digestivetract.html Campbell, M. (2014). Healthy Eating. Retrieved from http://healthyeating.sfgate.com