Human Digestion

Human Digestion

Digestion is the process in which food is broken down into smaller pieces to be absorbed into the body. The body sometimes needs helps in breaking down food, nutrients, and vitamins. Mucus helps to lubricate the digestive tract and enzymes help to speed up the breakdown process of food. The transit time for an average adult is 24 to 72 hours but can vary depending on the individual. When we eat food, it goes into our mouth where the food is then chewed and is mixed with our saliva (contains enzymes). Chewing helps to break up the fiber, which retains nutrients anything that cannot be broken up such as corn will be eliminated in the feces. Then it moves down the pharynx, has the job of swallowing. When we swallow our air passages are closed off and food to the esophagus. This connects the pharynx to the stomach. In the esophagus food is moved by muscular contractions which are controlled by the nervous system.

When food leaves the esophagus is passes through a sphincter, which is actually a valve. This valve works to prevent food from going back into the esophagus from the stomach. If there is a leakage you will get heartburn or be vomiting. Once in the stomach the food is mixed with highly acidic secretions and forms chyme. The stomach is also considered a temporary storage area for food. Chemical digestions occurs in the stomach with gastric juice. Gastric juice consist of water, mucus, hydrochloric acid and pepsin (protein enzyme). Your brain, stomach, and small intestine will determine how long food stays in your stomach, how much it is churned, and how much of the gastric juices are released.

When chyme leaves the stomach and it goes into the small intestine. The rate at which this happens is determines by your brain, stomach and small intestine by signals being sent. The stomach usually empties all the chyme in about two to six hours but will vary. Once in the small intestine it continues to mix and breakdown. The small intestine is a tube that is about 20 feet long. This is where most of the chemical digestion takes place and the main area