Human Digestion

Human Digestion

Sci/241

July 5, 2011

Khanh Nguyen

Digestion is the process of breaking food down for absorption. Proteins, carbohydrates, fats,

and other nutrients are broken down and used in the body. Food passes through the digestive

system first in the mouth where it is grinded into small pieces by the teeth and mixed with salvia

and digestion begins. Food moves into the pharnax which in turns, leads food to the esophagus.

The esophagus is a tube that food follows to the stomach. It uses muscle constrictions to move

food along the esophagus while secreting a mucus to lubricate food to the stomach.

Once inside the stomach, muscle surrounding the outside of the stomach start to churn the

food inside. The stomach contains hydrochloric acid ,which kills bacteria, and the stomach also

produces pepsin, an enzyme, used to help digest proteins. "The stomach also secretes a mucus to

protect itself from being digested by its own acids and enzymes". (Carter, 1996) After leaving

the stomach food enters the small intestine.

Because of the size of the small intestine absorption of nutrients is more likely to occur here.

Secretions from the small intestine help in digesting carbohydrates and fats. Other organs like

the pancreas, liver, and gall bladder secrete chemicals into the small intestine to help in the

breaking down of food for absorption. Food then travels to the large intestine.

The large intestine reabsorbs the water and other nutrients that the body has not absorbed. In

the large intestine the bacteria is produced to help in the final breaking down of food. Food is

broken down into waste which is stored in the rectum until eliminated.

References

Carter, J. (1996). Digestive System. Retrieved from http://Biology.clc.uc.edu