The digestive system enables the body to obtain nourishment from ingested food. In this paper, I look at some of the essential components and processes of the digestive system.
Amylase is a digestive enzyme that catalyzes the breakdown of starch into disaccharides and trisaccharides (Stevens & Hume, 2004). It is made by the pancreas and the salivary glands. Salivary amylase initiates the breakdown of starch in the mouth into disaccharides and trisaccharides, which are then broken down by other enzymes into monosaccharides.
Bile is a greenish-yellowish fluid with a bitter taste that is manufactured by the liver and stored in the gallbladder. Bile juice contains bile salts, which act as emulsifiers by reducing the surface area of fats. Emulsification increases the surface area of fats thereby enhancing the action of lipase enzymes on the fats.
Chymotrypsin is an enzyme that is secreted into the duodenum as part of the pancreatic juice (Smith & Morton, 2010). It is produced as an inactive precursor called chymotrypsinogen, which is triggered into activity by trypsin. Its main function is proteolysis by acting on the amide bonds of proteins and polypeptides.
Peristalsis is a chain of muscular movements of the walls of the alimentary canal during the process of digestion. It facilitates the movement of food from one section of the gastrointestinal tract to another. It also carries out mechanical digestion of food through its kneading motion in preparation for enzymatic digestion.
Villi are tiny protuberances in the inner lining of the ileum (Stevens & Hume, 2004). They are made up of smaller projections called microvilli, which comprise thin epithelia to enhance faster diffusion of digested into the bloodstream. The walls of the small intestines have numerous villi to enlarge the surface area that is meant for the absorption of digested food.
Understanding all components of the digestive system is crucial to the knowledge of the functioning of the entire body.
Smith, E. M., & Morton, D. G. (2010). The digestive system: Systems of the body series (2nd ed.). London: Elsevier.
Stevens, E. C., & Hume, I. D. (2004). Physiology of the vertebrate digestive system (2nd ed.). New York, NY: Cambridge University Press.