The Most Important Process Of The Digestion Of Food

Humans obtain energy needed to perform body functions and do work from food. Foods containing carbohydrates, fats and proteins are the important sources of energy every human need. In order to live healthily, one needs to eat a variety of foods and to take only the recommended amount as suggested in the food pyramid. However, the most important thing every human being has is a digestive system that performs the mechanical and chemical processes of digestion of food, absorption of nutrients, and elimination of wastes to maintain a healthy body. Digestion is the process of breaking down foods into a form the body can use, along with the absorption of nutrients into the blood. There are five important processes of digestion that are chewing, swallowing, churning, digestion and absorption of nutrients, and elimination of undigested food (refer to Figure 1 in Appendix 1).

Firstly, the food is chewed inside the mouth that marks the beginning of digestion. The incisor and pointed teeth are used to tear food while molars (flat teeth) are useful for grinding food into smaller pieces (Byrd-Bredbenner, Moe,

Stomach is a digestive organ that holds foods after it is moved down the esophagus and before propelling into the small intestine (Blake, 2012). During this time, the stomach produces a powerful digestive secretion called gastrin which acts to increase the secretions of the gastric cells and makes the gastric juices more acidic (Thompson & Manore, 2009). Gastrin then stimulates stomach contraction that started the process of mixing and churning of the food. The foods soon become chyme. According to Blake (2012), stomach can expand to hold two to four liters of chyme. Chyme is a liquid combination of partially digested food, water, hydrochloric acid (HCl) and digestives