The Digestive System
The Digestive System is a group of organs working together to convert food into energy and basic nutrients to feed the entire body. Food passes through a long tube inside the body known as the alimentary canal or the gastrointestinal tract (GI tract). The alimentary canal is made up of the oral cavity, pharynx, esophagus, stomach, small intestines, and large intestines. The digestive system is responsible for taking whole foods and turning them into energy and nutrients to allow the body to function, grow, and repair itself. The 6 primary processes of the digestive system include:
Mechanical digestion is simply the aspects of digestion achieved through a mechanism or movement. There are two basic types of mechanical digestion.
Chemical digestion is much like it sounds – those aspects of digestion achieved with the application of chemicals to our food.
Digestive enzymes and water are responsible for the breakdown of complex molecules such as fats, proteins, and carbohydrates into smaller molecules. These smaller molecules can then be absorbed for use by cells.
The presence of these digestive enzymes accelerates the digestion process, where absence of these enzymes slows overall reaction speed. Currently, there exist eight digestive enzymes mainly responsible for chemical digestion. (The following are direct quotes from the online medical dictionary.)
- Ingestion of food
- Secretion of fluids and digestive enzymes
- Mixing and movement of food and wastes through the body
- Digestion of food into smaller pieces
- Absorption of nutrients
- Excretion of wastes
Mechanical digestion is simply the aspects of digestion achieved through a mechanism or movement. There are two basic types of mechanical digestion.
- Mastication: The first step when it comes to digestion actually begins as soon as food enters the mouth. Mastication (chewing) begins the process of breaking down food into nutrients. As a type mechanical digestion, chewing our food is an important part of the digestive process because smaller pieces are more readily digested through chemical digestion.
- Peristalsis: Mechanical digestion also involves the process known as peristalsis. Peristalsis is simply the involuntary contractions responsible for the movement of food through the esophagus and intestinal tracts.
Chemical digestion is much like it sounds – those aspects of digestion achieved with the application of chemicals to our food.
Digestive enzymes and water are responsible for the breakdown of complex molecules such as fats, proteins, and carbohydrates into smaller molecules. These smaller molecules can then be absorbed for use by cells.
The presence of these digestive enzymes accelerates the digestion process, where absence of these enzymes slows overall reaction speed. Currently, there exist eight digestive enzymes mainly responsible for chemical digestion. (The following are direct quotes from the online medical dictionary.)
- Nuclease: Any of a group of enzymes that split nucleic acids into nucleotides and other products.
- Protease: Any of various enzymes, including the proteinases and peptidases, that catalyze the hydrolytic breakdown of proteins.
- Collagenase: Any of various enzymes that catalyze the hydrolysis of collagen and gelatin.
- Lipase: Any of a group of lipolytic enzymes that cleave a fatty acid residue from the glycerol residue in a neutral fat or a phospholipid.
- Amylase: Any of a group of enzymes that catalyze the hydrolysis of starch to sugar to produce carbohydrate derivatives.
- Elastase: An enzyme capable of catalyzing the digestion of elastic tissue.
- Trypsin: A proteolytic digestive enzyme produced by the exocrine pancreas that catalyzes in the small intestine the breakdown of dietary proteins to peptones, peptides, and amino acids.
- Chymotrypsin: A proteolytic enzyme produced by the pancreas that catalyzes the hydrolysis of casein and gelatin.