While the organs of the human body are divided neatly into organ systems for purposes of medical examination and discussion, in reality, organ systems are interdependent and work together to produce normal body function. The digestive system, for instance, is dependent upon the muscular system in order to move food in, out and through the digestive tract.
Significance
The partnership between the digestive system and the muscular system begins in the mouth, and continues all the way through the end of the digestive tract at the anus. While the digestive tract consists of a series of hollow tubes in which food reacts with digestive enzymes, and while the digestive organs produce the chemicals that digest food, without the muscular system, the digestive tract would have no way to move food into, out of or through the tract.
Types
There are two types of muscles that work with the digestive system--voluntary, or skeletal, muscles, and involuntary, or smooth, muscles. The voluntary muscles, Dr. Lauralee Sherwood notes in her book "Human Physiology," include those of the tongue, jaws and throat. Humans consciously chew and swallow their food. Muscles near the end of the tract are also voluntary, and allow elimination of waste. The muscles of the stomach and intestines are involuntary and operate without conscious direction.
Features
While the ingress and egress of food is important to digestive tract function, the majority of the tract relies upon smooth muscle action. Smooth muscles in the walls of the stomach contract irregularly, which grinds food together with fluid into a mixture called chyme, Dr. Gary Thibodeau explains in his book "Anatomy and Physiology." The smooth muscles of the intestines contract regularly to move food along the digestive tract in an efficient fashion.
Time Frame
While each individual is different, most meals remain in the digestive tract for anywhere from several hours to a day. Because the digestive tract therefore has to digest food in this relatively short period of time, the tract relies heavily upon chemicals called digestive enzymes that help speed the otherwise very slow process of chemically breaking down food. Explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry," enzymes are chemicals that speed up chemical reactions without being changed themselves.
Considerations
Because muscles move food through the digestive tract, the tract works most efficiently when muscles have relatively bulky portions of food with which to work. As such, foods that have high bulk relative to their nutritional density--in other words, foods that contain plenty of fiber--assist the muscular system in moving the food through the digestive tract. High fiber diets increase regularity and decrease the amount of time that food spends in the digestive tract, Sherwood notes.
References
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
- "Anatomy and Physiology"; Gary Thibodeau, Ph.D.; 2007
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
