The digestive system, or gastrointestinal tract (GIT) is a long muscular tube that functions as the food processor for the body. It contracts in a controlled rhythm to move food through the different sections (peristalsis). Variations in the strength and timing of the contractions can cause cramping (very strong contractions) and diarrhea (contractions are very frequent). When the contractions are slow and irregular, constipation may occur. The digestive system includes the following organs: mouth and salivary glands, stomach, small and large intestines, colon, liver and pancreas, and the gallbladder.

The digestive system has the capability to sense and react to the materials that are passed through it. For a healthy digestive system, every person requires different food selections that match their capacity.

The GIT first breaks down foods by means such as chewing and then by the application of a host of complex chemical processes. These chemical processes include everything from saliva to colon microbes. Since the GIT is the point of entry for the human body, everything eaten has an impact on the body. The food consumed and passed through the GIT contains nutrients as well as toxins. Toxins can be anything from food additives and pesticides to specific foods that induce a reaction from the GIT.

The process of digestion is accomplished by way of the surface of the GIT using secretions from accessory glands. The two glands providing the majority of these digestive chemicals are the liver and the pancreas. The function of the liver is to control the food supply for the rest of the body by further processing the food molecules absorbed through the intestines. The liver does this by dispensing those food molecules in a controlled manner and by filtering out toxins that may have passed through the GIT wall.

Chewing, swallowing, and peristalsis comprise mechanical digestion, in which food is broken down into tiny particles, mixed with digestive juices, and moved through the digestive tract. Digestive enzymes break down large food molecules into small molecules that can be absorbed into the blood or lymph in the process of chemical digestion.

Digestive System Links: