Facts & Functions
The digestive system is a series of organs that converts food into essential nutrients to be absorbed into the body, while eliminating unused waste material. If the digestive system shuts down, the body cannot be nourished or rid itself of waste.
This is also called the Gastrointestinal Tract (GI). It begins at the mouth, including the oesophagus, stomach, small intestine, large intestine (colon) and rectum, ending at the anus. The entire system is about 9 meters long.
Digestion begins at the mouth. Even the smell of food can generate saliva which contains an enzyme to break down starch. Teeth also play a key role in digestion.
Swallowing pushes chewed food into the oesophagus, where it passes through the oropharynx and hypopharynx. At this point, food forms small round masses and digestion becomes involuntary. A series of muscular contractions (peristalsis) transports food through the rest of the system. The oesophagus empties into the stomach.
The stomach’s gastric juice – a mix of hydrochloric acid and pepsin – starts breaking down proteins and killing potentially harmful bacteria. After an hour or two a thick semi-liquid paste (“chime”) forms which then enters the duodenum, where it mixes with digestive enzymes from the pancreas and acidic bile from the gall bladder.
Then it enters the 6m long small intestine where most of the nutrients are absorbed, move into the bloodstream and are transported to the liver.
The liver creates glycogen from sugars and carbohydrates to give the body energy, and converts dietary proteins into new proteins needed by the blood system. It also breaks down unwanted chemicals such as alcohol, which passes from the body as waste.
Whatever material is left passes into the 1, 5m long large intestine (colon) where indigestible matter is stored and fermented, while water from the chime is absorbed back into the body. Faeces is stored here until eliminated from the body.
Symptoms of problems in the GI Tract may include:
– Abdominal pain
– Blood in the stool
– Difficulty swallowing