1. Introduction
People are probably more aware of their digestive system than of any other
system because of its frequent messages. Hunger, thirst, wind (gas). And bowel
movements all affect daily life. Eating well and regular exercise are the
bedrocks of good digestive health. Plenty of fresh vegetables and fruits,
adequate fibre, and a low intake of animal fats and salt are simple guidelines
for maintaining not just the wellbeing of the digestive system but that of the
whole body.
After being eaten, or ingested, food embarks on a journey. It can take up to
24 hours to cover a distance of 9 m ( 30 ft), through various muscular tubes and
chambers. The process begins at the mouth, where food is crushed and ground down
by the teeth during chewing. The resulting ball, or bolus, of food continues
down the throat (pharynx), then travels through the gullet ( oesophagus) to the
stomach, small intestine, large intestine, and anus. In the small intestine,
chemicals break down food into molecules small enough to absorb onto the blood.
What cannot be digested is compacted as faeces in the large intestine and
eliminated through the anus. Food travels through the system by a process of
muscular contraction called peristalsis. The digestive system includes several
glands: the spilt-making salivary glands; the pancreas, which produces powerful
digestive juices; and the body’s major nutrient processor, the liver.
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