Category: Your Digestive System
The stomach is a hollow organ inside of your body that is part of the digestive tract. The stomach is in the upper abdomen, under your ribs.
The digestive tract is a series of organs joined in a long, twisting tube that help the body break down and absorb food.
The Wall of the Stomach Has Five Layers
- Inner Layer or Lining (mucosa) – Juices made by glands in the inner layer help digest food. Most stomach cancers begin in this layer.
- Submucosa – This is the support tissue for the inner layer.
Pronounced – GAWL-blah-dur
Your gallbladder is a small, pear-shaped organ located below your liver on the right side of the abdomen. The gallbladder is connected to the liver by bile ducts. The gallbladder is about 3 inches long and 1 inch wide at its thickest part.
Your gallbladder is most likely to give you trouble if something blocks the flow of bile through the bile ducts. That is usually a gallstone. Gallstone attacks usually happen after you eat.
It is estimated that as many as 20 million Americans have gallstones.
Gallstones are clusters of solid material that form in the gallbladder. The most common type is made mostly of cholesterol. Gallstones may occur as one large stone or as many small ones. They vary in size and may be as large as a golf ball or as small as a grain of sand.
Did You Know…
Organs that make up the digestive tract are:
- Mouth
- Esophagus
- Stomach
- Small Intestine
- Large Intestine (colon)
- Rectum
- Anus
Organs that help with digestion but are not part of the digestive tract are:
- Tongue
- Glands in the mouth that make saliva
- Pancreas
- Liver
- Gallbladder
An adult oesophagus (also spelled esophagus and also called gullet) ranges from 10 to 14 inches in length, and 1 inch in diameter.
We make 1 to 3 pints of saliva a day.
Hormone Regulators
A fascinating feature of the digestive system is that it contains its own regulators. The major hormones that control the functions of the digestive system are produced and released by cells in the mucosa of the stomach and small intestine. These hormones are released into the blood of the digestive tract, travel back to the heart and through the arteries, and return to the digestive system, where they stimulate digestive juices and cause organ movement.
Water and Salt
Most of the material absorbed from the cavity of the small intestine is water in which salt is dissolved. The salt and water come from the food and liquid we swallow and the juices secreted by the many digestive glands.
Fat molecules are a rich source of energy for the body.
The first step in digestion of a fat such as butter is to dissolve it into the watery content of the intestinal cavity. The bile acids produced by the liver act as natural detergents to dissolve fat in water and allow the enzymes to break the large fat molecules into smaller molecules, some of which are fatty acids and cholesterol.
Foods such as meat, eggs, and beans consist of giant molecules of protein that must be digested by enzymes before they can be used to build and repair body tissues.
An enzyme in the juice of the stomach starts the digestion of swallowed protein.
Further digestion of the protein is completed in the small intestine. Here, several enzymes from the pancreatic juice and the lining of the intestine carry out the breakdown of huge protein molecules into small molecules called amino acids.
Based on a 2,000 calorie diet, it is recommended that 55 to 60 percent of total daily calories be from carbohydrates.
Some of the most common foods contain mostly carbohydrates. Examples are:
- Bread
- Potatoes
- Legumes
Most digested molecules of food, as well as water and minerals from the diet, are absorbed from the cavity of the upper small intestine.
The mucosa of the small intestine contains many folds that are covered with tiny fingerlike projections called villi. In turn, the villi are covered with microscopic projections called microvilli. These structures create a vast surface area through which nutrients can be absorbed.