DISEASES AND DISORDERS OF THE GASTROINTESTINAL SYSTEM
Section I. DISEASES/DISORDERS OF THE UPPER GASTROINTESTINAL SYSTEM
a. General Information. The general function of the gastrointestinal system is
to break down and absorb foods and eliminate some of the waste products produced in
the process of metabolism. Foods are changed into simple forms that can be absorbed
into the bloodstream or lymphatics and, eventually, used by the cells of the body. Much
of the water we need comes from the foods we eat; water is necessary for cellular
activity. The gastrointestinal system prepares the food for consumption by the cells
through five basic activities: ingestion (eating); peristalsis (moving food along the
digestive tract); digestion (breaking down food chemically and mechanically); absorption
(moving digested food from the digestive tract into the cardiovascular and lymphatic
systems for absorption by the cells); and defecation (elimination of indigestible
substances from the body). The gastrointestinal tract is affected, however, by a variety
of factors, and sometimes there are problems in the functioning of the various organs.
At some time almost everyone has had a gastrointestinal disorder--an attack of
indigestion; a sudden loss of appetite; constipation; or diarrhea. Some disturbances
correct themselves; others are more serious.
b. Upper Gastrointestinal Diseases and Disorders. The organs of the upper
gastrointestinal tract are mainly concerned with the transportation of enzymes to break
down food substances. Organs in this system include the esophagus, stomach, and the
small intestine. Diseases and disorders of the esophagus and abdomen as well as
hernias are functional problems occurring in this part of the gastrointestinal tract.
COMMON DISEASES AND DISORDERS OF THE MOUTH
a. Aphthous Ulcer (Canker Sore, Ulcerative Stomatitis).
(1) Definition. Aphthous ulcer is a tiny ulcer which occurs on the muscosa
of the mouth, either singly or in batches.
(2) Etiology. The specific cause of these mouth ulcers is unknown. There
are some predisposing contributing factors:
Deficiency in iron, B12, and folic acid.