LESSON 1
NURSING CARE RELATED TO THE GASTROINTESTINAL SYSTEM
Section I. ANATOMY AND PHYSIOLOGY
1-1.
DIGESTION
a. The intake of food is necessary for life because the foods we eat provide
essential nutrients. Nutrients are substances necessary for growth and repair of tissue
and for maintenance of normal body functioning. A "nutritionally adequate" diet will
contain all the essential nutritive substances in the amounts and proportions required to
maintain life and health. These essential nutrients are carbohydrates, proteins, fats,
minerals, vitamins, and water.
(1)
Carbohydrates, proteins, and fats are the basic fuels for cellular activity.
(2) Minerals are inorganic substances that help to regulate body processes.
Some work with the enzymes, some act as catalysts, and some work within the buffer
systems.
(3) Vitamins are organic nutrients that function to regulate physiological
processes such as growth and metabolism.
(4) Water is an important nutrient with many functions. It acts as a coolant,
a lubricant, a suspending medium, and as a reactant in chemical processes.
b. Since the food we eat cannot be used for fuel in its consumed form, it must be
broken down (digested) to the molecular level. In molecular form, the chemicals can be
transported and absorbed through the cell membranes for utilization by the body cells.
This process of digestion consists of both mechanical breakdown and chemical
breakdown.
(1)
Mechanical digestion includes chewing, swallowing, peristalsis, and
defecation.
(2) Chemical digestion is the enzymatic breakdown of the food- stuffs into
chemically simple molecules that can be absorbed and utilized by the cells.
c. Carbohydrates, also known as sugars and starches, are organic compounds
that provide the most ready source of energy to the body. Carbohydrates are broken
down to their simplest form, called a monosaccharide, to be absorbed from the digestive
tract. Carbohydrates consist of three major groups: monosaccharides, disaccharides,
and polysaccharides.
MD0918
1-3