Ch. 03 DIGESTION
To survive, your body must have a system for transforming food and drink into
absorbable nutrients. Digestion begins when you see, smell, feel, or taste foods.
The hormonal and nervous systems signal the gastrointestinal
that food is on the way. Muscles flex and digestive secretions flow. A group of
cooperating organs orchestrates digestion including the mouth, esophagus, stomach,
small and large intestines, pancreas, liver, and gall bladder.
Digestion Intriduction Continued
To get the nourishment you need, nutrients must successfully traverse the gastrointestinal
tract, or the GIT. The GIT is a long, hollow tube that extends from the mouth to the anus.
Foods contain macronutrients that are broken down during digestion into smaller units
that are absorbed by cells lining the small intestine. Ultimately nutrients traverse
absorptive cells and are released into the bloodstream or lymph system and transported
throughout the body.
Sometimes problems arise such as regurgitation of stomach contents into the esophagus,
ulcers in the stomach, a blocked bile duct, or insufficient enzymes. Knowing more about
the digestive process helps you avoid these problems and stay healthy.
Recognize the system of cooperating organs
Outline the contribution each organ makes to digestion
Identify simple sugars, amino acids, and fatty acids as products of digestion
Describe the role of the mouth, teeth, tongue, epiglottis, and esophagus in chewing,
lubricating, and delivering food and drink to the stomach
Explain the cause of heartburn or gastro-esophageal reflux disease
Identify common sense habits that reduce esophageal damage
Discuss how the stomach is protected from the effects of acid and enzymes
Place stomach acid on a pH scale
Correlate stomach ulcers with known causes
Associate the small intestine and villi with their roles in transforming macromolecules
into small, absorbable units
Match types of absorption (passive, facilitated, active) with energy requirements
Connect the large intestine to its functions including conservation of water, absorption of
minerals, and concentration of digestive residues
Outline the benefits of bacterial colonies in the large intestine