Digestive System – Chapter 18
Vocabulary
Digestion - the mechanical and chemical breakdown of foods for use by the body’s cells.
Absorption - the passage of digested food from the digestive tract into the circulatory
system.
Elimination – the expulsion of undigested food or body wastes.
Ingestion - the taking of food in to the body.
Mastication - the process of chewing ( prepares the food to be swallowed ).
Peristalsis - a series of involuntary muscular contractions
( moves food through the esophagus )
Gastric Juices - secretions from the stomach lining that contain pepsin and hydrochloric acid.
Chyme - a creamy, fluid mixture of food and gastric juices.
( Peristalsis moves chyme in the into the small intestine ).
Bile - a yellowish-green, bitter fluid important in the breakdown of fats.
Indigestion - burning discomfort in the upper abdomen.
Hiatal Herina - a condition in which part of the stomach pushes through an opening
in the diaphragm.
Appendicitis - the inflammation of the appendix.
Peptic Ulcer - a sore in the lining of the digestive tract.
Fill In The Blank
Food is the body’s fuel.
Digestion is both mechanical and a chemical process.
Walking after eating helps digest food 40 to 50 percent faster.
The lining of the stomach is replaced every three days.
Organs That Aid Digestion – List each and explain each role.
Liver – second largest organ in your body ( skin is the largest ). It is your body’s chemical
factory and regulates the levels of most of the main chemicals in the blood.
Gallbladder - a small-pear shaped sac 3 to 4 inches long and located underneath the liver.
The gallbladder stores bile until food moves into the duodenum from the
stomach.
Pancreas - produces the hormone insulin. The pancreas produces three digestive enzymes,
they all digest fats.
Study Questions
1. What is the mechanical process that take place during digestion?
Biting, chewing, swallowing, peristalsis, absorption, and elimination.
2. What are the chemical processes that take place during digestion?
The breaking down of carbohydrates in salvia, the mixing of food with gastric
Acids in the stomach, and secretions from the liver, pancreas, and gallbladder.
3. In what part of the digestive system does most of the chemical breakdown of
food take place? Most of the chemical breakdown of food takes place in the small
intestine.
4. What are the two main functions of the large intestine?
Absorb water and eliminate food.