ANSWERS : Digestive System Study Guide
Learning Standard 1.2c
The digestive system consists of organs that are responsible for the mechanical and chemical breakdown of food. The breakdown process results in molecules that can be absorbed and transported to cells.
Complete the chart by identifying the function of the main organs of the digestive system.
digestive organ
1. mouth
2. esophagus
3. stomach
4. liver
5. small intestine
6. large intestine
function
1.
2.
3.
4.
5.
6.
What is absorption?
What role do the villi play in the process of absorption?
The millions of villi that line the walls of the small intestine contain a series of small blood vessels. The nutrient molecules are able to pass through the walls of each villus and into the blood stream.
Why is peristalsis important to digestion?
Peristalsis is involuntary muscle contractions that take place in the esophagus. These contractions move the food down the esophagus and into the stomach. The small and large intestine also use peristalsis to move the food through their lengthy tubes.
Explain how each term relates to digestion:
enzymes Enzymes are proteins that speed up chemical reactions in the body (pepsin). This allows organs to more quickly digest food for the cells of the body.
bile Bile is a substance that breaks up fat particles. It is produced in the liver and stored in the gall bladder and begins the process of allowing fats to be digested.
blood The blood is responsible for delivering the newly digested nutrient molecules to the cells of the body.
digestive process (defined)
mechanical: The physical breakdown of food into smaller pieces.
chemical: The use of acids and enzymes to change the food into nutrient molecules.
organs involved (explain)
mouth: teeth break food into pieces
esophagus: forms food into a ball
stomach: churns food into a liquid
mouth: adds saliva to begin digestion
stomach: adds acid and enzymes (pepsin)
small intestine: adds bile and pancreatic enzymes
large intestine: bacteria work on indigestible material