Question

name
how the digestive system works
to find out what you already know about the digestive system, write a word or words
from the word bank to complete each definition.
word bank
gastric juice digestion large intestine rectum tongue
appendix enzymes intestinal juice saliva villi
peristalsis esophagus mechanical small intestine bile
chemical salivary glands gallbladder pancreas stomach

1. ___ is the process by which food is broken down into

substances that can be used by the cells of the body.

1. in the digestive system, food undergoes two kinds of

digestion. ___ digestion occurs as the food is broken into
smaller pieces.

1. mechanical digestion prepares the food for ___ diges-

tion, which is the process by which foods are chemically
changed into simpler substances.

1. digestion begins as soon as food enters the mouth,

where the teeth and tongue work together to physically
break down the food into smaller pieces. as chewing
takes place, a secretion from the ___ softens and lubri-
cates the food.

1. this secretion from the salivary glands is called ___ .
2. saliva contains ___ , substances that speed up chemical

reactions and break down large starch molecules into
smaller molecules of sugar.

1. the ___ helps push food to the back of the mouth where

it is swallowed.

1. after being swallowed, the food passes into a muscular

tube called the ___ , which connects the mouth to the
stomach.

1. food in the esophagus is squeezed toward the stomach

by contraction and relaxation of the muscles in the
esophagus. this muscular action, known as ___ , also
helps to move food through the rest of the digestive
tract.

Explanation:

1. Digestion is the process of breaking food into usable substances.
2. Mechanical digestion breaks food into smaller pieces.
3. Mechanical digestion prepares for chemical digestion (chemical change of food).
4. Salivary glands secrete to soften/lubricate food.
5. Secretion from salivary glands is saliva.
6. Saliva has enzymes (speed chemical reactions, break starch).
7. Tongue pushes food for swallowing.
8. Esophagus connects mouth to stomach.
9. Peristalsis (muscle action) moves food.

Answer:

1. digestion
2. mechanical
3. chemical
4. salivary glands
5. saliva
6. enzymes
7. tongue
8. esophagus
9. peristalsis