Science Nine
Unit 2—Your Living Body
Science 9-Biology
Worksheet 7-1—Digestion in the Mouth, Esophagus and
Stomach -- KEY
Name __KEY_____________________
Due Date ________________________________
10
Show Me
Hand In
Correct and Hand In Again By ______________
Read pages 134-139 of SP to help you answer the following questions:
1.
What is meant by tissue? A group of cells with similar tasks (eg. muscle, nerve, bone)
2.
What is meant by an organ? Several types of tissue grouped together for a specific task.
(eg. stomach, heart, liver etc.)
3.
Organs that work together to perform a specific task (like digestion) make up a
__system__ of the body.
4.
What is saliva? The watery fluid in your mouth. (contains salivary amylase)
5.
Two main body parts that carry out mechanical digestion in the mouth are the _teeth_
and the tongue
6.
On the diagram, label each part and give it’s function.
Tongue- saliva
released under the
tongue as well as at
the back of the
mouth
Lower lip
Upper lip
Molars (grind)
Premolars (chew)
Canine (cut or tear)
Incisors (cut or tear)
Worksheet 7-1—Digestion in the Mouth, Esophagus and Stomach
Page 1
Science Nine
Unit 2—Your Living Body
7.
These glands are called
____salivary______glands.
They produce __saliva__ which
contains _digestive enzymes_ &
_water__
8.
Give two reasons why mechanical digestion is important in the mouth:
1. __food particles must be small enough to fit down the esophagus___
2. __allows better mixing of food with digestive enzymes__________
9.
At the back of your throat there are two separate tubes. They are called the
___esophagus______, which carries food to the stomach and the
_____trachea_________ which carries air to the lungs.
10. What is the epiglottis? _a fleshy flap which closes the entrance to the trachea while
swallowing_______
What is it’s function? _ closes the entrance to the trachea while swallowing ________
11. The walls of the esophagus are made up of ___muscle____ tissue.
12. What material, produced by the esophagus helps lubricate the food so it moves more easily
through? __mucus_______
13. Describe what happens during peristalsis. A series of muscle contractions that work
their way down the esophagus squeeze food down the esophagus.
14. Do you think food would pass from the throat to the stomach is you were in a no-gravity
environment? __yes______ Explain. It is forced toward the stomach by peristalsis.
15. Your stomach wall is made up of ___muscle______ tissue.
16. Your stomach can hold up to __2 L___L of food when stretched.
Worksheet 7-1—Digestion in the Mouth, Esophagus and Stomach
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Science Nine
Unit 2—Your Living Body
17. Where exactly is your stomach? Under the ribs on the left side of your body.
18. Mechanical digestion in your stomach is carried out by the ___contractions___ of
muscles in the stomach wall.(kneeding the food)
19. List the 3 materials present in stomach fluid and state the function of each one:
Material
Function
Pepsin
A digestive enzyme that breaks down
protein molecules into amino acids
Hydrochloric acid
Assists the pepsin, making it work better
to break down proteins
Protective material which coats the walls
of the stomach, protecting the lining from
the digestive action of pepsin and
hydrochloric acid
Mucus
20. What actually happens to produce what we call “heartburn”?
The acidic contents of the stomach are pushed up into the esophagus, producing a
burning sensation in the upper chest.
21. The enzyme pepsin works best when there is _hydrochloric acid_ present in the mixture.
22. If there was no protective lining of the stomach wall, what would the pepsin and acid do to
it?___digest it, breaking the protein down into amino acids__________
23. Sometimes the acid and pepsin can get through and cause an area of the stomach wall to be
damaged. This causes pain and if left untreated could cause serious damage. This type of
“sore” on the stomach wall is called a gastric __ulcer___________.
24. Which class (carbohydrates, fats, proteins etc.) of nutrients are broken down by the
enzymes in the stomach? ___proteins______________________.
25. What is located at the “exit” point of the stomach which can close to prevent food from
passing into the small intestine? _a circle of muscle (sphincter)___________
26. The process of __peristalsis_________causes the foods and stomach juices to continually
mix in the stomach.
Worksheet 7-1—Digestion in the Mouth, Esophagus and Stomach
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Science Nine
Unit 2—Your Living Body
27. Is the opening at the bottom of the stomach usually open or closed? _closed___
28. Food from a meal usually remains in the stomach from _2_ to _4_ hours.
29. Label the following diagram:
Circle of muscle
(sphincter)
Esophagus
Stomach
Inner layer of
stomach (muscle)
Worksheet 7-1—Digestion in the Mouth, Esophagus and Stomach
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