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1. Define digestion. ______________________
__________________________________________
2. Label the diagram of the digestive
system.
3. Shade in the parts of the digestive
system that food actually passes through.
4. Define alimentary canal.
__________________________________________
__________________________________________
5. Define accessory glands.
______________________________________
_______________________________________
Accessory Glands
Alimentary Canal
6. Complete the chart.
List all parts of the
digestive system.
The Mouth:
Did you know? Tooth enamel is the hardest substance in the human body.
7. What role do you think your teeth play in digestion? _________________________
______________________________________________________________________________
8. What is bolus? _____________________________________________________________
______________________________________________________________________________
9. List the functions of saliva.
_______________________________________________
________________________________________________
________________________________________________
Try the cracker test. Take one unsalted cracker; place it in your mouth and
chew, chew, chew. Compare the taste before and after chewing
10. What enzyme is responsible for this change of taste and what does it do?
_____________________________________________________________________________
11. Summarize the events that go on in the mouth.
12. What happens when you swallow, to channel bolus down the proper
channel? ____________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
The Esophagus:
Did you know? The esophagus is approximately 25 cm long.
13. What is peristalsis? _________________________________________________________
______________________________________________________________________________
The Stomach:
Did you know? Your stomach is J – shaped. It can hold 2 – 4 litres of food. It
secretes 2 -3 litres of digestive fluids in a normal 24 hour period.
Only proteins are broken down here.
14. The lining of the stomach contains 2 glands. State the two glands and their
function.
A) _________________:
______________________________________________________
______________________________________________________________________________
B) _________________:
______________________________________________________
______________________________________________________________________________
15. The pH of the stomach is usually 1.5 – 2.5. HCl kills those nasty bacteria lurking
there. If the stomach itself is large protein, why doesn’t it digest itself? __________
______________________________________________________________________________
16. What does a person suffer from if it does digest itself? _______________________
17. What is chyme? ___________________________________________________________
18. Pepsin is secreted in an inactive form called _______________, but when mixed
with HCl, the _______________ becomes activated and breaks down large protein
molecules.
19. What is the function of?
A) Cardiac sphincter
_______________________________
_______________________________
B) Pyloric sphincter
_______________________________
_______________________________
The Small Intestine:
Did you know? The small intestine is 2.5 cm in diameter but is approximately 6m
in length. Total surface area is equal to 300m2, the size of a tennis
court. The gall bladder and appendix are notorious trouble
makers.
20. What are the two main functions of the small intestine?
______________________________________________________________________________
______________________________________________________________________________
21. What does chyme mix with in the small intestines? _________________________ ,
______________________________ and ______________________________
22. Along with digestive juices in the wall of the small intestine itself, two glands
add their contribution. What are these two glands and how do they aid in
digestion?
A) _____________________________________________________________________
________________________________________________________________________
B) _____________________________________________________________________
________________________________________________________________________
23. Bile is made in the ______________ , but stored in the _______________________
24. Explain the role of bile as an emulsifier. _____________________
______________________________________________________________
25. Observe the diagram of the magnified interior of the small
intestine. Why is the lining folded with villi and microvilli?
______________________________________________________________
______________________________________________________________
26. Explain how nutrients are moved across the intestinal wall and ultimately to all
the cells in the body. _________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
27. List the structural features that the small intestines have that increase the
surface area which is idea for absorption. _____________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
The Large Intestine:
Did you know? The large intestine is 6 – 7cm in diameter, but only 1.5m in length.
28. What are the two main functions of the large intestines?
A) _____________________________________________________________________
B) _____________________________________________________________________
Conclusion
Digestion involves a mechanical and chemical process. Complete the following
chart.
Digestive Organ
Mouth
Esophagous
Stomach
Small Intestine
Large Intestine
Major Mechanical Actions
Major Chemical Actions