Digestion Unit Test Review Answers
Unit test Wednesday November 12th 2014
REMINDER
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Make sure you still review your
notes. The review is not for sure
the ONLY material on the test!
Study your digestion disorders
from your presentations!
Study the digestion questions and
the summary tables.
Study the worksheets you did in
class.
Study your notes on diabetes,
including the diagrams. 
Study digestive system anatomy
diagrams.
Digestion Unit Test
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24 multiple choice questions
6 marks - labelling diagrams (0.5 marks each)
5 marks - fill in the blanks (0.5 marks each – with word bank)
5 marks – true or false – you must correct the false statement
23 marks worth of short / long answer
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Things like:
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Step by step how food is digested
Digestion summary table information
Diabetes
Digestion disorders from brochure presentations etc...
TOTAL 63 marks
1. List the organs of the gastrointestinal tract of
humans in the correct order, starting with the mouth.
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G. I tract = the direct path that the food passes through.
Mouth
Pharynx
Esopahgus
Stomach
Small intestine
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(duodenum, jejunum, ileum)
Large intestine
Ascending colon, transverse colon,
descending colon
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Rectum
Anus
2. Define the term “Accessory organ” and list the
accessory organs that play a role in the digestion of food.
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Accessory organs are organs that assist the function of
other organs. They help with digestion but are not
directly a part of the gastrointestinal tract.
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Teeth and tongue  masticate food
Salivary glands  saliva
Pancreas  produces pancreatic juice
Liver  produces bile
Gall Bladder  stores bile
3. What is the overall function of the
digestive system?
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The digestive system’s role is to turn food into energy
and to get rid of waste.
Your digestive system breaks down the food we eat into
small usable particles.
4. What is the function of digestive enzymes?
Explain with the use of three examples of enzymes
and what each acts upon.
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Digestive enzymes chemically break down our food into
usable particles that can be absorbed by the body.
Amylase – in saliva – breaks down carbs into maltose
Pepsin – in stomach – converted from pepsinogen and
digests protein to amino acid chains.
Maltase – in S.I – breaks down maltose into glucose
Lipase – in pancreas – breaks down lipids to glycerol and
fatty acids in the S.I
Trypsinogen – S.I – Breaks down protein
Peptidase – breaks down small peptide proteins to amino
acids
etc
5. Explain what Mechanical and Chemical
digestion are and how they are different.
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Mechanical – physical breakdown of food into smaller
pieces – chewing food in the mouth (mastication), or
churning food in your stomach.
Chemical – enzymatic breakdown of food into usable
substances by the body – pepsin in the stomach breaks
down protein to peptides, amylase in saliva breaks
down carbs to simple sugars.
6. List a food source that is high in protein. Explain (in detail) how this protein
is digested in the body (include where it is being digested, what enzymes take
part in the digestion and where in the digestive system it is being absorbed into
the bloodstream).
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1.
2.
3.
Meat, nuts...
You ingest the food.Your mouth (tongue and teeth) break it down into smaller
pieces (mastication).Your saliva creates a bolus that you swallow.
Action of peristalsis moves the bolus down your esophagus into your stomach.
Once in your stomach:
1.
2.
3.
4.
5.
In Small intestine:
4.
1.
2.
5.
The presence of protein makes the glands in your gastric pits release pepsinogen.
The pepsinogen is converted into pepsin.
The pepsin breaks down protein into small amino acid chains (peptides)
The food mixes with HCl and forms Chyme.
Hormone gastrin – signals pyloric sphincter to relax allowing food to move into S.I.
Pancreatic juice from pancreas to duodenum neutralizes the stomach acid (bicarbonate
ions released)
The peptidase in the S.I breaks the peptides into amino acids
Once proteins are chemically broken down into amino acids, they are absorbed in
the villi of the S.I into the blood and circulated to cells of the body for use or
storage.
7. List a food source that is high in lipids. Explain (in detail) how this lipid is
digested in the body (include where it is being digested, what enzymes take part
in the digestion and where in the digestive system it is being absorbed into the
bloodstream).
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1.
2.
3.
French fries, pastries etc.
You ingest the food.Your mouth (tongue and teeth) break it down into smaller
pieces.Your saliva creates a bolus that you swallow.
Action of peristalsis moves the bolus down your esophagus into your stomach.
Once in your stomach:
1.
2.
3.
In Small intestine:
4.
1.
2.
3.
5.
Mechanical break down by churning.
Food mixes with HCl and forms chyme.
Hormone gastrin – signals pyloric sphincter to relax allowing food to move into S.I.
Pancreatic juice from pancreas to duodenum contains lipase that breaks down the lipids
into glycerol and fatty acids.
Pancreatic juice also contains secretin which neutralizes the stomach acid.
The bile produced in the liver and stored in the gallbladder is added to the duodenum
and emulsifies the fat into smaller droplets.
Once lipds are chemically broken down into glycerol and fatty acids, they are
absorbed in the villi of the S.I into the blood and circulated to cells of the body
for use or storage.
8. If you were a doctor with a patient with type 2 diabetes, how
would you explain the difference between type 2 and type 1
diabetes to your patient?
Type 1
•Early onset
•Diagnosed young (before 20)
•Requires daily insulin injections
•Symptoms are sudden and severe
•Complications can be severe
Type 2
•Late onset
•Occurs later in life (~40-65)
•Requires lifestyle change and oral
meds
•Rarely requires insulin injections
•Symptoms are not as severe
•Usually less complications
9. Explain how food travels down the esophagus.
What is the name of the process? Draw a picture to
show this movement.
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Peristalsis
The wave-like contraction and relaxation of the smooth
muscles surrounding the esophageal wall.
10. What is the importance of absorption in digestion? Where are the majority
of nutrients absorbed into the blood stream? What are the structures that
assist in this absorption? Draw a picture illustrating these structures.
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Absorption allows the uptake
of nutrients for use or
storage in the body.
The majority of nutrients are
absorbed in the small
intestine through the villi and
then into the bloodstream.
Villi: They are finger-like
protrusions that increase the
overall surface area of the
small intestine.
11. What occurs inside of our bodies when
we experience heart burn?
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A burning sensation begins to build in the upper
abdomen, behind the breastbone, and makes your chest
feel like it's on fire. It may be accompanied with a sour
taste and the sensation of food re-entering your mouth.
It has nothing to do with your heart.
It's a digestive problem that occurs when stomach acid
comes into contact with the lining of the esophagus,
causing irritation.
HCl from the stomach backs up into the
esophagus when the cardiac sphincter relaxes.
12. Explain what an ulcer is and how it
develops.
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An ulcer is a sore, which means it's an open, painful
wound.
Peptic ulcers are ulcers that form in the stomach or the
duodenum of the small intestine.
This is where a section of the stomach lining is weakened
by bacteria (Helicobacter pylori) and then eaten away by
the acids and exposed.
It is then irritated by food you eat, the churning of your
stomach, the acids causing further damage to the open
wound.
Treated by antibiotics and antacids.
13. Where is insulin produced? What
purpose does it serve in our body?
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In the pancreas
Purpose  to allow the uptake of glucose from the
bloodstream into individual cells for cellular respiration.
14. Where is bile produced? Where is bile stored?
What purpose does bile serve in our body?
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Bile is produced in the liver.
Stored in the gallbladder.
Bile emulsifies fats from large particles into smaller ones.
15. What are the components of pancreatic
juice?
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Alkaline solution, mucus, enzymes:
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Amylase –
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Trypsinogen –
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chemical breakdown of peptides into amino acids
Lipase –
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breaks down carbs like maltose into monosaccharides like glucose.
breaks down lipids into fatty acids and glycerol
Secretin –
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neutralizes acid from stomach
16. Describe four functions of the liver.
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Makes bile
Stores glycogen
Detoxifies blood of toxins
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Such as alcohol
Makes proteins for blood clotting
Stores vitamins
17. What is cirrhosis and what causes it?
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Cirrhosis is permanent damage or scarring of
the liver.
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This scar tissue replaces the healthy tissue
This leads to blockage of blood flow through
the liver thus preventing normal function.
This is usually caused by alcoholism but can also
be caused by:
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Viral infections (like hepatitis)
Certain diseases
Severe reactions to prescribed drugs
Prolonged exposure to environmental toxins
etc
18. Draw and label a diagram of the
stomach lining.
19. What do the glands in the stomach secrete?
What is the significance of this secretion?
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The stomach contains gastric pits that have glands that
release mucus which protects the stomach walls.
These glands also secrete pepsinogen which is converted
to pepsin in the presence of protein.
These cells are constantly being replaced by the body to
maintain a coating that will protect the stomach from the
acids.
20. What are two functions of the hormone
Gastrin?
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Gastrin (hormone) found in the stomach and released
when protein is digested.
It triggers the release of gastric juice (HCl)
Relaxes pyloric (gastric) sphincter.
21. If we do not ingest sufficient amounts of carbs
what will happen and how does our body respond?
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We won’t have enough energy.
Carbs get broken down into glucose which fuels our cells.
Without glucose from carbs...
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You won’t have a lot of energy.
You will feel tired, sluggish and dizzy since the glucose from
carbohydrates is the primary energy source for your brain.
Your muscles won’t respond properly or quickly.
Your body will have a lack of vitamins etc....
22. Fibre has no nutritional value to humans. What
is fibre and why do we need it?
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Fibre helps to:
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Keep your digestive system healthy and prevent constipation
by making stools bulky and soft.
Lower blood cholesterol and triglyceride levels.
Lower your risk of colon cancer, heart disease, and digestive
problems.
Improve blood sugar in people with diabetes.
Control weight gain by making you feel full so that you eat less.
23. Diarrhea, constipation, gas, odour from gas, and tapeworms
are all associated with the large intestine. Consider how these
different conditions might arise in an individual.
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Eating undercooked food
Eating contaminated food or food that has spoiled
Drinking contaminated water
Not consuming enough fibre
Eating foods that your body cannot properly digest
Eating foods you are allergic to