Digestive Review
Answers to review sheet
1. The principal
structure of the
digestive system is
an irregular tube,
open at both ends,
called the
_alimentary___
canal or the
_gastrointestinal
tract.
2. Food is broken down
physically, called
_mastication___
and chemically
called
__digestion_______
.
3. Chemical digestion
results from the action
of digestive enzymes.
The first enzyme,
_amylase_____, found
in saliva, breaks down
carbohydrates. An
antibacterial enzyme
called _lysozyme____
is also found in saliva.
1. The enzyme
_pepsinogen or
pepsin_ is excreted
by the stomach and
begins the chemical
digestion of
proteins.
1. The three salivary
glands are the
_parotid________,
_sublingual__ and
the
_submandibular___
___.
1. The inside, hollow space within the
digestive tract is the _lumen_______.
7. The inner layer of
the intestinal tract is
called the
_mucosa_____. It
secretes
_mucus______ to
allow food to move
easily through.
8. The second layer,
the _submucosa__,
is connective tissue
that contains blood
vessels, nerves and
lymphatic vessels.
1. The 2-3 layers of
muscle is called
the
_muscularis____
.
1. The outermost covering or coat of the
digestive tube is the _serosa____.
1. The wavelike,
rhythmic contraction
of the muscular
coat, called
_peristalsis moves
food through the
digestive system.
1. Another name for the throat is the __pharynx___.
1. The muscular,
mucus-lined tube
that connects the
throat to the
stomach is the
_esophagus______
___.
1. The _stretch_____
reflex brought on by
food entering the
stomach, signals
the release of
hormones that in
turn release more
enzymes.
• After food leaves the
mouth and enters the
esophagus, it is called
a bolus____.
16. The opening from the esophagus to the
stomach is the _cardiac________
sphincter.
17. When stomach
contents go back
onto the esophagus
two or more times a
week, it is called
__GERD, acid reflux
(gastroesophageal
reflux disease) or
heartburn.
18. Contraction of the stomach’s muscular
walls mixes the food thoroughly with the
gastric juice and breaks it down into a
semisolid mixture called _chyme_______.
19. The acidic gastric
juice secreted by
the cells of the
stomach is
_hydrochloric
acid___. It has a
pH of approximately
__2___.
20. The circular muscle
that releases food
from the stomach to
the duodenum is the
_pyloric________
__sphincter__.
21. The small intestine
is approximately
__22__ feet or 6.5
meters. The
surface area is
about _2000___
square feet.
22. The three parts of the small intestine are
_duodenum_____, __jejunum________
and _Ileum__________.
23. The folds of the
small intestine are
covered in small
finger-like
projections called
_villi____, which are
covered in even
smaller projections
called
___micro______
_villi___.
• Each villus in the
intestine contains a
lymphatic vessel or
_lacteal___ that
absorbs lipid or fat
materials from the
chyme passing
through the small
intestine.
25. Most of the
chemical digestion
occurs in the first
part of the small
intestine, called the
_duodenum______.
26. Bile is created by the _liver_______ and
stored in the _gall__ _bladder__
27. Bile is drained out of the liver by the
_hepatic___ ducts.
28.Bile contains salts that __emulsify__ or
break down fats.
29. When chyme
containing lipid or fat
enters the duodenum,
it initiates a trigger for
the hormone CCK,
_cholecystokinin_,
which stimulates the
contraction of the
_gall bladder_____ to
release bile into the
duodenum.
30. Solid clumps of material (mostly cholesterol)
that form in the gallbladder only cause
problems when they block a duct are called
__gallstone______.
31. The pancreas works as an
_exocrine_____ gland when it secretes
digestive enzymes and an
__endocrine____ gland when it secretes
hormones.
32. The pancreatic
juices are the most
important because
there are enzymes
to break down all
three major kinds of
foods:
_carbohydrates___
_, _lipids__, and
__proteins____.
33. Pancreatic juices empty into this part of the
small intestine: _duodenum______
34. The large intestine is approximately 1.5
meters or _5__ feet in length.
35. It is called the large intestine because it
is larger in _diameter____ than the small
intestine.
36. The small intestine empties into the
large intestine through the
__ileocecal______ valve. The name
makes sense because the unabsorbed
food moves from the _ileum_______ of
the small intestine to the _cecum__ of
the large intestine.
1. During its movement through the large
intestine, material that escaped digestion
in the small intestine is acted on by this
single celled organism: _bacteria_____
1. These single celled organisms are
responsible for the synthesis of Vitamin
__K_, which is important for normal
blood _clotting____.
1. The percentage of nutrients absorbed by
the small intestine: __95%____.
41. If enough water is not
absorbed by the large
intestine,
_diarrhea_____
results. If too much
water is absorbed,
then
__constipation______
_ can result.
•
The subdivisions of the
large intestine listed in
order are:
–
–
–
–
–
–
–
__cecum____________
___
__ascending colon_____
__transverse colon_____
___descending colon__
___sigmoid
colon_______
___rectum___________
___
____anal
canal_________
43. This vestigial organ can rupture sending
bacteria into the abdominal cavity:
___appendix_______________
1. This connective tissue extensions
between and around the digestive
organs in the abdomen provide blood
supply, insulation and anchors the small
intestine to the abdominal wall:
_mesentary__________.
1. The four major
types of teeth are
the __incisors____,
__canines_____,
__premolars______
and the
__molars________
__.
45. The portion of the
tooth that is
exposed and visible
in the mouth is the
__crown________
46. The tooth
_root_____ fits into
the socket of the
upper or lower jaw.
47. A fibrous _periodontal_________ membrane
lines each tooth socket.
48. Another name for the gums is the
__gingiva_______, thus the name of a
gum infection is gingivitis.
49. Even though animals could not live without
bacteria in the digestive system, sometimes
a bad bacteria can get in and cause
problems. H. pylori can cause holes in the
stomach walls called _ulcers_____,
50. Many people can
not digest milk
sugars and get
gastric distress.
These people are
_lactose_____
intolerant.
1. People over 50 years of age should be
checked for colon cancer through this
procedure: __colonoscopy_______.
• Another name for the formation and
removal of feces: __defecation____.
1. The largest
gland/internal organ
is the
__liver___________
_.
54. This holds the tongue to the floor of the
mouth: _lingual_frenelum_.
55. The main cause of
gall stone is
consuming too
much _fat______.
56. The flap of cartilage that directs food to
the esophagus and not the trachea is the
_epliglotis____.
57. Pouches of infection that form in the wall
of the colon is called
_diverticullitis_______________. This
condition can be prevented by water,
exercise and a high __fiber________
diet.
58. When an internal body part pushes into
an area where it doesn’t belong, it is
called a __hernia___________. Hiatal
hernias are found at the base of the
_esophagus______________ where it
leads into the stomach.
1. Flossing your teeth can prevent heart
disease and this dental gum disease:
___periodontal________________
disease.
1. Fruits and vegetables contain a high
amount of __water___________, so they
have a lot of volume, but not a lot of
calories.