Key Questions
for
Understanding
the Organs of
the Digestive
System
1. What are the 2 groupings of
the digestive organs?
 The
alimentary canal
 The accessory digestive organs
2. What are the functions of
the alimentary canal?
 It
ingests and digests food, absorbs
nutrients, and defecates wastes
3. What is the descriptive
definition of the alimentary
canal?
 It
is a continuous, coiled, hollow, muscular
tube that winds through the ventral body
cavity and is open at both ends.
4. List the organs of the
alimentary canal
 Mouth
 pharynx  esophagus 
stomach small intestine  large
intestine
5. To which 2 bones does the
tongue attach…
 The
tongue attaches to the hyoid bone
and the styloid process of the skull
 The lingual frenulum secures the tongue
to the floor of the mouth and limits its
posterior movements
6. Describe the process of
mastication that takes place
in the mouth
 Food
is mixed with saliva, then the cheeks
and closed lips hold it between the teeth.
The tongue mixes food with saliva and
initiates swallowing.
7. What is the location, length,
and function of the
esophagus?
 It
runs from the pharynx to the stomach
 It is about 10 inches long
 It is essentially a passageway that
conducts food to the stomach
8. Name and briefly describe
the 4 basic tunics…
1.
2.
3.
4.
mucosa—innermost layer, mainly epithelium
Submucosa—soft connective tissue;
contains blood vessels, nerves, and lymph
vessels
Muscularis externa—made up of a circular
and longitudinal layer of smooth muscle
Serosa—outermost layer, consists of the
peritoneum and mesentary
9. What is the function of the
nerve plexuses of the
alimentary canal?
 They
help regulate the mobility and
secretions of the GI tract organs
10. What is the maximum
capacity of the stomach?
4
liters (or 1 gallon) of food
11. Why does the stomach
contain a layer of obliquely
arranged muscle?
 It
allows the stomach to churn, mix, and
pummel the food; physically breaking it
down into smaller fragments
12. How is food chemically
broken down by the
stomach?
 Gastric
juice, which consists of proteindigesting enzymes and hydrochloric acid,
is produced by the cells of the stomach
walls.
13. What is the function of the
mucous neck cells?
 They
produce a sticky alkaline mucus,
which clings to the stomach wall and
protects it from being damaged by
stomach acid and enzymes
14. What is chyme?
 The
processed food product that exits the
stomach after being partially digested in
the pyloric region.
 It looks like heavy cream.
15. Name and describe the 3
subdivisions of the small
intestine
 Duodenum—about
10 inches long, first
part of the small intestine to receive
chyme
 Jejunum—about 8 feet long, extends from
the duodenum to the ileum
 Ileum—about 12 feet long, connects to
the large intestine at the ileocecal valve
16. What is the function of the
pyloric sphincter?
 It
controls food movement into the small
intestine and prevents too much food
from entering it at one time
17. How do pancreatic
enzymes and bile enter the
small intestine?
 Pancreatic
ducts transfer enzymes from
the pancreas into the duodenum
 Bile ducts transfer bile from the liver
18. What 3 structures increase
surface area in the small
intestine?
 Microvilli
 Villi
 Circular
folds
19. What are the functions of
the large intestine?
 To
dry out the indigestible food residue by
absorbing water
 To eliminate residue from the body as
feces
20. What is the function of the
goblet cells in the large
intestine?
 Goblet
cells produce mucus, which acts
as a lubricant to ease the passage of
feces to the end of the digestive tract