1. Lecture Outline: Digestive System (Chapter 22)
*Important Note about the Digestive System: Always remember that anatomically, the inside of the
digestive tract (and the respiratory, urinary and reproductive tracts) is considered to be the outside of
the body. Think of yourself as being like a bead. The hole through the bead represents the digestive
tract going from one end of the body to the other.
1. Functions of the Digestive System as a Whole
Explain what is meant by these
a. Ingestion of materials into the digestive system
b. Mechanical Processing of the materials
c. Digestion: Chemical breakdown of large food molecules into smaller ones.
d. Secretion: of enzymes and other materials to aid digestion and mechanical breakdown of food
Where does this happen? Hint: There may be more than one place
e. Absorption: The movement of materials from the digestive tract into the interstitial fluid Where
does this happen? Hint: There may be more than one place
f. Excretion: elimination of waste products from the body
2. For an overview of the Digestive System, See the following Figure in your text: Components of the
Digestive System Trace the path that food would follow as it moves through the Digestive System.
Which organs does the food actually travel through, and which organs are involved in Digestion, but
food does not pass directly through them.
Individual Digestive Organs Oral Cavity See the following Figure in your text: The Oral Cavity
a. Vestibule

2. b. Gingivae
c. Labia
d. Tongue Salivary Glands See the following Figure in your text: The Salivary Glands Pharynx How
would you distinguish the Pharynx from the Larynx, the Esophagus or the Trachea?
Esophagus How would you distinguish the Esophagus from the Larynx, the Pharynx, or the Trachea?
Esophageal Hiatus What is this? Stomach See the following Figure in your text: The Stomach Areas of
the Stomach: Where is each located?
a. Cardia
b. Fundus
c. Body
d. Pylorus
e. Rugae
f. Pyloric Sphincter What does this do?
Histology of the Stomach What substances do each of these types of cells secrete?

3. Parietal Cells
Chief Cells
Endocrine Cells
Goblet Cells
Small Intestine See the following Figure in your text: The Intestinal Wall. What are each of these, and
what do they secrete or absorb?
a. Duodenum
b. Jejunum
c. Ileum
d. Plica
e. Villi
f. Lacteals
g. Mesenteries

4. Large Intestine See the following Figure in your text: The Large Intestine What are each of these, and
what do they secrete or absorb?
a. Ileocecal Valve
b. Ascending Colon
c. Transverse Colon
d. Descending Colon
e. Sigmoid Colon
f. Rectum
g. Anus
3. Accessory Organs of the Digestive System How are Accessory organs different from the other organs
of the digestive system?
Pancreas What are the functions of this organ / gland? Where is it located?
Why is the pancreas considered both an exocrine and an endocrine gland?
Pancreatic Juice:

5. Enzymes of the Pancreas: What do each of these enzymes do?
Pancreatic Alpha-Amylase
Pancreatic Lipase
Nucleases
ProteolyticEnzymes Liver Describe the importance of the Liver
Three General Functions
1. Metabolic Regulation
a.
b.
c.
d.
e.
f.

6. g.
2. Hematological Regulation
a.
b.
c.
d.
e.
3. Bile Production
Emulsification Gallbladder Where is this organ located, and what is its function?
1.
2.
Common Bile Duct
Hepatic Duct

7. Cystic Duct
4. Substances and Processes of the Digestive System What are these and where would you find them?
Chyme:
Intestinal Juice:
Gastroenteric Reflex:
Gastroileal Reflex:
Mass Movements:
Defecation Reflex: What is the difference between secretion and excretion?