Lecture 8: Digestive System

Question 1

Which of the following statements concerning zymogens is FALSE?

a. They are secreted by the exocrine cells of the pancreas and by chief cells in the stomach.
b. They exist as a protein containing a proenzyme segment that has to be cleaved off in order to function.
c. They are a class of enzymes that do most of the digestion of macromolecules in the stomach and intestine.
d. They are secreted by exocrine cells of the pancreas and by parietal cells in the stomach.

Answer 1

d. They are secreted by exocrine cells of the pancreas and by parietal cells in the stomach.

Question 2

The esophagus has several variations from the standard plan of the gut tube. These include:

a. the lamina propria is dense regular CT.
b. epithelium of mucosa is simple columnar.
c. muscularis externa may be skeletal muscle.
d. epithelium of the mucosa is stratified squamous and simple columnar.

Answer 2

c. muscularis externa may be skeletal muscle.

Question 3

The ________ are double sheets of peritoneal membrane that suspend the visceral organs and carry nerves, lymphatics, and blood vessels.

a. serosas
b. adventitias
c. mesenteries
d. lamina proprias

Answer 3

c. mesenteries

Question 4

The stomach is different from other digestive organs in that it

a. has folds in the mucosa.
b. has three layers of muscle in the muscularis externa.
c. secretes digestive juice.
d. moves by peristalsis.

Answer 4

b. has three layers of muscle in the muscularis externa.

Question 5

The villi are most developed in the:

a. stomach.
b. duodenum.
c. jejunum.
d. colon.

Answer 5

c. jejunum.

Question 6

The villi are most developed in the:

a. stomach.
b. duodenum.
c. jejunum.
d. colon.

Answer 6

c. jejunum.

Question 7

In a liver lobule:

a. the hepatic portal vein and hepatic artery drain via the central vein, and the bile canaliculi and lymphatics leave via the porta hepatis
b. the hepatic portal vein and lymphatics drain via the central vein, and the bile canaliculi and hepatic portal vein leave via the porta hepatis
c. only the hepatic portal vein drains via the central vein, and only the bile canaliculi leaves via the porta hepatis
d. only the hepatic artery drains via the central vein, and only the lymphatics leaves via the porta hepatis

Answer 7

a. the hepatic portal vein and hepatic artery drain via the central vein, and the bile canaliculi and lymphatics leave via the porta hepatis

Question 8

In a liver lobule:

a. the hepatic portal vein and hepatic artery drain via the central vein, and the bile canaliculi and lymphatics leave via the porta hepatis
b. the hepatic portal vein and lymphatics drain via the central vein, and the bile canaliculi and hepatic portal vein leave via the porta hepatis
c. only the hepatic portal vein drains via the central vein, and only the bile canaliculi leaves via the porta hepatis
d. only the hepatic artery drains via the central vein, and only the lymphatics leaves via the porta hepatis

Answer 8

a. the hepatic portal vein and hepatic artery drain via the central vein, and the bile canaliculi and lymphatics leave via the porta hepatis

Question 9

The taenia coli are:

a. tears of the colon.
b. longitudinal bands of smooth muscle in the colon wall.
c. ridges in the mucosa of the colon.
d. polyps that obstruct the sigmoid colon.

Answer 9

b. longitudinal bands of smooth muscle in the colon wall.

Question 10

Waves of muscular contractions that propel the contents of the digestive tract are called

a. segmentation.
b. pendular movements.
c. peristalsis.
d. mastication.

Answer 10

c. peristalsis.