BIOS 256 Lower Digestive System
Questions & Answers with Rationales
Subject: Anatomy & Physiology / Digestive System
Source: Assessment / Quiz Questions
Format: Multiple-Choice, Matching, and Select-All-That-Apply Q&A
1. Which type of motility involves smooth muscle activity to
slowly propel food through the gastrointestinal (GI) tract?
A. Flexion
B. Mass movement
C. Retropulsion
D. Vomiting
E. Peristalsis
Correct Answer: E (Peristalsis)
Rationale:
1. Peristalsis is the primary, slow, wave-like contraction of smooth
muscle in the GI tract wall that propels contents forward.
,2. Mass movement is a rapid peristaltic wave in the colon, not a slow
propulsion throughout the entire GI tract.
3. Flexion is a joint movement. Retropulsion is a backward movement of
food in the stomach during mixing. Vomiting is the forceful expulsion
of stomach contents.
2. Why is the colon referred to as the large intestine?
A. The diameter of the colon is larger than that of the small intestine.
B. The colon absorbs the most nutrients.
C. The colon has the largest number of nerve endings in the digestive
system.
D. The colon is the longest portion of the gastrointestinal tract.
E. The colon is the heaviest organ in the body.
Correct Answer: A (The diameter of the colon is larger than that
of the small intestine.)
Rationale:
1. The colon is named for its larger diameter (lumen) compared to the
small intestine.
2. The small intestine is longer and is the primary site for nutrient
absorption. The liver is the heaviest internal organ.
3. Where does most digestion take place in the digestive tract?
A. Small intestine
, B. Stomach
C. Liver
D. Large intestine
E. Oral cavity
Correct Answer: A (Small intestine)
Rationale:
1. While digestion begins in the mouth and stomach, the small
intestine is the primary site for the completion of chemical digestion
(via pancreatic enzymes and brush border enzymes) and the vast
majority of nutrient absorption.
2. The liver is an accessory organ that produces bile but is not a site of
digestion. The large intestine primarily absorbs water and
electrolytes.
4. Drag and drop each description into its corresponding region of
the small intestine. Areas may have more than one description.
Duodenum: First region of the small intestine; Emulsification of
lipids
Jejunum: Majority of digestion and absorption; Middle region of the
small intestine
Ileum: Attached to the large intestine; Final region of the small
intestine
, 5. Match each modification of the small intestine to its
appropriate description.
Circular folds: Transverse spiral ridges within the mucosal and
submucosal layers of the small intestine
Villi: Projections that contain absorptive and goblet cells
Microvilli: Projections that secrete brush border enzymes into the
small intestine
6. Drag and drop to place the structures of the large intestine in
the correct order of flow of waste product beginning nearest to the
small intestine towards the rectum.
1. Cecum
2. Ascending colon
3. Right colic flexure
4. Transverse colon
5. Left colic flexure
6. Descending colon
7. Sigmoid colon
7. Which nervous system subdivision is responsible for the
defecation reflex?
A. Parasympathetic nervous system
B. Lumbar plexus
Questions & Answers with Rationales
Subject: Anatomy & Physiology / Digestive System
Source: Assessment / Quiz Questions
Format: Multiple-Choice, Matching, and Select-All-That-Apply Q&A
1. Which type of motility involves smooth muscle activity to
slowly propel food through the gastrointestinal (GI) tract?
A. Flexion
B. Mass movement
C. Retropulsion
D. Vomiting
E. Peristalsis
Correct Answer: E (Peristalsis)
Rationale:
1. Peristalsis is the primary, slow, wave-like contraction of smooth
muscle in the GI tract wall that propels contents forward.
,2. Mass movement is a rapid peristaltic wave in the colon, not a slow
propulsion throughout the entire GI tract.
3. Flexion is a joint movement. Retropulsion is a backward movement of
food in the stomach during mixing. Vomiting is the forceful expulsion
of stomach contents.
2. Why is the colon referred to as the large intestine?
A. The diameter of the colon is larger than that of the small intestine.
B. The colon absorbs the most nutrients.
C. The colon has the largest number of nerve endings in the digestive
system.
D. The colon is the longest portion of the gastrointestinal tract.
E. The colon is the heaviest organ in the body.
Correct Answer: A (The diameter of the colon is larger than that
of the small intestine.)
Rationale:
1. The colon is named for its larger diameter (lumen) compared to the
small intestine.
2. The small intestine is longer and is the primary site for nutrient
absorption. The liver is the heaviest internal organ.
3. Where does most digestion take place in the digestive tract?
A. Small intestine
, B. Stomach
C. Liver
D. Large intestine
E. Oral cavity
Correct Answer: A (Small intestine)
Rationale:
1. While digestion begins in the mouth and stomach, the small
intestine is the primary site for the completion of chemical digestion
(via pancreatic enzymes and brush border enzymes) and the vast
majority of nutrient absorption.
2. The liver is an accessory organ that produces bile but is not a site of
digestion. The large intestine primarily absorbs water and
electrolytes.
4. Drag and drop each description into its corresponding region of
the small intestine. Areas may have more than one description.
Duodenum: First region of the small intestine; Emulsification of
lipids
Jejunum: Majority of digestion and absorption; Middle region of the
small intestine
Ileum: Attached to the large intestine; Final region of the small
intestine
, 5. Match each modification of the small intestine to its
appropriate description.
Circular folds: Transverse spiral ridges within the mucosal and
submucosal layers of the small intestine
Villi: Projections that contain absorptive and goblet cells
Microvilli: Projections that secrete brush border enzymes into the
small intestine
6. Drag and drop to place the structures of the large intestine in
the correct order of flow of waste product beginning nearest to the
small intestine towards the rectum.
1. Cecum
2. Ascending colon
3. Right colic flexure
4. Transverse colon
5. Left colic flexure
6. Descending colon
7. Sigmoid colon
7. Which nervous system subdivision is responsible for the
defecation reflex?
A. Parasympathetic nervous system
B. Lumbar plexus
