BIOS 256 Lower Digestive System Questions & Answers with Rationales

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