BIOL 3442 UTA POLLOCK THE DIGESTIVE SYSTEM EXAM 3 – 200
QUESTIONS WITH COMPLETE VERIFIED SOLUTIONS
1. What is the primary composition of human saliva by percentage?
A) 90% water and 10% solutes
B) 99.5% water and 0.5% solutes
C) 80% water and 20% solutes
D) 95% water and 5% solutes
Correct Answer: B
Rationale: Saliva is predominantly water, making up 99.5% of its total
volume, with only 0.5% consisting of dissolved solutes.
2. Which of the following is NOT a typical solute found in saliva?
A) Mucus
B) Lysozyme
C) Salivary amylase
D) Pepsin
Correct Answer: D
Rationale: Pepsin is a digestive enzyme secreted by the stomach, not
the salivary glands. Saliva contains mucus, lysozyme, and salivary
amylase.
3. What is the definition of absorption in the context of the digestive
system?
A) The movement of food through the GI tract via peristalsis
B) The breakdown of large food molecules into smaller units
,C) The movement of digestion products from the GI lumen into the
blood or lymph
D) The elimination of undigested waste from the body
Correct Answer: C
Rationale: Absorption specifically refers to the transport of digested
nutrients from the lumen of the gastrointestinal tract across the
epithelial lining into the bloodstream or lymphatic system.
4. Which of the following organs is classified as an accessory digestive
organ?
A) Stomach
B) Small intestine
C) Esophagus
D) Pancreas
Correct Answer: D
Rationale: The pancreas is an accessory digestive organ. Accessory
organs include teeth, tongue, salivary glands, liver, gallbladder, and
pancreas. Food does not pass directly through them.
5. What is the function of the Ampulla of Vater?
A) It regulates the release of chyme from the stomach
B) It connects the pancreatic duct to the common bile duct
C) It is the primary site of water absorption
D) It secretes intrinsic factor for vitamin B12 absorption
Correct Answer: B
Rationale: The Ampulla of Vater is the anatomical junction where the
pancreatic duct and the common bile duct merge before emptying into
the duodenum.
,6. Where is the antrum located within the digestive system?
A) It is the upper portion of the stomach near the esophagus
B) It is the first segment of the small intestine
C) It is the lower portion of the stomach that extends from the body
D) It is the muscular sac that stores bile
Correct Answer: C
Rationale: The antrum is the lower portion of the stomach, extending
from the body and terminating at the pyloric sphincter.
7. How does the antrum of the stomach connect to the duodenum of
the small intestine?
A) Via the cardiac sphincter
B) Via the ileocecal valve
C) Via the pyloric sphincter
D) Via the sphincter of Oddi
Correct Answer: C
Rationale: The terminal end of the stomach antrum connects to the
duodenum through a ring of smooth muscle called the pyloric sphincter.
8. Which division of the nervous system controls the secretion and
composition of saliva?
A) Somatic Nervous System
B) Autonomic Nervous System
C) Central Nervous System
D) Peripheral Nervous System
Correct Answer: B
Rationale: Salivary secretion is controlled by the Autonomic Nervous
System (ANS), which regulates both the volume and composition of
saliva.
, 9. What is the primary effect of the Vagus (X) nerve on the
gastrointestinal tract?
A) It inhibits GI motility and secretion
B) It increases GI secretion and motility by increasing ENS neuron
activity
C) It controls the voluntary swallowing reflex
D) It closes the pyloric sphincter
Correct Answer: B
Rationale: The Vagus nerve supplies parasympathetic fibers to most of
the GI tract, which stimulates digestive processes by increasing GI
secretion and motility through activation of ENS neurons.
10. How does sympathetic stimulation affect the gastrointestinal
tract?
A) It stimulates the release of digestive enzymes
B) It increases blood flow to the digestive organs
C) It causes an increase in GI secretion and motility
D) It causes an opposite effect by inhibiting ENS neurons
Correct Answer: D
Rationale: Sympathetic stimulation opposes parasympathetic activity in
the GI tract. It decreases GI secretion and motility by inhibiting the
activity of ENS neurons.
11. Which enzyme found in saliva initiates the chemical digestion of
carbohydrates?
A) Pepsin
B) Trypsin
C) Salivary amylase
D) Lipase
Correct Answer: C
QUESTIONS WITH COMPLETE VERIFIED SOLUTIONS
1. What is the primary composition of human saliva by percentage?
A) 90% water and 10% solutes
B) 99.5% water and 0.5% solutes
C) 80% water and 20% solutes
D) 95% water and 5% solutes
Correct Answer: B
Rationale: Saliva is predominantly water, making up 99.5% of its total
volume, with only 0.5% consisting of dissolved solutes.
2. Which of the following is NOT a typical solute found in saliva?
A) Mucus
B) Lysozyme
C) Salivary amylase
D) Pepsin
Correct Answer: D
Rationale: Pepsin is a digestive enzyme secreted by the stomach, not
the salivary glands. Saliva contains mucus, lysozyme, and salivary
amylase.
3. What is the definition of absorption in the context of the digestive
system?
A) The movement of food through the GI tract via peristalsis
B) The breakdown of large food molecules into smaller units
,C) The movement of digestion products from the GI lumen into the
blood or lymph
D) The elimination of undigested waste from the body
Correct Answer: C
Rationale: Absorption specifically refers to the transport of digested
nutrients from the lumen of the gastrointestinal tract across the
epithelial lining into the bloodstream or lymphatic system.
4. Which of the following organs is classified as an accessory digestive
organ?
A) Stomach
B) Small intestine
C) Esophagus
D) Pancreas
Correct Answer: D
Rationale: The pancreas is an accessory digestive organ. Accessory
organs include teeth, tongue, salivary glands, liver, gallbladder, and
pancreas. Food does not pass directly through them.
5. What is the function of the Ampulla of Vater?
A) It regulates the release of chyme from the stomach
B) It connects the pancreatic duct to the common bile duct
C) It is the primary site of water absorption
D) It secretes intrinsic factor for vitamin B12 absorption
Correct Answer: B
Rationale: The Ampulla of Vater is the anatomical junction where the
pancreatic duct and the common bile duct merge before emptying into
the duodenum.
,6. Where is the antrum located within the digestive system?
A) It is the upper portion of the stomach near the esophagus
B) It is the first segment of the small intestine
C) It is the lower portion of the stomach that extends from the body
D) It is the muscular sac that stores bile
Correct Answer: C
Rationale: The antrum is the lower portion of the stomach, extending
from the body and terminating at the pyloric sphincter.
7. How does the antrum of the stomach connect to the duodenum of
the small intestine?
A) Via the cardiac sphincter
B) Via the ileocecal valve
C) Via the pyloric sphincter
D) Via the sphincter of Oddi
Correct Answer: C
Rationale: The terminal end of the stomach antrum connects to the
duodenum through a ring of smooth muscle called the pyloric sphincter.
8. Which division of the nervous system controls the secretion and
composition of saliva?
A) Somatic Nervous System
B) Autonomic Nervous System
C) Central Nervous System
D) Peripheral Nervous System
Correct Answer: B
Rationale: Salivary secretion is controlled by the Autonomic Nervous
System (ANS), which regulates both the volume and composition of
saliva.
, 9. What is the primary effect of the Vagus (X) nerve on the
gastrointestinal tract?
A) It inhibits GI motility and secretion
B) It increases GI secretion and motility by increasing ENS neuron
activity
C) It controls the voluntary swallowing reflex
D) It closes the pyloric sphincter
Correct Answer: B
Rationale: The Vagus nerve supplies parasympathetic fibers to most of
the GI tract, which stimulates digestive processes by increasing GI
secretion and motility through activation of ENS neurons.
10. How does sympathetic stimulation affect the gastrointestinal
tract?
A) It stimulates the release of digestive enzymes
B) It increases blood flow to the digestive organs
C) It causes an increase in GI secretion and motility
D) It causes an opposite effect by inhibiting ENS neurons
Correct Answer: D
Rationale: Sympathetic stimulation opposes parasympathetic activity in
the GI tract. It decreases GI secretion and motility by inhibiting the
activity of ENS neurons.
11. Which enzyme found in saliva initiates the chemical digestion of
carbohydrates?
A) Pepsin
B) Trypsin
C) Salivary amylase
D) Lipase
Correct Answer: C
