Question 1

When a person is chewing food,the concentration of ions in saliva changes with: A)A decrease in Na⁺,Cl^-,and HCO₃^-. B)A decrease in Na⁺ and Cl^- and an increase in HCO₃^-. C)A decrease in K⁺ and Na⁺. D)An increase in Na⁺,Cl^-,and HCO₃^-. E)A decrease in K⁺ and HCO₃^-.

Accepted Answer

When chewing food, the concentration of Na⁺, Cl^-, and HCO₃^- in saliva increases to aid in digestion and neutralize acids.

Question 2

A 50-year-old man complains to his primary care physician about a chronic burning sensation in his chest.The pain is worse when he lies down at night after a large meal,and it can be alleviated to some degree by the use of over-the-counter antacids.The pain experienced by the patient is probably caused by dysfunction of which of the following gastrointestinal structures?

A)Lower esophageal sphincter
B)Pylorus
C)Salivary glands
D)Pancreas
E)Gallbladder

A

Accepted Answer

The chronic burning sensation in the chest that worsens after a large meal and can be alleviated by antacids suggests gastroesophageal reflux disease (GERD), which is caused by dysfunction of the lower esophageal sphincter (LES). The pylorus controls the flow of chyme from the stomach into the small intestine, the salivary glands produce saliva to aid in digestion, the pancreas secretes digestive enzymes and hormones, and the gallbladder stores and releases bile for fat digestion, but none of these structures are directly related to GERD symptoms.

Question 3

In an experimental study,a researcher transects cranial nerve IX in a dog.In comparison with an animal with an intact cranial nerve IX,which of the following responses to the sight and smell of a meal will be reduced?

A)Pancreatic enzyme secretion
B)Relaxation of the sphincter of Oddi
C)Gastric acid secretion
D)Gastric relaxation
E)Salivation

E

Accepted Answer

Cranial nerve IX, also known as the glossopharyngeal nerve, is responsible for the sensation of taste and the initiation of salivation. Therefore, if this nerve is transected, the dog's salivation response to the sight and smell of a meal will be reduced.

Question 4

A patient is referred to a rheumatologist for treatment of an autoimmune disease.She complains of excessive dryness of her eyes and mouth.After tests,Sjögren's syndrome is diagnosed.The rheumatologist advises her that she is also at increased risk for which of the following?

A)Foodborne diarrheal diseases
B)Compression fractures
C)Hypertension
D)Tooth decay
E)Asthma

Accepted Answer

Sjögren's syndrome is an autoimmune disease that primarily affects the salivary and lacrimal glands, leading to dryness of the eyes and mouth. This dryness can increase the risk of tooth decay due to reduced saliva production and protective properties. The other options are not directly associated with Sjögren's syndrome.

Question 5

Swallowing initiates which of the following events?&#10;A)Contraction of the lower esophageal sphincter&#10;B)Relaxation of the gastric antrum&#10;C)Secondary esophageal peristalsis&#10;D)Relaxation of the pyloric sphincter&#10;E)Relaxation of the gastric cardia

Accepted Answer

Relaxation of the gastric cardia allows the bolus to enter the stomach.

Deck 28: The Cephalic, oral, and Esophageal Phases of the Integrated Response to a Meal