Question 1

Which of the following actions constitutes the voluntary stage of swallowing?

Accepted Answer

The voluntary stage of swallowing involves the conscious effort to move the bolus from the mouth into the pharynx, which is achieved by the action of the tongue.

Question 2

Which enzyme breaks down dietary triglycerides in the stomach?

Accepted Answer

Lingual lipase is the enzyme that breaks down some dietary triglycerides in the stomach, specifically those found in milk fat.

Question 3

The soupy liquid obtained as a result of repeated propulsion and retropulsion is called _____.

Accepted Answer

The answer of The soupy liquid obtained as a result...

Question 4

Identify the ion that the proton pump transports into the parietal cells.

Accepted Answer

The proton pump (H+/K+ ATPase) in parietal cells transports K+ ions into the cells in exchange for H+ ions being pumped out into the stomach lumen.

Question 5

The secretion of saliva is stimulated by the action potentials returning from the superior and inferior salivatory nuclei along parasympathetic fibers of the

Accepted Answer

The facial and glossopharyngeal nerves are part of the parasympathetic division of the autonomic nervous system and carry fibers from the superior and inferior salivatory nuclei, respectively. These fibers stimulate the secretion of saliva.

Question 6

The cells in the stomach that produce the intrinsic factor needed for absorption of vitamin B12 are

Accepted Answer

Parietal cells in the stomach produce intrinsic factor, which is necessary for the absorption of vitamin B12 in the small intestine.

Question 7

Identify the labeled regions of the stomach where gastric emptying occurs?

Accepted Answer

The answer of Identify the labeled regions of the stomach...

Question 8

How does mastication help in the digestion process?

Accepted Answer

Mastication reduces food to a soft, flexible, and easily swallowed mass, which facilitates further digestion in the stomach and small intestine.

Question 9

The presence of which layer of the muscularis externa enhances gastric motility in the stomach?

Accepted Answer

The oblique layer, unique to the stomach, enhances gastric motility by contributing to the churning and mixing actions necessary for digestion.

Question 10

Which enzyme is inactivated when chyme mixes with acidic gastric juice?

Accepted Answer

Salivary amylase is inactivated by the acidic environment of the stomach, which is created when chyme mixes with gastric juice.

Question 11

Imagine that you have just finished a meal. A few minutes later, you regurgitate everything you had eaten. In addition to this, you experience a burning sensation near your heart. Which is a likely explanation for your symptoms?

Accepted Answer

The regurgitation of food and burning sensation near the heart are classic symptoms of gastroesophageal reflux disease, where stomach acid backflows into the esophagus causing irritation and discomfort. Pulmonary edema, chronic obstructive pulmonary disease, an aneurysm, and cardiogenic shock would not typically present with these specific symptoms.

Question 12

Identify the function of the epiglottis in coordination with organs A and B in the image.  v

Accepted Answer

The epiglottis is a flap of tissue that covers the trachea during swallowing, preventing food and liquid from entering the lungs (organ A) and directing it to the esophagus (organ B). Therefore, it prevents the passage of food from organ A to organ B.

Question 13

Which cells are primarily concerned with the secretion of pepsinogen and gastric lipase?

Accepted Answer

Chief cells are primarily responsible for secreting pepsinogen and gastric lipase into the stomach. Pepsinogen is a precursor to the enzyme pepsin, which breaks down proteins, while gastric lipase plays a role in digesting fats. Parietal cells secrete hydrochloric acid, and mucous neck cells secrete mucus to protect the stomach lining. Surface mucous cells secrete a thick layer of mucus to protect the stomach from the acidic environment. Mast cells are a type of immune cell that releases histamine and other chemicals in response to allergens or injury.

Question 14

Identify the statement that correctly describes premolars.

Accepted Answer

Premolars are two-cusped teeth that are used for crushing and grinding food.

Question 15

_____, or swallowing, is the movement of food from the mouth into the stomach.

Accepted Answer

The answer of _____, or swallowing, is the movement of...

Question 16

Identify a step involved in the esophageal stage of swallowing.

Accepted Answer

Peristalsis is a series of muscle contractions that move the bolus down the esophagus and into the stomach. This is a crucial step in the esophageal stage of swallowing.

Question 17

What is most likely to happen if the parts labeled A in the image fail to relax?

Accepted Answer

The answer of What is most likely to happen if...

Question 18

Retropulsion occurs because

Accepted Answer

Most food particles in the stomach initially are too large to fit through the narrow pyloric sphincter.

Question 19

The _____ _____ extends and develops into the upper esophageal sphincter (UES) and the lower esophageal sphincter (LES).

Accepted Answer

The answer of The _____ _____ extends and develops into...

Question 20

Propulsion is the movement of gastric contents from the body of the stomach to the antrum. This movement is brought about by

Accepted Answer

Peristalsis is the series of coordinated muscle contractions that move the chyme (combination of food and digestive juices) down the gastrointestinal tract. In the case of the stomach, peristalsis is responsible for moving the gastric contents from the body of the stomach to the antrum, where further mixing and digestion occurs. Elastic recoil and diffusion are not mechanisms involved in propulsion in the digestive system. Opsonization is a process involving the coating of foreign substances with immune proteins to enhance their recognition and destruction by immune cells, and is not involved in digestion or propulsion. Segmentation is a type of movement of the small intestine that involves the mixing of chyme with digestive enzymes, rather than propulsion.

Quiz 21: The Digestive System