Question 1

What are rugae?

Accepted Answer

Rugae are folds in the stomach that can flatten to expand the stomach volume. They allow the stomach to stretch to accommodate food and drink.

Question 2

A person is considered obese if their body fat composition is what percentage above normal?

Accepted Answer

A person is considered obese if their body fat composition is 20% or more above the normal range.

Question 3

Which of the following increases gastric motility?

Accepted Answer

Distension of the stomach stimulates gastric motility through the activation of stretch receptors, which enhance the activity of the enteric nervous system and increase the release of gastrin.

Question 4

Pancreatic lipase degrades triglycerides into a

Accepted Answer

Pancreatic lipase breaks down triglycerides into one monoglyceride and two free fatty acids.

Question 5

What layer of the gastrointestinal wall is a thick layer of connective tissue that provides the gastrointestinal tract with much of its elasticity and distensibility?

Accepted Answer

The submucosa is a thick layer of connective tissue that provides the gastrointestinal tract with elasticity and distensibility, allowing it to stretch and accommodate varying amounts of content.

Question 6

What sphincter is composed of smooth muscle between the anus and external environment?

Accepted Answer

The internal anal sphincter is composed of smooth muscle and is located between the anus and the external environment, controlling involuntary defecation.

Question 7

The central component of the long reflex pathway typically involves the nervous system, which acts to promote an increase in gastrointestinal activity.

Accepted Answer

The parasympathetic nervous system is responsible for promoting increased gastrointestinal activity as part of the long reflex pathway.

Question 8

What is a mass movement?

Accepted Answer

Mass movements are strong peristaltic-like waves in the large intestine that propel the contents toward the rectum.

Question 9

Which hormone primarily simulates pancreatic bicarbonate secretion (and enzyme secretion, to a lesser extent)?

Accepted Answer

Secretin is the hormone that primarily stimulates the pancreas to secrete bicarbonate, which helps neutralize stomach acid in the small intestine.

Question 10

What are liver sinusoids?

Accepted Answer

Liver sinusoids are blood-filled cavities that allow for the exchange of materials between the blood and hepatocytes, the liver cells.

Question 11

Where does peristalsis occur?

Accepted Answer

Peristalsis occurs in the esophagus, stomach, and small intestine. It is the coordinated contraction and relaxation of the smooth muscle in these organs that propels food and fluids through the digestive system.

Question 12

Carbonic anhydrase is located in which of the following digestive structures?

Accepted Answer

The answer of Carbonic anhydrase is located in which of...

Question 13

What is the function of segmentation in the small intestines?

Accepted Answer

Segmentation in the small intestines primarily serves to mix the chyme with digestive juices and increase contact with the intestinal walls for nutrient absorption.

Question 14

What protects the stomach wall from the acidic lumenal contents?

Accepted Answer

The gastric mucosal barrier is a protective mechanism that prevents the stomach wall from being damaged by the acidic environment. It consists of a thick layer of mucus and bicarbonate that neutralizes acid and protects the epithelial cells.

Question 15

Once the chyme begins to enter the duodenum, it must first be before any of the enzymes in the pancreatic juices can be activated.

Accepted Answer

The chyme must be deacidified (neutralized) by bicarbonate ions in the pancreatic juices to create an optimal pH environment for the activation of pancreatic enzymes.

Question 16

Which of the following structures is continuous with the mesenteries?

Accepted Answer

The serosa is the outermost layer of the gastrointestinal tract and is continuous with the mesenteries, which are folds of the peritoneum that support the intestines.

Question 17

Which sphincter is composed of skeletal muscle between the pharynx and esophagus?

Accepted Answer

The upper esophageal sphincter is composed of skeletal muscle and is located between the pharynx and esophagus, controlling the passage of food into the esophagus.

Question 18

What enzyme is responsible for cleavage of the amino acid at the amine portion of the peptide fragment?

Accepted Answer

Aminopeptidase is the enzyme responsible for cleaving amino acids from the amine (N-terminal) end of a peptide fragment.

Question 19

In order to convert amino acids to gluconeogenic precursors, their ammonium ion must be removed in the liver, which is then converted to what substance, thereby making it water soluble enough to be excreted by the kidneys?

Accepted Answer

The liver converts ammonium ions to urea, which is water-soluble and can be excreted by the kidneys.

Question 20

What contains the muscularis mucosae?

Accepted Answer

The muscularis mucosae is a thin layer of muscle found within the mucosa layer of the gastrointestinal tract.

Quiz 20: The Gastrointestinal System