Digestive system

Question 1

3 During the intestinal phase of gastric regulation,

A. hormones reduce chief cell activity.
B. secretin causes more HCl release.
C. the enterogastric reflex is turned off.
D. the stomach is initially stimulated, and later inhibited.
E. the gastroenteric reflex reduces stomach activity.

Answer 1

D. the stomach is initially stimulated, and later inhibited.

During this time intestinal gastrin is released until the duodenum distends.

Question 2

4 Protective collections of lymphocytes and macrophages occur in

  	the muscularis mucosae.
  	the gastric pits.
  	the intestinal crypts.
  	the Peyer's patches.
  	the muscularis externa.

Answer 2

the Peyer’s patches.

These structures increase in numbers toward the end of the ileum.

Question 3

5 Starch is chemically digested by enzymes produced in the

  	salivary glands and stomach.
  	intestine and stomach.
  	pancreas and stomach.
  	mouth and stomach.
  	salivary glands and pancreas.

Answer 3

salivary glands and pancreas.

Amylase breaks starch into smaller oligosaccharides.
6.

Question 4

6 Swallowing reflexes begin when receptors are stimulated by food in this structure.

  	Oral cavity
  	Pharynx
  	Esophagus
  	Teeth
  	Stomach

Answer 4

Pharynx

Stretch receptors in the throat trigger the involuntary phases of deglutition.

Question 5

The function of a lacteal is to

  	produce enzymes.
  	absorb amino acids.
  	regulate muscle contraction.
  	absorb carbohydrates.
  	absorb lipids.

Answer 5

absorb lipids.

Lacteals are lymph capillaries found in the villus.

Question 6

What is the main organic molecule digested in the stomach?

  	Sugars
  	Lipids
  	Proteins
  	Carbohydrates
  	Nucleic acids

Answer 6

Proteins

The only significant enzyme in the stomach is pepsin.

Question 7

The propulsive function that occurs in the esophagus is called

  	peristalsis.
  	defecation.
  	segmentation.
  	ingestion.
  	swallowing.

Answer 7

peristalsis.

This occurs as a wave of contraction.

Question 8

This structure is a modified portion of the small intestine mucosa that greatly increases the absorptive surface area.

  	Villus
  	Lacteal
  	Lumen
  	Microvillus
  	Circular fold

Answer 8

Villus

They are finger-like projections

Question 9

Which activity below is a mixing action that exposes materials to secretions and absorptive surfaces?

  	Vagovagal reflexes
  	Peristalsis
  	Enteroendocrine reflex
  	Deglutition
  	Segmentation

Answer 9

Segmentation

This is a mechanical digestive activity.

Question 10

The final product of carbohydrate digestion is

monosaccharides.
glycogen.
disaccharides.
polysaccharides.

Answer 10

monosaccharides.

All macromolecules are broken down to their monomers EXCEPT fatty acids

Question 11

Most absorption takes place in the ______.

  	ileum
  	duodenum
  	stomach
  	jejunum
  	large intestine

Answer 11

jejunum

The jejunum absorbs 80-90% of all nutrients.