chapter 23

A ruptured appendix is life threatening because ________.

•  

  it is likely to cause severe internal bleeding

  
  

•  

  it is likely to cause massive infection of the abdominopelvic cavity

  
  

•  

  the large intestine will no longer be able to receive digested material from the small intestine

  
  

•  

  loss of the appendix's function will cause an immune deficiency in the digestive system

  
  

Bile salts break up the fat globule into smaller fat droplets. This role of bile salts is best described as ________.

•  

  lipid ingestion

  
  

•  

  lipid absorption

  
  

•  

  lipid digestion

  
  

•  

  lipid emulsification

  
  

Most nutrients are absorbed through the mucosa of the intestinal villi by active transport.

•  

  True

  
  

• False

The major means of propulsion through the alimentary canal is peristalsis.

• True

• False

Food often contains bacteria, but the HCl of the stomach is effective in killing most ingested microbes.

• True

• False

From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.

•  

  muscularis externa, serosa, mucosa, and submucosa

  
  

•  

  submucosa, serosa, muscularis externa, and mucosa

  
  

•  

  mucosa, submucosa, muscularis externa, and serosa

  
  

•  

  serosa, mucosa, submucosa, and muscularis externa

  
  

The tube that leaves the stomach (and is the first part of the small intestine) is called the ________.

•  

  jejunum

  
  

•  

  duodenum

  
  

•  

  ileum

  
  

• cecum

Peristaltic waves are ________.

•  

  pendular movements of the gastrointestinal tract

  
  

•  

  waves of muscular contractions that propel contents from one point to another

  
  

•  

  segmental regions of the gastrointestinal tract

  
  

•  

  churning movements of the gastrointestinal tract that aid in mechanical breakdown of chyme

  
  

Select the best explanation for why protease enzymes are secreted in inactive forms.

•  

  The immunoglobulins protecting the digestive tract would be digested without proper regulation of protein digesting enzymes.

  
  

•  

  The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract.

  
  

•  

  Inactive enzymes will simply be expelled with the feces if no protein is present in the digesting food; this will help to conserve energy.

  
  

•  

  The enzymes would digest each other if they were not properly regulated.

  
  

Which of the following is the best explanation of the benefit in the digestive system having the largest collection of lymphoid tissue (MALT) at the distal end of the small intestine?

•  

  The body will actively excrete pathogens out of the body, into the digestive system, to be removed from the body in feces.

  
  

•  

  The alkaline secretions of the small intestine aid in the growth of bacteria and these bacteria must be controlled.

  
  

•  

  The digestive systems first and foremost job is to digest and absorb nutrients so it puts off immunity for last.

  
  

•  

  The huge numbers of bacteria living in the large intestine must be prevented from entering the lumen of the small intestine and being absorbed with food's nutrients into the blood stream.