Chapter 23 The Digestive System Flashcards
wavelike smooth muscle contractions that move foodstuffs through the alimentary tube.
peristalsis
chemical or mechanical process of breaking down foodstuffs into simpler units
digestion
enzymatic breakdown of any type of food molecule
hydrolysis
process by which simpler chemical units pass through the lumen of the gastrointestinal tract
absorption
increases output of enzymatic rich pancreatic juice
cholecystokinin
increases output of pancreatic juice rich in bicarbonate ions
secretin
increases Hcl secretion and stimulates contraction of intestinal muscle
gastrin
stimulates insulin release and mildly inhibits HCl production
gastric inhibitory peptide
The relatively unchanging pressure in a filling stomach is due to the contraction of the stomach oblique muscle layer. False, why?
False, why.
The pharyngeal-esophageal phase of swallowing is involuntary and is controlled by the swallowing center in the thalamus and lower pons. False, why?
medulla oblongata and pons
Pepsinogen is the precursor to the gastric enzyme for protein digestions and is secreted by the parietal cells. False, why?
secreted by gastric chief cells
The only essential function of the stomach is to begin the digestion of proteins. False, why?
One function*
Peyer’s patches are primarily found in the submucosa of the duodenum. False, why?
mucosa and submucosa of ileum
The submucosal nerve plexus provides the major nerve supply to the GI tract wall and controls GI mobility. False, why?
enteric nervous system
Dentin anchors the tooth in place. False, why?
periodontal ligament
The digestive function of the liver is to produce digestive enyzmes. False, why?
is to process the nutrients absorbed from small intestine
The stomach’s contractile rhythm is set by pacemaker cells found in the spinal cord. False, why?
found in greater curvature region of fundus
The soft palate reflexively opens the nasopharynx to allow the passage of food, which is now called a bolus. False, why?
soft palate rises to prevent food from entering nose
When swallowing, the glottis covers the epiglottis. False, why?
covers the larynx
Most gastric ulcers are due to excessive production oh hydrochloric acid. False, why?
due to h pylori bacteria
The enterohepatic circulation reabsorbs bile salts in the distal portion of the small intestine (ileum). All of the following statements about the enterohepatic circulation are true except one. Select the statement below that is not true of the enterohepatic circulation?
all of the components of bile are recycled in this circulation
Which of the following is the best illustration of the difference between metabolism and digestion?
Metabolism comprises all of the chemical reactions preformed with in the body while digestion is only the breakdown of food within the G.I. Tract.
Which of the following is least involved in the mechanical breakdown of food, digestion or absorption of nutrients?
esophagus
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 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.
Which of the following would likely be absorbed in the stomach?
a serving of alcohol
Bile salts break up the fat globule into smaller fat droplets. This role of bile salts is best described as ________.
lipid emulsification
A doctor consulting a patient that recently has had their gallbladder removed would most likely advise ______.
eating foods that are low in fat
A ruptured appendix is life threatening because _________.
it is likely to cause massive infection of the abdominopelvic cavity
All but one of the following is a function of the low pH found in the stomach. Select the description below that does NOT reflect a role of stomach acid.
The stomach’s acid catabolically breaks down food stuffs in preparation for absorption.
Fat absorption through the plasma membrane of epithelial cells _______.
occurs by simple diffusion because lipids are able to penetrate the hydrophobic fatty acid tails within the plasma membrane
Select the best explanation for why protease enzymes are secreted in inactive forms
The cells producing inactive enzymes are themselves protected from enzymes until they are safely within the lumen of the GI tract
Select the description below that illustrates a difference between a sphincter and circular muscle.
A sphincter is a thickening of circular muscle that can prevent the movement of digesting materials while circular muscle is involved in propulsion digesting material.
In the enteric nervous system, a long reflexive pathway has an advantage over a short reflexive pathway in the fact that ________.
long reflexive pathways can be stimulated by things outside of the GI tract
The sight of food can trigger a series of events that results in the release of gastric juice. All but one of the following is true in regards to the previous statement. Select the one answer that is not true.
The motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system.
All of the following are true of swallowing (deglutition) except one. Select the statement that is not true of swallowing.
The epiglottis assists in propelling food into the trachea.
Some antacid drugs block histamine receptors, resulting in reduction of the production and excretion of stomach acid. These drugs have the biggest effect on which of the following?
parietal cells
All of the following are true of swallowing except one. Select the statement that is not true of swallowing.
the epiglottis assists in propelling food into trachea.
Which of the following is NOT a function of CCK?
increase production of stomach acid
Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________.
slow the activities of the stomach
Select the one response below that would not result from a drug that blocks histamine receptors in the cells lining the stomach.
It would cause the release of secretin and cholecystokinin.
Specific enteroendocrine cells of the stomach, called G cells, are stimulated by partially digested proteins, caffeine, and rising pH. When stimulated, G cells secrete ______.
hydrochloric acid
The mechanical and chemical receptors that control digestive activity are located ________.
in the walls of the tract organs
The function of the hepatic portal circulation is to ________.
collect absorbed nutrients for metabolic processing in the liver
The chemical and mechanical processes of food breakdown are called ________.
digestion
When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________.
chemical digestion
The sheets of peritoneal membrane that hold the digestive tract in place are called ________.
mesenteries