Exam 3 (Ch 24)
Match the gastric phase on the left (1-3) with the correct description on the right (4-6): 1. intestinal phase 4. prepares stomach for arrival of food 2. gastric phase 5. stomach empties and decreases secretions 3. cephalic phase 6. stomach secretes juice and mixes food into chyme
1 and 5; 2 and 6; 3 and 4
Which structure controls the contraction of the muscularis externa?
10
Put the following steps of stomach acid production in the correct order starting with the reaction that requires an enzyme. 1. H2CO3 dissociates. 2. Chloride ion combines with H+ in the gastric lumen. 3. Water and CO2 combine to form carbonic acid. 4. H+ and bicarbonate ion are transported into the gastric lumen. 5. Cl- diffuses into the gastric lumen.
3, 1, 4, 5, 2
Put the following layers of the digestive tract wall in order from the lumen to the deepest layer. 1. lamina propria 4. digestive (mucous) epithelium 2. muscularis externa 5. serosa 3. submucosa 6. muscularis mucosae
4, 1, 6, 3, 2, 5
Which structure(s) help(s) the stomach to stretch as it fills with food?
9
The greater omentum is
a fatty sheet that hangs like an apron over the abdominal viscera
A drug that blocks the action of carbonic anhydrase in parietal cells would result in
a higher pH during gastric digestion
Mary had her stomach mostly removed to try to overcome obesity. As a result, you would expect Mary to be at risk for
abnormal erythropoiesis.
Functions of the stomach include all of the following except
absorption of triglycerides.
The digestive tract is also referred to as the
alimentary canal and the GI tract
Each of the following is a function of the liver except
antibody production
The part of the stomach that functions as a mixing chamber for food and secretions is the
body
An intestinal hormone that stimulates the gallbladder to release bile is
cholecystokinin
A feature of the digestive tract wall that increases surface area available for absorption is the
circular folds.
Identify the structure labeled "4."
circular muscle layer
The duodenal ampulla receives secretions from the
common bile duct and the pancreatic duct
Contraction of the muscle layer labeled "9" causes the digestive tract to
constrict
Which of the following descriptions best matches the term myenteric plexus?
coordinates activity of muscularis externa
A disease that attacks and disables the myenteric plexus would
decrease intestinal motility
Brunner glands are characteristic of the
duodenum
Submucosal glands that secrete mucus are characteristic of the
duodenum
An intestinal hormone that stimulates mucin production by the submucosal duodenal glands is
enterocrinin
The gastric phase of gastric secretion is triggered by the
entry of food into the stomach.
All of the following contain mucous cells in the epithelium except the
esophagus
Which of the following is not a function of the digestive system?
filtration
During deglutition, which of the following phases is not present?
gastric
An intestinal hormone that stimulates the release of insulin from the pancreatic islet cells is
gastric inhibitory peptide (GIP)
An intestinal hormone that stimulates gastric secretion is
gastrin
G cells of the stomach secrete
gastrin
The hormone that stimulates secretion and contraction by the stomach is
gastrin
The term "alkaline tide" implies that the pH of the blood in gastric veins is
greater during digestion of a large meal than following a 24-hour fast.
Which of the following contains adipose tissue and provides padding for the anterior and lateral portions of the abdomen?
greater omentum
The stomach is different from other digestive organs in that it
has three layers of muscle in the muscularis externa.
Parietal cells secrete
hydrochloric acid
Peyer's patches are characteristic of the
ileum
The portion of the small intestine that attaches to the cecum is the
ileum
Circular folds and intestinal villi
increase the surface area of the mucosa of the small intestine.
During the cephalic phase of gastric secretion,
increased production of gastric juice occurs.
The middle segment of the small intestine is the
jejunum
The villi are most developed in the
jejunum
The layer of loose connective tissue that directly supports the digestive epithelium is the
lamina propria
Which layer of the digestive tract has a layer of areolar tissue that surrounds the muscularis mucosae?
lamina propria
Which organ is responsible for dehydration and compaction of indigestible materials?
large intestine
What provides access for blood vessels entering and leaving the liver?
lesser omentum
Distension of the gastric wall leads to secretion of histamines from the lamina propria. This is an example of ________ response.
local
Identify the structure labeled "3."
longitudinal muscle layer
Digestion refers to the
mechanical and chemical breakdown of food.
The ________ are double sheets of peritoneal membrane that suspend the visceral organs and carry nerves, lymphatics, and blood vessels.
mesenteries
The double-layer sheets of serous membrane that support the viscera are called
mesenteries
The ________ supports all but 25 cm of the small intestine and provides stability and limited movement.
mesentery proper
The lamina propria and mucous epithelium are components of the
mucosa
The esophagus has several variations from the standard plan of the GI tract. These include
muscularis externa has some skeletal muscle.
Contraction of the ________ alters the shape of the intestinal lumen and moves epithelial pleats and folds.
muscularis mucosa
Sandwiched between the layer of circular and longitudinal muscle in the muscularis externa is the
myenteric plexus.
Identify the structure labeled "10."
oblique muscle layer
Which of the following is not a pharyngeal muscle involved in swallowing?
omohyoid
Gastric pits are
openings into gastric glands.
The exocrine portion of the pancreas is composed of
pancreatic acini
Chief cells secrete
pepsinogen
Waves of muscular contractions that propel the contents of the digestive tract are called
peristalsis
Circular folds are
pleats in the lining of the small intestine
All of the following are true of the intestinal phase of gastric digestion except that it
precedes the gastric phase.
What is the function of the structure labeled "7"?
protection from bacteria
The enzyme pepsin digests
proteins
All of the following are true of the lining of the stomach except that it
recycles bile.
What is the function of the structure labeled "6"?
regulates gastric emptying
An enzyme secreted by the gastric mucosa of a newborn that coagulates milk proteins is
rennin
The intestinal hormone that stimulates the pancreas to release a watery, bicarbonate-rich fluid is
secretin
Which of the following descriptions best matches the term submucosal plexus?
sensory neural network
What type of epithelium covers the structure labeled "6"?
simple columnar
The stomach secretes the hormone ghrelin which functions to
stimulate hunger.
Which of the following descriptions best matches the term gastrin?
stimulates gastric secretion
The oral mucosa has ________ epithelium.
stratified squamous
The epithelium lining the oropharynx is
stratified squamous.
Large blood vessels and lymphatics are found in
submucosa
What is the layer labeled "3"?
submucosa
Sensory nerve cells, parasympathetic ganglia, and sympathetic postganglionic fibers can be found in the
submucosal plexus.
Muscles known as the pharyngeal constrictors function in
swallowing