Chapter 23
The deciduous dentition consists of __________ teeth. 10 16 20 32
20
How many total permanent teeth should an adult have, assuming none have been lost or removed? 8 16 20 32
32
Select the description below that illustrates a difference between a sphincter and circular muscle. Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract. A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue. Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions. 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.
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.
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? The reabsorption of bile salts allows them to be reused within new bile. Reabsorbing bile salts in the ileum gives more time to emulsify lipid and aid in their absorption within a greater length of the small intestine. All of the components of bile are recycled by this circulation. Reabsorption of bile salts reduces the need to synthesize new bile salts.
All of the components of bile are recycled by this circulation.
Before and during vomiting, the emetic center initiates motor responses that involve ______. sympathetic neurons parasympathetic neurons the somatic nervous system All of the listed responses are correct.
All of the listed responses are correct.
Choose the incorrect statement regarding bile. Bile functions to carry bilirubin formed from breakdown of worn-out RBCs. Bile contains enzymes for digestion. Bile functions to emulsify fats. Bile is both an excretory product and a digestive secretion.
Bile contains enzymes for digestion.
The ingestion of a meal high in fat content would cause which of the following to occur? The acid secretions from the stomach would be sufficient to digest this food but may cause heartburn. Increased production of trypsinogen. This type of food would cause secretion of gastrin to cease, resulting in faster gastric emptying. Bile would be released from the gallbladder to emulsify the fat in the duodenum.
Bile would be released from the gallbladder to emulsify the fat in the duodenum.
__________ can result if food passes too slowly through the large intestine. Constipation Diarrhea Colitis Irritable bowel syndrome
Constipation
What type of blood capillary located in this sublayer is uniquely suited for absorption of nutrient material? Sinusoidal Continuous Fenestrated Lacteals
Fenestrated
Select the correct statement about the regulation of gastric secretion. Vagus stimulation of the stomach results in decreased secretion of gastric juice. The presence of food in the stomach prevents hormonal control of gastric secretion. Gastric secretion can be stimulated before food has entered the mouth. Gastric secretion is enhanced by very low pH (below a pH of 2).
Gastric secretion can be stimulated before food has entered the mouth.
Which of the following is the best illustration of the difference between metabolism and digestion? Digestions must happen first for metabolism to follow it. Digestion requires enzymes for it to take place while metabolism does not necessarily need or use them. Metabolism comprises all of the chemical reactions preformed within the body while digestion is only the breakdown of food within the GI tract. Digestion has a wide variety of chemical reactions while metabolism is restricted to only a few reaction types.
Metabolism comprises all of the chemical reactions preformed within the body while digestion is only the breakdown of food within the GI tract.
Which of the following is NOT a function of saliva? Saliva contains enzymes that begin the chemical breakdown of proteins. Saliva cleanses the mouth. Saliva dissolves food chemicals so that they can be tasted. Saliva moistens food and helps compact it into a bolus.
Saliva contains enzymes that begin the chemical breakdown of proteins.
Which of the following best describes the capillary wall structure found in the liver lobules? The capillary walls have openings that allow large proteins and small cells to pass through. The capillary walls only allow water to pass through. The capillary walls have openings that allow small proteins to pass through but not cells. The capillary walls are continuous, only allowing small molecules and water to pass through.
The capillary walls have openings that allow large proteins and small cells to pass through.
Select the best explanation for why protease enzymes are secreted in inactive forms. 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 immunoglobulins protecting the digestive tract would be digested without proper regulation of protein digesting enzymes. The enzymes would digest each other if they were not properly regulated.
The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract.
All of the following are true of swallowing (deglutition) except one. Select the statement that is NOT true of swallowing. The involuntary portion of swallowing takes place in the pharynx. The voluntary phase of swallowing takes place within the mouth. The epiglottis assists in propelling food into the trachea. The mouth, pharynx and esophagus all take part in swallowing.
The epiglottis assists in propelling food into the trachea.
Which of the following is NOT a characteristic of the stomach? The stomach produces a double-layered coat of alkaline mucus. The muscularis externa has three layers of smooth muscle. The mucosa is organized into large, longitudinal folds called rugae. The stomach releases enzymes that digest carbohydrates.
The stomach releases enzymes that digest carbohydrates.
What is the benefit of having tonsils at the oral entry to the pharynx? The tonsils secrete amylase to begin digestion of carbohydrates in the oral cavity. The tonsils gather and remove many of the pathogens entering the pharynx in food or liquid. Tonsils secrete an alkaline mucus that protects the esophagus from acid reflux. Tonsils secrete intrinsic factor, which is required for absorption of vitamin B12 in the stomach.
The tonsils gather and remove many of the pathogens entering the pharynx in food or liquid.
Which of the following is true concerning the number and type of permanent teeth? There are 32 permanent teeth, and the wisdom teeth are the last to emerge. There are 27 permanent teeth, and the first molars are usually the last to emerge. The number of upper permanent teeth is not equal to the number of lower permanent teeth. The number of permanent teeth is always equal to the number of primary teeth.
There are 32 permanent teeth, and the wisdom teeth are the last to emerge.
Which of the following constitute a portal triad? a bile duct along with a portal venule and arteriole three lobules sharing a common central vein the hepatic artery and two hepatic veins the porta hepatis
a bile duct along with a portal venule and arteriole
Which of these best describes a lacteal? special blood capillaries in the villi designed for absorbing food effectively a projection of the small intestine wall designed to increase surface area a lymphatic vessel designed to help introduce fats to the blood a deep pocket in the intestinal wall where endocrine and antimicrobial cells are located
a lymphatic vessel designed to help introduce fats to the blood
The end products of protein digestion are transported across the apical membranes of enterocytes by __________. active transport osmosis phagocytosis diffusion
active transport
Which enzyme(s) is/are responsible for the chemical breakdown of carbohydrates? trypsin proteases amylases nuclease Submit
amylases
Which of these structures is found in the stomach but nowhere else in the alimentary canal? mucus-forming cells an oblique muscle layer a circular muscle layer a lining of columnar epithelium
an oblique muscle layer
Your patient has had a total gastrectomy (removal of the stomach). Which of these potential problems are you MOST concerned about? Excessive bleeding as a result of absent clotting factors in the blood. Inability to tolerate fats because of absent bile salts Inability to digest starch because of the absence of amylase Anemia
anemia
Which vitamin requires intrinsic factor in order to be absorbed? C A B12 K
b12
Which of the following inhibits salivation? being stressed or frightened ingestion of spicy foods the sight or smell of food relaxing after a meal
being stressed or frightened
Which of the following is not a secretion of the pancreas? nutrient digesting enzymes bile insulin bicarbonate
bile
Chemical digestion reduces large complex molecules to simpler compounds by the process of ________. mastication catabolism anabolism excretion
catabolism
Pepsinogen, an inactive digestive enzyme, is secreted by the ________. chief cells of the stomach Brunner's glands in the duodenum parietal cells of the stomach goblet cells of the small intestine
chief cells of the stomach
What structural modification of the small intestine slows the movement of chyme through the lumen? microvilli circular folds villi intestinal crypts Submit
circular folds
The function of the hepatic portal circulation is to ________. carry toxins to the kidney for disposal through the urinary tract distribute hormones throughout the body return glucose to the general circulation when blood sugar is low collect absorbed nutrients for metabolic processing in the liver
collect absorbed nutrients for metabolic processing in the liver
An obstruction by a gallstone is least likely to occur in the ______. common hepatic duct bile duct cystic duct lumen of the hepatopancreatic sphincter
common hepatic duct
You are caring for a patient with late-stage cirrhosis that has led to a decrease in the number of functioning hepatocytes. Which of the following would NOT be typical for a patient with this condition? Decreased half-life for drugs processed by the liver Jaundice (yellow discoloration of the skin) Inability to digest fats Abnormal bleeding
decreased half-life for drugs processed by the liver
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 ________. secretion digestion absorption mechanical breakdown
digestion
Which of the following is not an important contribution of the bacterial microbiota found in the large intestine? fermentation of carbohydrates vitamin synthesis digestion of proteins suppress the growth of harmful bacteria
digestion of proteins
When the diet lacks fiber and the volume of residues in the colon is small, the colon narrows and its contractions become more powerful, increasing the pressure on its walls. This promotes formation of __________. gallstones irritable bowel syndrome (IBS) cystic fibrosis diverticula
diverticula
The __________ is the first segment of the small intestine. ileum jejunum duodenum colon
duodenum
A doctor consulting a patient that recently has had their gall bladder removed would likely advise ________. eating fewer, but larger meals eating a low to no carb diet eating foods that are low in fat increasing unsaturated fats while eliminating trans fats in their diets
eating foods that are low in fat
Which of the following structural elements is common to both cardiac and smooth muscle? Gap junctions T tubules Caveolae Epimysium
epimysium
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 gastrin pepsin ghrelin
gastrin
Which cells in the small intestine's mucosa secrete mucus? goblet cells absorptive cells Paneth cells enteroendocrine cells
goblet cells
The __________ circulation collects nutrient-rich venous blood draining from the digestive viscera. splanchnic enterohepatic pulmonary hepatic portal
hepatic portal
Which vessel delivers nutrient-rich blood to the liver from the digestive tract? central vein hepatic vein inferior vena cava hepatic portal vein
hepatic portal vein
The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ________. bile canaliculus portal vein pancreatic acini hepatopancreatic ampulla
hepatopancreatic ampulla
In what form do fats first enter the bloodstream? in the form of glycerol in the form of micelles in the form of chylomicrons in the form of fatty acids and glycerol
in the form of chylomicrons
The mechanical and chemical receptors that control digestive activity are located ________. .in the walls of the tract organs in the pons and medulla in the oral cavity in the glandular tissue that surround the organ lumen
in the walls of the tract organs
Which of the following is NOT a function of cholecystokinin (CCK)? open hepatopancreatic sphincter increase production of pancreatic juice stimulate gallbladder to release bile increase production of stomach acid
increase production of stomach acid
Generally, the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________. increase the release of digestive enzymes and bile increase stomach emptying decrease the activities of the accessory digestive organs increase the force of stomach contractions
increase the release of digestive enzymes and bile
Which of these is NOT part of the splanchnic circulation? hepatic portal vein inferior vena cava superior mesenteric artery celiac artery
inferior vena cava
The __________ phase of gastric secretion begins as chyme enters the duodenum. gastric phase reflux cephalic intestinal
intestinal
What stomach secretion is necessary for normal hemoglobin production in RBCs? intrinsic factor pepsinogen gastric lipase HCl
intrinsic factor
Which of the following is produced in the stomach and contributes directly to the absorption of vitamin B12? intrinsic factor Vasoactive intestinal peptide (VIP) pepsinogen hydrochloric acid
intrinsic factor
A ruptured appendix is life threatening because ________. loss of the appendix's function will cause an immune deficiency in the digestive system it is likely to cause severe internal bleeding the large intestine will no longer be able to receive digested material from the small intestine it is likely to cause massive infection of the abdominopelvic cavity
it is likely to cause massive infection of the abdominopelvic cavity
Most absorption of nutrients occurs in the __________. stomach and duodenum cecum and ascending colon jejunum and ileum descending and sigmoid colon
jejunum and ileum
A child with restricted tongue movement may have a surgery that involves the cutting of the ________. uvula palatine tonsils terminal sulcus lingual frenulum
lingual frenulum
Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible? chymotrypsin lipase amylase pepsin
lipase
Bile salts break up the fat globule into smaller fat droplets. This role of bile salts is best described as ________. lipid emulsification lipid ingestion lipid digestion lipid absorption
lipid emulsification
The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure. liver stomach pancreas spleen
liver
Bile is secreted by the __________ under hormonal influence of __________. small intestine; CCK pancreas; secretin liver; secretin gallbladder; gastrin
liver; secretin
In the enteric nervous system, a long reflexive pathway has an advantage over a short reflexive pathway in the fact that ________. long reflexive pathways last much longer than short reflexive pathways long reflexive pathways are quicker to respond than short reflexive pathways long reflexive pathways can be stimulated by things outside of the GI tract long reflexive pathways can respond throughout the entire length of the GI tract while short reflexive pathways can only respond in the proximal end
long reflexive pathways can be stimulated by things outside of the GI tract
The lamina propria is composed of ________. loose connective tissue reticular connective tissue dense regular connective tissue dense irregular connective tissue
loose connective tissue
Which of the following propels food residue over large areas of the colon three to four times a day? mass movement Valsalva's maneuver defecation reflex haustral contractions
mass movement
Which of the following is the major process or function that occurs in the stomach? defecation deglutition absorption mechanical breakdown
mechanical breakdown
The sheets of peritoneal membrane that hold the digestive tract in place are called ________. mucosal lining lamina propria serosal lining mesenteries
mesenteries
Carbohydrates are digested into __________. amino acids glycerol monosaccharides nucleotides
monosaccharides
Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium? muscularis externa mucosa submucosa serosa
mucosa
Which layer of the stomach contains the gastric pits that secrete mucus, acid, and digestive enzymes? serosa mucosa muscularis externa submucosa
mucosa
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. submucosa, serosa, muscularis externa, and mucosa mucosa, submucosa, muscularis externa, and serosa muscularis externa, serosa, mucosa, and submucosa serosa, mucosa, submucosa, and muscularis externa
mucosa, submucosa, muscularis externa, and serosa
Which layer of the alimentary canal is responsible for segmentation and peristalsis? submucosa muscularis externa mucosa serosa
muscularis externa
Which layer of the digestive tract contains the effectors for digestive propulsion? serosa muscularis externa mucosa submucosa
muscularis externa
What is a major function of pancreatic juice? neutralizing chyme entering the small intestine from the stomach emulsifying fats by breaking them into smaller pieces secreting hormones that help digest food in the duodenum acidifying the contents of the small intestine
neutralizing chyme entering the small intestine from the stomach
Fat absorption through the plasma membrane of epithelial cells ________. requires vesicular, active transport of the relatively large fatty acids and monoglyceride is accomplished by cotransporters that use the concentration gradient of Na+ outside of the cells occurs by simple diffusion because lipids are able to penetrate the hydrophobic fatty acid tails within the plasma membrane requires enzymes attached to the brush border to further breakdown the fats
occurs by simple diffusion because lipids are able to penetrate the hydrophobic fatty acid tails within the plasma membrane
What muscle forms the labia of the mouth and controls most lip movement, including puckering? zygomaticus buccinator levator labii superioris orbicularis oris
orbicularis oris
Which of the following produce intrinsic factor? enteroendocrine cells mucous neck cells parietal cells zymogenic cells
parietal cells
What event triggers the opening of the gastroesophageal sphincter? constriction of the upper esophageal sphincter detection of nutrients in the esophagus peristalsis in the esophagus pH changes in the esophagus
peristalsis in the esophagus
Which of the following is NOT a means of mechanically breaking down food? segmentation churning mastication peristalsis
peristasis
Hepatocytes do NOT ________. process nutrients detoxify toxic chemicals store fat-soluble vitamins produce digestive enzymes
produce digestive enzymes
The function of goblet cells is to ________. produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion secrete buffers in order to keep the pH of the digestive tract close to neutral provide protection against invading bacteria and other disease-causing organisms that enter the digestive tract in food absorb nutrients from digested food and store them for future use
produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
Which of the following functions is NOT correctly matched with its description? mechanical breakdown: churning movements in the GI tract absorption: transport of chemically digested nutrients into the blood or lymph ingestion: taking food into the digestive tract propulsion: physical breakdown of ingested food in the GI tract
propulsion: physical breakdown of ingested food in the GI tract
Which of the following is NOT found in saliva? lysozyme electrolytes urea and uric acid protease
protease
Which of the following are NOT correctly matched? nuclease: DNA and RNA digestion lipase: fat digestion protease: lipid digestion amylase: carbohydrate digestion
protease: lipid digestion
Paneth cells ________. secrete digestive enzymes secrete hormones secrete bicarbonate ions secrete enzymes that kill bacteria
secrete enzymes that kill bacteria
Which digestive process does NOT occur in the mouth? segmentation digestion ingestion mechanical breakdown
segmentation
From the esophagus to the anus, the walls of the alimentary canal have the same four basic tunics. The __________ is the outermost layer of the walls of the intraperitoneal organs. mucosa muscularis serosa submucosa
serosa
Which organ of the digestive tract is the body's major digestive organ? liver large intestine small intestine stomach
small intestine
The uvula is an extension of the __________. palatopharyngeal arch soft palate oral vestibule lingual frenulum
soft palate
Hyposalivation can be treated with a drug that ______. binds to adrenergic receptors in salivary gland serous cells is sympathomimetic stimulates muscarinic receptors in salivary gland serous cells mimics the action of epinephrine secreted by the adrenal medullae
stimulates muscarinic receptors in salivary gland serous cells
The bolus is liquefied in the ________ and it is now called chyme. small intestine mouth stomach esophagus
stomach
Which other organ can affect small-intestine motility? pancreas stomach mouth large intestine
stomach
Which layer of the alimentary canal contains not only glands and blood vessels but also a nerve plexus that helps regulate digestive activity? serosa submucosa mucosa muscularis externa
submucosa
Which of the following is an essential role played by large intestine bacteria? synthesize vitamins C and D produce gas synthesis of vitamin K absorb bilirubin
synthesis of vitamin k
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 cerebral cortex, hypothalamus and medulla oblongata are all involved in processing the stimulatory information. This prepares the stomach for food before its arrival in the stomach. The motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system. This is an example of a long reflexive pathway.
the motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system
The palatine tonsils are located between which two structures? the soft palate and the hard palate the palatopharyngeal arch and the throat the palatopharyngeal arch and the palatoglossal arch the tongue and the floor of the oral cavity
the palatopharyngeal arch and the palatoglossal arch
Nervous control of gastric secretion is provided by ________. the vagus nerve and enteric plexus somatic neurons in the spinal cord the reticulospinal and vestibulospinal tracts the rubrospinal tracts
the vagus nerve and enteric plexus
Impacted wisdom teeth is a problem that is never observed in children because ______. their teeth are generally too small to become impacted the childhood lengthening of their jaw bones provides the deciduous teeth with lots of room to erupt through the gums they lack third molar teeth their wisdom teeth fall out before there is any opportunity for them to become impacted
they lack third moral teeth
Most nutrients are absorbed through the mucosa of the intestinal villi by active transport. True False
true
The pancreas has both an endocrine and an exocrine function. True False
true
The splanchnic circulation refers to the arteries that serve the digestive organs and the veins that carry blood from the digestive organs to the liver. True False
true
Which of the following enzymes would be most active in the presence of high concentrations of protein fragments? lipase dextrinase trypsin amylase
trypsin
The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task? villi, and microvilli the rugae and haustra the vast array of digestive enzymes Brunner's glands and Peyer patches
villi, and microvilli
The __________ is the serous membrane that covers most digestive organs. mesentery visceral peritoneum omenta parietal peritoneum
visceral peritoneum
Which of the following is the primary physiological function of the large intestine? mechanical breakdown of food water absorption and feces elimination primary digestion of food nutrient absorption
water absorption of feces elimination
Peristaltic waves are ________. pendular movements of the gastrointestinal tract segmental regions of the gastrointestinal tract waves of muscular contractions that propel contents from one point to another churning movements of the gastrointestinal tract that aid in mechanical breakdown of chyme
waves of muscular contractions that propel contents from one point to another