Chapter 13 Digestion
In general, the parasympathetic nervous system is _______ to the digestive tract. inhibitory excitatory
excitatory
Absorption of nutrients and water is greatest in the _________ portion of the small intestine. duodenum jejunum ileum
jejunum
Emulsification of which organic molecules would be most affected if the liver were severely damaged? proteins nucleic acids lipids carbohydrates
lipids
The organ of highest importance in providing the enzymes required for the digestion of food is the: stomach parotid salivary gland pancreas liver
pancreas
Which of the following cells produce HCl? enteroendocrine cells parietal cells chief cells mucous cells
parietal cells
Gastrin is a powerful stimulus for HCl (hydrochloric acid) secretion from ____________ cells and pepsinogen secretion from _______________ cells. parietal; chief parietal; enteroendocrine chief; parietal chief; enteroendrocrine
parietal; chief
One of the following enzymes functions best when the pH of its environment is very low. Which one? pepsin amylase trypsin pancreatic lipase
pepsin
The enzyme that breaks down proteins in the lumen of the stomach is: gastrin lipase pepsin amylase
pepsin
Which of the following is (are) not present in saliva? peptidase water mucin amylase
peptidase
The ____________ glands are entirely under neural control. Parasympathetics stimulate the release of thin, enzyme-rich saliva, whereas sympathetics stimulate release of a thick, mucin-rich saliva. duodenal hepatic gastric salivary
salivary
This hormone secreted by the small intestine when stimulated by acid in chyme causes the pancreas to secrete sodium bicarbonate. gastrin cholecystokinin secretin enterokinase
secretin
The _____________ reflex involves elevation of the soft palate as well as the epiglottis and glottis closing off the larynx. gastroileal enterogastric swallowing gastrocolic
swallowing
The short reflexes in the digestive system are stimulated by __________. higher brain centers the sympathetic division of the autonomic nervous system the enteric nerve plexuses the parasympathetic division of the autonomic nervous system
the enteric nerve plexuses
The only stomach function that is essential to life is __________. the secretion of pepsinogen the presence of HCl the secretion of intrinsic factor mechanical digestion
the secretion of intrinsic factor
The hormone that stimulates gallbladder contraction, stimulates pancreatic secretion of enzyme-rich pancreatic juice, relaxes the hepatopancreatic sphincter, and inhibits gastric motility and secretion is: insulin cholecystokinin secretin gastrin
cholecystokinin
Which of the following products does the stomach produce? pepsinogen and secretin bile and trypsin HCl and intrinsic factor mucus and amylase
HCl and intrinsic factor
Chylomicrons are large, protein-coated droplets of fat (triglycerides) formed within the intestinal cells and then exocytosed to enter lacteals. True False
True
Haustal contractions are responsible for mixing the colonic contents, whereas mass movements periodically propel the colonic contents long distances. True False
True
Sphincters control the passage of food materials through the alimentary canal. True False
True
The duodenum is that part of the small intestine that receives pancreatic secretions, whereas the ileum is the part that connects to the colon. True False
True
The duodenum is that part of the small intestine that receives pancreatic secretions, whereas the ileum is the part that connects to the colon. True False
True
Which of the following does not control the passage of food material through the alimentary canal? cardiac (lower esophageal) sphincter upper esophageal sphincter pyloric sphincter ileo-cecal sphincter hepatopancreatic sphincter (sphincter of Oddi)
hepatopancreatic sphincter (sphincter of Oddi)
During deglutition, the bolus passes into the stomach from the esophagus through the __________. gastroesophageal sphincter esophageal sphincter urethral sphincter pyloric sphincter ileocecal valve
gastroesophageal sphincter
The liver produces digestive enzymes. True False
False
The liver produces digestive enzymes. True False
False
Worn-out red blood cells are destroyed and the hemoglobin is degraded to a yellow pigment known as _________________, which is excreted into the bile. sarcoplasmic reticulum gastrin bilirubin myoglobin
bilirubin
Peptidases: break bonds between amino acids split fatty acids from triglycerides are produced in the appendix are found in saliva
break bonds between amino acids
Which of the following cells produce pepsinogen? mucous cells parietal cells enteroendocrine cells chief cells
chief cells
Which substance promotes the release of bile from the gallbladder? cholecystokinin secretin norepinephrine gastrin
cholecystokinin
amylase
digests starch
Production of vitamins B and K occurs in the ______________. small intestine large intestine stomach mouth
large intestine
Gastric secretion is stimulated by the hormone gastrin. Cholecystokinin, gastric inhibitory peptide, and secretin (collectively known as enterogastrones) function to ____________ stomach secretion and motility. inhibit stimulate
inhibit
The rate of gastric emptying is: inversely proportional to the fluidity of chyme increased when fats enter the duodenum inhibited by fats in chyme and distension of the duodenum primarily controlled by the amount of sugar in saliva
inhibited by fats in chyme and distension of the duodenum
The enterogastric reflex involves: inhibition of gastric peristalsis by the duodenum inhibition of duodenal peristalsis by the colon stimulation of gastric peristalsis by the duodenum stimulation of duodenal peristalsis by the stomach
inhibition of gastric peristalsis by the duodenum
The pancreatic acinar cell secretions include the proteases trypsinogen, chymotrypsinogen, and procarboxypeptidase that will be modified into their active form by the brush border enzyme enterokinase in the small intestine. True False
True
Bile salts: help form micelles in the lumen of the small intestine aid digestion by emulsifying fats are produced in the liver all of these are true
all of these are true
Swallowing: involves CN VII (facial), IX (glossopharyngeal), X (vagus), XII (hypoglossal) relaxation of esophageal sphincters uvula elevating to close nasopharnyx epiglottis covering the opening to the larynx all these are involved in swallowing
all these are involved in swallowing
Pancreatic lipase: release is stimulated by cholecystokinin is produced by acinar cells of the pancreas digests triglycerides into free fatty acids and glycerol in the lumen of the small intestine all these are true
all these are true
Which of the following inhibit gastric motility? all these inhibit gastric motility enterogastric reflex enterogastrones secretin cholecystokinin
all these inhibit gastric motility
Which of the following is NOT an endopeptidase? enterokinase amylase trypsin pepsin
amylase
What substances from different organs would mix together at the hepatopancreatic ampulla? secretin and CCK brush border enzymes and intrinsic factor HCl and pepsin bile and pancreatic enzymes
bile and pancreatic enzymes
lipase
digests triglycerides into glycerol and free fatty acids
In order to prevent self-digestion of the pancreas, activation of pancreatic proteases occurs in the __________. gallbladder stomach duodenum pancreas liver
duodenum
Which regulatory chemical stimulates gastric gland activity and motility? histamine secretin gastrin cholecystokinin
gastrin
The smallest end-product resulting from lipase activity is (are): glycerol monosaccharides triglycerides amino acids
glycerol
The gastrointestinal reflex relaxes the ________ valve and distension of the proximal large intestine constricts it. The sphincter (valve) is the: cardiac pyloric ileocecal external anal
ileocecal
The swallowing reflex is controlled by: salivary glands hypothalamic hormones spinal reflexes medulla oblongata and lower pons
medulla oblongata and lower pons
The final product of carbohydrate digestion is __________. glycogen monosaccharides starch disaccharides
monosaccharides
The most potent stimulus for gastrin release is _____________ in the lumen of the stomach. protein carbohydrates vitamins and minerals fat
protein
What are the main organic molecules digested in the stomach? lipids proteins salts carbohydrates nucleic acids
proteins
Distension of the duodenum: reflexively inhibits jejunum motility reflexively stimulates gastric motility reflexively releases the cardiac sphincter reflexively contracts the pyloric sphincter
reflexively contracts the pyloric sphincter
The various processes of the gastrointestinal system are directly associated with certain types of gastrointestinal cells. Which of the following associations is NOT valid? absorption - small intestinal epithelial cells motility - esophageal smooth muscle cells secretion - gallbladder epithelial cells enzymatic digestion - pancreatic acinar cells
secretion - gallbladder epithelial cells
The three structural modifications of the _______________ mucosa that greatly increase the surface area available for absorption are circular folds, villi, and microvilli. small intestine liver large intestine stomach
small intestine
Secretin stimulates the duct cells in the pancreas to secrete fluid that is rich in: enzymes bile sodium bicarbonate chylomicrons
sodium bicarbonate
carboxypeptidase
splits amino acids from peptides in the small intestine
pepsin
splits protein into peptide fragments in the stomach
Gastrin digests proteins stimulates pepsinogen secretion buffers HCl is a stomach enzyme
stimulates pepsinogen secretion
Cholecystokinin (CCK): stimulates gastric peristalsis stimulates the release of pancreatic hormones inhibits the release of bile stimulates release of trypsinogen, procarboxypeptidase, and chymotrypsinogen
stimulates release of trypsinogen, procarboxypeptidase, and chymotrypsinogen
Pernicious anemia would result from the total removal of the ___________ due to the lack of intrinsic factor produced by parietal cells. intestinal crypts gallbladder large intestine stomach
stomach
The volume and fluidity of chyme in the ______________ are the main factors that influence gastric emptying. pancreas small intestine stomach large intestine
stomach