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