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40 terms

(Quiz) Structure and Function of the Digestive System, Ch 38

STUDY
PLAY
1. Which of the following organs is NOT part of the alimentary or GI tract?
A. Mouth
B. Esophagus
C. Stomach
D. Liver
* Liver
The liver is not part of the GI tract. The mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus are considered part of the GI tract.
Which of the following is NOT one of the three salivary glands?
A. Thyroid
B. Submandibular
C. Sublingual
D. Parotid
*Thyroid
The three salivary glands include the submandibular, sublingual, and parotid
Which of the following is TRUE regarding salivation?
A. Salivation is controlled by the parasympathetic nervous system.
B. Cholinergic fibers stimulate the salivary glands.
C. Atropine increases salivary secretion.
D. ß-Adrenergic stimulation decreases salivary secretion.
*Cholinergic fibers stimulate the salivary glands.
Salivary secretion is controlled by the sympathetic and parasympathetic systems but not by hormones. The parasympathetic system increases secretions, and an anticholinergic-like atropine actually makes the mouth dry. The ß-adrenergic stimulation also increases secretion.
Which of the following is TRUE regarding the esophagus?
A. The upper third is mixed striated and smooth muscle.
B. The middle third is innervated by motor fibers.
C. The lower third is innervated by striated muscle.
D. The lower third is innervated by preganglionic fibers from the vagus nerve.
* The lower third is innervated by preganglionic fibers from the vagus nerve.
The upper third is striated muscle and is innervated by motor neurons. The middle third is striated and smooth muscle. The lower third is smooth muscle innervated by preganglionic fibers from the vagus nerve.
Which blood vessel provides blood to the stomach?
A. Celiac artery
B. Gastric artery
C. Splenic artery
D. Mesenteric artery
*Celiac artery
A branch of the celiac artery supplies the stomach. The splenic vein drains the right side of the stomach, and the gastric vein drains the left.
Which of the following hormones is responsible for inhibition of the stomach contraction?
A. Gastrin
B. Motilin
C. Secretin
D. Cholecystokinin
*Secretin
Secretin is responsible for inhibition by raising the threshold potential. Gastrin and motilin increase contraction by lowering the threshold potential of muscle fibers. Cholecystokinin causes relaxation in the esophagus.
Which cells of the stomach secrete hydrochloric acid and intrinsic factor?
A. Parietal cells
B. Chief cells
C. G cells
D. Enterochromaffin-like cells
*Parietal cells
Parietal cells secrete hydrochloric acid and intrinsic factor. Chief cells secrete pepsinogen. G cells secrete gastrin in the antrum of the stomach. Enterochromaffin-like cells secrete histamine.
Which of the following is NOT one of the functions of stomach acid?
A. Dissolve food fibers
B. Act as a bactericide
C. Convert intrinsic factor into its active form
D. Convert pepsinogen into pepsin
* Convert intrinsic factor into its active form
Intrinsic factor is secreted from parietal cells within the stomach. Acid is responsible for dissolving food fibers and acts against bacteria. It also cleaves pepsinogen to pepsin.
Which of the following is NOT part of the cephalic phase of gastric juice secretion?
A. Smelling food
B. Seeing food
C. Tasting food
D. Eating food
* Eating food
The arrival of food in the stomach is the beginning of the gastric phase of secretion. The cephalic phase includes smelling, seeing, tasting, chewing, and swallowing food.
Which enzyme is responsible for breaking the end amino acids away from the ingested protein?
A. Trypsin
B. Chymotrypsin
C. Lipase
D. Carboxypeptidases
*Carboxypeptidases
Carboxypeptidases break away the end amino acids. Trypsin and chymotrypsin hydrolyze the interior bonds of the large molecules. Lipase is a pancreatic enzyme.
Which enzyme is responsible for cleaving fatty acids from phospholipids?
A. Cholesterol esterase
B. Phospholipase
C. Lipase
D. Chylomicron
*Phospholipase
Phospholipase cleaves fatty acids from phospholipids. Cholesterol esterase breaks cholesterol esters into fatty acids and glycerol. Lipase breaks down triglycerides to diglycerides, monoglycerides, free fatty acids, and glycerol. Chylomicrons are particles that consist of triglycerides covered with phospholipids.
When iron is being absorbed into the small bowel, to what protein is it bound in the epithelial cells?
A. Transferrin
B. Calcium phosphate
C. Transcobalamin
D. Ferritin
* Ferritin
Ferritin is the protein to which iron is bound in epithelial cells. Initially it is bound to intestinal transferrin. Calcium phosphate and phosphoproteins bind iron in the intestinal lumen and reduce absorption. Transcobalamin is the protein carrier for vitamin B12 to enter the plasma.
Which of the following is NOT one of the four phases of digestion and absorption of fat?
A. Emulsification and lipolysis
B. Micelle formation
C. Hydrolysis
D. Fat absorption
* Hydrolysis
Hydrolysis is not a function of digestion and absorption of fat. It is a part of protein digestion. The four phases of digestion and absorption of fat include emulsification and lipolysis, micelle formation, fat absorption, and resynthesis of triglycerides and phospholipids.
Which cells of the liver store lipids?
A. Hepatocytes
B. Sinusoids
C. Lipocytes
D. Kupffer cells
* Lipocytes
Lipocytes store lipids. The hepatocytes are the functional cells of the liver. Sinusoids are small capillaries located between hepatocytes. Kupffer cells are phagocytes that line the sinusoids.
Which of the following is the appropriate description for unconjugated bilirubin?
A. It is bilirubin that binds to albumin.
B. It is found within the hepatocytes.
C. It is found at the terminal end of the ileum and the colon.
D. It is water soluble.
* It is bilirubin that binds to albumin
Unconjugated bilirubin binds to albumin and is lipid soluble. Conjugated bilirubin is water soluble and is secreted in the bile. In the hepatocytes unconjugated bilirubin turns into conjugated bilirubin after it combines with glucuronic acid. Urobilinogen is found in the ileum and colon.
The muscularis of the gastointestinal tract is:
a. skeletal muscle throughout the tract, particularly in the esophagus and lg intestine
b. the layer that contains the blood capillaries for the entire wall of the tract
c. composed principally of keratinized epithelium
d. composed of circular fibers and longitudinal fibers
Composed of circular and longitudinal fibers
The digestive functions performed by the saliva and salivary amylase, respectively, are:
a. moistening and protein digestion
b. deglutition and fat digestion
c. peristalsis and polysaccharide digestion
d. lubrication and carbohydrate digestion
Lubrication and carbohydrate digestion
The nervous pathway involved in salivary secretion requires the stimulation of:
a. receptors in the taste buds, impulses to the motor cortex, and somatic motor impulses to salivary glands
b. receptors in the mouth, sensory impulses to a center in the brainstem, and parasympathetic impulses to salivary glands
c. taste receptors, sensory impulses to centers in the brainstem, and somatic motor impulses to salivary glands.
d. pressoreceptors in blood vessels, motor impulses, and autonomic impulses to salivary glands
Receptors in the mouth, sensory impulses to a center in the brainstem, and parasympathetic impulses to salivary glands
Food would pass rapidly from the stomach into the duodenum if it were not for the:
a. fundus
b. epiglottis
c. rugae
d. cardiac sphincter
e. pyloric sphincter
pyloric sphincter
The secretion of gastric juice:
a. occurs only when the stomach comes in contact with swallowed food
b. is entirely under the control of the hormone gastrin
c. is entirely under the control of the hormone enterogastrone
d. is stimulated by the presence of saliva in the stomach
e. occurs in three phases: cephalic, gastric, and intestinal
occurs in three phases: cephalic, gastric, and intestinal
During nervous control of gastric secretion, the gastric glands secrete before food enters the stomach. This stimulus to the glands comes from:
a. gastrin
b. impulses over somatic nerves from the hypothalamus
c. motor impulses from the cerebral cortex and cerebellum
d. parasympathetic impulses over the vagus nerve
Parasympathetic impulses over the vagus nerve
Pepsinogen:
a. must be activated by HCl
b. is secreted by the chief cells
c. is important in the breakdown of proteins
d. all of the above are correct
All are correct
Beginning at the lumen, the sequence of layers of the gastrointestinal tract is:
a. mucosa, submucosa, muscularis, serosa
b. submucosa, mucosa, serous membrane, muscularis
c. submucosa, mucosa, muscularis, skeletal muscle
d. serous membranes, muscularis, mucosa, submucos
mucosa, submucosa, muscularis, serosa
Normally, when chyme leaves the stomach:
a. the nutrients are ready for absorption into the blood
b. the amount of inorganic salts has been increased by the action of hydrochloric acid
c. its pH is neutral
d. the proteins have been partly digested
e. all of the above
The proteins have been partially digested
Which layer of the small intestine includes microvilli?
a. submucosa
b. mucosa
c. muscularis
d. serosa
Mucosa
Which of the following is not an example of mechanical digestion?
a. chewing
b. churning and mixing of food in the stomach
c. peristalsis and mastication
d. conversion of protein molecules into amino acids
conversion of protein molecules into amino acids
Pancreatic juice is to trypsin as gastric juice is to:
a. salivary amylase
b. pepsin
c. mucin
d. intrinsic factor
pepsin
Which part of the small intestine is most distal from the pylorus?
a. jejunum
b. pyloric sphincter
c. duodenum
d. cardiac sphincter
e. common bile duct
jejunum
The pancreas:
a. lies mostly on the left side of the abdominal cavity, anterior to the stomch and the spleen
b. secretes all of its products directly into the blood-stream
c. is a slender, flattened gland with its duct ultimately opening into the duodenum
d. contains cells with endocrine function for the determination of secondary sex characteristics
Is a slender, flattened gland with its duct ultimately opening into the duodenum
The chief role played by the pancreas in digestion is to:
a. secrete insulin and glucagon
b. churn the food and bring it into contact with digestive enzymes
c. secrete enzymes that digest food in the small intestine
d. assist in absorbing the digested food
secrete enzymes that digest food in the small intestine
Among the structural features of the small intestine are villi, microvilli, and circular folds. Their function is to:
a. liberate hormones
b. promote peristalsis
c. liberate digestive enzymes
d. increase the surface area for absorption
increase the surface area for absorption
The fate of carbohydrates in the small intestine is:
a. digestion by amylase, sucrase, maltase, and lactase to monosaccharide
b. conversion to simple sugars by the activity of trypsin and lipase
c. hydrolysis to amino acids by the activity of amylase, sucrase, maltase, and lactase
d. conversion to glycerol and fatty acids by the activity of lipase and amylase
digestion by amylase, sucrase, maltase, and lactase to monosaccharide
The absorptive fate of the end products of digestion may be summarized as:
a. most fatty acids are absorbed into the blood; glucose and amino acids are absorbed into the lymphatic system
b. amino acids and monosaccharids are absorbed into blood capillaries; most fatty acids are absorbed into lymph
c. amino acids and fatty acids are absorbed into the lymph capillaries; glycerol and glucose are absorbed into the blood capillaries
d. fatty acids are absorbed into blood capillaries; glycerol, glucose, and amino acids are absorbed into lymph
amino acids and monosaccharids are absorbed into blood capillaries; most fatty acids are absorbed into lymph
A lobule of the liver contains a centrally located:
a. vein, with radiating hepatocytes and sinusoids
b. arteriole, with radiating capillaries and Kupffer's cells
c. hepatic sinus, with radiating siusoids
d. hepatic duct, with radiating Kupffer's cells and cords of hepatic cells
vein, with radiating hepatocytes and sinusoids
An obstruction of the common bile duct would cause the blockage of bile coming from:
a. the gallbaladder
b. the liver but not the gallbladder
c. both the liver and the gallbladder
d. the pancreatic duct but not the gallbladder
both the liver and the gallbladder
The human adult liver does not:
a. store glycogen
b. produce erythrocytes
c. convert ammonia to urea
d. produce blood coagulation proteins
produce erythrocytes
The chyme that enters the large intestine is converted to feces by activity of:
a. specific mucosal enzymes
b. gastric and duodenal hormones
c. bacteria and water reabsorption
d. the microvilli, villi, and circular muscles
bacteria and water reabsorption
The pyloric gland mucosa in the stomach antrum synthesizes and releases the hormone ____ from G cells.
gastrin
Total serum bilirubin is normally less than ____.
1 mg/dl
Aging is associated with a greater frequency of ____ infection.
H. pylori