ZOO 113 Ch 14 Digestive System
What is lactase?
A brush border enzyme
The _____ cells of the gastric glands produce hydrochloric acid.
Parietal
What do chief cells secrete?
Pepsinogen
What produces amylase?
Salivary Glands and Pancreas
Which of the following statements regarding secretin and CCK is false? a. Secretin primarily stimulates pancreatic enzyme production b. Secretin secretion is stimulated by acidic chyme in the duodenum c. CCK secretion is most stimulated by fatty chyme in the duodenum d. CCK stimulates contraction of the gallbladder
Secretin primarily stimulates pancreatic enzyme production
Which of the following statements about pepsin is false? a. It completely digests proteins into separate amino acids b. It is formed in the stomach lumen c. It has a pH optimum of about 2 d. It is produced when 1 pepsinogen molecule removes an amino acid sequence from another pepsinogen molecule
It completely digests proteins into separate amino acids
Which of the following statements about the enteric nervous system is false? a. In contains interneurons, like the CNS b. It must relay information to the CNS for reflex contractions, including peristalsis c. It has about the same number of neurons as the spinal cord d. It contains sensory and autonomic neurons
It must relay information to the CNS for reflex contractions, including peristalsis
Which of the following statements regarding pancreatic juice is false? a. Its produced by the pancreatic acini b. Trypsinogen is activated by a brush border enzyme in the small intestine c. Pancreatic juice enzymes are produced as zymogens d. Its enzymes digest disaccharides into monosaccharides
Its enzymes digest disaccharides into monosaccharides
Which of the following statements about the emulsification of fat by bile is true? a. Emulsification is produced by the action of bile salts in the colon b. Triglycerides are hydrolyzed into their subunits during emulsification c. Larger fat globules are broken up into a finer suspension d. Bile acids are derived from lecithen
Larger fat globules are broken up into a finer suspension
The pH of gastric juice is
Less than 2
The first organ to receive monosaccharides and amino acids from the small intestine is the...
Liver
What produces lipase?
Pancreas
Which of the following is not a function of the liver? a. bile production b.digestive enzyme production c. glycogen storage d. lipid metabolism e. synthesis of plasma proteins
Digestive enzyme production
T/F: A dieter who is actively losing fat tissue may fell hungry due to increased leptin secretion.
False
T/F: The common bile duct carries bile from the cystic duct into the stomach.
False
T/F: The first and shortest segment of the small intestine is the jejunum.
False
T/F: The products of carbohydrate and protein are absorbed into the blood but products of triglyceride digestion are not.
False
T/F: The pyloric sphincter is located at the junction of the stomach and esophagus.
False
What do G cells secrete?
Gastrin
The main hormone that stimulates hunger is _____.
Ghrelin
The blood vessel(s) that transport blood into the liver is the
Hepatic Artery and Hepatic Portal Vein
Hydrochloric acid secretion in the stomach is most directly stimulated by...
Histamine
What do ECL cells secrete?
Histamine
What do parietal cells secrete?
Hydrochloric Acid
The brain region that contains the hunger center is the ______.
Hypothalamus
The Intestinal Phase is...
Inhibited by enterogastrone and neural reflexes
The movement of the subunits of food molecules across the wall of the digestive tract into the blood is known as...
Absorption
Which of the following is not a function of the digestive system? a. absorption b. excretion c. motility d. secretion e. All of these choices are functions of the digestive system.
All of these choices are functions of the digestive system.
Components of pancreatic juice digest all of the following nutrient molecules except _____. a.nucleic acids b. proteins c. starch d. triglycerides e. All of these nutrients are digested by components of pancreatic juice.
All of these nutrients are digested by components of pancreatic juice
Which of the following are absorbed into the epithelial cells of the intestinal villi, but not into the blood? a. amino acids b. dipeptides c. tripeptides d. Both B and C are correct. e. A, B, and C are all correct.
B and C
The greatest component of a resting body's caloric expenditure is the _____.
Basal Metabolic Rate
Which of the following regarding bile pigment is true? a. It's produced only in the liver b. The liver converts conjugated bilirubin into free bilirubin c. The liver converts conjugated bilirubin into urobilinogen d. Bilirubin is derived from heme, minus the iron
Bilirubin is derived from heme, minus the iron
The HCl in the stomach serves to perform all of the following except: a. activate the enzyme pepsinogen. b. break peptide bonds in proteins. c. denature proteins in food. d. provide optimum pH for pepsin.
Break peptide bonds in proteins.
The _____ phase of stomach regulation may involve gastric secretion prior to eating.
Cephalic
The esophagus contains _____ muscle in its wall.
Smooth
In peristaltic contractions of the esophagus...
Smooth muscle behind the bolus contracts while smooth muscle ahead of it relaxes
The Gastric Phase is...
Stimulated by partially digested food proteins
The Cephalic Phase is...
Stimulated by the vagus nerve
The layer in the wall of the gastrointestinal tract that contains the most connective tissue is the _____.
Submucosa
Which of the following about proton pumps is true? a. They are carrier proteins located in the duodenum b. The are protein channels that allow passive transport in the stomach c. They are H/K ATPase active transport carriers in the stomach d. The are Na/K ATPase active transport carriers in the colon
They are H/K ATPase active transport carriers in the stomach
Which of the following statements about brush border enzymes is true? a. They are located in the lacteals b. They are secreted by the gastric glands c. They are secreted by the intestinal crypts d. They are stuck into the plasma membrane of microvilli
They are stuck into the plasma membrane of microvilli
Which of the following statements regarding chylomicrons is true? a. They consist of a carrier protein bound to fatty acids and monoglycerides b. They are absorbed from the intestinal lumen into epithelial cells c.They transport triglycerides from the intestine through the lymphatic system d. They enter the blood capillaries in the villi, and then the hepatic portal vein
They transport triglycerides from the intestine through the lymphatic system
T/F: A healthy large intestine harbors a large number of beneficial bacteria.
True
T/F: Bile acids from the liver break fat globules into droplets but do not digest the triglycerides.
True
T/F: Brush-border enzymes function in the digestion of disaccharides and polypeptides
True
T/F: Chyme is a mixture of food gastric juice.
True
T/F: Enzymes that digest starch are secreted by two accessory organs in the digestive system.
True
T/F: Histamine is a paracrine regulator that stimulates HCl secretion in the gastric glands.
True
T/F: The hormone that stimulates bile secretion and release is cholecystokinin.
True
The large intestine is _____ than the small intestine.
Wider
The hormone leptin is secreted by ________ and _______.
adipose tissue and reduces appetite
