What tissue contains white blood cells and protects against ingested microorganisms?
C. mucosa-associated lymphoid tissue
The volume of a normal stomach ranges from _____ when empty to 1.5 L (~6 cups) when full.
D. 50 mL (~0.25 cup)
The pancreas is a digestive system accessory organ with two types of active tissue, the ducted exocrine tissue that produces digestive enzymes and the:
D. ductless endocrine tissue that secretes insulin and glucagon
Pancreatic juice that enters the duodenum through the sphincter of Oddi contains _____.
B. anions such as bicarbonate and chloride
Digestive enzymes functioning at the brush border are produced by:
D. the intestinal mucosal cells
Which of the following is a neuropeptide that functions to regulate digestion and absorption?
C. substance P
Gastrin is a hormone released by G-cells in the stomach and functions to:
C. stimulate release of HCl and cellular growth in the GI tract
Somatostatin is a regulatory peptide synthesized in the pancreatic and intestinal cells that appears to:
D. inhibit release of gastrin, secretin, and motilin
Which structural component of the GI tract controls GI secretions and local blood flow?
A. submucosal nerve plexus
What is the general term for the inactive secreted form of many digestive enzymes?
A. zymogen
The purpose of secretion of mucus by neck cells in the oxyntic gland of the stomach is to:
B. protect the epithelium from mechanical and chemical damage.
Parietal cells, found both in oxyntic glands and pyloric glands of the stomach, secrete _____.
D. hydrochloric acid
Chief cells, found in oxyntic glands in the body of the stomach, secrete _____.
B. pepsinogen
A function of hydrochloric acid in the gastric juice is to:
B. denature secondary and tertiary protein structure
Which of the following digestive fluids is the most acidic?
D. gastric juice
Approximately 1 - 5 mL (~1 tsp) of chyme enters the duodenum about:
D. twice per minute
The majority of all digestive enzymes are produced in what organ?
B. pancreas
Secretin is the major hormone responsible for:
C. alkalizing the chyme that has entered the small intestine
Cholecystokinin is the hormone primarily responsible for:
B. causing release of bile into the small intestine
The gallbladder:
A. concentrates and stores bile
Cholic acid and chenodeoxycholic acid ionize and form micelles more efficiently when they are:
A. conjugated with glycine or taurine
Resins such as cholestyramine bind bile in the GI tract, thus decreasing serum cholesterol because enterohepatic recirculation of bile acid is reduced from the usual _____ reabsorption.
C. 90%
What percent of cholesterol in bile is usually excreted?
A. 50%
Foods such as yogurt that contain live cultures of certain bacteria are known as:
a probiotics
b. predigestives
c. foods that stimulate the growth of gut flora
d. prebiotics
a. probiotics
It takes only about 30 minutes for most of the carbohydrate, protein and fat to be absorbed from chyme after it enters the small intestine, and it takes about _____ for fecal matter to move through the colon.
A. 12 to 70 hours
The mechanisms responsible for absorption of nutrients into the epithelial cell of the vilus depend upon all of the following EXCEPT:
D. the length of the large intestine
What percentage of the water and sodium entering the colon each day is absorbed?
C. 90-95%
Of the 3 short-chain fatty acids providing energy for bacteria, which one is absorbed by colonic epithelial cells and taken up for use in the liver?
B. propionate
What normal process that occurs in the colon must be controlled in individuals who have liver disease to prevent coma?
D. absorption of ammonia generated by gut bacteria
Fecal material contains all of the following EXCEPT: