موضوع: Answered MCQs on GIT by dr Khaled A Abulfadle الأحد أكتوبر 30, 2011 1:11 pm
Choose the correct answer (s):
1-Bile………………… a. Contains enzymes required for the digestion of fat. b. Contains unconjugated bilirubin. c. Salts make cholesterol more water-soluble. d. Pigments contain iron. e. Becomes more alkaline during storage in the gallbladder.
2-Saliva…………… a. From different salivary glands has a similar composition. b. Contains enzymes essential for the digestion of carbohydrates. c. Has less than half the ionic calcium level of plasma. d. Has more than twice the iodide level of plasma. e. Has a pH between 5 and 6.
3-Swallowing is a reflex which…………………. a. Has its reflex center in the cervical segments of the spinal cord. b. Includes inhibition of respiration. c. Is initiated by a voluntary act. d. Is dependent on intrinsic nerve networks in the esophagus. e. Is more effective when the person is standing rather than when lying down.
4-Defaecation is a reflex action………….. a. That is coordinated by reflex centers in the sacral cord. b. Whose afferent limb carries impulses from stretch receptors in the colon. c. Whose efferent limb travels mainly in sympathetic autonomic nerves. d. Which is more likely to be initiated just after a meal than just before it. e. Which can be voluntarily inhibited or facilitated.
5-In the stomach…………………. a. PH rarely falls below 4.0. b. Pepsinogen is converted to pepsin by hydrochloric acid. c. Ferrous iron is reduced to ferric iron by hydrochloric acid. d. Acid secretion is inhibited by pentagastrin. e. There is a rise in the bacterial count after histamine H1 receptor blockade.
6-Pancreatic secretion……….. a. In response to vagal stimulation is copious, rich in bicarbonate but poor in enzymes. b. In response to acid in the duodenum is scanty but rich in enzymes. c. In response to secretin secretion is low in bicarbonate. d. Contains enzymes that digest neutral fat to glycerol and fatty acids. e. Contains enzymes that convert disaccharides to monosaccharides.
7-The liver is the principal site for……….. a. Synthesis of plasma albumin. b. Synthesis of plasma globulins. c. Synthesis of vitamin B12. d. Storage of vitamin C. e. Storage of iron.
8-Gastric juice……………….. a. Is secreted when the vagus nerves are stimulated. b. Is secreted in vagotomized animals when food is chewed but not swallowed. c. Inactivates the digestive enzymes secreted with saliva. d. Does not digest the gastric mucosa because it is protected by a pepsin inactivator. e. Irritates the esophageal mucosa if regurgitated from the stomach.
9-Bile salts…………………….. a. Are the only constituents of bile necessary for digestion. b. Have a characteristic molecule, part water-soluble and part fat-soluble. c. Are reabsorbed mainly in the upper small intestine. d. Are derived from cholesterol. e. Inhibit bile secretion by the liver.
10-In the small intestine a. The enzyme concentration in intestinal juice is lower in the ileum than in the jejunum. b. Vitamin B12 is absorbed mainly in the jejunum. c. Water absorption is dependent on the active absorption of sodium and glucose. d. Absorption of calcium occurs mainly in the terminal ileum. e. Glucose absorption is dependent on sodium absorption.