1. From the surface of villi protrude smaller projection known as __________
a) Microvilli
b) Villus
c) Fingers
d) Cilia
Explanation: The surface of the small intestine folds into projections called villi. The surface of each villus has further smaller projections known as microvilli. About 600 protrudes from each absorptive cell that lines the villi. Thus increases the surface area by 600 times
2. Which of the following sentences will be the actual definition of folds of Kerckring?
a) Folds of the intestinal mucosa
b) Finger-like projections whose other name is villi
c) Protruding surface from the villi
d) Cilia over the surface of villi
Explanation: The fold of the intestinal mucosa is known as the folds of Kerckring. This result in a 3 fold increase in the intestinal surface area. The surface of these folds possesses finger-like projections known as villi. The surface of villi, from each absorptive cell several microvilli protrudes thus increasing the surface area 6000 times.
3. Which one of the following is not a characteristic for the small intestine?
a) Peristaltic movement
b) Long transit time
c) High permeability
d) PH 4-9
Explanation: The pH of the small intestine is in the range of 5-7.5. It gives the most favourable drugs to remain unionized. The permeability movement of the intestine is slow, transit time is long and the permeability is high
4. How can we increase the time of gastric emptying?
a) By drinking a lot of water
b) By taking a drug in empty stomach
c) By taking the drug after food
d) Cannot increase the time of gastric emptying at all
Explanation: Gastric emptying time can be delayed by administering food. Since the gastric content without being fluid with particle size below 2mm cannot enter the intestine through the pylorus. Thus it increases the time of gastric emptying.
5. What is the gastric emptying rate?
a) The time required for the gastric contents to empty into the small intestine
b) Time is taken for half of the contents in the stomach to empty
c) The speed at which the stomach contents empty into the intestine
d) There is no such term
Explanation: Gastric emptying rate is the speed at which the contents of the stomach contents empty into the small intestine. Time taken for half of the contents in the stomach to empty is known as gastric emptying t1/2. The time required for the gastric contents to empty into the small intestine is known as gastric emptying time.
6. How can we study the gastric emptying of a given drug?
a) By mixing the colour with the drug
b) Waiting for the subject man to throw-up
c) Tagging the drug with a radioisotope and scanning the stomach
d) Waiting for the patient to pass feces
Explanation: In vivo gastric emptying of a drug can be studied by using radio-opaque contrast materials like barium sulphate. It can also be studied by tagging the drug with a radioisotope and scanning the stomach at regular intervals
7. Up to how much the microvilli in the small intestine increases the relative surface area of the small intestine?
a) 3 times
b) 30 times
c) 100 times
d) 600 times
Explanation: The surface of villi protrudes to several small projections known as microvilli. About 600 projections come up from each absorptive cell that lines the wall of villi. Thus it increases the surface area to about 600 times.
8. What is the main role of the large intestine?
a) Absorption of water and electrolytes
b) Absorption of minerals
c) Absorption of glucose
d) Absorption of only water
Explanation: The environment if the large intestine is mostly neutral or alkaline. The main role of the large intestine is the absorption of water and electrolytes. It cannot absorb glucose, amino acids, lipids, etc
9. The liver is the major site of drug metabolism.
a) True
b) False
Explanation: Liver is the most important and the major site for drug metabolism. It also includes the first pass metabolism.
10. In infants, the gastric pH is quite low.
a) True
b) False
Explanation: The statement is false since the gastric pH of infants is high. The intestinal surface and the blood flow to the GIT is low thus results in altered absorption pattern in comparison to adults.