This set of Drug Biotechnology Multiple Choice Questions & Answers (MCQs) focuses on “Absorption of Drugs from Non Oral Extravascular Sites – 1”.
1. What is the mean length of GIT?
a) 350 cm
Explanation: The mean length of Git tract is 450 cm. The gastrointestinal tract comprises of a number of components whose primary function is secretion, digestion, and absorption.
2. The entire length of the GI is lined by ___________
a) Blood vessels
d) No lining direct contact with the cell
Explanation: The entire GI tract is lined by mucus or mucopolysaccharides. It acts as an impermeable barrier to the particles such as that of bacteria, cells or food particles protecting our body from harmful organisms.
3. Which drugs get absorbed in the stomach mostly?
a) Basic drugs
b) Acidic Drugs
c) Neutral drugs
d) No drug gets absorbed in the stomach
Explanation: Due to the acidic pH of the stomach, which is due to the secretion of HCL into the stomach, only acidic drug absorption is favoured. But this is possible only if the drugs are soluble in the gastric fluids because most of the drugs get unionized because of the lower pH.
4. Which drugs gets mostly absorbed from the mouth?
a) Acidic drugs and lipophilic drugs
b) Lipophilic drugs and neutral drugs
c) Neutral drugs and lipophilic drugs
d) Lipophilic, neutral, basic drugs
Explanation: The pH of the mouth is 6.8. So no acidic drug can get absorbed through the lining of our mouth. Only lipophilic drugs, neutral drugs, and basic drugs get absorbed into systemic circulation.
5. From the surface of villi protrude smaller projection known as __________
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.
6. 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.
7. 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.
8. 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.
9. What is 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.
10. 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 faeces
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 interval.
11. 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.
12. 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.
13. The liver is the major site of drug metabolism
Explanation: Liver is the most important and the major site for drug metabolism. It also includes the first pass metabolism.
14. In infants, the gastric pH is quite low.
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.
15. The passage from the stomach to the small intestine is called gastric emptying.
Explanation: The passage from the stomach to the small intestine is called gastric emptying. This also is the rate-limiting step in case of drug absorption because the major site of drug absorption is small intestine.
Sanfoundry Global Education & Learning Series – Drug and Pharmaceutical Biotechnology.
To practice all areas of Drug and Pharmaceutical Biotechnology, here is complete set of 1000+ Multiple Choice Questions and Answers.