Title Ex- 2. Digestion and absorption (Q-A-Sol).docx.pdf ✅

8 DIGESTION AND ABSORPTION EXERCISE – 2: Previous Year Questions 1. Succus entericus is referred to as: (NEET 2021) (a) Pancreatic juice (b) Intestinal juice (c) Gastric juice (d) Chyme Ans. (b) Sol. The intestinal juice is also known as the Succus entericus. It is secreted from the glands present in the duodenum of the small intestine. It consists of two enzymes maltase and amylase. 2. Sphincter of oddi is present at: (NEET 2021) (a) Ileo-caecal junction (b) Gastro-oesophageal junction (c) Junction of hepato-pancreatic duct and duodenum (d) Junction of jejunum and duodenum Ans. (c) Sol. Sphincter of oddi is a smooth muscle valve which regulates the flow of biliary and pancreatic secretions into the duodenum. It was initially described in 1887 by the Italian anatomist Ruggero Oddi. 3. The enzyme enterokinase helps in conversion of: (NEET 2020) (a) Caseinogen into casein (b) Pepsinogen into pepsin (c) Protein into polypeptides (d) Trypsinogen into trypsin Ans. (d) Sol. Trypsinogen is present in inactive form in pancreatic juice. When it reaches the duodenum, The enterokinase enzyme converts inactive trypsinogen to active trypsin. This in turn activates the other enzymes in the pancreatic juice. 4. Identify the correct statement with reference to human digestive system. (NEET 2020) (a) Ileum is a highly coiled part (b) Vermiform appendix arises from duodenum (c) Ileum opens into small intestine (d) Serosa is the innermost layer of the alimentary canal. Ans. (a) Sol. - Small intestine is distinguishable into three regions, a ‘U’ shaped duodenum, a long coiled middle portion jejunum and a highly coiled ileum. - A narrow finger-like tubular projection, the vermiform appendix which is a vestigial organ, arises from the caecum. - Ileum opens into the large intestine. - The wall of alimentary canal possesses four layers from outer to inner namely serosa, muscularis, submucosa and mucosa. Serosa is the outermost layer and mucosa is the innermost layer. 5. The intrixnsic factor that helps in ansorption of vitamin B12 is secreted by (NEET 2020) (a) Goblet cells (b) Hepatic cells (c) Peptic cells (d) Parietal cell Ans. (d) Sol. Parietal or oxyntic cells which secrete HCl and intrinsic factor. Intrinsic factor is essential for absorption of vitamin B12. 6. The proteolytic enzyme rennin is found in (NEET 2020) (a) Intestine juice (b) Bile juice (c) Gastric juice (d) Pancreatic juice Ans. (c) Sol. Rennin is a proteolytic enzyme found in the gastric juice in the stomach of infants which helps in the digestion of casein (milk protein). 7. Match the following structures with their respective location in organs: (NEET 2019) (p) Crypts of Lieberkühn (i) Pancreas (q) Glisson’s’ Capsule (ii) Duodenum (r) Islets of Langerhans (iii) Small intestine (s) Brunner’s Glands (iv) Liver (a) p → (ii); q → (iv); r → (i); s → (iii) (b) p → (iii); q → (iv); r → (i); s → (ii) (c) p → (iii); q → (ii); r → (i); s → (iv) (d) p → (iii); q → (i); r → (ii); s → (iv) Ans. (b) Sol. Crypts of Lieberkühn are present in small intestine. Glisson's capsule is present in liver. Islets of langerhans constitutes the endocrine portion of
9 DIGESTION AND ABSORPTION pancreas. Brunner's glands are found in submucosa of duodenum. 8. Identify the cells whose secretion protects the lining of gastro-intestinal tract from various enzymes (NEET 2019) (a) Goblet Cells (b) Oxyntic Cells (c) Duodenal Cells (d) Chief Cells Ans. (a) Sol. Goblet cells secrete mucus and bicarbonate ions which play an important role in lubrication and protection of the epithelial lining of the gastro-intestinal tract. 9. Match the following structures with their respective location in organs: (NEET 2019) (p) Rennin (i) Vitamin B12 (q) Enterokinase (ii)Facilitated transport (r) Oxyntic cells (iii) Milk proteins (s) Fructose (iv) Trypsinogen (a) p → (ii); q → (iv); r → (i); s → (iii) (b) p → (iii); q → (iv); r → (i); s → (ii) (c) p → (iii); q → (ii); r → (i); s → (iv) (d) p → (iii); q → (i); r → (ii); s → (iv) Ans. (b) Sol. Rennin is a proteolytic enzyme found in the gastric juice in the stomach of infants which helps in the digestion of Casein (milk protein). Enterokinase acts upon trypsinogen and converts it into trypsin. Oxyntic cells secrete HCl and intrinsic factor. Fructose and mannose are absorbed through facilitated diffusion. 10. Kwashiorkar disease is due to (NEET 2019) (a) Simultaneous deficiency of proteins and fats (b) Simultaneous deficiency of proteins and calories (c) Deficiency of carbohydrates (d) Protein deficiency not accompanied by calorie deficiency Ans. (d) Sol. Kwashiorkar is produced by protein deficiency unaccompanied by calorie deficiency. It results from the replacement of mother’s milk by a high calorie low protein diet in a child more than one year in age. 11. Which of the following gastric cells indirectly help in erythropoiesis? (NEET 2018) (a) Goblet cells (b) Mucous cells (c) Chief cells (d) Parietal cells Ans. (d) Sol. Parietal cell is a gastric cell which secretes Castle’s factor. This factor is responsible for the absorption of vitamin B12. Vitamin B12 is involved in the proliferation and differentiation of erythrocytes and help indirectly in erythropoiesis. 12. Which of the following terms describe human dentition? (NEET 2018) (a) Pleurodont, Monophyodont, Homodont (b) Thecodont, Diphyodont, Heterodont (c) Thecodont, Diphyodont, Homodont (d) Pleurodont, Diphyodont, Heterodont Ans. (b) Sol. Human dentition refers to the teeth structure of humans. In humans, teeth are present in their individual sockets hence called thecodont. They are diphyodont which means there will be two successive sets of teeth, where the first set is called the milk teeth which later fall off and permanent teeth erupt. The human teeth are heterodont, which means different kinds of teeth viz. incisors, canines, pre-molars and molars. 13. Which cells of ‘Crypts of Lieberkühn’ secrete antibacterial lysozyme? (NEET 2017) (a) Argentaffin cells (b) Paneth cells (c) Zymogen cells (d) Kupffer cells Ans. (b) Sol. The Crypts of Lieberkühn contain cells which form the part of the intestinal mucosa. There are many cells, among which paneth cells are those which are highly secretory. These cells primarily secrete antibacterial lysozyme. This provides host defense against microbes. 14. A baby boy aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent? (NEET 2017) (a) Incisors (b) Canines (c) Pre-molars (d) Molars Ans. (c)
10 DIGESTION AND ABSORPTION Sol. The dental formula of milk teeth is 2102/2102, which tells that in the upper jaw or lower jaw, there will be four incisors, two canine and four molars. These molars appear by the age of two. However, premolars appear later. Pre-molars are thus absent at the age of 2. Hence, the dentist will observe ten teeth in either jaw (4+2+4), and 20 in total. 15. Which of the following options best represent the enzyme composition of pancreatic juice? (NEET 2017) (a) Amylase, peptidase, trypsinogen, rennin (b) Amylase, pepsin, trypsinogen, maltase (c) peptidase, Amylase, pepsin, rennin (d) lipase, amylase, trypsinogen, procarboxypeptidase Ans. (d) Sol. The exocrine portion of the pancreas secrete a juice containing the enzymes which are transported to the duodenum for their action. These enzymes include lipase, amylase, trypsinogen and procarboxypeptidase. 16. Which of the following guards the opening of hepatopancreatic duct into the duodenum. (NEET 2016) (a) Semilunar valve (b) Ileocaecal valve (c) Pyloric sphincter (d) Sphincter of Oddi Ans. (d) Sol. Sphincter of Oddi guards and regulates the hepato- pancreatic secretion via the hepato-pancreatic duct into the duodenum. The secretion involves bile juice and the exocrine secretion of the pancreas. 17. In the stomach, gastric acid is secreted by the (NEET 2016) (a) Gastrin secreting cells (b) Parietal cells (c) Peptic cells (d) Acidic cells Ans. (b) Sol. Among the gastric cells present in the mucosa of the stomach, parietal cells are the one that produce HCl and create an acidic medium in the stomach. This converts pepsinogen to pepsin and also provides host defense against microbes present in the ingested food. 18. Which hormones do stimulate the production of pancreatic juice and bicarbonate? (NEET 2016) (a) Angiotensin and epinephrine (b) Gastrin and insulin (c) Cholecystokinin and secretin (d) Insulin and glucagon Ans. (c) Sol. Cholecystokinin and secretin are examples of local hormones which are released in close proximity from their target cells. The production of pancreatic juice is stimulated by cholecystokinin. Secretin stimulate the release of bicarbonate ions by the pancreas. The ions create an alkaline medium to activate the inactive enzymes present in the pancreatic juice. 19. The primary dentition in human differs from permanent dentition in not having one of the following type of teeth- (NEET 2015) (a) Incisors (b) Canine (c) Premolars (d) Molars Ans. (c) Sol. The primary dentition which is also known as the milk teeth do not contain any pre-molars. The first set of premolars appear between 9-13 years of age. The second set erupts in 11-13 years of age, and the last set erupts in 19-21 years of age. 20. The enzyme that is not present in succus entericus is- (NEET 2015) (a) lipase (b) maltase (c) nucleases (d) nucleosidase Ans. (c) Sol. Nuclease enzyme is a part of the pancreatic juice. Whereas enzymes such as disaccharidases (like maltase), lipase and nucleosidase are a part of intestinal juice which is also known as succus entericus. 21. Fructose is absorbed into the blood through mucosa cells of intestine by the process called (NEET 2014) (a) Active transport (b) Facilitated transport (c) Simple diffusion (d) Co-transport mechanism Ans. (b) Sol. Fructose is a monosaccharide which is absorbed through the villi blood vessels in the intestine. It is absorbed by the process of facilitated diffusion through GLUT-5 transporter. 22. Anxiety and eating spicy food together in an otherwise normal human, may lead to (AIPMT 2012) (a) Indigestion (b) Jaundice (c) Diarrhoea (d) Vomiting Ans. (a)
11 DIGESTION AND ABSORPTION Sol. Anxiety and spicy food together lead to indigestion as it causes a problem in proper secretion of gastric juices which include the enzyme and hydrochloric acid. This condition leads to improper digestion of food. 23. Two friends are eating together on a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of (AIPMT 2011) (a) Diaphragm (b) Neck (c) Tongue (d) Epiglottis Ans. (d) Sol. Epiglottis is a cartilage structure which prevents food from entering the windpipe while it is swallowed. However, during eating if one laughs or talks it can lead to improper movement of the epiglottis and the food might enter the windpipe. This will trigger coughing to eject the food particles out. 24. If for some reason our goblet cells are non-functional, this will adversely affect (AIPMT 2010) (a) Production of somatostatin (b) Secretion of sebum from the sebaceous glands (c) Maturation of sperms (d) Smooth movement of food down the intestine Ans. (d) Sol. The function of goblet cells is to release mucus in our small intestine. This allows proper movement and smooth passage of food in the lumen of small intestine. Hence, when affected, clogged food in the intestine can lead to congestion and ultimately constipation. 25. A young infant may be feeding entirely on mother's milk, which is white in colour but the stool, which the infant passes out is quite yellowish. What is this yellow colour due to? (AIPMT 2009) (a) Intestinal juice (b) Bile pigments passed through bile juice (c) Undigested milk protein casein (d) Pancreatic juice poured into duodenum Ans. (b) Sol. The yellow colour is due to the presence of bile pigments (bilirubin-yellow). Bile assists the digestion and absorption of fats by the action of bile salts. When the milk is digested in the stomach and then pass into the small intestine where its components will be absorbed, the bile and pancreatic juice is mixed with it. The excess and degraded bile pigments which are not required by the body give yellow colour to the stool.