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Question 1
Incorrect
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H+ ions used in the production of acid by parietal cells is produced with the help of which enzyme?
Your Answer: Gastrin
Correct Answer: Carbonic anhydrase ii
Explanation:Carbonic anhydrase enzyme catalyses the rapid interconversion of carbon dioxide and water to bicarbonate and protons (or vice versa). This is a reversible reaction that takes place in the gastric parietal cells.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 2
Correct
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Which of the following proteins are NOT synthesized in the liver?
Your Answer: Steroid
Explanation:Human steroidogenesis occurs in a number of locations:- Corticosteroids are produced in the adrenal cortex.- Oestrogen and progesterone are made primarily in the ovary and the placenta during pregnancy, and testosterone in the testes.- Testosterone is also converted to oestrogen to regulate the supply of each in females and males.- Some neurons and glia in the central nervous system (CNS) express the enzymes required for the local synthesis of pregnant neurosteroids, de novo or from peripheral sources.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 3
Correct
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The blood supply to the liver is by
Your Answer: Hepatic artery and hepatic portal vein
Explanation:The liver receives a dual blood supply from the hepatic portal vein and hepatic arteries. The hepatic portal vein delivers approximately 75% of the liver’s blood supply, and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 4
Incorrect
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Which of the following is not secreted by cells in the antrum of the stomach?
Your Answer: Somatostatin
Correct Answer: Hydrochloric acid
Explanation:Cells in the body of the stomach secrete mucus, HCl and pepsinogen. Cells in the antrum secrete pepsinogen, gastrin and mucus.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 5
Incorrect
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At rest, proton pumps are sequestered within the parietal cell in a series of membrane compartments known as:
Your Answer: Canaliculi
Correct Answer: Tubulovesicles
Explanation:The gastric H, K-ATPase pump, which pumps gastric acid (HCl), in the resting state is found in cytoplasmic tubular membranes. In the stimulated state this pump moves from the tubulovesicles to the apical membrane.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 6
Incorrect
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Colipase is secreted in an inactive form. Its activation in the intestinal lumen is by
Your Answer: Chymotrypsin
Correct Answer: Trypsin
Explanation:The enzyme trypsin exists in pancreatic juice in the inactive form trypsinogen, it is activated by the intestinal enterokinase in intestinal juice. Trypsin can then activate other protease enzymes and catalyse the reaction pro-colipase → colipase. Colipase is necessary, along with bile salts, to enable lipase function.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 7
Incorrect
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Absorption of protein antigens i.e. bacterial and viral proteins takes place in the:
Your Answer: Mucosa-associated lymphoid tissue
Correct Answer: Microfold cells (m cells) of the intestine
Explanation:M cells are specialized epithelial cells. They have a high capacity of transcytosis of microorganisms and macromolecules. They rapidly uptake antigens and present them to immune cells associated with the gut. In contrast to absorptive enterocytes, M cells do not exert direct defence mechanisms to antigens and pathogens in the intestinal cavity. Crypts of Lieberkühn are located mainly in the small intestine and large intestine and the main function is to replenish epithelial cells and to secrete intestinal enzymatic juice as well as mucous. Brunner’s glands empty into intestinal glands and their main function is to secrete mucin and to form a protective mucus layer on the duodenal epithelial cells to protect it from acidic chyme coming from the stomach. Islets of Langerhans are located in the pancreas and secrets insulin mainly. Mucosa associated lymphoid tissue plays a role in inducing immune response after presentation of antigens.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 8
Incorrect
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Question 9
Correct
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Carbohydrates digestion starts in the
Your Answer: Mouth
Explanation:Digestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the oesophagus from where it enters the stomach through the action of peristalsis.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 10
Incorrect
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The ATPase of parietal cells moves:
Your Answer: K+ from the gastric lumen in exchange for a Cl-
Correct Answer: H+ into the gastric lumen in exchange for a k+
Explanation:ATPase of the parietal cell is also known as the proton pump, which moves H+ ions into the gastric lumen in exchange for K+ ions into the cell.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 11
Correct
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Cells responsible for completely renewing the epithelium of the intestine are located:
Your Answer: At the base of the crypts
Explanation:Epithelial cells are renewed every 4-5 days through a process of renewal and migration. Renewal relies on proliferative cells or stem cells that reside at the crypt base of the intestinal glands. Crypts are epithelial invasions into the underlying connective tissue.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 12
Incorrect
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All of the following constitute small intestinal brush border enzymes except:
Your Answer: Isomaltase
Correct Answer: Alpha-amylase
Explanation:The final step in digestion of carbohydrates, which is conversion of disaccharides to absorbable monosaccharides occurs on the small intestinal epithelial cells. The enzymes responsible for this final stage of digestion are not freely found in the intestinal lumen, but they are found as integral membrane proteins in the plasma membrane of the epithelial cell. The apical plasma membrane of the intestinal epithelial cell has numerous microvilli which extend from the cell known as the brush border. Thus, the enzymes embedded in those microvilli are referred to as brush border enzymes. All these enzymes except alfa amylase are brush border enzymes. Alfa amylase is secreted by pancreatic acinar cells.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 13
Correct
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Where does protein digestion begin?
Your Answer: Stomach
Explanation:Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the small intestine.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 14
Incorrect
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Dietary starch is mainly:
Your Answer: Glucose
Correct Answer: Amylopectin
Explanation:Dietary starch consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight but depends in the plant. Glycogen, the glucose store of animals, is a more branched version of amylopectin.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 15
Correct
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Which of the following is NOT a component of bile?
Your Answer: Unconjugated bilirubin
Explanation:The composition of gallbladder bile is 97% water, 0.7% bile salts, 0.2% bilirubin, 0.51% fats (cholesterol, fatty acids and lecithin), and 200 meq/l inorganic salts (electrolytes).
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 16
Correct
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The cells that secrete pepsinogen and gastric lipase are found in which part of the stomach?
Your Answer: Body and antrum
Explanation:Stomach can be divided in to different regions. Cardia, fundus, body, antrum and pylorus from proximal end to distal end respectively. Cells that secret the inactive form of pepsin or pepsinogen are chief cells and are abundant in the body and the antral region of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 17
Incorrect
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Where is the myenteric plexus (Auerbach’s plexus) located in the GIT?
Your Answer:
Correct Answer: Between the outer longitudinal and middle circular muscle layers.
Explanation:A part of the enteric nervous system, the myenteric plexus exists between the longitudinal and circular layers of muscularis externa in the gastrointestinal tract. It is found in the muscles of the oesophagus, stomach, and intestine.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 18
Incorrect
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Which pair is correct concerning enteroendocrine cells in the GIT mucosa and their products?
Your Answer:
Correct Answer: D cells and somatostatin
Explanation:Somatostatin, an inhibitory hormone is secreted form the D cells of the Pancreatic Islets.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 19
Incorrect
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Regarding the anatomy of the intestine, the muscularis propria contains all of which of the following constituents?
Your Answer:
Correct Answer: Circular muscle, myenteric plexus, longitudinal muscle
Explanation:The muscularis mucosa/propria consists of the inner circular muscles and the outer longitudinal muscles. Between these muscles is the myenteric plexus.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 20
Incorrect
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The hepatic portal vein:
Your Answer:
Correct Answer: Carries mainly nutrients from the GIT.
Explanation:The portal vein contains oxygen as any other vein in the body does. The hepatic veins are responsible for venous drainage of the liver. The main function of the portal vein is to carry absorbed nutrients in the gut for metabolism and detoxification.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 21
Incorrect
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Which of the following acts on the pancreas to secrete pancreatic juice that is rich in enzymes?
Your Answer:
Correct Answer: CCK
Explanation:CCK has a primary action of increasing the motility of the gallbladder by contracting the muscles in the mucosa of the gall bladder. Apart from this, it augments the action of secretin resulting in the production of an alkaline pancreatic juice. It increases the synthesis of enterokinase, inhibits gastric emptying and may also enhance the motility of the small intestine and colon.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 22
Incorrect
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Which of the following is NOT a pancreatic enzyme?
Your Answer:
Correct Answer: Pepsinogen 1
Explanation:Pancreatic juice, composed of the secretions of both ductal and acinar cells, is made up of the following digestive enzymes:Trypsinogen, which is an inactive(zymogenic) protease that, once activated in the duodenum into trypsin, breaks down proteins at the basic amino acids. Trypsinogen is activated via the duodenal enzyme enterokinase into its active form trypsin.Colipase is a protein co-enzyme required for optimal enzyme activity of pancreatic lipase. It is secreted by the pancreas in an inactive form, procolipase, which is activated in the intestinal lumen by trypsin.Chymotrypsinogen, which is an inactive (zymogenic) protease that, once activated by duodenal enterokinase, breaks down proteins at their aromatic amino acids. Chymotrypsinogen can also be activated by trypsin.Carboxypeptidase, which is a protease that takes off the terminal amino acid group from a proteinSeveral elastases that degrade the protein elastin and some other proteins.Pancreatic lipase that degrades triglycerides into fatty acids and glycerol.Sterol esterasePhospholipaseSeveral nucleases that degrade nucleic acids, like DNase and RNase.Pancreatic amylase that breaks down starch and glycogen which are alpha-linked glucose polymers.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 23
Incorrect
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The infoldings or spaces between the bases of the villi are known as
Your Answer:
Correct Answer: Crypts of Lieberkühn
Explanation:An intestinal gland (also crypt of Lieberkühn and intestinal crypt) is a gland found in the intestinal epithelium lining of the small intestine and large intestine (colon) between the villi.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 24
Incorrect
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Pancreatic juice is usually?
Your Answer:
Correct Answer: Alkaline
Explanation:Pancreatic juice is alkaline in nature and has a high amount of bicarbonate ions. About 1500 ml is secreted every day. It also contains a large quantity of enzymes in the inactive form.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 25
Incorrect
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The lamina propria contains all of the following except:
Your Answer:
Correct Answer: Plasma cells
Explanation:The connective tissue of the lamina propria is very loose, allowing it to be very cell rich. The cell population of the lamina propria is variable and can include, for example, fibroblasts, lymphocytes, plasma cells, macrophages, eosinophilic leukocytes, and mast cells. It provides support and nutrition to the epithelium, as well as the means to bind to the underlying tissue.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 26
Incorrect
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Which of the following is responsible for transporting both glucose and fructose into the interstitium?
Your Answer:
Correct Answer: GLUT 2
Explanation:Absorption of glucose involves transport from the intestinal lumen, across the epithelium and into blood. The transporter that carries glucose and galactose into the enterocyte is the sodium-dependent hexose transporter, known as SGLT1. As the name indicates, this molecule transports both glucose and sodium ions into the cell. Once absorbed into the enterocyte, glucose must be exported from the cell into blood. Sodium is rapidly shuttled out in exchange for potassium by Na+/K+ ATPase pumps on the basolateral membrane, and that process maintains the electrochemical gradient across the epithelium. Glucose, galactose and fructose are transported out of the enterocyte into the interstitium and in turn into the blood through another hexose transporter (called GLUT-2) in the basolateral membrane. These monosaccharides then diffuse down a concentration gradient into capillary blood.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 27
Incorrect
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Select the correct statement regarding cholecystokinin:
Your Answer:
Correct Answer: It causes gallbladder contraction and pancreatic enzyme secretion.
Explanation:CCK has a primary action of increasing the motility of the gallbladder by contracting the muscles in the mucosa of the gall bladder. Apart from this, it augments the action of secretin, resulting in the production of an alkaline pancreatic juice. It increases the synthesis of enterokinase, inhibits gastric emptying and may also enhance the motility of the small intestine and colon.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 28
Incorrect
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Which enzyme facilitates the function of pancreatic lipase by increasing exposure of its active site?
Your Answer:
Correct Answer: Colipase
Explanation:Colipase is a co enzyme that optimize the activity of lipase by facilitating the exposure of its active sites.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 29
Incorrect
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Which of the following happens when anterograde neurons are stimulated?
Your Answer:
Correct Answer: Smooth muscle relaxation ahead of the stimulus
Explanation:Nitric oxide is thought to act as an anterograde neurotransmitter. Nitric oxide causes relaxation of smooth muscles ahead of the stimulus. Clinically used as a potent vasodilator.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 30
Incorrect
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The parietal cells of the stomach secrete which of the following?
Your Answer:
Correct Answer: Hydrochloric acid
Explanation:Parietal cells are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and in the body of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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