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Question 1
Incorrect
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Which of the following forms an important constituent of the brush border on the microvilli of the intestinal epithelium?
Your Answer: None of the above
Correct Answer: Hydrolases
Explanation:There are certain enzymes which are part of the brush border cells including hydrolases also known as the brush border hydrolases. They perform the final step in digestion of certain nutrients.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 2
Correct
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HCL is secreted by which cells in the stomach
Your Answer: Parietal cells
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
- Medicine
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Question 3
Correct
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Which intestinal cells play a major role in secretory immunity?
Your Answer: M cells
Explanation:M cells are specialized epithelial cells of the MALT or mucosa-associated lymphoid tissues. They transport antigens from the intestinal lumen to cells of the immune system, thereby initiating an immune response. T and B cells are lymphocytes found in blood. Mucous cells secrete mucous and can be considered as a part of innate immunity. Chief cells in the gastric mucosa secret pepsin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 4
Correct
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Cholesterol is synthesized in all of these organs EXCEPT?
Your Answer: Stomach
Explanation:The liver primarily synthesizes about 20-25% of the total daily cholesterol. Cholesterol is also synthesized to smaller extents in the adrenal glands, reproductive organs (as cholesterol is the precursor of sex hormones), skin and is also produced in the intestines.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 5
Incorrect
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A patient with achalasia
Your Answer: Will have chronic oesophagitis
Correct Answer: Has decreased production of vasoactive intestinal polypeptide (VIP)
Explanation:Oesophageal achalasia is an oesophageal motility disorder involving the smooth muscle layer of the oesophagus and the lower oesophageal sphincter (LES). It is characterized by incomplete LES relaxation, increased LES tone, and lack of peristalsis of the oesophagus (inability of smooth muscle to move food down the oesophagus) in the absence of other explanations like cancer or fibrosis. In achalasia, there is loss of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) releasing inhibitory neurons.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 6
Incorrect
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The blood supply to the greater curvature of the stomach is via the:
Your Answer: Right and left gastric arteries
Correct Answer: Right and left gastro-epiploic arteries
Explanation:The blood supply to the greater curvature of the stomach is via the left and the right gastro-epiploic arteries branching from the splenic artery near the hilum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 7
Correct
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Which of the following is a product of D cells
Your Answer: Somatostatin
Explanation:Somatostatin is secreted by D cells, HCL and intrinsic factor secreted by parietal cells. Trefoil peptides are secreted by mucus secreting goblet cells and gastrin releasing peptide (grp) by post-ganglionic fibers of the vagus nerve (which innervate the G cells of the stomach).
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 8
Correct
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Di and tri peptides are absorbed via a different mechanism as amino acids, this is due to the working of which transporter?
Your Answer: PEPT 1
Explanation:GLUT and SGLT are glucose transporters. Peptides which are longer that four amino acids are not absorbed. There is abundant absorption of di and tri peptidases in the small intestine. They are absorbed into the epithelial cells of the small intestine via a transporter called PepT1 by co-transport with H+ ions.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 9
Incorrect
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One function of the liver is synthesis and storage of protein. Which of the following will result in hypoalbuminemia?
Your Answer: Nephropathy
Correct Answer: All of the above
Explanation:Both trauma and sepsis cause an acute inflammatory response causing plasma leakage of albumin. Nephropathy causes leakage of albumin from glomeruli and excretion of albumin in urine known as albuminuria. A hypercatabolic state is characterized by increased circulating catabolic hormones and increase break down of proteins.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 10
Incorrect
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Where does secretin work in the pancreas?
Your Answer: Acinar cells
Correct Answer: Pancreatic ducts
Explanation:Secretin, a hormone produced by the duodenal S cells in response to the stomach chyme containing high hydrogen atom concentration (high acidity), is released into the blood stream; upon return to the digestive tract, secretion decreases gastric emptying, increases secretion of the pancreatic ductal cells, as well as stimulating pancreatic acinar cells to release their zymogenic juice.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 11
Correct
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Where is Basic Electrical rhythm initiated
Your Answer: Interstitial cells of cajal
Explanation:The interstitial cells of Cajal are specialized pacemaker cells located in the wall of the stomach, small intestine, and large intestine. These cells are connected to the smooth muscle via gap junctions and the myenteric plexus. The cell membranes of the pacemaker cells undergo a rhythmic depolarization and repolarization from -65mV to -45mV. This rhythm of depolarization-repolarization of the cell membrane creates a slow wave known as a basic electrical rhythm (BER), and it is transmitted to the smooth muscle cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 12
Correct
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Which hormone results in the production of pancreatic juice rich in enzymes but low in volume?
Your Answer: Cholecystokinin
Explanation:Cholecystokinin (CCK) mediates digestion in the small intestine by inhibiting gastric emptying and decreasing gastric acid secretion. It stimulates the acinar cells of the pancreas to release a juice rich in pancreatic digestive enzymes, hence the old name pancreozymin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 13
Incorrect
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VIP, GIP and somatostatin play an inhibitory role in gastric acid secretion by inactivating?
Your Answer: Parietal cells
Correct Answer: G cells
Explanation:Gastrin is secreted from the G cells. VIP, GIP and somatostatin all inhibit acid production by inhibiting the G cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 14
Incorrect
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Which of the following initiates migrating motor complex
Your Answer: Acetylcholine
Correct Answer: Motilin
Explanation:Migrating motor complexes (MMC) are thought to be partially regulated by motilin, which is initiated in the stomach as a response to vagal stimulation, and does not directly depend on extrinsic nerves.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 15
Correct
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With regard to carbohydrate absorption, which sodium-dependent glucose transporter (SGLT) is responsible for the uptake of dietary glucose from the gut?
Your Answer: SGLT 1
Explanation:SGLT- Sodium-dependent glucose cotransporter or sodium-glucose linked transporter are family of proteins of different types. SGLT1 transporter is found in the intestinal mucosa of the small intestine.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 16
Correct
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Sympathetic supply to the stomach is derived from
Your Answer: T5-T9 spinal segments via the coeliac ganglion
Explanation:Parasympathetic innervation to the stomach is from the vagus nerve and the sympathetic innervation is from the T5-T9 spinal segments via the coeliac ganglion through the greater splanchnic nerve.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 17
Correct
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The sympathetic supply to the stomach comes from the:
Your Answer: Celiac plexus
Explanation:The vagus nerve supplies the stomach and up to proximal two-thirds of the large intestine and has parasympathetic stimulation. The sympathetic chain which begins at the level of he 1st thoracic vertebra and extends up to 3rd lumbar vertebra gives off the celiac plexus which mainly supplies the stomach. The mesenteric plexus mainly supplies the small intestine and is located below the celiac plexus in the sympathetic chain.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 18
Incorrect
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The lower oesophageal sphincter is under neural control. Which of the following causes contraction of the intrinsic sphincter?
Your Answer: Vasoactive intestinal polypeptide (VIP)
Correct Answer: Acetylcholine
Explanation:The lower oesophageal sphincter (LOS) is a specific region of the oesophageal circular smooth muscle. It allows the passage of a food bolus to the stomach and prevents the reflux of gastric contents into the oesophagus. The tone of the LOS is myogenic in origin and depends on smooth muscle properties that lead to the opening of Ca2+ channels but can also be modulated by enteric motor neurons, the parasympathetic and sympathetic extrinsic nervous system and several neurohumoral substances. Nitric oxide causes LOS relaxation. Acetylcholine and tachykinins are involved in the LOS contraction.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 19
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
- Medicine
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Question 20
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
- Medicine
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Question 21
Correct
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The oligosaccharidases responsible for further digestion of starch after breakdown by the above mentioned enzymes is located where?
Your Answer: Brush border of small intestine
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 known as the brush border. Thus, the enzymes embedded in those microvilli are referred to as brush border enzymes.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 22
Correct
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A patient with a VIPoma (VIP secreting tumour) is likely to exhibit which of the following?
Your Answer: Severe diarrhoea
Explanation:Vasoactive inhibitory peptide (VIP) is found in the nerves innervating the GIT. It markedly stimulates the secretion of intestinal electrolytes and also with them water. This results in secretary diarrhoea. Along with that it also relaxes intestinal smooth muscle including the sphincters, it also results in dilation of the peripheral blood vessels and along with this its also inhibits gastric acid secretions. A VIPoma will exaggerate all this.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 23
Correct
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The parietal cells of the stomach secrete which of the following?
Your 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
- Medicine
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Question 24
Incorrect
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Gastrin activates all of the following cells except:
Your Answer: Stomach smooth muscle
Correct Answer: Mucus neck cells
Explanation:The G cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasionally in the pancreas and duodenum. Gastrin-releasing peptide, as well as the presence of amino acids in the stomach, stimulates the release of gastrin from the G cells. Gastrin stimulates enterochromaffin-like cells to secrete histamine. Gastrin also targets parietal cells by increasing the amount of histamine and the direct stimulation by gastrin, causing the parietal cells to increase HCl secretion in the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 25
Incorrect
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Vagotomy leads to the following:
Your Answer: Dysfunction of antegrade neurons
Correct Answer: Irregular and chaotic peristalsis
Explanation:The Vagus nerve is primarily responsible for autonomic regulation involved in heart, lung and gastrointestinal function. The gastric branches supply the stomach. The right branch joins the celiac plexus and supplies the intestines. Vagotomy involves cutting of the vagus nerve or its branches which is a now-obsolete therapy that was performed for peptic ulcer disease. Vagotomy causes a decrease in peristalsis and a change in the emptying patterns of the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 26
Correct
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Which of the following enzymes is mainly responsible for the hydrolysis of polysaccharide 1:6a linkages?
Your Answer: Isomaltase
Explanation:Isomaltase is mainly responsible for hydrolysis of 1:6α linkages. Along with maltase and sucrase, it also breaks down maltotriose and maltose.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 27
Correct
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Which pair is correct concerning enteroendocrine cells in the GIT mucosa and their products?
Your 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
- Medicine
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Question 28
Incorrect
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What is the primary problem of achalasia
Your Answer: Neuronal death in lower oesophageal sphincter
Correct Answer: Deficiency of myenteric plexus at the lower oesophageal sphincter
Explanation:Oesophageal achalasia is an oesophageal motility disorder involving the smooth muscle layer of the oesophagus is characterized by the failure of the lower oesophageal sphincter (LES) relaxation and aperistalsis, caused primarily by the loss of the inhibitory innervation of the oesophageal myenteric plexus.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 29
Correct
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The pressure in the sinusoids is normally:
Your Answer: Lower than portal venous pressure
Explanation:The direction of transport of nutrients in the portal vein occurs from the portal vein to the hepatic sinusoids. Thus, he pressure of sinusoids should be lower than the pressure of he portal vein.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 30
Incorrect
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The following can cause steatorrhea except
Your Answer: Diseases of the distal ileum
Correct Answer: Diseases that destroy the endocrine portion of the pancreas
Explanation:Dietary fats and lipids are usually efficiently digested and over 90% absorbed. Impaired digestion or absorption can result in fatty stools. Possible causes include exocrine (not endocrine) pancreatic insufficiency, with poor digestion from lack of lipases, loss of bile salts, which reduces micelle formation, and small intestinal disease producing malabsorption. Various other causes including certain medicines that block fat absorption, or indigestible or excess oil/fat in diet.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 31
Correct
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Absorption of fructose is via:
Your Answer: Facilitated diffusion
Explanation:Dietary fructose may be ingested as a monosaccharide or as a disaccharide. Sucrose is hydrolysed by sucrase to produce equal amounts of glucose and fructose and in this form, is usually completely absorbed. Fructose is mostly absorbed in the small intestine through GLUT-5 transporter mediated facilitative diffusion. This is an energy independent process.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 32
Incorrect
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Histamine, acetylcholine and gastrin act by way of which second messengers in the release of acid by parietal cells:
Your Answer: Ca++
Correct Answer: A and D
Explanation:Acetylcholine, Histamine and Gastrin receptors are located on the basolateral membrane of the parietal cell and control its activity. Stimulation of these receptors modulates the levels of protein kinases in the cell and brings about the changes from a resting to stimulated structure. Protein kinase catalyses conversion of ATP to cyclic AMP which activates the proton pump. Calcium ions increase gastric acid secretion elicited by gastrin released through a vagal mechanism, and also by a direct effect on parietal cells.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 33
Incorrect
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The alpha amylases hydrolyse which linkages in the ingested polysaccharides?
Your Answer:
Correct Answer: 1:4α linkages
Explanation:Alfa amylase hydrolyses the α (1-4) glyosidic bonds in amylose and amylopectin and leave primarily maltose.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 34
Incorrect
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All of the following constitute small intestinal brush border enzymes except:
Your Answer:
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
- Medicine
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Question 35
Incorrect
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Anti-gastroesophageal reflux mechanisms include the following except:
Your Answer:
Correct Answer: Peristaltic movements of the oesophagus
Explanation:The lower oesophageal sphincter contracts preventing reflux of acid into the oesophagus. The sling muscles of the stomach, the crura of the diaphragm and the phreno-oesophageal ligament all play an important role in constricting the lower portion of the oesophagus and preventing reflux. Peristaltic movements do not stop the acid reflux.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 36
Incorrect
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The lamina propria contains all of the following except:
Your Answer:
Correct Answer: Neutrophils
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
- Medicine
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Question 37
Incorrect
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Where in the gastrointestinal tract are Brunner glands?
Your Answer:
Correct Answer: Duodenum
Explanation:Brunner’s glands (or duodenal glands) are compound tubular submucosal glands found in that portion of the duodenum which is above the hepatopancreatic sphincter (aka sphincter of Oddi). The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate) in order to:- protect the duodenum from the acidic content of chyme (which is introduced into the duodenum from the stomach);- provide an alkaline condition for the intestinal enzymes to be active, thus enabling absorption to take place; lubricate the intestinal walls.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 38
Incorrect
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G cells release which of the following substances
Your Answer:
Correct Answer: Gastrin
Explanation:The G cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasionally in the pancreas and duodenum. Gastrin-releasing peptide, as well as the presence of amino acids in the stomach, stimulates the release of gastrin from the G cells. Gastrin stimulates enterochromaffin-like cells to secrete histamine. Gastrin also targets parietal cells by increasing the amount of histamine and the direct stimulation by gastrin, causing the parietal cells to increase HCl secretion in the stomach.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 39
Incorrect
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What is the function of migrating motor complex
Your Answer:
Correct Answer: Clears the gut of luminal contents in preparation of the next meal
Explanation:Migrating motor complexes (MMC) are waves of electrical activity that sweep through the intestines in a regular cycle during fasting. These motor complexes trigger peristaltic waves, which facilitate transportation of indigestible substances such as bone, fiber, and foreign bodies from the stomach, through the small intestine, past the ileocecal sphincter, and into the colon. The MMC occurs every 90–120 minutes during the interdigestive phase (between meals), and is responsible for the rumbling experienced when hungry. It also serves to transport bacteria from the small intestine to the large intestine, and to inhibit the migration of colonic bacteria into the terminal ileum.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 40
Incorrect
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Regarding short-chain fatty acids, all the following are true except:
Your Answer:
Correct Answer: They are produced in the small intestine but their absorption occurs in the colon
Explanation:Short chain fatty acids (SCFAs) have carbon chains of 2-5 carbon atoms. They are produced in the large intestine and are also absorbed there. They exert a trophic effect on the colonic epithelial layer in absorption of sodium. In the absence of short chain fatty acids there is a loss of sodium and water. Transport of SCFA is coupled with sodium thus absorption leads to the accumulation in the lumen of HCO3, a rise in pH, fall in pCO2 and stimulation of Na+ and water transport. The effect on Na+ transport is thought to indicate the presence of a Na+/H+ exchange in the cell membrane.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 41
Incorrect
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Role of bile salts in digestion of fats include
Your Answer:
Correct Answer: Reduce surface tension, emulsification and transportation
Explanation:Bile acts to some extent as a surfactant reducing surface tension, helping to emulsify the lipids in food. Bile salt anions are hydrophilic on one side and hydrophobic on the other side; consequently, they tend to aggregate around droplets of lipids (triglycerides and phospholipids) to form micelles, with the hydrophobic sides towards the fat and hydrophilic sides facing outwards. The hydrophilic sides are negatively charged, and this charge prevents fat droplets coated with bile from re-aggregating into larger fat particles.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 42
Incorrect
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Which of the following proteins are NOT synthesized in the liver?
Your Answer:
Correct 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
- Medicine
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Question 43
Incorrect
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Which of the following can trigger parietal cell secretion?
Your Answer:
Correct Answer: Gastrin
Explanation:The three agonists of parietal cell secretion are gastrin, acetylcholine and histamine. Parietal cells are responsible for the secretion of HCl and intrinsic factor.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 44
Incorrect
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The central veins in the liver:
Your Answer:
Correct Answer: Coalesce to form the hepatic vein
Explanation:The central veins coalesce to form the hepatic vein which in turn drains into the inferior vena cava. The portal vein mainly carries blood from different parts of the GIT and is not drained to the inferior vena cava.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 45
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 it is used as a potent vasodilator.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 46
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
- Medicine
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Question 47
Incorrect
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What percentage of blood to the liver is supplied by hepatic artery?
Your Answer:
Correct Answer: 25%
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
- Medicine
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Question 48
Incorrect
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How are the long chain fatty acids (more than 10 to 12 carbon atoms) absorbed?
Your Answer:
Correct Answer: Re-esterified to triglycerides and enter the lymphatics as chylomicrons
Explanation:Short and medium chain fatty acids are absorbed into the blood via intestinal capillaries and travel through the portal vein. Long chain fatty acids are not directly released into the intestinal capillaries. They are re-esterified to triglycerides and are coated with cholesterol and protein, forming chylomicrons. Chylomicrons are released in the lymphatic system.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 49
Incorrect
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The pressure in the portal circulation is normally adjusted in the:
Your Answer:
Correct Answer: Sinusoids
Explanation:The pressure in the portal circulation depends on the pressure of the hepatic sinusoids mainly because the direction of transport of nutrients in the portal vein occurs from the portal vein to the hepatic sinusoids.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 50
Incorrect
-
Which of the following is NOT a component of bile?
Your Answer:
Correct 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
- Medicine
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Question 51
Incorrect
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In paralytic ileus the following are true except:
Your Answer:
Correct Answer: Opioid blocking drugs will exacerbate the symptoms
Explanation:Paralytic ileus causes adynamic intestinal obstruction or decreased peristalsis and the most common reason being postoperative ileus. Opioid drugs like morphine are given for pain management and cause decreased peristalsis in the gut resulting in constipation. Theoretically opioid blocking drugs or opioid antagonists can increase peristalsis and can alleviate paralytic ileus symptoms.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 52
Incorrect
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Which of the following is true with regard to the acini?
Your Answer:
Correct Answer: The central zone (Zone III) is the least oxygenated
Explanation:The acini are divided into zone I (periportal), zone II (transition zone), and zone III (pericentral). Cells located close to the portal triad or peripheral zone which consist of an arteriole from the hepatic artery are the most oxygenated cells. Cells in the central zone (III) are least oxygenated and mainly receive blood supply from the central vein which is a branch of hepatic vein.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 53
Incorrect
-
Where does most fat digestion begin?
Your Answer:
Correct Answer: Duodenum
Explanation:Digestion of some fats can begin in the mouth where lingual lipase breaks down some short chain lipids into diglycerides. However fats are mainly digested in the small intestine (in the duodenum). The presence of fat in the small intestine produces hormones that stimulate the release of pancreatic lipase from the pancreas and bile from the liver which helps in the emulsification of fats for absorption of fatty acids.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 54
Incorrect
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Question 55
Incorrect
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Which glucose transporter is responsible for the uptake of dietary glucose from the gut?
Your Answer:
Correct Answer: SGLT1
Explanation:SGLT 1 is responsible for the uptake of glucose via secondary active transport from the small intestine and the renal tubules.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 56
Incorrect
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The intestine is lined by:
Your Answer:
Correct Answer: Simple columnar epithelium
Explanation:In the small intestine, epithelium is simple columnar and specialised for absorption. The epithelium is arranged into villi, creating a brush border and increasing the area for absorption. The epithelium is simple columnar with microvilli.In the colon, epithelium is simple columnar and without villi. Goblet cells, which secrete mucous, are also present.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 57
Incorrect
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Interruption of the entero-hepatic circulation causes:
Your Answer:
Correct Answer: The amount of fat in the stool to be increased
Explanation:Enterohepatic circulation refers to the circulation of biliary acids, bilirubin, drugs, or other substances from the liver to the bile, followed by entry into the small intestine, absorption by the enterocyte and transport back to the liver. One of the causes of the interruption of enterohepatic circulation is the resection of the ileum where fat is mainly absorbed. Fat malabsorption results in increased fat in stools. Pale stools and dark urine is caused by obstruction of the biliary ductal system especially the common bile duct where urobilin and stercobilin are formed.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 58
Incorrect
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The following are synthesized in the liver EXCEPT?
Your Answer:
Correct Answer: Cholecystokinin
Explanation:The liver is responsible for the mainstay of protein metabolism, synthesis as well as degradation. It is also responsible for a large part of amino acid synthesis. The liver plays a role in the production of clotting factors as well as red blood cell production. Some of the proteins synthesized by the liver include coagulation factors I (fibrinogen), II (prothrombin), V, VII, VIII, IX, X, XI, XIII, as well as protein C, protein S and antithrombin. The liver is a major site of production for thrombopoietin, a glycoprotein hormone that regulates the production of platelets by the bone marrow. The liver also produces albumin, the most abundant protein in blood serum and angiotensinogen. Cholecystokinin, previously called pancreozymin, is synthesized and secreted by enteroendocrine cells in the duodenum
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 59
Incorrect
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Select the correct statement regarding cholecystokinin (CCK):
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. It is released (secreted) by your small intestine during the digestive process. It’s sometimes called pancreozymin.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 60
Incorrect
-
Which of the following is the most common route of hepatitis B transmission worldwide?
Your Answer:
Correct Answer: Perinatal transmission
Explanation:The virus is transmitted by exposure to infectious blood or body fluids. Infection around the time of birth or from contact with other people’s blood during childhood is the most frequent method by which hepatitis B is acquired in areas where the disease is common. In areas where the disease is rare, intravenous drug use and sexual intercourse are the most frequent routes of infection. Perinatal transmission is the most common and without intervention, a mother who is positive for HBsAg has a 20% risk of passing the infection to her offspring at the time of birth. This risk is as high as 90% if the mother is also positive for HBeAg.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 61
Incorrect
-
The haustral pattern seen in the normal colon is produced by
Your Answer:
Correct Answer: Taenia coli
Explanation:The haustra (singular haustrum) of the colon are the small pouches caused by sacculation (sac formation), which give the colon its segmented appearance. The teniae coli run the length of the large intestine. Because the taeniae coli are shorter than the intestine, the colon becomes sacculated between the taeniae coli, forming the haustra.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 62
Incorrect
-
Glucose absorption in the small intestine is coupled with which of the following electrolytes?
Your Answer:
Correct Answer: Na
Explanation:Sodium-glucose linked transporter are family of proteins of different types. SGLT1 transporter is found in the intestinal mucosa of the small intestine and absorbs glucose via cotransport of Na+ ions.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 63
Incorrect
-
The chief cells of the stomach secrete which of the following?
Your Answer:
Correct Answer: Pepsinogens
Explanation:A gastric chief cell (or peptic cell, or gastric zymogenic cell) is a type of cell in the stomach that releases pepsinogen and gastric lipase.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 64
Incorrect
-
Which of the following would provide relief from nausea and vomiting?
Your Answer:
Correct Answer: Cannabinoids
Explanation:Ondansetron, chlorpromazine and haloperidol are effective antiemetic agents. Corticosteroids, cannabinoids, and benzodiazepines, alone or in combination with 5-HT3 and D2 antagonists, are also useful in the treatment of vomiting produced by chemotherapy.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 65
Incorrect
-
Cholecystokinin causes the pancreas to
Your Answer:
Correct Answer: Produce pancreatic juice rich in enzymes
Explanation:Cholecystokinin (CCK) mediates digestion in the small intestine by inhibiting gastric emptying and decreasing gastric acid secretion. It stimulates the acinar cells of the pancreas to release a juice rich in pancreatic digestive enzymes, hence the old name pancreozymin. Together these enzymes catalyse the digestion of fat, protein, and carbohydrates.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 66
Incorrect
-
In addition to its role in digestion and absorption of fats, bile:
Your Answer:
Correct Answer: Is the major excretory route for lipid-soluble waste products
Explanation:The end product of haem metabolism is bilirubin and jaundice is caused by increased bilirubin levels in the blood. Gallstones are mainly caused by cholesterol and bile pigments. Bile is the main route of excretion for lipid soluble waste products whereas urine is the main route of excretion of water soluble waste products.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 67
Incorrect
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Which three parietal cell agonists bind at the basolateral membrane at specific receptors respectively: M3 , H2 , CCK-B, to stimulate acid secretion?
Your Answer:
Correct Answer: Acetylcholine, histamine , gastrin
Explanation:The three agonists of parietal cell secretion are gastrin, acetylcholine and histamine. Parietal cells are responsible for the secretion of HCl and intrinsic factor.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 68
Incorrect
-
H+ ions used in the production of acid by parietal cells is produced with the help of which enzyme?
Your Answer:
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
- Medicine
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Question 69
Incorrect
-
Peristalsis is an example of:
Your Answer:
Correct Answer: Enteric nervous system
Explanation:Peristalsis is a type of contraction where radial symmetrical contraction and relaxation of muscles propagates food in a downward wave through the gut. The enteric nervous system is one of the main divisions of the nervous system and consists of a mesh-like system of neurons that controls the function of the gastrointestinal tract. It has an independent reflex activity. The neurons of this system re collected into two types of ganglia: myenteric (or Auerbach’s) and submucosal (or Meissner’s plexuses). Myenteric plexuses are located between the inner and outer layers of the muscularis externa, while submucosal plexuses are located in the submucosa.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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Question 70
Incorrect
-
The pyloric sphincter is largely made up of thickening of
Your Answer:
Correct Answer: The circular muscle layer
Explanation:The pyloric sphincter, or valve, is a strong ring of smooth muscle (circular muscle layer) at the end of the pyloric canal which lets food pass from the stomach to the duodenum. It controls the outflow of gastric contents into the duodenum. It receives sympathetic innervation from the celiac ganglion.
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This question is part of the following fields:
- Gastrointestinal
- Medicine
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