-
Question 1
Correct
-
A woman undergoes a high anterior resection for carcinoma of the upper rectum. Which one of the following vessels will require ligation?
Your Answer: Inferior mesenteric artery
Explanation:Anterior resection typically involves dividing the IMA, which is necessary for oncological reasons and also allows for adequate mobilization of the colon for anastomosis.
The colon begins with the caecum, which is the most dilated segment of the colon and is marked by the convergence of taenia coli. The ascending colon follows, which is retroperitoneal on its posterior aspect. The transverse colon comes after passing the hepatic flexure and becomes wholly intraperitoneal again. The splenic flexure marks the point where the transverse colon makes an oblique inferior turn to the left upper quadrant. The descending colon becomes wholly intraperitoneal at the level of L4 and becomes the sigmoid colon. The sigmoid colon is wholly intraperitoneal, but there are usually attachments laterally between the sigmoid and the lateral pelvic sidewall. At its distal end, the sigmoid becomes the upper rectum, which passes through the peritoneum and becomes extraperitoneal.
The arterial supply of the colon comes from the superior mesenteric artery and inferior mesenteric artery, which are linked by the marginal artery. The ascending colon is supplied by the ileocolic and right colic arteries, while the transverse colon is supplied by the middle colic artery. The descending and sigmoid colon are supplied by the inferior mesenteric artery. The venous drainage comes from regional veins that accompany arteries to the superior and inferior mesenteric vein. The lymphatic drainage initially follows nodal chains that accompany supplying arteries, then para-aortic nodes.
The colon has both intraperitoneal and extraperitoneal segments. The right and left colon are part intraperitoneal and part extraperitoneal, while the sigmoid and transverse colon are generally wholly intraperitoneal. The colon has various relations with other organs, such as the right ureter and gonadal vessels for the caecum/right colon, the gallbladder for the hepatic flexure, the spleen and tail of pancreas for the splenic flexure, the left ureter for the distal sigmoid/upper rectum, and the ureters, autonomic nerves, seminal vesicles, prostate, and urethra for the rectum.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 2
Correct
-
Sophie, a 5-year-old girl, visits her doctor with her mother, complaining of a lump in her groin that appears and disappears. The lump is easily reducible.
The doctor suspects an indirect inguinal hernia, although it is difficult to differentiate between femoral, direct inguinal, and indirect inguinal hernias in such a young patient.
Sophie's mother is curious about the cause of her daughter's hernia. What is the pathology of an indirect inguinal hernia?Your Answer: Protrusion through the failure of the processus vaginalis to regress
Explanation:Indirect inguinal hernias are caused by the failure of the processus vaginalis to regress, resulting in a protrusion through the deep inguinal ring and into the inguinal canal. In males, it may progress into the scrotum, while in females, it may enter the labia. This type of hernia is located lateral to the epigastric vessels.
On the other hand, direct inguinal hernias are usually caused by weakening in the abdominal musculature, which occurs with age. The protrusion enters the inguinal canal through the posterior wall, which is medial to the epigastric vessels. It may exit through the superficial inguinal ring.
The tunica vaginalis is a layer that surrounds the testes and contains a small amount of serous fluid, reducing friction between the scrotum and the testes. Meanwhile, the tunica albuginea is a layer of connective tissue that covers the ovaries, testicles, and corpora cavernosa of the penis.
Understanding Inguinal Hernias
Inguinal hernias are the most common type of abdominal wall hernias, with 75% of cases falling under this category. They are more prevalent in men, with a 25% lifetime risk of developing one. The main symptom is a lump in the groin area, which disappears when pressure is applied or when the patient lies down. Discomfort and aching are also common, especially during physical activity. However, severe pain is rare, and strangulation is even rarer.
The traditional classification of inguinal hernias into indirect and direct types is no longer relevant in clinical management. Instead, the current consensus is to treat medically fit patients, even if they are asymptomatic. A hernia truss may be an option for those who are not fit for surgery, but it has limited use in other patients. Mesh repair is the preferred method, as it has the lowest recurrence rate. Unilateral hernias are usually repaired through an open approach, while bilateral and recurrent hernias are repaired laparoscopically.
After surgery, patients are advised to return to non-manual work after 2-3 weeks for open repair and 1-2 weeks for laparoscopic repair. Complications may include early bruising and wound infection, as well as late chronic pain and recurrence. It is important to seek medical attention if any of these symptoms occur.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 3
Incorrect
-
A 24-year-old male patient visits the GP with recurring diarrhoea and urinary symptoms. The patient is currently undergoing tests for inflammatory bowel disease (IBD). He reports dysuria and describes his urine as dark brown and frothy. What aspect of IBD is likely responsible for these symptoms?
Your Answer: Skip lesions
Correct Answer: Fistula
Explanation:Fistulas are often seen in patients with Crohn’s disease due to the erosion of the submucosal layer, which can lead to full-thickness ulcers. If these ulcers penetrate the bowel and reach the bladder, they can create a pathway for undigested food to enter the bladder.
While bloody stool is commonly associated with ulcerative colitis (UC), it can also occur in Crohn’s disease. However, this symptom alone cannot explain the patient’s urinary tract infections or the passing of tomato skin.
Crypt abscesses are not present in Crohn’s disease and are only associated with UC. Therefore, they cannot explain the patient’s symptoms.
Goblet cell loss, which refers to the loss of mucin-secreting cells in the intestine, is only seen in UC and not in Crohn’s disease.
Inflammatory bowel disease (IBD) is a condition that includes two main types: Crohn’s disease and ulcerative colitis. Although they share many similarities in terms of symptoms, diagnosis, and treatment, there are some key differences between the two. Crohn’s disease is characterized by non-bloody diarrhea, weight loss, upper gastrointestinal symptoms, mouth ulcers, perianal disease, and a palpable abdominal mass in the right iliac fossa. On the other hand, ulcerative colitis is characterized by bloody diarrhea, abdominal pain in the left lower quadrant, tenesmus, gallstones, and primary sclerosing cholangitis. Complications of Crohn’s disease include obstruction, fistula, and colorectal cancer, while ulcerative colitis has a higher risk of colorectal cancer than Crohn’s disease. Pathologically, Crohn’s disease lesions can be seen anywhere from the mouth to anus, while ulcerative colitis inflammation always starts at the rectum and never spreads beyond the ileocaecal valve. Endoscopy and radiology can help diagnose and differentiate between the two types of IBD.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 4
Incorrect
-
A 59-year-old male arrives at the emergency department complaining of severe abdominal pain, vomiting, and swelling in the central abdomen.
During his last visit to his family doctor two weeks ago, he experienced colicky abdominal pain and was diagnosed with gallstones after further testing. He was scheduled for an elective cholecystectomy in 8 weeks.
The patient is administered pain relief and scheduled for an urgent abdominal X-ray (AXR).
What is the most probable finding on the AXR that indicates a cholecystoenteric fistula?Your Answer: Pneumoperitoneum
Correct Answer: Pneumobilia
Explanation:The presence of air in the gallbladder and biliary tree on an abdominal X-ray is most likely caused by a cholecystoenteric fistula. This is a serious complication of gallstones, particularly those larger than 2 cm, and can result in symptoms of small bowel obstruction such as severe abdominal pain, vomiting, and abdominal distension. While pneumoperitoneum may also be present in cases of cholecystoenteric fistula, it is not a specific finding and can be caused by other factors that weaken or tear hollow viscus organs. On the other hand, the presence of an appendicolith, a small calcified stone in the appendix, is highly indicative of appendicitis in patients with right iliac fossa pain and other associated symptoms, but is not seen in cases of cholecystoenteric fistula on an abdominal X-ray.
Gallstones are a common condition, with up to 24% of women and 12% of men affected. Local infection and cholecystitis may develop in up to 30% of cases, and 12% of patients undergoing surgery will have stones in the common bile duct. The majority of gallstones are of mixed composition, with pure cholesterol stones accounting for 20% of cases. Symptoms typically include colicky right upper quadrant pain that worsens after fatty meals. Diagnosis is usually made through abdominal ultrasound and liver function tests, with magnetic resonance cholangiography or intraoperative imaging used to confirm suspected bile duct stones. Treatment options include expectant management for asymptomatic gallstones, laparoscopic cholecystectomy for symptomatic gallstones, and surgical management for stones in the common bile duct. ERCP may be used to remove bile duct stones, but carries risks such as bleeding, duodenal perforation, cholangitis, and pancreatitis.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 5
Correct
-
A patient with moderate gastro-oesophageal reflux disease undergoes upper gastrointestinal endoscopy and biopsy. Upon examination of the biopsy specimen, the pathologist observes that the original epithelium of the oesophagus (A) has been substituted by a distinct type of epithelium (B) that is typically present in the intestine.
What is the epithelium (B) that the pathologist is most likely to have identified?Your Answer: Columnar epithelium
Explanation:Barrett’s oesophagus is characterized by the replacement of the original stratified squamous epithelium with columnar epithelium, which is typically found lining the intestines. Simple cuboidal epithelium is present in small gland ducts, kidney tubules, and secretory portions. Pseudostratified columnar epithelium is found in the upper respiratory tract and trachea, while stratified squamous epithelium lines areas that experience tension, such as the mouth, oesophagus, and vagina.
Barrett’s oesophagus is a condition where the lower oesophageal mucosa is replaced by columnar epithelium, which increases the risk of oesophageal adenocarcinoma by 50-100 fold. It is usually identified during an endoscopy for upper gastrointestinal symptoms such as dyspepsia, as there are no screening programs for it. The length of the affected segment determines the chances of identifying metaplasia, with short (<3 cm) and long (>3 cm) subtypes. The prevalence of Barrett’s oesophagus is estimated to be around 1 in 20, and it is identified in up to 12% of those undergoing endoscopy for reflux.
The columnar epithelium in Barrett’s oesophagus may resemble that of the cardiac region of the stomach or that of the small intestine, with goblet cells and brush border. The single strongest risk factor for Barrett’s oesophagus is gastro-oesophageal reflux disease (GORD), followed by male gender, smoking, and central obesity. Alcohol is not an independent risk factor for Barrett’s, but it is associated with both GORD and oesophageal cancer. Patients with Barrett’s oesophagus often have coexistent GORD symptoms.
The management of Barrett’s oesophagus involves high-dose proton pump inhibitor, although the evidence base for its effectiveness in reducing the progression to dysplasia or inducing regression of the lesion is limited. Endoscopic surveillance with biopsies is recommended every 3-5 years for patients with metaplasia but not dysplasia. If dysplasia of any grade is identified, endoscopic intervention is offered, such as radiofrequency ablation, which is the preferred first-line treatment, particularly for low-grade dysplasia, or endoscopic mucosal resection.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 6
Correct
-
A 45-year-old man experiences a pelvic fracture with a complication involving the junction of the membranous urethra and bulbar urethra. What is the most probable direction for the leaked urine to flow?
Your Answer: Anteriorly into the connective tissues surrounding the scrotum
Explanation:The superficial perineal pouch is a compartment that is bordered superficially by the superficial perineal fascia, deep by the perineal membrane (which is the inferior fascia of the urogenital diaphragm), and laterally by the ischiopubic ramus. It contains various structures such as the crura of the penis or clitoris, muscles, viscera, blood vessels, nerves, the proximal part of the spongy urethra in males, and the greater vestibular glands in females. In cases of urethral rupture, the urine will tend to pass forward because the fascial condensations will prevent the urine from passing laterally and posteriorly.
The Urogenital Triangle and Superficial Perineal Pouch
The urogenital triangle is a structure formed by the ischiopubic inferior rami and ischial tuberosities, with a fascial sheet attached to its sides, creating the inferior fascia of the urogenital diaphragm. It serves as a pathway for the urethra in males and both the urethra and vagina in females. The membranous urethra is located deep to this structure and is surrounded by the external urethral sphincter.
In males, the superficial perineal pouch lies superficial to the urogenital diaphragm and contains the bulb of the penis, crura of the penis, superficial transverse perineal muscle, posterior scrotal arteries, and posterior scrotal nerves. Meanwhile, in females, the internal pudendal artery branches to become the posterior labial arteries in the superficial perineal pouch.
Understanding the anatomy of the urogenital triangle and superficial perineal pouch is crucial in diagnosing and treating urogenital disorders. Proper knowledge of these structures can aid in the identification of potential issues and the development of effective treatment plans.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 7
Incorrect
-
A 63-year-old man arrives at the emergency department complaining of dizziness and haematemesis that started 2 hours ago. He has a medical history of hypertension and type 2 diabetes mellitus.
The patient is stabilized after receiving 2 litres of normal saline for fluid resuscitation. The next day, a gastroscopy is performed, revealing a peptic ulcer that is no longer actively bleeding. The CLO test is positive, indicating the presence of the likely organism.
What is the name of the enzyme secreted by this organism to aid its survival in the stomach?Your Answer: Trypsin
Correct Answer: Urease
Explanation:Helicobacter pylori uses urease to survive in the stomach by neutralizing gastric acid. This enzyme produces ammonia, which creates a more suitable environment for bacterial growth. The patient’s CLO positive peptic ulcer is consistent with a Helicobacter pylori infection. It is important to note that Helicobacter pylori does not use arginase, beta-lactamase, protease, or trypsin to neutralize stomach acid.
Helicobacter pylori: A Bacteria Associated with Gastrointestinal Problems
Helicobacter pylori is a type of Gram-negative bacteria that is commonly associated with various gastrointestinal problems, particularly peptic ulcer disease. This bacterium has two primary mechanisms that allow it to survive in the acidic environment of the stomach. Firstly, it uses its flagella to move away from low pH areas and burrow into the mucous lining to reach the epithelial cells underneath. Secondly, it secretes urease, which converts urea to NH3, leading to an alkalinization of the acidic environment and increased bacterial survival.
The pathogenesis mechanism of Helicobacter pylori involves the release of bacterial cytotoxins, such as the CagA toxin, which can disrupt the gastric mucosa. This bacterium is associated with several gastrointestinal problems, including peptic ulcer disease, gastric cancer, B cell lymphoma of MALT tissue, and atrophic gastritis. However, its role in gastro-oesophageal reflux disease (GORD) is unclear, and there is currently no role for the eradication of Helicobacter pylori in GORD.
The management of Helicobacter pylori infection involves a 7-day course of treatment with a proton pump inhibitor, amoxicillin, and either clarithromycin or metronidazole. For patients who are allergic to penicillin, a proton pump inhibitor, metronidazole, and clarithromycin are used instead.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 8
Correct
-
A 50-year-old male presents to his primary care physician with complaints of edema around his eyes and ankles. Upon further inquiry, he reports having foamy urine and is diagnosed with hypertension. The physician suggests that a biopsy of the affected organ would be the most informative diagnostic tool.
Considering the organ most likely involved in his symptoms, what would be the optimal approach for obtaining a biopsy?Your Answer: Posteriorly, inferior to the 12 rib and adjacent to the spine
Explanation:The safest way to access the kidneys is from the patient’s back, as they are retroperitoneal structures. Attempting to access them from the front or side would involve passing through the peritoneum, which increases the risk of infection. The kidneys are located near the spine and can be accessed below the 12th rib.
The retroperitoneal structures are those that are located behind the peritoneum, which is the membrane that lines the abdominal cavity. These structures include the duodenum (2nd, 3rd, and 4th parts), ascending and descending colon, kidneys, ureters, aorta, and inferior vena cava. They are situated in the back of the abdominal cavity, close to the spine. In contrast, intraperitoneal structures are those that are located within the peritoneal cavity, such as the stomach, duodenum (1st part), jejunum, ileum, transverse colon, and sigmoid colon. It is important to note that the retroperitoneal structures are not well demonstrated in the diagram as the posterior aspect has been removed, but they are still significant in terms of their location and function.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 9
Incorrect
-
Which one of the following statements relating to the pancreas is not true?
Your Answer: The fundus is usually intra peritoneal
Correct Answer: Cholecystokinin causes relaxation of the gallbladder
Explanation:The contraction of the gallbladder is caused by CCK.
The gallbladder is a sac made of fibromuscular tissue that can hold up to 50 ml of fluid. Its lining is made up of columnar epithelium. The gallbladder is located in close proximity to various organs, including the liver, transverse colon, and the first part of the duodenum. It is covered by peritoneum and is situated between the right lobe and quadrate lobe of the liver. The gallbladder receives its arterial supply from the cystic artery, which is a branch of the right hepatic artery. Its venous drainage is directly to the liver, and its lymphatic drainage is through Lund’s node. The gallbladder is innervated by both sympathetic and parasympathetic nerves. The common bile duct originates from the confluence of the cystic and common hepatic ducts and is located in the hepatobiliary triangle, which is bordered by the common hepatic duct, cystic duct, and the inferior edge of the liver. The cystic artery is also found within this triangle.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 10
Correct
-
A 50-year-old woman presents with an unknown cause of jaundice. She noticed the yellowing of her skin and eyes in the mirror that morning. Upon examination, a palpable mass is found in the right upper quadrant of her abdomen. Her lab results show a total bilirubin level of 124 umol/L and high levels of conjugated bilirubin in her urine. What is the most probable diagnosis?
Your Answer: Cholangiocarcinoma
Explanation:To correctly diagnose this patient, knowledge of Courvoisier’s sign is necessary. This sign indicates that a palpable gallbladder in the presence of painless jaundice is unlikely to be caused by gallstones. Therefore, biliary colic is an incorrect answer as it is a painful condition. Haemolytic anaemia is also an incorrect answer as the blood test results would differ from this patient’s results. The correct answer is cholangiocarcinoma, which is a cancer of the biliary tree that can cause painless obstructive jaundice. Gilbert’s syndrome is not the most appropriate answer as it only presents with a raised bilirubin and does not cause an increase in ALP.
Understanding Cholangiocarcinoma
Cholangiocarcinoma, also known as bile duct cancer, is a serious medical condition that can be caused by primary sclerosing cholangitis. This disease is characterized by persistent biliary colic symptoms, which can be accompanied by anorexia, jaundice, and weight loss. In some cases, a palpable mass in the right upper quadrant may be present, which is known as the Courvoisier sign. Additionally, periumbilical lymphadenopathy (Sister Mary Joseph nodes) and left supraclavicular adenopathy (Virchow node) may be seen.
One of the main risk factors for cholangiocarcinoma is primary sclerosing cholangitis. This condition can cause inflammation and scarring of the bile ducts, which can lead to the development of cancer over time. To detect cholangiocarcinoma in patients with primary sclerosing cholangitis, doctors often use a blood test to measure CA 19-9 levels.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 11
Incorrect
-
A 65-year-old obese male presents with recurrent episodes of colicky pain and bloating in the left iliac fossa. The patient has no significant medical history but has been a smoker for 25 years and does not consume alcohol. He works at a fast-food restaurant and usually eats his meals there.
Upon examination, the patient's vital signs are stable with a temperature of 37ºC, respiratory rate of 14 breaths per minute, oxygen saturations of 99% on air, heart rate of 60 beats per minute, and blood pressure of 125/70 mmHg. Abdominal and digital rectal examination reveal no significant findings. A colonoscopy was subsequently performed, which revealed multiple diverticula along the sigmoid colon.
What is the most appropriate course of management for this patient?Your Answer: Encourage smoking cessation
Correct Answer: Encourage high-fibre diet
Explanation:The development of intestinal diverticula is strongly linked to a low fibre diet, making it a major risk factor. To manage mild symptoms, patients are advised to modify their diet by gradually increasing fibre intake over several weeks and staying hydrated.
IV antibiotics and fluids are not necessary for diverticular disease, as it is not the same as diverticulitis.
Surgery is not recommended for uncomplicated diverticular disease.
While encouraging smoking cessation is important, dietary modification is the most suitable option for this patient.
Diverticulosis is a common condition where multiple outpouchings occur in the bowel wall, typically in the sigmoid colon. It is more accurate to use the term diverticulosis when referring to the presence of diverticula, while diverticular disease is reserved for symptomatic patients. Risk factors for this condition include a low-fibre diet and increasing age. Symptoms of diverticulosis can include altered bowel habits and colicky left-sided abdominal pain. A high-fibre diet is often recommended to alleviate these symptoms.
Diverticulitis is a complication of diverticulosis where one of the diverticula becomes infected. The typical presentation includes left iliac fossa pain and tenderness, anorexia, nausea, vomiting, diarrhea, and signs of infection such as pyrexia, raised WBC, and CRP. Mild attacks can be treated with oral antibiotics, while more severe episodes require hospitalization. Treatment involves nil by mouth, intravenous fluids, and intravenous antibiotics such as a cephalosporin and metronidazole. Complications of diverticulitis include abscess formation, peritonitis, obstruction, and perforation.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 12
Incorrect
-
An 80-year-old man comes to his doctor with a complaint of dysphagia that has been going on for three months. Initially, he could swallow some solid foods, but now he is only able to eat pureed foods. He has no difficulty swallowing liquids. He has a history of heavy smoking and alcohol consumption and is currently taking omeprazole for heartburn. He has lost a significant amount of weight due to his reduced caloric intake.
What is the likely cause of his dysphagia?Your Answer: Gastro-oesophageal reflux disease (GORD) is likely to be the cause of her dysphagia
Correct Answer: There is likely a structural disorder of the oesophagus
Explanation:If a person has difficulty swallowing only solids, it is likely due to a structural disorder in the oesophagus such as cancer, strictures, or webs/rings. On the other hand, if they have difficulty swallowing both liquids and solids, it is probably due to a motility disorder in the oesophagus such as achalasia, scleroderma, or nutcracker oesophagus.
If the dysphagia is progressive, it may indicate cancer as the cause, as the ability to swallow foods that were previously manageable becomes increasingly difficult over time. Weight loss could also be a result of either cancer or reduced food intake.
It is important to note that although GORD can cause heartburn, it is not a likely cause of dysphagia.
Understanding Dysphagia and its Causes
Dysphagia, or difficulty in swallowing, can be caused by various conditions affecting the oesophagus, including cancer, oesophagitis, candidiasis, achalasia, pharyngeal pouch, systemic sclerosis, myasthenia gravis, and globus hystericus. These conditions have distinct features that can help in their diagnosis, such as weight loss and anorexia in oesophageal cancer, heartburn in oesophagitis, dysphagia of both liquids and solids in achalasia, and anxiety in globus hystericus. Dysphagia can also be classified as extrinsic, intrinsic, or neurological, depending on the underlying cause.
To diagnose dysphagia, patients usually undergo an upper GI endoscopy, a full blood count, and fluoroscopic swallowing studies. Additional tests, such as ambulatory oesophageal pH and manometry studies, may be needed for specific conditions. It’s important to note that new-onset dysphagia is a red flag symptom that requires urgent endoscopy, regardless of age or other symptoms. By understanding the causes and features of dysphagia, healthcare professionals can provide timely and appropriate management for their patients.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 13
Incorrect
-
A 50-year-old man is admitted to the general medical ward with complaints of abdominal crampy pain and diarrhoea. He has had five loose stools in the past 24 hours. The patient was diagnosed with a lung abscess three days ago and is currently being treated with cefaclor in the ward. His blood pressure is 120/70 mmHg, pulse rate is 98 beats per minute, and temperature is 38.2 ºC. Blood investigations reveal Hb of 135 g/L, platelets of 280 * 109/L, and WBC of 13.4 * 109/L. A stool sample is sent for testing, and the results show the presence of gram-positive bacteria. The consultant prescribes metronidazole along with bezlotoxumab that binds to the toxin B of this bacterium. What is the most likely organism responsible for this patient's condition?
Your Answer: Escherichia coli
Correct Answer: Clostridium difficile
Explanation:Bezlotoxumab targets the Clostridium difficile toxin B, making it a monoclonal antibody used for treatment. Clostridium difficile is a gram-positive rod that can cause diarrhoea and abdominal pain when normal gut flora is suppressed by broad-spectrum antibiotics. Bacillus cereus, Campylobacter jejuni, and Escherichia coli are incorrect answers as they are either associated with different symptoms or are gram-negative, making bezlotoxumab ineffective for their treatment.
Clostridium difficile is a type of bacteria that is commonly found in hospitals. It produces a toxin that can damage the intestines and cause a condition called pseudomembranous colitis. This bacteria usually develops when the normal gut flora is disrupted by broad-spectrum antibiotics, with second and third generation cephalosporins being the leading cause. Other risk factors include the use of proton pump inhibitors. Symptoms of C. difficile infection include diarrhea, abdominal pain, and a raised white blood cell count. The severity of the infection can be determined using the Public Health England severity scale.
To diagnose C. difficile infection, a stool sample is tested for the presence of the C. difficile toxin. Treatment involves reviewing current antibiotic therapy and stopping antibiotics if possible. For a first episode of infection, oral vancomycin is the first-line therapy for 10 days, followed by oral fidaxomicin as second-line therapy and oral vancomycin with or without IV metronidazole as third-line therapy. Recurrent infections may require different treatment options, such as oral fidaxomicin within 12 weeks of symptom resolution or oral vancomycin or fidaxomicin after 12 weeks of symptom resolution. In life-threatening cases, oral vancomycin and IV metronidazole may be used, and surgery may be considered with specialist advice. Other therapies, such as bezlotoxumab and fecal microbiota transplant, may also be considered for preventing recurrences in certain cases.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 14
Correct
-
A 25-year-old male with Gilbert's syndrome (GS) visits his doctor worried about a recent change in skin tone. During the examination, his skin appears to be normal, but he insists that it was yellow earlier today.
What is true about Gilbert's syndrome?Your Answer: Transient jaundice after physiological stress such as exercise and fasting is seen in Gilbert’s syndrome
Explanation:Gilbert’s syndrome is a harmless liver condition that is characterized by increased levels of bilirubin in the blood. While some individuals may not experience any symptoms, others may develop temporary jaundice following physical stressors such as fasting or exercise. Treatment and regular monitoring are not necessary for this condition. It is important to reassure patients that Gilbert’s syndrome does not progress to chronic liver disease. The condition is caused by a mutation in the UGT1A1 gene, which leads to reduced activity of the UGT1A1 enzyme. Gilbert’s syndrome is more prevalent in males.
Gilbert’s syndrome is a genetic disorder that affects the way bilirubin is processed in the body. It is caused by a deficiency of UDP glucuronosyltransferase, which leads to unconjugated hyperbilirubinemia. This means that bilirubin is not properly broken down and eliminated from the body, resulting in jaundice. However, jaundice may only be visible during certain conditions such as fasting, exercise, or illness. The prevalence of Gilbert’s syndrome is around 1-2% in the general population.
To diagnose Gilbert’s syndrome, doctors may look for a rise in bilirubin levels after prolonged fasting or the administration of IV nicotinic acid. However, treatment is not necessary for this condition. While the exact mode of inheritance is still debated, it is known to be an autosomal recessive disorder.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 15
Incorrect
-
A 36-year-old female patient presents to her GP with complaints of epigastric pain that worsens after consuming takeaways or alcohol. During the consultation, she also reports experiencing a cough at night. The doctor diagnoses her with GORD, which is caused by the irritation of stomach acid (H+) released by cells stimulated by which hormone?
Which cell type is stimulated by gastrin?Your Answer: G cells
Correct Answer: Gastric parietal cells
Explanation:Gastrin stimulates gastric parietal cells to increase their secretion of H+. The hormone is released by G cells in the stomach and acts on the parietal cells to enhance their production of H+. It is important to note that G cells do not release H+ themselves, but rather release gastrin to stimulate the parietal cells. Other cell types in the stomach, such as gastric chief cells and gastric mucosal cells, have different functions and do not secrete H+ in response to gastrin.
Overview of Gastrointestinal Hormones
Gastrointestinal hormones play a crucial role in the digestion and absorption of food. These hormones are secreted by various cells in the stomach and small intestine in response to different stimuli such as the presence of food, pH changes, and neural signals.
One of the major hormones involved in food digestion is gastrin, which is secreted by G cells in the antrum of the stomach. Gastrin increases acid secretion by gastric parietal cells, stimulates the secretion of pepsinogen and intrinsic factor, and increases gastric motility. Another hormone, cholecystokinin (CCK), is secreted by I cells in the upper small intestine in response to partially digested proteins and triglycerides. CCK increases the secretion of enzyme-rich fluid from the pancreas, contraction of the gallbladder, and relaxation of the sphincter of Oddi. It also decreases gastric emptying and induces satiety.
Secretin is another hormone secreted by S cells in the upper small intestine in response to acidic chyme and fatty acids. Secretin increases the secretion of bicarbonate-rich fluid from the pancreas and hepatic duct cells, decreases gastric acid secretion, and has a trophic effect on pancreatic acinar cells. Vasoactive intestinal peptide (VIP) is a neural hormone that stimulates secretion by the pancreas and intestines and inhibits acid secretion.
Finally, somatostatin is secreted by D cells in the pancreas and stomach in response to fat, bile salts, and glucose in the intestinal lumen. Somatostatin decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, and decreases insulin and glucagon secretion. It also inhibits the trophic effects of gastrin and stimulates gastric mucous production.
In summary, gastrointestinal hormones play a crucial role in regulating the digestive process and maintaining homeostasis in the gastrointestinal tract.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 16
Incorrect
-
A 35-year-old man is suspected of having appendicitis. During surgery, an inflamed Meckel's diverticulum is discovered. What is the vessel responsible for supplying blood to a Meckel's diverticulum?
Your Answer: Internal iliac artery
Correct Answer: Vitelline artery
Explanation:The Meckel’s arteries, which are typically sourced from the ileal arcades, provide blood supply to the vitelline.
Meckel’s diverticulum is a congenital diverticulum of the small intestine that is a remnant of the omphalomesenteric duct. It occurs in 2% of the population, is 2 feet from the ileocaecal valve, and is 2 inches long. It is usually asymptomatic but can present with abdominal pain, rectal bleeding, or intestinal obstruction. Investigation includes a Meckel’s scan or mesenteric arteriography. Management involves removal if narrow neck or symptomatic, with options between wedge excision or formal small bowel resection and anastomosis. Meckel’s diverticulum is typically lined by ileal mucosa but ectopic gastric, pancreatic, and jejunal mucosa can also occur.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 17
Incorrect
-
A 72-year-old retired fisherman presents with a sudden episode of rectal bleeding. The bleeding was significant and included clots. He feels dizzy and has collapsed.
He reports experiencing heartburn regularly and takes lisinopril and bendroflumethiazide for hypertension, as well as aspirin and ibuprofen for hangovers. He drinks six large whisky measures and smokes 10 cigarettes daily.
During examination, he is apyrexial, his heart rate is 106 bpm, blood pressure is 108/74 mmHg, and his respiratory rate is 18. He appears pale and has epigastric tenderness.
What is the immediate action that should be taken?Your Answer: Give 1litre 0.9% NaCl over eight hours
Correct Answer: Give 1litre 0.9% NaCl over one hour
Explanation:Urgent Resuscitation Needed for Patient in Hypovolaemic Shock
A patient is experiencing hypovolaemic shock and requires immediate infusion of colloid or crystalloid. Waiting for eight hours is not an option, and dextrose is not recommended as it quickly moves out of the intravascular space. The patient will undergo endoscopy, but only after initial resuscitation. While regular omeprazole may help prevent recurrence, it is not urgent.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 18
Incorrect
-
A 50-year-old man has been experiencing reflux oesophagitis for a prolonged period. In a recent endoscopy, a biopsy is obtained from the distal oesophagus. The histopathology report reveals the presence of cells with coarse chromatin and abnormal mitoses, which are limited to the superficial epithelial layer. What is the cause of this process?
Your Answer: Infection with Helicobacter pylori
Correct Answer: Dysplasia
Explanation:Dysplasia is a condition that is considered pre-cancerous. It typically arises due to prolonged exposure to certain triggers. However, it may be possible to reverse these changes by eliminating the triggers. It is important to note that dysplasia involves the replacement of differentiated cells with abnormal cells, but it is not the same as metaplasia. Unlike cancer, dysplasia does not involve the invasion of surrounding tissues.
Understanding Dysplasia: A Premalignant Condition
Dysplasia is a premalignant condition characterized by disordered growth and differentiation of cells. It is a condition where there is an alteration in the size, shape, and organization of cells, resulting in increased abnormal cell growth, including an increased number of mitoses/abnormal mitoses and cellular differentiation. Dysplasia is often caused by factors such as smoking, Helicobacter pylori, and Human papillomavirus.
One of the main differences between dysplasia and metaplasia is that dysplasia is considered to be part of carcinogenesis (pre-cancerous) and is associated with a delay in the maturation of cells rather than differentiated cells replacing one another. Another key difference is that the underlying connective tissue is not invaded in dysplasia, which differentiates it from invasive malignancy.
It is important to note that severe dysplasia with foci of invasion is well recognized. Therefore, early detection and treatment of dysplasia are crucial in preventing the development of invasive malignancy. Understanding dysplasia and its causes can help individuals take preventive measures and seek medical attention if necessary.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 19
Incorrect
-
A 55-year-old woman presents to the emergency department complaining of vomiting and a severe headache that developed after experiencing blurred vision. The physician prescribes an antiemetic. Which of the following antiemetics aids in gastric emptying?
Your Answer: Cyclizine
Correct Answer: Metoclopramide
Explanation:The effectiveness of antiemetics depends on their ability to interact with different receptors to varying degrees. Therefore, the selection of an antiemetic will be based on the patient’s condition and the underlying cause of their nausea.
Metoclopramide functions as a dopamine antagonist, but it also has an agonistic impact on peripheral 5HT3 receptors and an antagonistic effect on muscarinic receptors, which helps to facilitate gastric emptying.
Understanding the Mechanism and Uses of Metoclopramide
Metoclopramide is a medication primarily used to manage nausea, but it also has other uses such as treating gastro-oesophageal reflux disease and gastroparesis secondary to diabetic neuropathy. It is often combined with analgesics for the treatment of migraines. However, it is important to note that metoclopramide has adverse effects such as extrapyramidal effects, acute dystonia, diarrhoea, hyperprolactinaemia, tardive dyskinesia, and parkinsonism. It should also be avoided in bowel obstruction but may be helpful in paralytic ileus.
The mechanism of action of metoclopramide is quite complicated. It is primarily a D2 receptor antagonist, but it also has mixed 5-HT3 receptor antagonist/5-HT4 receptor agonist activity. Its antiemetic action is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone, and at higher doses, the 5-HT3 receptor antagonist also has an effect. The gastroprokinetic activity is mediated by D2 receptor antagonist activity and 5-HT4 receptor agonist activity.
In summary, metoclopramide is a medication with multiple uses, but it also has adverse effects that should be considered. Its mechanism of action is complex, involving both D2 receptor antagonist and 5-HT3 receptor antagonist/5-HT4 receptor agonist activity. Understanding the uses and mechanism of action of metoclopramide is important for its safe and effective use.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 20
Incorrect
-
A 50-year-old woman is suspected to have hepatitis B. She presents with jaundice and upper abdominal pain. A liver function test was conducted to assess her liver's synthetic capacity.
Which characteristic will provide the most precise indication of her condition?Your Answer: Liver function tests
Correct Answer: Prothrombin time
Explanation:Liver enzymes are not reliable indicators of liver function, especially in end-stage cirrhosis. Instead, coagulation and albumin levels are better measures to assess liver function.
Prothrombin time is a useful indicator because it reflects the liver’s ability to produce the necessary coagulation factors for blood clotting. A high PT suggests that the liver is not functioning properly.
C-reactive protein (CRP) is not a specific indicator of liver function as it can be elevated in response to any infection in the body.
Hemoglobin levels are not a reliable indicator of liver function as they can be affected by other factors such as anemia or polycythemia.
Liver function tests are not accurate in assessing synthetic liver function as they only reflect damage to the liver and its surrounding areas. Additionally, some LFTs can be elevated due to other conditions, not just liver disease. For example, elevated GGT levels in an LFT can indicate damage to the bile ducts, which can be caused by a gallstone blocking the duct.
Understanding Acute Liver Failure
Acute liver failure is a condition characterized by the sudden onset of liver dysfunction, which can lead to various complications in the body. The causes of acute liver failure include paracetamol overdose, alcohol, viral hepatitis (usually A or B), and acute fatty liver of pregnancy. The symptoms of acute liver failure include jaundice, raised prothrombin time, hypoalbuminaemia, hepatic encephalopathy, and hepatorenal syndrome. It is important to note that liver function tests may not always accurately reflect the synthetic function of the liver, and it is best to assess the prothrombin time and albumin level to determine the severity of the condition. Understanding acute liver failure is crucial in managing and treating this potentially life-threatening condition.
-
This question is part of the following fields:
- Gastrointestinal System
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Secs)