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Question 1
Correct
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A 35-year-old man has arrived at the emergency department following a car crash. He is experiencing tachycardia and his blood pressure is rapidly decreasing from 90/60mmHg. He is feeling dizzy and disoriented, and is experiencing pain in his left upper quadrant and left shoulder. Which organ is most likely to have sustained damage?
Your Answer: Spleen
Explanation:The patient’s tachycardia and low blood pressure indicate internal bleeding due to trauma. Although he experiences pain in his upper left abdominal quadrant, it does not rule out the possibility of internal bleeding. However, it makes heart and lung injuries less likely as he would have also complained of chest pain. The pain in his left shoulder suggests that the left phrenic nerve has been affected, which indicates damage to the spleen rather than the liver, as it would have been on the right side. The spleen is commonly damaged in trauma and could explain the rapid drop in blood pressure.
Understanding the Anatomy of the Spleen
The spleen is a vital organ in the human body, serving as the largest lymphoid organ. It is located below the 9th-12th ribs and has a clenched fist shape. The spleen is an intraperitoneal organ, and its peritoneal attachments condense at the hilum, where the vessels enter the spleen. The blood supply of the spleen is from the splenic artery, which is derived from the coeliac axis, and the splenic vein, which is joined by the IMV and unites with the SMV.
The spleen is derived from mesenchymal tissue during embryology. It weighs between 75-150g and has several relations with other organs. The diaphragm is superior to the spleen, while the gastric impression is anterior, the kidney is posterior, and the colon is inferior. The hilum of the spleen is formed by the tail of the pancreas and splenic vessels. The spleen also forms the apex of the lesser sac, which contains short gastric vessels.
In conclusion, understanding the anatomy of the spleen is crucial in comprehending its functions and the role it plays in the human body. The spleen’s location, weight, and relations with other organs are essential in diagnosing and treating spleen-related conditions.
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This question is part of the following fields:
- Gastrointestinal System
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Question 2
Incorrect
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Which one of the following is not true of gastric cancer?
Your Answer: In Western Countries a more proximal disease distribution has been noted
Correct Answer: Individuals with histological evidence of signet ring cells have a lower incidence of lymph node metastasis
Explanation:Poorly differentiated gastric cancer is characterized by the presence of signet ring cells, which is linked to a higher likelihood of metastasis.
Gastric cancer is a relatively uncommon type of cancer, accounting for only 2% of all cancer diagnoses in developed countries. It is more prevalent in older individuals, with half of patients being over the age of 75, and is more common in males than females. Several risk factors have been identified, including Helicobacter pylori infection, atrophic gastritis, certain dietary habits, smoking, and blood group. Symptoms of gastric cancer can include abdominal pain, weight loss, nausea, vomiting, and dysphagia. In some cases, lymphatic spread may result in the appearance of nodules in the left supraclavicular lymph node or periumbilical area. Diagnosis is typically made through oesophago-gastro-duodenoscopy with biopsy, and staging is done using CT. Treatment options depend on the extent and location of the cancer and may include endoscopic mucosal resection, partial or total gastrectomy, and chemotherapy.
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This question is part of the following fields:
- Gastrointestinal System
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Question 3
Correct
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During an Ivor Lewis Oesophagectomy for carcinoma of the upper third of the oesophagus which structure is divided to allow mobilisation of the oesophagus?
Your Answer: Azygos vein
Explanation:The azygos vein is divided during oesophagectomy to allow mobilisation. It inserts into the SVC on the right side.
Treatment Options for Oesophageal Cancer
Oesophageal cancer is typically treated through surgical resection, with neoadjuvant chemotherapy given prior to the procedure. In situ disease may be managed through endoscopic mucosal resection, while unresectable disease may benefit from local ablative procedures, palliative chemotherapy, or stent insertion. However, resections are not typically offered to patients with distant metastasis or N2 disease, and local nodal involvement is not a contraindication to resection.
For lower and middle third oesophageal tumours, an Ivor-Lewis procedure is commonly performed. This involves a combined laparotomy and right thoracotomy, with the stomach mobilized through a rooftop incision and the oesophagus removed through a thoracotomy. The chest is then closed with underwater seal drainage and tube drains to the abdominal cavity. Postoperatively, patients will typically recover in the intensive care unit and may experience complications such as atelectasis, anastomotic leakage, and delayed gastric emptying.
Overall, treatment options for oesophageal cancer depend on the extent of the disease and the patient’s individual circumstances. While surgical resection is the mainstay of treatment, other options such as chemotherapy and local ablative procedures may be considered for unresectable disease.
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This question is part of the following fields:
- Gastrointestinal System
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Question 4
Incorrect
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A 65-year-old woman visits her GP after discovering a lump in her groin that has been present for the past 2 weeks. The patient reports that she can push the lump back in, but it returns when she coughs. During the examination, the GP identifies the lump located superior and medial to the pubic tubercle. The GP successfully reduces the lump by applying pressure 2 cm above the midpoint of the inguinal ligament and asking the patient to cough. Based on the findings, the GP suspects an indirect inguinal hernia. What structures will the hernia pass through anatomically?
Your Answer: Transversalis fascia and superficial inguinal ring
Correct Answer: Deep inguinal ring and superficial inguinal ring
Explanation:The correct answer is that an indirect inguinal hernia enters the inguinal canal through the deep inguinal ring and exits at the superficial inguinal ring. This type of hernia is diagnosed by preventing re-herniation through pressure on the deep ring.
In contrast, a direct inguinal hernia enters the inguinal canal by passing through the posterior wall of the canal. This type of hernia would reappear upon increased intra-abdominal pressure, such as coughing.
The inguinal canal is located above the inguinal ligament and measures 4 cm in length. Its superficial ring is situated in front of the pubic tubercle, while the deep ring is found about 1.5-2 cm above the halfway point between the anterior superior iliac spine and the pubic tubercle. The canal is bounded by the external oblique aponeurosis, inguinal ligament, lacunar ligament, internal oblique, transversus abdominis, external ring, and conjoint tendon. In males, the canal contains the spermatic cord and ilioinguinal nerve, while in females, it houses the round ligament of the uterus and ilioinguinal nerve.
The boundaries of Hesselbach’s triangle, which are frequently tested, are located in the inguinal region. Additionally, the inguinal canal is closely related to the vessels of the lower limb, which should be taken into account when repairing hernial defects in this area.
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This question is part of the following fields:
- Gastrointestinal System
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Question 5
Incorrect
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A 79-year-old woman comes to the emergency department complaining of abdominal pain that has been present for 2 days. The pain started gradually and has been constant without radiation. She denies any history of blood in her stool.
Upon assessment, her blood pressure is 124/78 mmHg, heart rate 80 beats per minute, respiratory rate 18 breaths per minute, temperature 38.1ºC, and spO2 98%.
During the physical examination, the patient experiences pain when the left iliac fossa is superficially palpated.
What is the most probable diagnosis?Your Answer: Ischaemic colitis
Correct Answer: Diverticulitis
Explanation:The most likely cause of left lower quadrant pain and low-grade fever in an elderly patient is diverticulitis. Treatment for mild cases may include oral antibiotics, a liquid diet, and pain relief. Acute mesenteric ischemia, appendicitis, and ischemic colitis are less likely causes of these symptoms in an elderly patient.
Understanding Diverticulitis
Diverticulitis is a condition where an out-pouching of the intestinal mucosa becomes infected. This out-pouching is called a diverticulum and the presence of these pouches is known as diverticulosis. Diverticula are common and are thought to be caused by increased pressure in the colon. They usually occur in the sigmoid colon and are more prevalent in Westerners over the age of 60. While only a quarter of people with diverticulosis experience symptoms, 75% of those who do will have an episode of diverticulitis.
Risk factors for diverticulitis include age, lack of dietary fiber, obesity (especially in younger patients), and a sedentary lifestyle. Patients with diverticular disease may experience intermittent abdominal pain, bloating, and changes in bowel habits. Those with acute diverticulitis may experience severe abdominal pain, nausea and vomiting, changes in bowel habits, and urinary symptoms. Complications may include colovesical or colovaginal fistulas.
Signs of diverticulitis include low-grade fever, tachycardia, tender lower left quadrant of the abdomen, and possibly a palpable mass. Imaging tests such as an erect chest X-ray, abdominal X-ray, and CT scan may be used to diagnose diverticulitis. Treatment may involve oral antibiotics, a liquid diet, and analgesia for mild cases. More severe cases may require hospitalization for intravenous antibiotics. Colonoscopy should be avoided initially due to the risk of perforation.
In summary, diverticulitis is a common condition that can cause significant discomfort and complications. Understanding the risk factors, symptoms, and signs of diverticulitis can help with early diagnosis and treatment.
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This question is part of the following fields:
- Gastrointestinal System
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Question 6
Correct
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A 78-year-old man reports experiencing discomfort behind his breastbone and occasional backflow of stomach acid into his mouth, especially after meals and at bedtime, causing sleep disturbance. What is a potential risk factor for GORD?
Your Answer: Smoking
Explanation:Gastro-Oesophageal Reflux Disease (GORD)
Gastro-oesophageal reflux disease (GORD) is a chronic condition where stomach acid flows back up into the oesophagus, causing discomfort and increasing the risk of oesophageal cancer. Obesity is a known risk factor for GORD, as excess weight around the abdomen increases pressure in the stomach. Hiatus hernia, which also results from increased intra-abdominal pressure, is also associated with GORD. This is because the widening of the diaphragmatic hiatus in hiatus hernia reduces the effectiveness of the lower oesophageal sphincter in preventing acid reflux.
Smoking is another risk factor for GORD, although the exact mechanism by which it weakens the lower oesophageal sphincter is not fully understood. Interestingly, male sex does not appear to be associated with GORD. Overall, the risk factors for GORD can help individuals take steps to prevent or manage this chronic condition.
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This question is part of the following fields:
- Gastrointestinal System
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Question 7
Correct
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A 67-year-old man is brought to the emergency department after a fall and head injury he sustained while walking home. He has a history of multiple similar admissions related to alcohol excess. During his hospital stay, his blood sugar levels remain consistently high and he appears disheveled. There is no significant past medical history.
What could be the probable reason for the patient's elevated blood glucose levels?Your Answer: Destruction of islets of Langerhans cells
Explanation:Chronic pancreatitis can cause diabetes as it destroys the islet of Langerhans cells in the pancreas. This patient has a history of recurrent admissions due to alcohol-related falls, indicating excessive alcohol intake, which is the most common risk factor for chronic pancreatitis. A high sugar diet alone should not consistently elevated blood sugar levels if normal insulin control mechanisms are functioning properly. Gastrointestinal bleeding and the stress response to injury would not immediately raise blood sugar levels. In this case, the patient’s alcohol intake suggests chronic pancreatitis as the cause of elevated blood sugar levels rather than type 2 diabetes mellitus.
Understanding Chronic Pancreatitis
Chronic pancreatitis is a condition characterized by inflammation that can affect both the exocrine and endocrine functions of the pancreas. While alcohol excess is the leading cause of this condition, up to 20% of cases are unexplained. Other causes include genetic factors such as cystic fibrosis and haemochromatosis, as well as ductal obstruction due to tumors, stones, and structural abnormalities.
Symptoms of chronic pancreatitis include pain that worsens 15 to 30 minutes after a meal, steatorrhoea, and diabetes mellitus. Abdominal x-rays and CT scans are used to detect pancreatic calcification, which is present in around 30% of cases. Functional tests such as faecal elastase may also be used to assess exocrine function if imaging is inconclusive.
Management of chronic pancreatitis involves pancreatic enzyme supplements, analgesia, and antioxidants. While there is limited evidence to support the use of antioxidants, one study suggests that they may be beneficial in early stages of the disease. Overall, understanding the causes and symptoms of chronic pancreatitis is crucial for effective management and treatment.
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This question is part of the following fields:
- Gastrointestinal System
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Question 8
Correct
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A 67-year-old woman is currently admitted to the female orthopedic ward following a left total hip replacement after a femoral neck fracture. The surgery was uncomplicated, and the patient is expected to be discharged in four days. However, in the evening, the patient complains of feeling unwell and experiencing pain in the left hip area. The nurse records her vital signs, which include a pulse rate of 94 beats per minute, a respiratory rate of 20 breaths per minute, a blood pressure of 105/63 mmHg, and a temperature of 38.1ºC (100.6 degrees Fahrenheit). The ward doctor suspects a bone infection around the hip prosthesis and initiates treatment with clindamycin while awaiting review by the orthopedic surgeon. The patient's pain and suspected bone infection eventually subside, but after two days, the patient develops severe abdominal pain and diarrhea. What is the most likely causative organism responsible for this patient's condition?
Your Answer: Gram-positive anaerobic bacilli
Explanation:Pseudomembranous colitis is caused by the gram-positive bacillus Clostridium difficile, which can overgrow in the intestine following broad-spectrum antibiotic use. A patient recovering from a total hip replacement who develops signs of infection and is treated with clindamycin may develop severe abdominal pain and diarrhea, indicating a diagnosis of pseudomembranous colitis. Treatment options include metronidazole or oral vancomycin for more severe cases. Staphylococcus bacteria are gram-positive, catalase-positive cocci that can be differentiated based on coagulase positivity and novobiocin sensitivity. Listeria, Bacillus, and Corynebacterium are gram-positive aerobic bacilli, while Campylobacter jejuni, Vibrio cholerae, and Helicobacter pylori are gram-negative, oxidase-positive comma-shaped rods with specific growth characteristics.
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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 9
Correct
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A case of ischaemic left colon is diagnosed in a patient. Which artery, originating from the aorta at approximately the level of L3, is the most probable cause of this condition?
Your Answer: Inferior mesenteric artery
Explanation:The left side of the colon is most likely to be affected by the IMA, which typically originates at L3.
The Inferior Mesenteric Artery: Supplying the Hindgut
The inferior mesenteric artery (IMA) is responsible for supplying the embryonic hindgut with blood. It originates just above the aortic bifurcation, at the level of L3, and passes across the front of the aorta before settling on its left side. At the point where the left common iliac artery is located, the IMA becomes the superior rectal artery.
The hindgut, which includes the distal third of the colon and the rectum above the pectinate line, is supplied by the IMA. The left colic artery is one of the branches that emerges from the IMA near its origin. Up to three sigmoid arteries may also exit the IMA to supply the sigmoid colon further down the line.
Overall, the IMA plays a crucial role in ensuring that the hindgut receives the blood supply it needs to function properly. Its branches help to ensure that the colon and rectum are well-nourished and able to carry out their important digestive functions.
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This question is part of the following fields:
- Gastrointestinal System
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Question 10
Correct
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A surgeon is scheduled to perform a laparotomy for a perforated duodenal ulcer on a pediatric patient. An upper midline incision will be made. Which structure is most likely to be divided by the incision?
Your Answer: Linea alba
Explanation:When performing upper midline abdominal incisions, the linea alba is typically divided. It is not common to divide muscles in this approach, as it does not typically enhance access and encountering them is not a routine occurrence.
Abdominal Incisions: Types and Techniques
Abdominal incisions are surgical procedures that involve making an opening in the abdominal wall to access the organs inside. The most common approach is the midline incision, which involves dividing the linea alba, transversalis fascia, extraperitoneal fat, and peritoneum. Another type is the paramedian incision, which is parallel to the midline and involves dividing the anterior rectus sheath, rectus, posterior rectus sheath, transversalis fascia, extraperitoneal fat, and peritoneum. The battle incision is similar to the paramedian but involves displacing the rectus medially.
Other types of abdominal incisions include Kocher’s incision under the right subcostal margin for cholecystectomy, Lanz incision in the right iliac fossa for appendicectomy, gridiron oblique incision centered over McBurney’s point for appendicectomy, Pfannenstiel’s transverse supra-pubic incision primarily used to access pelvic organs, McEvedy’s groin incision for emergency repair of a strangulated femoral hernia, and Rutherford Morrison extraperitoneal approach to the left or right lower quadrants for access to iliac vessels and renal transplantation.
Each type of incision has its own advantages and disadvantages, and the choice of incision depends on the specific surgical procedure and the surgeon’s preference. Proper closure of the incision is crucial to prevent complications such as infection and hernia formation. Overall, abdominal incisions are important techniques in surgical practice that allow for safe and effective access to the abdominal organs.
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This question is part of the following fields:
- Gastrointestinal System
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Question 11
Correct
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A 49-year-old woman presents to the emergency department with severe abdominal pain that started an hour ago. She reports feeling unwell recently, but this is the first time she has experienced this type of pain, which is mainly located in the right upper quadrant. During the examination, the physician notes hepatomegaly and ascites, and the patient's eyes have a slight yellow tint. An ultrasound scan reveals reduced blood flow in the hepatic veins, and there is no history of recent travel, drug use, or needlestick injury. The patient has not experienced recent weight loss, and her last menstrual period was two weeks ago. She is not taking any regular or over-the-counter medications. What condition could potentially be causing this patient's symptoms?
Your Answer: Protein C deficiency
Explanation:Budd-Chiari syndrome, which is characterized by abdominal pain, ascites, hepatomegaly, and jaundice, can be caused by hypercoagulable states such as protein C and S deficiencies. In this case, the patient’s protein C deficiency increased their risk of developing a thrombus in the hepatic veins, leading to Budd-Chiari syndrome. Other risk factors for thrombus formation include pregnancy and hepatocellular carcinoma. The use of oral contraceptives would also increase the risk of thrombus formation, while warfarin treatment would decrease it. Atrial fibrillation, on the other hand, would predispose a patient to systemic embolism, which can cause ischaemic symptoms in various arterial circulations.
Understanding Budd-Chiari Syndrome
Budd-Chiari syndrome, also known as hepatic vein thrombosis, is a condition that is often associated with an underlying hematological disease or another procoagulant condition. The causes of this syndrome include polycythemia rubra vera, thrombophilia, pregnancy, and the use of combined oral contraceptive pills. The symptoms of Budd-Chiari syndrome typically include sudden onset and severe abdominal pain, ascites leading to abdominal distension, and tender hepatomegaly.
To diagnose Budd-Chiari syndrome, an ultrasound with Doppler flow studies is usually the initial radiological investigation. This test is highly sensitive and can help identify the presence of the condition. It is important to diagnose and treat Budd-Chiari syndrome promptly to prevent complications such as liver failure and portal hypertension.
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This question is part of the following fields:
- Gastrointestinal System
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Question 12
Incorrect
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Sophie presents acutely to the hospital with severe epigastric pain that is radiating to the back, nausea and vomiting. Upon questioning, she has suffered from several episodes of biliary colic in the past. A blood test reveals a lipase level of 1000U/L.
What is the underlying pathophysiology of Sophie's condition?Your Answer: The pancreatic enzymes produced are defective and unable to aid in food digestion
Correct Answer: Pancreatic enzymes released as a result of inflammation autodigest the pancreatic tissue
Explanation:The cause of acute pancreatitis is the autodigestion of pancreatic tissue by pancreatic enzymes, which results in tissue necrosis. The patient is experiencing typical symptoms of acute pancreatitis, including epigastric pain that radiates to the back, nausea, and vomiting. The presence of elevated lipase levels, which are more than three times the upper limit of normal, is also indicative of acute pancreatitis. The patient’s history of biliary colic suggests that gallstones may be the underlying cause of this condition.
During acute pancreatitis, inflammation of the pancreas triggers the release and activation of pancreatic enzymes, which then begin to digest the pancreatic tissue. This process is known as autodigestion. Autodigestion of fat can lead to tissue necrosis, while autodigestion of blood vessels can cause retroperitoneal hemorrhage, which can be identified by the presence of Grey Turner’s sign and Cullen’s sign.
Understanding Acute Pancreatitis
Acute pancreatitis is a condition that is commonly caused by alcohol or gallstones. It occurs when the pancreatic enzymes start to digest the pancreatic tissue, leading to necrosis. The most common symptom of acute pancreatitis is severe epigastric pain that may radiate through to the back. Vomiting is also common, and examination may reveal epigastric tenderness, ileus, and low-grade fever. Although rare, periumbilical discolouration (Cullen’s sign) and flank discolouration (Grey-Turner’s sign) may also be present.
To diagnose acute pancreatitis, doctors typically measure the levels of serum amylase and lipase in the blood. While amylase is raised in 75% of patients, it does not correlate with disease severity. Lipase, on the other hand, is more sensitive and specific than amylase and has a longer half-life, making it useful for late presentations. Imaging, such as ultrasound or contrast-enhanced CT, may also be necessary to assess the aetiology of the condition.
Scoring systems, such as the Ranson score, Glasgow score, and APACHE II, are used to identify cases of severe pancreatitis that may require intensive care management. Factors indicating severe pancreatitis include age over 55 years, hypocalcaemia, hyperglycaemia, hypoxia, neutrophilia, and elevated LDH and AST. However, the actual amylase level is not of prognostic value.
In summary, acute pancreatitis is a condition that can cause severe pain and discomfort. It is important to diagnose and manage it promptly to prevent complications.
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This question is part of the following fields:
- Gastrointestinal System
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Question 13
Incorrect
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A 25-year-old soldier sustains a gunshot wound to the abdomen resulting in severe damage to the abdominal aorta. The surgeons opt to place a vascular clamp just below the diaphragm to control the bleeding. What is the potential risk of injury to one of the vessels during this procedure?
Your Answer: Renal arteries
Correct Answer: Inferior phrenic arteries
Explanation:The inferior phrenic arteries, which are the first branches of the abdominal aorta, are most vulnerable. On the other hand, the superior phrenic arteries are located in the thorax. The area around the diaphragmatic hiatus could be a valuable location for aortic occlusion, but keeping the clamp on for more than 10-15 minutes typically results in unfavorable results.
The abdominal aorta is a major blood vessel that originates from the 12th thoracic vertebrae and terminates at the fourth lumbar vertebrae. It is located in the abdomen and is surrounded by various organs and structures. The posterior relations of the abdominal aorta include the vertebral bodies of the first to fourth lumbar vertebrae. The anterior relations include the lesser omentum, liver, left renal vein, inferior mesenteric vein, third part of the duodenum, pancreas, parietal peritoneum, and peritoneal cavity. The right lateral relations include the right crus of the diaphragm, cisterna chyli, azygos vein, and inferior vena cava (which becomes posterior distally). The left lateral relations include the fourth part of the duodenum, duodenal-jejunal flexure, and left sympathetic trunk. Overall, the abdominal aorta is an important blood vessel that supplies oxygenated blood to various organs in the abdomen.
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This question is part of the following fields:
- Gastrointestinal System
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Question 14
Correct
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A 9-month-old baby girl is brought to the clinic by her parents who recently moved from the Philippines. The baby has a noticeable mass in her abdomen, resembling a sausage shape. During questioning, the father mentions that the baby had vomited green substance a few hours ago. The baby is immediately referred to the hospital. What is the probable diagnosis?
Your Answer: Intussusception
Explanation:Understanding Intussusception
Intussusception is a medical condition where one part of the bowel folds into the lumen of the adjacent bowel, usually around the ileocecal region. This condition is most common in infants between 6-18 months old, with boys being affected twice as often as girls. Symptoms of intussusception include severe, crampy abdominal pain, inconsolable crying, vomiting, and bloodstained stool, which is a late sign. During a paroxysm, the infant will draw their knees up and turn pale, and a sausage-shaped mass may be felt in the right upper quadrant.
To diagnose intussusception, ultrasound is now the preferred method of investigation, which may show a target-like mass. Treatment for intussusception involves reducing the bowel by air insufflation under radiological control, which is now widely used first-line compared to the traditional barium enema. If this method fails, or the child has signs of peritonitis, surgery is performed. Understanding the symptoms and treatment options for intussusception is crucial for parents and healthcare professionals to ensure prompt and effective management of this condition.
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This question is part of the following fields:
- Gastrointestinal System
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Question 15
Correct
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A 25-year-old female presents to her GP with a 3-month history of bloating. She has tried excluding nightshades from her diet which provided some relief but her symptoms persist. Upon further questioning, she reports a lifelong feeling of incomplete bowel emptying after defecation. This symptom was previously investigated with endoscopy and biopsies, but no definitive diagnosis was made.
Additionally, she reports the presence of mucus in her stool and intermittent abdominal pain. She has no significant medical history or regular medications, but does have a peanut allergy. Her mother has coeliac disease and her father has type 2 diabetes which is managed with insulin.
What is the most likely diagnosis for this patient?Your Answer: Irritable bowel syndrome
Explanation:Diagnosis and Management of Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects many people. To diagnose IBS, a patient must have experienced abdominal pain, bloating, or a change in bowel habit for at least six months. A positive diagnosis of IBS is made if the patient has abdominal pain relieved by defecation or associated with altered bowel frequency stool form, in addition to two of the following four symptoms: altered stool passage, abdominal bloating, symptoms made worse by eating, and passage of mucus. Other features such as lethargy, nausea, backache, and bladder symptoms may also support the diagnosis.
It is important to enquire about red flag features such as rectal bleeding, unexplained/unintentional weight loss, family history of bowel or ovarian cancer, and onset after 60 years of age. Primary care investigations such as a full blood count, ESR/CRP, and coeliac disease screen (tissue transglutaminase antibodies) are suggested. The National Institute for Health and Care Excellence (NICE) published clinical guidelines on the diagnosis and management of IBS in 2008 to help healthcare professionals provide the best care for patients with this condition.
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This question is part of the following fields:
- Gastrointestinal System
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Question 16
Correct
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A 72-year-old woman visits her doctor complaining of painful legs, particularly in her thighs, which occur after walking and subside on rest. She occasionally takes paracetamol to alleviate the pain. Her medical history includes hyperlipidaemia, type II diabetes mellitus, hypertension, and depression. The physician suspects that her pain may be due to claudication of the femoral artery, which is a continuation of the external iliac artery. Can you correctly identify the anatomical landmark where the external iliac artery becomes the femoral artery?
Your Answer: Inguinal ligament
Explanation:After passing the inguinal ligament, the external iliac artery transforms into the femoral artery. This means that the other options provided are not accurate. Here is a brief explanation of their anatomical importance:
– The medial edge of the sartorius muscle creates the lateral wall of the femoral triangle.
– The medial edge of the adductor longus muscle creates the medial wall of the femoral triangle.
– The femoral vein creates the lateral border of the femoral canal.
– The pectineus muscle creates the posterior border of the femoral canal.The inguinal canal is located above the inguinal ligament and measures 4 cm in length. Its superficial ring is situated in front of the pubic tubercle, while the deep ring is found about 1.5-2 cm above the halfway point between the anterior superior iliac spine and the pubic tubercle. The canal is bounded by the external oblique aponeurosis, inguinal ligament, lacunar ligament, internal oblique, transversus abdominis, external ring, and conjoint tendon. In males, the canal contains the spermatic cord and ilioinguinal nerve, while in females, it houses the round ligament of the uterus and ilioinguinal nerve.
The boundaries of Hesselbach’s triangle, which are frequently tested, are located in the inguinal region. Additionally, the inguinal canal is closely related to the vessels of the lower limb, which should be taken into account when repairing hernial defects in this area.
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This question is part of the following fields:
- Gastrointestinal System
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Question 17
Correct
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As an observer in the colorectal surgical department, you spend a morning watching a colonoscopy list. A number of patients who arrive during the morning are individuals with Hereditary Non-Polyposis Colorectal Cancer (HNPCC), who are being screened to detect any early signs of colorectal cancer. What is the lifetime risk of developing colorectal cancer for individuals with this condition?
Your Answer: 90%
Explanation:Colorectal cancer can be classified into three types: sporadic, hereditary non-polyposis colorectal carcinoma (HNPCC), and familial adenomatous polyposis (FAP). Sporadic colon cancer is believed to be caused by a series of genetic mutations, including allelic loss of the APC gene, activation of the K-ras oncogene, and deletion of p53 and DCC tumor suppressor genes. HNPCC, which is an autosomal dominant condition, is the most common form of inherited colon cancer. It is caused by mutations in genes involved in DNA mismatch repair, leading to microsatellite instability. The most common genes affected are MSH2 and MLH1. Patients with HNPCC are also at a higher risk of other cancers, such as endometrial cancer. The Amsterdam criteria are sometimes used to aid diagnosis of HNPCC. FAP is a rare autosomal dominant condition that leads to the formation of hundreds of polyps by the age of 30-40 years. It is caused by a mutation in the APC gene. Patients with FAP are also at risk of duodenal tumors. A variant of FAP called Gardner’s syndrome can also feature osteomas of the skull and mandible, retinal pigmentation, thyroid carcinoma, and epidermoid cysts on the skin. Genetic testing can be done to diagnose HNPCC and FAP, and patients with FAP generally have a total colectomy with ileo-anal pouch formation in their twenties.
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This question is part of the following fields:
- Gastrointestinal System
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Question 18
Incorrect
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A 32-year-old man is having surgery to remove his appendix. During the procedure, the external oblique aponeurosis is cut and the underlying muscle is split along its fibers. A strong fibrous structure is found at the medial edge of the incision. What is the most likely structure that will be encountered upon entering this fibrous structure?
Your Answer: Linea alba
Correct Answer: Rectus abdominis
Explanation:Upon entry, the structure encountered will be the rectus abdominis muscle, which is surrounded by the rectus sheath.
Abdominal Incisions: Types and Techniques
Abdominal incisions are surgical procedures that involve making an opening in the abdominal wall to access the organs inside. The most common approach is the midline incision, which involves dividing the linea alba, transversalis fascia, extraperitoneal fat, and peritoneum. Another type is the paramedian incision, which is parallel to the midline and involves dividing the anterior rectus sheath, rectus, posterior rectus sheath, transversalis fascia, extraperitoneal fat, and peritoneum. The battle incision is similar to the paramedian but involves displacing the rectus medially.
Other types of abdominal incisions include Kocher’s incision under the right subcostal margin for cholecystectomy, Lanz incision in the right iliac fossa for appendicectomy, gridiron oblique incision centered over McBurney’s point for appendicectomy, Pfannenstiel’s transverse supra-pubic incision primarily used to access pelvic organs, McEvedy’s groin incision for emergency repair of a strangulated femoral hernia, and Rutherford Morrison extraperitoneal approach to the left or right lower quadrants for access to iliac vessels and renal transplantation.
Each type of incision has its own advantages and disadvantages, and the choice of incision depends on the specific surgical procedure and the surgeon’s preference. Proper closure of the incision is crucial to prevent complications such as infection and hernia formation. Overall, abdominal incisions are important techniques in surgical practice that allow for safe and effective access to the abdominal organs.
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This question is part of the following fields:
- Gastrointestinal System
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Question 19
Correct
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A 15-year-old boy, with a family history of Gilbert's syndrome, is showing symptoms of hepatic dysfunction. Upon conducting liver function tests, it is found that he has elevated levels of unconjugated bilirubin. After genetic testing, it is confirmed that he has Gilbert's syndrome. What is the reason behind the increased levels of unconjugated bilirubin in Gilbert's syndrome?
Your Answer: Reduced levels of UDP-glucuronosyl transferase-1
Explanation:Gilbert’s syndrome is characterized by a decrease in UDP glucuronosyltransferase levels.
Enhanced drug effects can occur due to reduced warfarin metabolism caused by CYP2C9 deficiency.
Elevated GGT levels are often caused by pancreatic disease, cholestasis, excessive alcohol consumption, and certain medications.
Dubin-Johnson syndrome is associated with defective hepatocyte excretion of conjugated bilirubin.
Disordered metabolism of clopidogrel and other drugs, including proton-pump inhibitors, anticonvulsants, and sedatives, can result from reduced CYP2C19 levels.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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 20
Correct
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A 65-year-old man presents to the emergency department with left-sided abdominal pain and rectal bleeding. He has a past medical history of atrial fibrillation and is on apixaban. He does not smoke cigarettes or drink alcohol.
His observations are heart rate 111 beats per minute, blood pressure 101/58 mmHg, respiratory rate 18/minute, oxygen saturation 96% on room air and temperature 37.8ºC.
Abdominal examination reveals tenderness in the left lower quadrant. Bowel sounds are sluggish. Rectal examination demonstrates a small amount of fresh red blood but no mass lesions, haemorrhoids or fissures. His pulse is irregular. Chest auscultation is normal.
An ECG demonstrates atrial fibrillation.
Blood tests:
Hb 133 g/L Male: (135-180)
Female: (115 - 160)
Platelets 444 * 109/L (150 - 400)
WBC 18.1 * 109/L (4.0 - 11.0)
Na+ 131 mmol/L (135 - 145)
K+ 4.6 mmol/L (3.5 - 5.0)
Urea 8.2 mmol/L (2.0 - 7.0)
Creatinine 130 µmol/L (55 - 120)
CRP 32 mg/L (< 5)
Lactate 2.6 mmol/L (0.0-2.0)
Based on the presumed diagnosis, what is the likely location of the pathology?Your Answer: Splenic flexure
Explanation:Ischaemic colitis most frequently affects the splenic flexure.
Understanding Ischaemic Colitis
Ischaemic colitis is a condition that occurs when there is a temporary reduction in blood flow to the large bowel. This can cause inflammation, ulcers, and bleeding. The condition is more likely to occur in areas of the bowel that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries, such as the splenic flexure.
When investigating ischaemic colitis, doctors may look for a sign called thumbprinting on an abdominal x-ray. This occurs due to mucosal edema and hemorrhage. It is important to diagnose and treat ischaemic colitis promptly to prevent complications and ensure a full recovery.
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This question is part of the following fields:
- Gastrointestinal System
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Question 21
Incorrect
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A 2-year-old girl is brought to the emergency department with acute abdominal pain that is generalised across her abdomen. Her parents report that the pain comes and goes and that she has been pulling her legs up to her chest when she screams, which is unusual for her. They also mention that she has been off her feeds and that her stools appear redder. During the examination, a mass is felt in the abdomen in the right lower quadrant. The girl's vital signs are as follows: blood pressure- 50/40mmHg, pulse- 176bpm, respiratory rate-30 breaths per minute, 02 saturations- 99%. What is the most likely diagnosis?
Your Answer: Meckel's diverticulum
Correct Answer: Intussusception
Explanation:The infant in this scenario is displaying symptoms of intussusception, including red current jelly stools and shock. Malrotation, which typically causes obstruction, can be ruled out as there is evidence of the passage of red stools. Meckel’s diverticulitis does not cause the infant to draw their knees up and is not typically associated with shock. Pyloric stenosis is characterized by projectile vomiting and not bloody stools. Acute appendicitis is not a likely diagnosis based on this presentation.
Understanding Intussusception
Intussusception is a medical condition where one part of the bowel folds into the lumen of the adjacent bowel, usually around the ileocecal region. This condition is most common in infants between 6-18 months old, with boys being affected twice as often as girls. Symptoms of intussusception include severe, crampy abdominal pain, inconsolable crying, vomiting, and bloodstained stool, which is a late sign. During a paroxysm, the infant will draw their knees up and turn pale, and a sausage-shaped mass may be felt in the right upper quadrant.
To diagnose intussusception, ultrasound is now the preferred method of investigation, which may show a target-like mass. Treatment for intussusception involves reducing the bowel by air insufflation under radiological control, which is now widely used first-line compared to the traditional barium enema. If this method fails, or the child has signs of peritonitis, surgery is performed. Understanding the symptoms and treatment options for intussusception is crucial for parents and healthcare professionals to ensure prompt and effective management of this condition.
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This question is part of the following fields:
- Gastrointestinal System
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Question 22
Correct
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Which of the following characteristics is atypical for Crohn's disease?
Your Answer: Pseudopolyps on colonoscopy
Explanation:Pseudopolyps manifest in ulcerative colitis as a result of extensive mucosal ulceration. The remaining patches of mucosa can resemble individual polyps.
Understanding Crohn’s Disease
Crohn’s disease is a type of inflammatory bowel disease that can affect any part of the digestive tract, from the mouth to the anus. The exact cause of Crohn’s disease is unknown, but there is a strong genetic component. Inflammation occurs in all layers of the affected area, which can lead to complications such as strictures, fistulas, and adhesions.
Symptoms of Crohn’s disease typically appear in late adolescence or early adulthood and can include non-specific symptoms such as weight loss and lethargy, as well as more specific symptoms like diarrhea, abdominal pain, and perianal disease. Extra-intestinal features, such as arthritis, erythema nodosum, and osteoporosis, are also common in patients with Crohn’s disease.
To diagnose Crohn’s disease, doctors may look for raised inflammatory markers, increased faecal calprotectin, anemia, and low levels of vitamin B12 and vitamin D. It’s important to note that Crohn’s disease shares some features with ulcerative colitis, another type of inflammatory bowel disease, but there are also important differences between the two conditions. Understanding the symptoms and diagnostic criteria for Crohn’s disease can help patients and healthcare providers manage this chronic condition more effectively.
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This question is part of the following fields:
- Gastrointestinal System
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Question 23
Incorrect
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A 35-year-old female who has previously had a colectomy for familial adenomatous polyposis coli complains of a solid mass located at the lower part of her rectus abdominis muscle. What type of cell is commonly linked with these types of tumors?
Your Answer: Lipoblasts
Correct Answer: Myofibroblasts
Explanation:The most probable differential diagnosis in this case would be desmoid tumors, which involve the abnormal growth of myofibroblast cells.
Desmoid tumours are growths that arise from musculoaponeurotic structures and are made up of clonal proliferations of myofibroblasts. They are typically firm and have a tendency to infiltrate surrounding tissue. These tumours are often seen in patients with familial adenomatous polyposis coli, and are most commonly found in women after childbirth in the rectus abdominis muscle. Bi allelic APC mutations are usually present in desmoid tumours.
The preferred treatment for desmoid tumours is radical surgical resection, although radiotherapy and chemotherapy may be considered in some cases. Non-surgical therapy is generally less effective than surgical resection. In certain cases of abdominal desmoids, observation may be preferred as some tumours may spontaneously regress. However, desmoids have a high likelihood of local recurrence. These tumours consist of sheets of differentiated fibroblasts.
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This question is part of the following fields:
- Gastrointestinal System
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Question 24
Incorrect
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You eagerly begin your second laparoscopic cholecystectomy and encounter unexpected difficulties with the anatomy of Calots triangle. While attempting to apply a haemostatic clip, you accidentally tear the cystic artery, resulting in profuse bleeding. What is the most probable source of this bleeding?
Your Answer: Common hepatic artery
Correct Answer: Right hepatic artery
Explanation:The most frequent scenario is for the cystic artery to originate from the right hepatic artery, although there are known variations in the anatomy of the gallbladder’s blood supply.
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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 25
Correct
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A 25-year-old male patient complains of mucous passage and diarrhea, leading to a suspicion of ulcerative colitis. Which of the following is not commonly associated with this disease?
Your Answer: Episodes of large bowel obstruction during acute attacks
Explanation:Crohn’s disease is associated with a higher risk of colorectal cancer compared to the general population, particularly if the disease has been present for over 20 years. Granulomas are a common feature of Crohn’s disease. The disease typically affects the rectum and can spread upwards, and contact bleeding may occur. In cases of longstanding ulcerative colitis, there may be crypt atrophy and metaplasia/dysplasia.
Understanding Ulcerative Colitis
Ulcerative colitis is a type of inflammatory bowel disease that causes inflammation in the rectum and spreads continuously without going beyond the ileocaecal valve. It is most commonly seen in people aged 15-25 years and 55-65 years. The symptoms of ulcerative colitis are insidious and intermittent, including bloody diarrhea, urgency, tenesmus, abdominal pain, and extra-intestinal features. Diagnosis is done through colonoscopy and biopsy, but in severe cases, a flexible sigmoidoscopy is preferred to avoid the risk of perforation. The typical findings include red, raw mucosa that bleeds easily, widespread ulceration with preservation of adjacent mucosa, and inflammatory cell infiltrate in lamina propria. Extra-intestinal features of inflammatory bowel disease include arthritis, erythema nodosum, episcleritis, osteoporosis, uveitis, pyoderma gangrenosum, clubbing, and primary sclerosing cholangitis. Ulcerative colitis is linked with sacroiliitis, and a barium enema can show the whole colon affected by an irregular mucosa with loss of normal haustral markings.
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This question is part of the following fields:
- Gastrointestinal System
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Question 26
Correct
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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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 27
Incorrect
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A 46-year-old male has presented with bruises on his legs. He also reports that he bleeds excessively whenever he gets a cut on his limbs. He has a past medical history of familial hypercholesterolaemia. His body mass index is 31 kg/m2. He does not have a medical history of bleeding disorders and denies a family history of haemophilia.
During his last visit, his lipid profile showed elevated total cholesterol, elevated LDL and low HDL. He was prescribed a medication to help lower his LDL cholesterol.
What medication was he most likely prescribed?Your Answer: Clomiphene
Correct Answer: Cholestyramine
Explanation:Cholestyramine has the potential to decrease the absorption of fat-soluble vitamins, including vitamin A, D, E, and K. Vitamin K is particularly important for the production of clotting factors II, VII, IX, and X, and a deficiency in this vitamin can result in clotting abnormalities.
Clomiphene is a medication used to stimulate ovulation in women with polycystic ovary syndrome (PCOS), and it is not linked to an elevated risk of bleeding.
Psyllium husk is not known to cause any bleeding disorders.
Cholestyramine: A Medication for Managing High Cholesterol
Cholestyramine is a medication used to manage high levels of cholesterol in the body. It works by reducing the reabsorption of bile acid in the small intestine, which leads to an increase in the conversion of cholesterol to bile acid. This medication is particularly effective in reducing LDL cholesterol levels. In addition to its use in managing hyperlipidaemia, cholestyramine is also sometimes used to treat diarrhoea following bowel resection in patients with Crohn’s disease.
However, cholestyramine is not without its adverse effects. Some patients may experience abdominal cramps and constipation while taking this medication. It can also decrease the absorption of fat-soluble vitamins, which can lead to deficiencies if not properly managed. Additionally, cholestyramine may increase the risk of developing cholesterol gallstones and raise the level of triglycerides in the blood. Therefore, it is important for patients to discuss the potential benefits and risks of cholestyramine with their healthcare provider before starting this medication.
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This question is part of the following fields:
- Gastrointestinal System
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Question 28
Correct
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A 36-year-old female patient presents with persistent dyspepsia of 6 months duration. She failed multiple trials of conservative treatment by her GP, therefore, she was referred for the gastroenterologist for further review.
Investigations were done and her urea breath test was negative for Helicobacter pylori. Gastroscopy revealed multiple gastroduodenal ulcers. What type of cells are affected by the high levels of fasting gastrin detected?Your Answer: Gastric parietal cells
Explanation:The secretion of gastrin hormone from G cells in the antrum of the stomach is responsible for increasing the secretion of H+ by gastric parietal cells. Additionally, chief cells secrete pepsin, which is a proteolytic enzyme, while D cells in the pancreas and stomach secrete somatostatin hormone. Gastrin hormone is released in response to distension of the stomach and vagal stimulation.
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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 29
Correct
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A 32-year-old woman undergoes a colonoscopy and a biopsy reveals a malignant tumour in her sigmoid colon. Her grandmother died of colorectal cancer at 30-years-old and her father developed endometrial cancer at 40-years-old. Which gene is suspected to be responsible for this condition?
Your Answer: Mismatch repair genes
Explanation:The patient’s familial background indicates the possibility of Lynch syndrome, given that several of his close relatives developed cancer at a young age. This is supported by the fact that his family has a history of both colorectal cancer, which may indicate a defect in the APC gene, and endometrial cancer, which is also linked to Lynch syndrome. Lynch syndrome is associated with mutations in mismatch repair genes such as MSH2, MLH1, PMS2, and GTBP, which are responsible for identifying and repairing errors that occur during DNA replication, such as insertions and deletions of bases. Mutations in these genes can increase the risk of developing cancers such as colorectal, endometrial, and renal cancer.
Colorectal cancer can be classified into three types: sporadic, hereditary non-polyposis colorectal carcinoma (HNPCC), and familial adenomatous polyposis (FAP). Sporadic colon cancer is believed to be caused by a series of genetic mutations, including allelic loss of the APC gene, activation of the K-ras oncogene, and deletion of p53 and DCC tumor suppressor genes. HNPCC, which is an autosomal dominant condition, is the most common form of inherited colon cancer. It is caused by mutations in genes involved in DNA mismatch repair, leading to microsatellite instability. The most common genes affected are MSH2 and MLH1. Patients with HNPCC are also at a higher risk of other cancers, such as endometrial cancer. The Amsterdam criteria are sometimes used to aid diagnosis of HNPCC. FAP is a rare autosomal dominant condition that leads to the formation of hundreds of polyps by the age of 30-40 years. It is caused by a mutation in the APC gene. Patients with FAP are also at risk of duodenal tumors. A variant of FAP called Gardner’s syndrome can also feature osteomas of the skull and mandible, retinal pigmentation, thyroid carcinoma, and epidermoid cysts on the skin. Genetic testing can be done to diagnose HNPCC and FAP, and patients with FAP generally have a total colectomy with ileo-anal pouch formation in their twenties.
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This question is part of the following fields:
- Gastrointestinal System
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Question 30
Correct
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A 25-year-old man comes to the emergency department complaining of abdominal pain and vomiting. He reports not having a bowel movement for the past five days.
His medical history includes a ruptured appendix three years ago. There is no significant medical or family history.
During the examination, you observe abdominal distension and tinkling bowel sounds.
An abdominal X-ray shows dilated loops of small bowel.
What is the leading cause of the probable diagnosis in this scenario?Your Answer: Adhesions
Explanation:The leading cause of small bowel obstruction is adhesions, which can occur due to previous abdominal surgery and cause internal surfaces to stick together. An abdominal X-ray showing dilated small bowel loops is a common indicator of this condition. While a hernia can also cause small bowel obstruction, it is less likely in this case due to the patient’s surgical history. Intussusception is rare in adults and more commonly seen in young children. Malignancy is a less common cause of small bowel obstruction, especially in patients without risk factors or demographic factors that suggest a higher likelihood of cancer.
Small bowel obstruction occurs when the small intestines are blocked, preventing the passage of food, fluids, and gas. The most common causes of this condition are adhesions resulting from previous surgeries and hernias. Symptoms include diffuse, central abdominal pain, nausea and vomiting (often bilious), constipation, and abdominal distension. Tinkling bowel sounds may also be present in early stages of obstruction. Abdominal x-ray is typically the first imaging test used to diagnose small bowel obstruction, showing distended small bowel loops with fluid levels. CT is more sensitive and considered the definitive investigation, particularly in early stages of obstruction. Management involves NBM, IV fluids, and a nasogastric tube with free drainage. Conservative management may be effective for some patients, but surgery is often necessary.
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This question is part of the following fields:
- Gastrointestinal System
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