-
Question 1
Incorrect
-
A 72-year-old woman is being evaluated on the ward due to concerns raised by the nursing staff regarding her altered bowel habits. The patient has been experiencing bowel movements approximately 12 times a day for the past two days and is experiencing crampy abdominal pain.
The patient's blood test results are as follows:
- Hemoglobin (Hb) level of 124 g/L (normal range for females: 115-160 g/L)
- Platelet count of 175 * 109/L (normal range: 150-400 * 109/L)
- White blood cell (WBC) count of 16.4 * 109/L (normal range: 4.0-11.0 * 109/L)
Upon reviewing her medication chart, it is noted that she recently finished a course of ceftriaxone for meningitis.
Based on the likely diagnosis, what would be the most probable finding on stool microscopy?Your Answer: Gram-negative cocci
Correct Answer: Gram-positive bacilli
Explanation:The likely diagnosis for this patient is a Clostridium difficile infection, which is a gram-positive bacillus bacteria. This infection is triggered by recent broad-spectrum antibiotic use, as seen in this patient who was prescribed ceftriaxone for meningitis. The patient’s symptoms of crampy abdominal pain and sudden onset diffuse diarrhoea, along with a marked rise in white blood cells, are consistent with this diagnosis. Gram-negative bacilli, gram-negative cocci, and gram-negative spirillum bacteria are unlikely causes of this patient’s symptoms.
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 2
Incorrect
-
At which of the subsequent spinal levels does the esophagus pass through the diaphragm and enter the abdominal cavity?
Your Answer: T12
Correct Answer: T10
Explanation:The point at which the oesophagus enters the abdomen is located at T10.
Anatomy of the Oesophagus
The oesophagus is a muscular tube that is approximately 25 cm long and starts at the C6 vertebrae, pierces the diaphragm at T10, and ends at T11. It is lined with non-keratinized stratified squamous epithelium and has constrictions at various distances from the incisors, including the cricoid cartilage at 15cm, the arch of the aorta at 22.5cm, the left principal bronchus at 27cm, and the diaphragmatic hiatus at 40cm.
The oesophagus is surrounded by various structures, including the trachea to T4, the recurrent laryngeal nerve, the left bronchus and left atrium, and the diaphragm anteriorly. Posteriorly, it is related to the thoracic duct to the left at T5, the hemiazygos to the left at T8, the descending aorta, and the first two intercostal branches of the aorta. The arterial, venous, and lymphatic drainage of the oesophagus varies depending on the location, with the upper third being supplied by the inferior thyroid artery and drained by the deep cervical lymphatics, the mid-third being supplied by aortic branches and drained by azygos branches and mediastinal lymphatics, and the lower third being supplied by the left gastric artery and drained by posterior mediastinal and coeliac veins and gastric lymphatics.
The nerve supply of the oesophagus also varies, with the upper half being supplied by the recurrent laryngeal nerve and the lower half being supplied by the oesophageal plexus of the vagus nerve. The muscularis externa of the oesophagus is composed of both smooth and striated muscle, with the composition varying depending on the location.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 3
Incorrect
-
A 23-year-old woman presents to the gastroenterology clinic with a 6-month history of cramping abdominal pain and weight loss. She reports looser bowel motions and opening her bowels 2-4 times per day. There is no history of fever or vomiting. During the examination, the physician observes 4 oral mucosal ulcers. Mild tenderness is noted in the right iliac fossa. An endoscopy is ordered.
What are the expected endoscopy findings for this patient's most likely diagnosis?Your Answer: Loss of haustra
Correct Answer: Cobble-stoned appearance
Explanation:This patient has been diagnosed with Crohn’s disease, which is characterized by a long history of abdominal pain, weight loss, and diarrhea. Unlike ulcerative colitis, which only affects the colon, Crohn’s disease can affect any part of the gastrointestinal tract. In this case, oral mucosal ulceration is also present. The classic cobblestone appearance on endoscopy is due to deep ulceration in the gut mucosa with skip lesions in between.
On the other hand, loss of haustra is a finding seen in chronic ulcerative colitis on fluoroscopy. The chronic inflammatory process in the mucosal and submucosal layers of the colon can cause luminal narrowing, resulting in a drainpipe colon that is shortened and narrowed. In UC, shallow ulceration occurs in the mucosa, with spared mucosa giving rise to the appearance of polyps, also known as pseudopolyps. These can cause bloody diarrhea.
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 32-year-old female with a history of iron deficiency anemia presents to the hospital with pain in the right upper quadrant. After diagnosis, she is found to have acute cholecystitis. Which of the following is NOT a risk factor for the development of gallstones?
Your Answer: Female
Correct Answer: Iron deficiency anaemia
Explanation:The following factors increase the likelihood of developing gallstones and can be remembered as the ‘5 F’s’:
– Being overweight (having a body mass index greater than 30 kg/m2)
– Being female
– Being of reproductive age
– Being of fair complexion (Caucasian)
– Being 40 years of age or olderGallstones 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
Incorrect
-
A 55-year-old male has been diagnosed with a transverse colon carcinoma. What is the recommended structure to ligate near its origin for optimal tumor clearance?
Your Answer:
Correct Answer: Middle colic artery
Explanation:During cancer resections, the transverse colon is supplied by the middle colic artery, which is a branch of the superior mesenteric artery and requires ligation at a high level.
The Transverse Colon: Anatomy and Relations
The transverse colon is a part of the large intestine that begins at the hepatic flexure, where the right colon makes a sharp turn. At this point, it becomes intraperitoneal and is connected to the inferior border of the pancreas by the transverse mesocolon. The middle colic artery and vein are contained within the mesentery. The greater omentum is attached to the superior aspect of the transverse colon, which can be easily separated. The colon undergoes another sharp turn at the splenic flexure, where the greater omentum remains attached up to this point. The distal 1/3 of the transverse colon is supplied by the inferior mesenteric artery.
The transverse colon is related to various structures. Superiorly, it is in contact with the liver, gallbladder, the greater curvature of the stomach, and the lower end of the spleen. Inferiorly, it is related to the small intestine. Anteriorly, it is in contact with the greater omentum, while posteriorly, it is in contact with the descending portion of the duodenum, the head of the pancreas, convolutions of the jejunum and ileum, and the spleen. Understanding the anatomy and relations of the transverse colon is important for medical professionals in diagnosing and treating various gastrointestinal conditions.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 6
Incorrect
-
A 30-year-old man presents with an inguinal hernia. What structure needs to be divided during open surgery to access the inguinal canal?
Your Answer:
Correct Answer: External oblique aponeurosis
Explanation:What forms the front wall of the inguinal canal? The external oblique aponeurosis forms the front wall. To access the canal and perform a hernia repair, the aponeurosis is divided. The posterior wall is made up of the transversalis fascia and conjoint tendons, which are not typically cut to gain entry to the inguinal canal.
The External Oblique Muscle: Anatomy and Function
The external oblique muscle is one of the three muscles that make up the anterolateral aspect of the abdominal wall. It is the outermost muscle and plays an important role in supporting the abdominal viscera. The muscle originates from the outer surfaces of the lowest eight ribs and inserts into the anterior two-thirds of the outer lip of the iliac crest. The remaining portion of the muscle becomes the aponeurosis, which fuses with the linea alba in the midline.
The external oblique muscle is innervated by the ventral rami of the lower six thoracic nerves. Its main function is to contain the abdominal viscera and raise intra-abdominal pressure. Additionally, it can move the trunk to one side. The aponeurosis of the external oblique muscle also forms the anterior wall of the inguinal canal, which is an important anatomical landmark in the groin region.
Overall, the external oblique muscle is a crucial component of the abdominal wall and plays an important role in maintaining the integrity of the abdominal cavity. Its unique anatomy and function make it an important muscle for both movement and protection of the internal organs.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 7
Incorrect
-
A 57-year-old man is having a pancreatectomy for cancer. While removing the gland, which structure will the surgeon not come across behind the pancreas?
Your Answer:
Correct Answer: Gastroduodenal artery
Explanation:At the superior part of the pancreas, the gastroduodenal artery splits into the pancreaticoduodenal and gastro-epiploic arteries.
Anatomy of the Pancreas
The pancreas is located behind the stomach and is a retroperitoneal organ. It can be accessed surgically by dividing the peritoneal reflection that connects the greater omentum to the transverse colon. The pancreatic head is situated in the curvature of the duodenum, while its tail is close to the hilum of the spleen. The pancreas has various relations with other organs, such as the inferior vena cava, common bile duct, renal veins, superior mesenteric vein and artery, crus of diaphragm, psoas muscle, adrenal gland, kidney, aorta, pylorus, gastroduodenal artery, and splenic hilum.
The arterial supply of the pancreas is through the pancreaticoduodenal artery for the head and the splenic artery for the rest of the organ. The venous drainage for the head is through the superior mesenteric vein, while the body and tail are drained by the splenic vein. The ampulla of Vater is an important landmark that marks the transition from foregut to midgut and is located halfway along the second part of the duodenum. Overall, understanding the anatomy of the pancreas is crucial for surgical procedures and diagnosing pancreatic diseases.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 8
Incorrect
-
During a left hemicolectomy the sigmoid colon is mobilised. As the bowel is retracted medially a vessel is injured, anterior to the colon. Which one of the following is the most likely vessel?
Your Answer:
Correct Answer: Gonadal vessels
Explanation:During a right hemicolectomy, the gonadal vessels and ureter are crucial structures located at the posterior aspect that may be vulnerable to injury.
The Caecum: Location, Relations, and Functions
The caecum is a part of the colon located in the proximal right colon below the ileocaecal valve. It is an intraperitoneal structure that has posterior relations with the psoas, iliacus, femoral nerve, genitofemoral nerve, and gonadal vessels. Its anterior relations include the greater omentum. The caecum is supplied by the ileocolic artery and its lymphatic drainage is through the mesenteric nodes that accompany the venous drainage.
The caecum is known for its distensibility, making it the most distensible part of the colon. However, in cases of complete large bowel obstruction with a competent ileocaecal valve, the caecum is the most likely site of eventual perforation. Despite this potential complication, the caecum plays an important role in the digestive system. It is responsible for the absorption of fluids and electrolytes, as well as the fermentation of indigestible carbohydrates. Additionally, the caecum is a site for the growth and proliferation of beneficial bacteria that aid in digestion and immune function.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 9
Incorrect
-
A man in his early 50s arrives at the Emergency Department complaining of abdominal pain and haematemesis. Upon diagnosis, he is found to have a peptic ulcer. During his treatment, he reveals that he has been taking ibuprofen for several years. His physician informs him that this may have caused the bleeding and recommends taking omeprazole, a gastroprotective medication, in addition to his ibuprofen to lower his chances of recurrence. What is the mechanism of action of omeprazole?
Your Answer:
Correct Answer: Gastric parietal cell H+/K+-ATPase inhibition
Explanation:The irreversible blockade of H+/K+ ATPase is caused by PPIs.
Parietal cells contain H+/K+-ATPase, which is inhibited by omeprazole, a proton pump inhibitor. Therefore, any answer indicating chief cells or H+/K+-ATPase stimulation is incorrect and potentially harmful.
Ranitidine is an example of a different class of gastroprotective drugs that inhibits H2 receptors.
Understanding Proton Pump Inhibitors
Proton pump inhibitors (PPIs) are medications that work by blocking the H+/K+ ATPase in the stomach’s parietal cells. This action is irreversible and helps to reduce the amount of acid produced in the stomach. Examples of PPIs include omeprazole and lansoprazole.
Despite their effectiveness in treating conditions such as gastroesophageal reflux disease (GERD) and peptic ulcers, PPIs can have adverse effects. These include hyponatremia and hypomagnesemia, which are low levels of sodium and magnesium in the blood, respectively. Prolonged use of PPIs can also increase the risk of osteoporosis, leading to an increased risk of fractures. Additionally, there is a potential for microscopic colitis and an increased risk of C. difficile infections.
It is important to weigh the benefits and risks of PPIs with your healthcare provider and to use them only as directed. Regular monitoring of electrolyte levels and bone density may also be necessary for those on long-term PPI therapy.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 10
Incorrect
-
A 67-year-old male with long standing chronic obstructive pulmonary disease (COPD) presents to the emergency department (ED) with shortness of breath over the last 2 hours and wheezing. On examination, he is cyanosed, has a third heart sound present and has widespread wheeze on auscultation. The emergency doctor also notices hepatomegaly which was not present 10 days ago when he was in the ED for a moderative exacerbation of COPD.
What is the likely cause of the newly developed hepatomegaly in this 67-year-old male with chronic obstructive pulmonary disease?Your Answer:
Correct Answer: Cor pulmonale
Explanation:The cause of the patient’s hepatomegaly is likely subacute onset cor pulmonale, which is right sided heart failure secondary to COPD. This is supported by the presence of shortness of breath, cyanosis, and a third heart sound. Left sided heart failure is unlikely to be the cause of his symptoms and hepatomegaly. While ascites can be a complication of right sided heart failure and portal hypertension, it does not cause hepatomegaly. Cirrhosis and liver cancer are also unlikely causes given the patient’s presentation, which is more consistent with a cardiorespiratory issue.
Understanding Hepatomegaly and Its Common Causes
Hepatomegaly refers to an enlarged liver, which can be caused by various factors. One of the most common causes is cirrhosis, which can lead to a decrease in liver size in later stages. In this case, the liver is non-tender and firm. Malignancy, such as metastatic spread or primary hepatoma, can also cause hepatomegaly. In this case, the liver edge is hard and irregular. Right heart failure can also lead to an enlarged liver, which is firm, smooth, and tender. It may even be pulsatile.
Aside from these common causes, hepatomegaly can also be caused by viral hepatitis, glandular fever, malaria, abscess (pyogenic or amoebic), hydatid disease, haematological malignancies, haemochromatosis, primary biliary cirrhosis, sarcoidosis, and amyloidosis.
Understanding the causes of hepatomegaly is important in diagnosing and treating the underlying condition. Proper diagnosis and treatment can help prevent further complications and improve overall health.
-
This question is part of the following fields:
- Gastrointestinal System
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Mins)