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Question 1
Correct
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A 72-year-old female presents to her local physician complaining of general fatigue and tiredness. She reports no fever, night sweats, or weight loss. She maintains an active lifestyle and attends fitness classes weekly. Her medical history includes hypertension, type II diabetes mellitus, constipation, and depression.
The physician orders blood tests, and the results are as follows:
- Hb: 113 g/l
- Platelets: 239 * 109/l
- WBC: 6 * 109/l
- Neuts: 2 * 109/l
- Lymphs: 2 * 109/l
- Eosin: 0.3 * 109/l
- Na+: 142 mmol/l
- K+: 3.2 mmol/l
- Bilirubin: 12 µmol/l
- ALP: 23 u/l
- ALT: 10 u/l
- γGT: 23 u/l
- Urea: 4 mmol/l
- Creatinine: 50 µmol/l
- Albumin: 30 g/l
Which medication is most likely causing her symptoms?Your Answer: Senna
Explanation:Prolonged use of senna increases the risk of hypokalemia, which is evident in the patient’s blood results. The symptoms of mild hypokalemia are non-specific and include fatigue, muscle weakness, constipation, and rhabdomyolysis. Given the patient’s medical history of constipation, it is likely that she has been taking a laxative, which could be either osmotic or a stimulant. Both types of laxatives are known to cause hypokalemia, and in this case, senna is the likely culprit.
Heparin can cause hyperkalemia, especially when used in conjunction with spironolactone, ACE inhibitors, non-steroidal anti-inflammatory drugs, and trimethoprim. Heparin inhibits aldosterone synthesis, leading to increased potassium retention and sodium excretion. This effect is more pronounced in elderly individuals, diabetics, and those with renal failure. The risk of hyperkalemia increases with higher doses, prolonged use, and unfractionated heparin therapy.
Amiloride is a potassium-sparing diuretic that works by inhibiting sodium reabsorption in the kidneys. It promotes the loss of sodium and water from the body without depleting potassium. Amiloride causes hyperkalemia by inhibiting sodium reabsorption at various points in the kidneys, which reduces potassium and hydrogen secretion and subsequent excretion.
Losartan is an angiotensin II receptor blocker that is known to cause hyperkalemia and is therefore not the cause of the patient’s hypokalemia.
Understanding Laxatives
Laxatives are frequently prescribed medications in clinical practice, with constipation being a common issue among patients. While constipation may be a symptom of underlying pathology, many patients experience simple idiopathic constipation. The British National Formulary (BNF) categorizes laxatives into four groups: osmotic, stimulant, bulk-forming, and faecal softeners.
Osmotic laxatives, such as lactulose, macrogols, and rectal phosphates, work by drawing water into the bowel to soften stools and promote bowel movements. Stimulant laxatives, including senna, docusate, bisacodyl, and glycerol, stimulate the muscles in the bowel to contract and move stool along. Co-danthramer, a combination of a stimulant and a bulk-forming laxative, should only be prescribed to palliative patients due to its potential carcinogenic effects.
Bulk-forming laxatives, such as ispaghula husk and methylcellulose, work by increasing the bulk of stool and promoting regular bowel movements. Faecal softeners, such as arachis oil enemas, are not commonly prescribed but can be used to soften stool and ease bowel movements.
In summary, understanding the different types of laxatives and their mechanisms of action can help healthcare professionals prescribe the most appropriate treatment for patients experiencing constipation.
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This question is part of the following fields:
- Gastrointestinal System
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Question 2
Correct
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A 48-year-old man is under your care after being diagnosed with pneumonia. On the day before his expected discharge, he experiences severe diarrhea without blood and needs intravenous fluids. A request for stool culture is made.
What would the microbiology report likely indicate as the responsible microbe?Your Answer: Gram-positive bacillus
Explanation:Clostridium difficile is a type of gram-positive bacillus that can cause pseudomembranous colitis, particularly after the use of broad-spectrum antibiotics.
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 3
Correct
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A 10-year-old girl presents to her doctor with a 2-month history of flatulence, foul-smelling diarrhoea, and a weight loss of 2kg. Her mother reports observing greasy, floating stools during this time.
During the examination, the patient appears to be in good health. There are no palpable masses or organomegaly during abdominal examination.
The child's serum anti-tissue transglutaminase antibodies are found to be elevated. What is the most probable HLA type for this child?Your Answer: HLA-DQ2
Explanation:The HLA most commonly associated with coeliac disease is HLA-DQ2. HLA, also known as human leukocyte antigen or major histocompatibility complex, is expressed on self-cells in the body and plays a role in presenting antigens to the immune system. The child’s symptoms of coeliac disease include fatty, floaty stools (steatorrhoea), weight loss, and positive tissue transglutaminase antibodies.
HLA-A01 is not commonly associated with autoimmune conditions, but has been linked to methotrexate-induced liver cirrhosis.
HLA-B27 is associated with psoriatic arthritis, reactive arthritis, ankylosing spondylitis, and inflammatory bowel disease.
HLA-B35 is not commonly associated with autoimmune conditions.
Understanding Coeliac Disease
Coeliac disease is an autoimmune disorder that affects approximately 1% of the UK population. It is caused by sensitivity to gluten, a protein found in wheat, barley, and rye. Repeated exposure to gluten leads to villous atrophy, which causes malabsorption. Coeliac disease is associated with various conditions, including dermatitis herpetiformis and autoimmune disorders such as type 1 diabetes mellitus and autoimmune hepatitis. It is strongly linked to HLA-DQ2 and HLA-DQ8.
To diagnose coeliac disease, NICE recommends screening patients who exhibit signs and symptoms such as chronic or intermittent diarrhea, failure to thrive or faltering growth in children, persistent or unexplained gastrointestinal symptoms, prolonged fatigue, recurrent abdominal pain, sudden or unexpected weight loss, unexplained anemia, autoimmune thyroid disease, dermatitis herpetiformis, irritable bowel syndrome, type 1 diabetes, and first-degree relatives with coeliac disease.
Complications of coeliac disease include anemia, hyposplenism, osteoporosis, osteomalacia, lactose intolerance, enteropathy-associated T-cell lymphoma of the small intestine, subfertility, and unfavorable pregnancy outcomes. In rare cases, it can lead to esophageal cancer and other malignancies.
The diagnosis of coeliac disease is confirmed through a duodenal biopsy, which shows complete atrophy of the villi with flat mucosa and marked crypt hyperplasia, intraepithelial lymphocytosis, and dense mixed inflammatory infiltrate in the lamina propria. Treatment involves a lifelong gluten-free diet.
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This question is part of the following fields:
- Gastrointestinal System
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Question 4
Correct
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A 48-year-old female patient complains of pain in the right hypochondrium. Upon palpation of the abdomen, she experiences tenderness in the right upper quadrant and reports that the pain worsens during inspiration. Based on the history and examination, the probable diagnosis is cholecystitis caused by a gallstone. If the gallstone were to move out of the gallbladder, which of the ducts would it enter first?
Your Answer: Cystic duct
Explanation:The biliary tree is composed of various ducts, including the cystic duct that transports bile from the gallbladder. The right and left hepatic ducts in the liver merge to form the common hepatic duct, which then combines with the cystic duct to create the common bile duct. The pancreatic duct from the pancreas also connects to the common bile duct, and they both empty into the duodenum through the hepatopancreatic ampulla (of Vater). The accessory duct, which may or may not exist, is a small supplementary duct(s) to the biliary tree.
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 5
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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Question 6
Correct
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During a splenectomy, which structure will need to be divided in a 33-year-old man?
Your Answer: Short gastric vessels
Explanation:When performing a splenectomy, it is necessary to cut the short gastric vessels located in the gastrosplenic ligament. The mobilization of the splenic flexure of the colon may also be required, but it is unlikely that it will need to be cut. This is because it is a critical area that would require a complete colonic resection if it were divided.
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 7
Incorrect
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Which of the following cell types is most likely to be found in the wall of a fistula in a 60-year-old patient?
Your Answer: Columnar cells
Correct Answer: Squamous cells
Explanation:A fistula is a connection that is not normal between two surfaces that are lined with epithelial cells. In the case of a fistula in ano, it will be lined with squamous cells.
Fistulas are abnormal connections between two epithelial surfaces, with various types ranging from those in the neck to those in the abdomen. The majority of fistulas in surgical practice arise from diverticular disease and Crohn’s. In general, all fistulas will heal spontaneously as long as there is no distal obstruction. However, this is particularly true for intestinal fistulas. There are four types of fistulas: enterocutaneous, enteroenteric or enterocolic, enterovaginal, and enterovesicular. Management of fistulas involves protecting the skin, managing high output fistulas with octreotide, and addressing nutritional complications. When managing perianal fistulas, it is important to avoid probing the fistula in cases of acute inflammation and to use setons for drainage in cases of Crohn’s disease. It is also important to delineate the fistula anatomy using imaging studies.
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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 65-year-old patient is scheduled for a right hemicolectomy to treat a caecum carcinoma. Which of the following vessels will need to be high ligated for optimal oncological control?
Your Answer: Ileo-colic artery
Explanation:During a right hemicolectomy, the caecum is supplied by the ileo-colic artery which requires high ligation. It is generally recommended to preserve the middle colic artery when resecting a caecal lesion. It should be noted that the SMA does not directly supply the caecum.
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.
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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 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.
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This question is part of the following fields:
- Gastrointestinal System
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Question 10
Incorrect
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A 75-year-old woman with caecal carcinoma is having a right hemicolectomy done via a transverse incision. During the procedure, the incision is extended medially by dividing the rectus sheath, and a brisk arterial hemorrhage occurs. What vessel is the source of the damage?
Your Answer: Internal iliac artery
Correct Answer: External iliac artery
Explanation:The damaged vessel is the epigastric artery, which has its origin in the external iliac artery (as shown below).
The Inferior Epigastric Artery: Origin and Pathway
The inferior epigastric artery is a blood vessel that originates from the external iliac artery just above the inguinal ligament. It runs along the medial edge of the deep inguinal ring and then continues upwards to lie behind the rectus abdominis muscle. This artery is responsible for supplying blood to the lower abdominal wall and pelvic region. Its pathway is illustrated in the image below.
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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 57-year-old man with a history of hyperlipidemia, hypertension, and type II diabetes presents to the emergency department with dull chest pain accompanied by sweating and nausea. He is promptly administered oxygen, aspirin, morphine, metoclopramide, atenolol, and nitrates.
Upon examination, angiography reveals significant blockage in all four coronary vessels. As a result, he is scheduled for an urgent coronary artery bypass graft, which will necessitate the removal of a vein from his lower limb.
Which nerve is most frequently affected during a vein harvest for CABG?Your Answer: Saphenous nerve
Explanation:During a coronary artery bypass graft (CABG), the great saphenous vein is often harvested. However, this procedure can lead to damage of the saphenous nerve, which runs closely alongside the vein in the medial aspect of the leg. Saphenous neuralgia, characterized by numbness, heightened sensitivity, and pain in the saphenous nerve distribution area, can result from such injury. Other nerves are not typically affected during a vein harvest for CABG.
During surgical procedures, there is a risk of nerve injury caused by the surgery itself. This is not only important for the patient’s well-being but also from a legal perspective. There are various operations that carry the risk of nerve damage, such as posterior triangle lymph node biopsy, Lloyd Davies stirrups, thyroidectomy, anterior resection of rectum, axillary node clearance, inguinal hernia surgery, varicose vein surgery, posterior approach to the hip, and carotid endarterectomy. Surgeons must have a good understanding of the anatomy of the area they are operating on to minimize the incidence of nerve lesions. Blind placement of haemostats is not recommended as it can also cause nerve damage.
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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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An 83-year-old woman comes to your clinic with a painful red swelling on her cheek that she noticed this morning. She has been feeling fatigued for a few days. The patient lives alone and has a history of pressure ulcers due to limited mobility. During the examination, you observe an erythematous swelling above the right angle of the mandible that is warm and tender to the touch. You suspect that the patient has a parotid gland infection. What is the nerve that provides sensation to the parotid gland capsule?
Your Answer: Facial nerve
Correct Answer: Greater auricular nerve
Explanation:The greater auricular nerve (GAN) supplies sensation to the parotid gland, skin overlying the gland, mastoid process, and outer ear. The facial nerve supplies muscles of facial expression, taste from the anterior two-thirds of the tongue, and sensation from parts of the external acoustic meatus, auricle, and retro-auricular area. The mandibular nerve carries sensory and motor fibers, supplying sensation to the lower lip, lower teeth and gingivae, chin, and jaw, and motor innervation to muscles of mastication. The lingual nerve supplies sensation to the tongue and travels with taste fibers from the chorda tympani of the facial nerve. The glossopharyngeal nerve carries taste and sensation from the posterior third of the tongue, sensation from the pharyngeal wall and tonsils, the middle ear, external auditory canal, and auricle, and parasympathetic fibers that supply the parotid gland. Infective parotitis is uncommon and has increased risk in dehydrated or intubated elderly patients.
The parotid gland is located in front of and below the ear, overlying the mandibular ramus. Its salivary duct crosses the masseter muscle, pierces the buccinator muscle, and drains adjacent to the second upper molar tooth. The gland is traversed by several structures, including the facial nerve, external carotid artery, retromandibular vein, and auriculotemporal nerve. The gland is related to the masseter muscle, medial pterygoid muscle, superficial temporal and maxillary artery, facial nerve, stylomandibular ligament, posterior belly of the digastric muscle, sternocleidomastoid muscle, stylohyoid muscle, internal carotid artery, mastoid process, and styloid process. The gland is supplied by branches of the external carotid artery and drained by the retromandibular vein. Its lymphatic drainage is to the deep cervical nodes. The gland is innervated by the parasympathetic-secretomotor, sympathetic-superior cervical ganglion, and sensory-greater auricular nerve. Parasympathetic stimulation produces a water-rich, serous saliva, while sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.
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This question is part of the following fields:
- Gastrointestinal System
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Question 13
Correct
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A 75-year-old man presents with a sizable abdominal aortic aneurysm. While undergoing a laparotomy for scheduled surgical intervention, the medical team discovers that the aneurysm is situated much closer to the origin of the SMA. While dissecting the area, a transverse vessel running across the aorta sustains damage. What is the most probable identity of this vessel?
Your Answer: Left renal vein
Explanation:During the repair of a juxtarenal aneurysm, intentional ligation of the left renal vein may be necessary as it travels over the aorta.
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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Which of the following genes is not involved in the adenoma-carcinoma sequence of colorectal cancer?
Your Answer: src
Explanation:Additional genes implicated include MCC, DCC, c-yes, and bcl-2.
Colorectal cancer is a prevalent type of cancer in the UK, ranking third in terms of frequency and second in terms of cancer-related deaths. Every year, approximately 150,000 new cases are diagnosed, and 50,000 people die from the disease. The cancer can occur in different parts of the colon, with the rectum being the most common location, accounting for 40% of cases. The sigmoid colon follows closely, with 30% of cases, while the descending colon has only 5%. The transverse colon has 10% of cases, and the ascending colon and caecum have 15%.
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This question is part of the following fields:
- Gastrointestinal System
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Question 15
Incorrect
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A 6-year-old boy complains of pain in the right iliac fossa and there is a suspicion of appendicitis. What is the embryological origin of the appendix?
Your Answer: Hindgut
Correct Answer: Midgut
Explanation:Periumbilical pain may be a symptom of early appendicitis due to the fact that the appendix originates from the midgut.
Appendix Anatomy and Location
The appendix is a small, finger-like projection located at the base of the caecum. It can be up to 10cm long and is mainly composed of lymphoid tissue, which can sometimes lead to confusion with mesenteric adenitis. The caecal taenia coli converge at the base of the appendix, forming a longitudinal muscle cover over it. This convergence can aid in identifying the appendix during surgery, especially if it is retrocaecal and difficult to locate. The arterial supply to the appendix comes from the appendicular artery, which is a branch of the ileocolic artery. It is important to note that the appendix is intra-peritoneal.
McBurney’s Point and Appendix Positions
McBurney’s point is a landmark used to locate the appendix during physical examination. It is located one-third of the way along a line drawn from the Anterior Superior Iliac Spine to the Umbilicus. The appendix can be found in six different positions, with the retrocaecal position being the most common at 74%. Other positions include pelvic, postileal, subcaecal, paracaecal, and preileal. It is important to be aware of these positions as they can affect the presentation of symptoms and the difficulty of locating the appendix during surgery.
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This question is part of the following fields:
- Gastrointestinal System
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Question 16
Incorrect
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A 61-year-old man is having surgery for a cancerous tumor in the splenic flexure of his colon. During the procedure, the surgeons cut the middle colic vein near its source. What is the primary drainage location for this vessel?
Your Answer: Portal vein
Correct Answer: Superior mesenteric vein
Explanation:If the middle colonic vein is torn during mobilization, it can lead to severe bleeding that may be challenging to manage as it drains into the SMV.
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.
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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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A gynaecologist is performing a laparoscopic hysterectomy on a 45-year-old patient. He is being careful to avoid damaging a structure that runs close to the vaginal fornices.
What is the structure that the gynaecologist is most likely being cautious of?Your Answer: Ureter
Explanation:The correct statements are:
– The ureter enters the bladder trigone after passing only 1 cm away from the vaginal fornices, which is closer than other structures.
– The ilioinguinal nerve originates from the first lumbar nerve (L1).
– The femoral artery is a continuation of the external iliac artery.
– The descending colon starts at the splenic flexure and ends at the beginning of the sigmoid colon.
– The obturator nerve arises from the ventral divisions of the second, third, and fourth lumbar nerves.Anatomy of the Ureter
The ureter is a muscular tube that measures 25-35 cm in length and is lined by transitional epithelium. It is surrounded by a thick muscular coat that becomes three muscular layers as it crosses the bony pelvis. This retroperitoneal structure overlies the transverse processes L2-L5 and lies anterior to the bifurcation of iliac vessels. The blood supply to the ureter is segmental and includes the renal artery, aortic branches, gonadal branches, common iliac, and internal iliac. It is important to note that the ureter lies beneath the uterine artery.
In summary, the ureter is a vital structure in the urinary system that plays a crucial role in transporting urine from the kidneys to the bladder. Its unique anatomy and blood supply make it a complex structure that requires careful consideration in any surgical or medical intervention.
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This question is part of the following fields:
- Gastrointestinal System
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Question 18
Correct
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A 63-year-old male presents to his GP with a complaint of blood in his stools. The blood is bright red and occurs during defecation, but it is not painful. He has been feeling more tired lately, but he has not experienced night sweats, weight loss, loss of appetite, or changes in bowel habits.
The patient has a history of liver cirrhosis and underwent an oesophageal endoscopy two years ago, but he cannot recall the results. He is a known alcoholic and attends AA.
Upon examination, the patient appears pale with conjunctival pallor, and ascites is present.
What is the most likely diagnosis?Your Answer: Haemorrhoids
Explanation:Haemorrhoids in Portal Hypertension
A likely diagnosis for a patient with a history of portal hypertension, ascites, endoscopy, and cirrhotic liver is haemorrhoids. Portal hypertension causes pressure to be passed on to the middle and inferior rectal veins, leading to their dilation and the development of haemorrhoids. While haemorrhoids are common in the general population, significant blood loss is rare. However, in patients with established cirrhosis, large amounts of blood can be lost through these varices.
An anal fissure is unlikely in this case, as there is no history of straining or a low-fibre diet, and they are typically painful. While colorectal carcinoma is an important diagnosis to consider, painless bright fresh blood is more likely to be caused by haemorrhoids in patients with a strong history of portal hypertension. In malignancy, fresh blood is less common, and a change in bowel habit is often a prominent feature.
A perianal haematoma is a thrombosed haemorrhoid that typically presents with severe pain, making it an unlikely diagnosis in this case. The patient’s presentation of painless bleeding further supports the diagnosis of haemorrhoids in the context of portal hypertension.
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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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On examining the caecum, what structure is most likely to be detected at the point where all the tenia coli converge?
Your Answer: Appendix base
Explanation:The tenia coli come together at the bottom of the appendix.
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.
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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 23-year-old male complains of crampy abdominal pain, bloating, and diarrhea. He recently came back from a trip to Egypt where he swam in the local pool a few days ago. He reports having 5 bowel movements per day, and his stool floats in the toilet water without any blood. What is the probable cause of his symptoms?
Your Answer: Giardia lamblia
Explanation:Giardia can lead to the occurrence of greasy stool due to its ability to cause fat malabsorption. Additionally, it is important to note that Giardia is resistant to chlorination, which increases the risk of transmission in swimming pools.
Understanding Diarrhoea: Causes and Characteristics
Diarrhoea is defined as having more than three loose or watery stools per day. It can be classified as acute if it lasts for less than 14 days and chronic if it persists for more than 14 days. Gastroenteritis, diverticulitis, and antibiotic therapy are common causes of acute diarrhoea. On the other hand, irritable bowel syndrome, ulcerative colitis, Crohn’s disease, colorectal cancer, and coeliac disease are some of the conditions that can cause chronic diarrhoea.
Symptoms of gastroenteritis may include abdominal pain, nausea, and vomiting. Diverticulitis is characterized by left lower quadrant pain, diarrhoea, and fever. Antibiotic therapy, especially with broad-spectrum antibiotics, can also cause diarrhoea, including Clostridium difficile infection. Chronic diarrhoea may be caused by irritable bowel syndrome, which is characterized by abdominal pain, bloating, and changes in bowel habits. Ulcerative colitis may cause bloody diarrhoea, crampy abdominal pain, and weight loss. Crohn’s disease may cause crampy abdominal pain, diarrhoea, and malabsorption. Colorectal cancer may cause diarrhoea, rectal bleeding, anaemia, and weight loss. Coeliac disease may cause diarrhoea, abdominal distension, lethargy, and weight loss.
Other conditions associated with diarrhoea include thyrotoxicosis, laxative abuse, appendicitis, and radiation enteritis. It is important to seek medical attention if diarrhoea persists for more than a few days or is accompanied by other symptoms such as fever, severe abdominal pain, or blood in the stool.
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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 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 22
Correct
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A 67-year-old woman visits her GP after discovering a lump in her groin subsequent to relocating. 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 reduces the lump, applies pressure to the midpoint of the inguinal ligament, and instructs the patient to cough. The lump reappears, leading the GP to tentatively diagnose the patient with a direct inguinal hernia. Through which anatomical structures will the hernia pass?
Your Answer: Transversalis fascia and superficial inguinal ring
Explanation:The correct structures for a direct inguinal hernia to pass through are the transversalis fascia (which forms the posterior wall of the inguinal canal) and the superficial ring. If the hernia were to pass through other structures, such as the deep inguinal ring, it would reappear upon increased intra-abdominal pressure. In contrast, an indirect inguinal hernia enters the canal through the deep inguinal ring and exits at the superficial ring, so it would not reappear if the deep inguinal ring were blocked.
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 23
Incorrect
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A 65-year-old man visits his GP complaining of a lump in his groin. He reports no other symptoms such as abdominal pain or changes in bowel habits. Upon examination, the GP notes that the lump is soft and can be reduced without causing discomfort to the patient. The GP suspects an inguinal hernia but is unsure if it is direct or indirect. To determine this, the GP reduces the lump and applies pressure to the anatomical landmark for the deep inguinal ring. What is this landmark?
Your Answer: Superior and medial to the pubic tubercle
Correct Answer: Superior to the midpoint of the inguinal ligament
Explanation: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 24
Incorrect
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A 40-year-old male visits a private vascular clinic for his long-standing varicose veins. He had been referred by his family physician and is concerned about the appearance of his legs. He experiences heaviness and aching in his legs. As a professional athlete, he often wears shorts during games and is worried that his condition might affect his performance.
After being informed of the risks associated with varicose vein surgery, he decides to proceed with the operation. However, during his follow-up appointment, he reports a loss of sensation over the lateral foot and posterolateral leg.
Which nerve is most likely to have been damaged during the surgery?Your Answer: Femoral nerve
Correct Answer: Sural nerve
Explanation:During varicose vein surgery, there is a potential for damage to the sural nerve, which innervates the posterolateral leg and lateral foot. Additionally, the saphenous nerve, responsible for sensation in the medial aspect of the leg and foot, and the lateral femoral cutaneous nerve, which innervates the lateral thigh, may also be at risk.
During surgical procedures, there is a risk of nerve injury caused by the surgery itself. This is not only important for the patient’s well-being but also from a legal perspective. There are various operations that carry the risk of nerve damage, such as posterior triangle lymph node biopsy, Lloyd Davies stirrups, thyroidectomy, anterior resection of rectum, axillary node clearance, inguinal hernia surgery, varicose vein surgery, posterior approach to the hip, and carotid endarterectomy. Surgeons must have a good understanding of the anatomy of the area they are operating on to minimize the incidence of nerve lesions. Blind placement of haemostats is not recommended as it can also cause nerve damage.
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This question is part of the following fields:
- Gastrointestinal System
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Question 25
Incorrect
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A 50-year-old obese woman presents with right upper quadrant abdominal pain, nausea and vomiting. She has a family history of gallstone disease. Upon physical examination, a positive Murphy's sign is observed. An abdominal ultrasound reveals gallstones in the thickened gallbladder. The surgeon opts for a laparoscopic cholecystectomy to remove the gallbladder. During the procedure, the surgeon identifies and dissects the hepatobiliary triangle to safely ligate and divide two structures.
What are the two structures being referred to in the above scenario?Your Answer: Common hepatic duct and common bile duct
Correct Answer: Cystic duct and cystic artery
Explanation:During laparoscopic cholecystectomy, the hepatobiliary triangle plays a crucial role in ensuring the safe ligation and division of the cystic duct and cystic artery. Surgeons must carefully dissect this area to identify these structures and avoid any potential biliary complications.
The hepatobiliary triangle is bordered by the common hepatic duct, which is formed by the union of the common bile duct and cystic duct. The cystic artery branches off from the right hepatic artery, while Lund’s node serves as the sentinel lymph node of the gallbladder.
The accessory duct is considered auxiliary to the biliary tree, and the left and right hepatic ducts merge into the common hepatic duct. The gastroduodenal artery arises from the common hepatic artery, and the cystic vein helps distinguish between the cystic and common hepatic ducts during surgery, but is not ligated.
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 26
Correct
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A 16-year-old female was admitted to the paediatric unit with a history of anorexia nervosa and a body mass index of 16kg/m². Despite being uncooperative initially, she has shown improvement in her willingness to participate with the team. However, she now presents with complaints of abdominal pain and weakness. Upon blood testing, the following results were obtained:
Hb 125 g/L Male: (135-180) Female: (115 - 160)
Platelets 180 * 109/L (150 - 400)
WBC 4.5 * 109/L (4.0 - 11.0)
Na+ 138 mmol/L (135 - 145)
K+ 3.2 mmol/L (3.5 - 5.0)
Bicarbonate 26 mmol/L (22 - 29)
Urea 5 mmol/L (2.0 - 7.0)
Creatinine 70 µmol/L (55 - 120)
Calcium 2.1 mmol/L (2.1-2.6)
Phosphate 0.5 mmol/L (0.8-1.4)
Magnesium 0.6 mmol/L (0.7-1.0)
What is the likely cause of the patient's abnormal blood results?Your Answer: Extended period of low calories then high carbohydrate intake
Explanation:Refeeding syndrome can occur in patients who have experienced prolonged catabolism and then suddenly switch to carbohydrate metabolism. This can lead to a rapid uptake of phosphate, potassium, and magnesium into the cells, caused by spikes in insulin and glucose. Patients with low BMI and poor nutritional intake over a long period of time are at a higher risk. Taking vitamin tablets would not affect blood results, but excessive intake can result in hypervitaminosis. While exogenous insulin could also cause this syndrome, there is no indication that the patient has taken it. To reduce the risk of refeeding syndrome, some patients may be advised to follow initial high-fat, low-carbohydrate diets.
Understanding Refeeding Syndrome
Refeeding syndrome is a condition that occurs when a person who has been starved for an extended period suddenly begins to eat again. This metabolic abnormality is caused by the abrupt switch from catabolism to carbohydrate metabolism. The consequences of refeeding syndrome include hypophosphataemia, hypokalaemia, hypomagnesaemia, and abnormal fluid balance, which can lead to organ failure.
To prevent refeeding syndrome, it is important to identify patients who are at high risk of developing the condition. According to guidelines produced by NICE in 2006, patients are considered high-risk if they have a BMI of less than 16 kg/m2, have experienced unintentional weight loss of more than 15% over 3-6 months, have had little nutritional intake for more than 10 days, or have hypokalaemia, hypophosphataemia, or hypomagnesaemia prior to feeding (unless high).
If a patient has two or more of the following risk factors, they are also considered high-risk: a BMI of less than 18.5 kg/m2, unintentional weight loss of more than 10% over 3-6 months, little nutritional intake for more than 5 days, or a history of alcohol abuse, drug therapy (including insulin, chemotherapy, diuretics, and antacids).
To prevent refeeding syndrome, NICE recommends that patients who haven’t eaten for more than 5 days should be re-fed at no more than 50% of their requirements for the first 2 days. By following these guidelines, healthcare professionals can help prevent the potentially life-threatening consequences of refeeding syndrome.
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This question is part of the following fields:
- Gastrointestinal System
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Question 27
Correct
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A patient with a history of diverticular disease presents to the surgical assessment unit with abdominal pain and a fever. Her white blood cell count is elevated, but she is otherwise stable. The diagnosis is diverticulitis. What is the best course of action for managing this condition?
Your Answer: Antibiotics, a liquid diet and analgesia
Explanation:The initial management approach for mild diverticulitis typically involves a combination of oral antibiotics, a liquid diet, and analgesia.
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 28
Correct
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A 50-year-old woman arrives at the emergency department complaining of abrupt abdominal pain. She has a 35-pack-year smoking history and has been managing polycythemia vera for 10 years with intermittent phlebotomy. Upon initial evaluation, she appears alert and has a distended abdomen with shifting dullness and tender hepatomegaly. What is the probable diagnosis based on these observations?
Your Answer: Budd-Chiari syndrome
Explanation:Budd-Chiari syndrome is the correct diagnosis for this patient, as it is caused by hepatic vein thrombosis. The patient has significant risk factors for thrombophilia and is presenting with the classic triad of right upper quadrant abdominal pain, ascites (as evidenced by shifting dullness on examination), and hepatomegaly.
While decompensated cirrhosis can also cause ascites and hepatomegaly, it is unlikely to cause an acute abdomen and is more likely to present with associated jaundice and encephalopathy. Therefore, this option is incorrect.
Right-sided heart failure can also lead to ascites due to raised portosystemic pressure, but this option is incorrect as the patient does not have risk factors for heart failure apart from smoking and does not have other typical findings of heart failure such as dyspnea and peripheral edema.
Nephrotic syndrome can also cause ascites due to hypoalbuminemia-related fluid retention, but there is no mention of proteinuria or hypoalbuminemia, which typically causes peri-orbital edema. Therefore, this option is also incorrect.
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 29
Incorrect
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Which hormone is primarily responsible for sodium-potassium exchange in the salivary ducts?
Your Answer: Somatostatin
Correct Answer: Aldosterone
Explanation:The regulation of ion exchange in salivary glands is attributed to aldosterone. This hormone targets a pump that facilitates the exchange of sodium and potassium ions. Aldosterone is classified as a mineralocorticoid hormone and is produced in the zona glomerulosa of the adrenal gland.
The parotid gland is located in front of and below the ear, overlying the mandibular ramus. Its salivary duct crosses the masseter muscle, pierces the buccinator muscle, and drains adjacent to the second upper molar tooth. The gland is traversed by several structures, including the facial nerve, external carotid artery, retromandibular vein, and auriculotemporal nerve. The gland is related to the masseter muscle, medial pterygoid muscle, superficial temporal and maxillary artery, facial nerve, stylomandibular ligament, posterior belly of the digastric muscle, sternocleidomastoid muscle, stylohyoid muscle, internal carotid artery, mastoid process, and styloid process. The gland is supplied by branches of the external carotid artery and drained by the retromandibular vein. Its lymphatic drainage is to the deep cervical nodes. The gland is innervated by the parasympathetic-secretomotor, sympathetic-superior cervical ganglion, and sensory-greater auricular nerve. Parasympathetic stimulation produces a water-rich, serous saliva, while sympathetic stimulation leads to the production of a low volume, enzyme-rich saliva.
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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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During an abdominal aortic aneurysm repair, a 78-year-old man has two clamps placed on his aorta, with the inferior clamp positioned at the point of aortic bifurcation. Which vertebral body will be located posterior to the clamp at this level?
Your Answer: L4
Explanation:The point at which the aorta divides into two branches is known as the bifurcation, which is a crucial anatomical landmark that is frequently assessed. This bifurcation typically occurs at the level of the fourth lumbar vertebrae (L4).
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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