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  • Question 1 - A 32-year-old female patient arrives at the emergency department with suspected pulmonary embolism....

    Correct

    • A 32-year-old female patient arrives at the emergency department with suspected pulmonary embolism. The patient has a history of multiple deep vein thromboses on separate occasions and has few risk factors for thrombosis, but a significant family history of DVT. The consultant suspects an inherited thrombophilia.

      What could be the possible diagnosis in this scenario?

      Your Answer: Factor V Leiden

      Explanation:

      The most probable diagnosis for this case is factor V Leiden, which is the most common inherited thrombophilia. This condition causes resistance to activated protein C, which normally breaks down clotting factor V to prevent excessive clotting. As a result, individuals with factor V Leiden have an increased risk of developing blood clots, particularly deep vein thrombosis.

      Antiphospholipid syndrome is another thrombophilia, but it is an acquired autoimmune disorder that is less common than factor V Leiden. It is characterized by inappropriate clotting and miscarriage, which are not present in this case.

      Haemophilia A and von Willebrand disease are bleeding disorders that increase the risk of excessive bleeding, not clotting. Therefore, they are unlikely to be the cause of the patient’s thrombosis.

      Protein C deficiency has a similar mechanism and presentation to factor V Leiden, but it is less common. Hence, it is not the most probable diagnosis in this case.

      Thrombophilia is a condition that causes an increased risk of blood clots. It can be inherited or acquired. Inherited thrombophilia is caused by genetic mutations that affect the body’s natural ability to prevent blood clots. The most common cause of inherited thrombophilia is a gain of function polymorphism called factor V Leiden, which affects the protein that helps regulate blood clotting. Other genetic mutations that can cause thrombophilia include deficiencies of naturally occurring anticoagulants such as antithrombin III, protein C, and protein S. The prevalence and relative risk of venous thromboembolism (VTE) vary depending on the specific genetic mutation.

      Acquired thrombophilia can be caused by conditions such as antiphospholipid syndrome or the use of certain medications, such as the combined oral contraceptive pill. These conditions can affect the body’s natural ability to prevent blood clots and increase the risk of VTE. It is important to identify and manage thrombophilia to prevent serious complications such as deep vein thrombosis and pulmonary embolism.

    • This question is part of the following fields:

      • Haematology And Oncology
      9.8
      Seconds
  • Question 2 - A 78-year-old male visits his doctor complaining of fresh red blood in his...

    Incorrect

    • A 78-year-old male visits his doctor complaining of fresh red blood in his stool, tenesmus, and a change in bowel habit that has persisted for 7 weeks. The patient has a medical history of hypertension and takes amlodipine and amlodipine without any allergies. During a digital rectal examination, an irregular mass is detected in the anterior aspect of the rectum. The patient is immediately referred for a flexible sigmoidoscopy, which reveals an adenocarcinoma in the anal canal below the pectinate line.

      In this patient, what is the lymph node region where metastatic spread is most likely to occur initially?

      Your Answer: Internal iliac nodes

      Correct Answer: Superficial inguinal nodes

      Explanation:

      The lymphatic drainage of the anal canal below the pectinate line is provided by the superficial inguinal nodes. These nodes also drain the lower limbs, scrotum/vulva, and the rectum below the pectinate line. The ileocolic nodes primarily drain the ileum and proximal ascending colon, while the inferior mesenteric nodes drain the hindgut structures. The internal iliac nodes drain the inferior rectum, anal canal above the pectinate line, and pelvic viscera. The para-aortic nodes do not directly drain the portion of the rectum below the pectinate line, but they do drain the testes/ovaries.

      Lymphatic drainage is the process by which lymphatic vessels carry lymph, a clear fluid containing white blood cells, away from tissues and organs and towards lymph nodes. The lymphatic vessels that drain the skin and follow venous drainage are called superficial lymphatic vessels, while those that drain internal organs and structures follow the arteries and are called deep lymphatic vessels. These vessels eventually lead to lymph nodes, which filter and remove harmful substances from the lymph before it is returned to the bloodstream.

      The lymphatic system is divided into two main ducts: the right lymphatic duct and the thoracic duct. The right lymphatic duct drains the right side of the head and right arm, while the thoracic duct drains everything else. Both ducts eventually drain into the venous system.

      Different areas of the body have specific primary lymph node drainage sites. For example, the superficial inguinal lymph nodes drain the anal canal below the pectinate line, perineum, skin of the thigh, penis, scrotum, and vagina. The deep inguinal lymph nodes drain the glans penis, while the para-aortic lymph nodes drain the testes, ovaries, kidney, and adrenal gland. The axillary lymph nodes drain the lateral breast and upper limb, while the internal iliac lymph nodes drain the anal canal above the pectinate line, lower part of the rectum, and pelvic structures including the cervix and inferior part of the uterus. The superior mesenteric lymph nodes drain the duodenum and jejunum, while the inferior mesenteric lymph nodes drain the descending colon, sigmoid colon, and upper part of the rectum. Finally, the coeliac lymph nodes drain the stomach.

    • This question is part of the following fields:

      • Haematology And Oncology
      32.7
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  • Question 3 - A 47-year-old man from Pakistan is on a visit to the UK to...

    Incorrect

    • A 47-year-old man from Pakistan is on a visit to the UK to meet his family. He has approached a doctor with concerns about blood in his urine, but he is uncertain whether it is more red or orange in color. The man has a medical history of tuberculosis and is currently undergoing quadruple therapy. Which medication from his treatment plan could be causing his symptoms?

      Your Answer: Pyrazinamide

      Correct Answer: Rifampicin

      Explanation:

      Tuberculosis can be treated with all of these drugs, but Rifampicin is notorious for causing bodily fluids like urine, tears, and sweat to turn red-orange in color. Isoniazid can cause numbness, tingling, and unsteadiness in the hands and feet, while Ethambutol can lead to visual changes like color vision deterioration and decreased visual acuity. Pyrazinamide may cause fatigue, joint pain, and gastrointestinal issues.

      Tuberculosis is a bacterial infection that can be treated with a combination of drugs. Each drug has a specific mechanism of action and can also cause side-effects. Rifampicin works by inhibiting bacterial DNA dependent RNA polymerase, which prevents the transcription of DNA into mRNA. However, it is a potent liver enzyme inducer and can cause hepatitis, orange secretions, and flu-like symptoms.

      Isoniazid, on the other hand, inhibits mycolic acid synthesis. It can cause peripheral neuropathy, which can be prevented with pyridoxine (Vitamin B6). It can also cause hepatitis and agranulocytosis, but it is a liver enzyme inhibitor.

      Pyrazinamide is converted by pyrazinamidase into pyrazinoic acid, which inhibits fatty acid synthase (FAS) I. However, it can cause hyperuricaemia, leading to gout, as well as arthralgia and myalgia. It can also cause hepatitis.

      Finally, Ethambutol inhibits the enzyme arabinosyl transferase, which polymerizes arabinose into arabinan. However, it can cause optic neuritis, so it is important to check visual acuity before and during treatment. The dose also needs adjusting in patients with renal impairment.

    • This question is part of the following fields:

      • General Principles
      16.9
      Seconds
  • Question 4 - Which one of the following statements relating to osteomyelitis is not true? ...

    Incorrect

    • Which one of the following statements relating to osteomyelitis is not true?

      Your Answer: The presence of associated septic joint involvement will significantly alter management

      Correct Answer: Should be treated by aggressive surgical debridement initially

      Explanation:

      The initial management involves medical treatment with an antistaphylococcal antibiotic, as opposed to septic joints where prompt joint washout is necessary.

      Understanding Osteomyelitis: Types, Causes, and Treatment

      Osteomyelitis is a bone infection that can be classified into two types: haematogenous and non-haematogenous. Haematogenous osteomyelitis is caused by bacteria in the bloodstream and is usually monomicrobial. It is more common in children and can be caused by risk factors such as sickle cell anaemia, intravenous drug use, immunosuppression, and infective endocarditis. On the other hand, non-haematogenous osteomyelitis is caused by the spread of infection from adjacent soft tissues or direct injury to the bone. It is often polymicrobial and more common in adults, with risk factors such as diabetic foot ulcers, pressure sores, diabetes mellitus, and peripheral arterial disease.

      Staphylococcus aureus is the most common cause of osteomyelitis, except in patients with sickle-cell anaemia where Salmonella species are more prevalent. To diagnose osteomyelitis, MRI is the imaging modality of choice, with a sensitivity of 90-100%.

      The treatment for osteomyelitis involves a course of antibiotics for six weeks. Flucloxacillin is the preferred antibiotic, but clindamycin can be used for patients who are allergic to penicillin. Understanding the types, causes, and treatment of osteomyelitis is crucial in managing this bone infection.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      20.3
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  • Question 5 - A newly diagnosed patient with acute myeloid leukaemia (AML) is about to begin...

    Correct

    • A newly diagnosed patient with acute myeloid leukaemia (AML) is about to begin treatment. What would be a favorable prognostic factor for this individual?

      Your Answer: Acute promyelocytic leukaemia (APML) subtype

      Explanation:

      Prognostic Factors in Acute Myeloid Leukemia

      Acute myeloid leukemia (AML) is a type of cancer that affects the blood and bone marrow. The APML subtype of AML has a higher five-year survival rate of 70% compared to the average rate of 25%. However, it is a medical emergency upon presentation due to the risk of coagulopathy, tumor lysis, and life-threatening infections. Urgent treatment with ATRA chemotherapy is necessary. Younger patients tend to have a better prognosis and can tolerate intensive chemotherapy better. Certain cytogenetic changes, such as t(15;17) in APML and t(8;21) and inv(16), are associated with a favorable prognosis. However, complex cytogenetics are not. A performance status of 3, which indicates that an individual spends more than 50% of the day in bed, is not ideal for intensive chemotherapy. AML that arises from a pre-existing condition, such as a myeloproliferative neoplasm, has a worse prognosis than AML that arises de novo.

      Overall, the prognostic factors in AML is crucial for determining the appropriate treatment plan and predicting outcomes.

    • This question is part of the following fields:

      • Haematology And Oncology
      18.6
      Seconds
  • Question 6 - A young woman presents with a bilateral intention tremor. She is also found...

    Correct

    • A young woman presents with a bilateral intention tremor. She is also found to have a range of other bilateral deficits, including dysdiadochokinesia, ataxia, nystagmus, and dysarthria. Which anatomical structure has likely been affected?

      Your Answer: Cerebellar vermis

      Explanation:

      The individual has a defect in the cerebellar vermis, which is located between the two hemispheres of the cerebellum. As a result, they are experiencing bilateral cerebellar abnormalities, which is evident from their symptoms. Vermin lesions can be caused by conditions such as Joubert Syndrome, Dandy Walker malformation, and rhombencephalosynapsis. On the other hand, lesions in the spinocerebellar tract or one side of the cerebellar hemisphere would cause unilateral, ipsilateral symptoms, making these options incorrect.

      Spinal cord lesions can affect different tracts and result in various clinical symptoms. Motor lesions, such as amyotrophic lateral sclerosis and poliomyelitis, affect either upper or lower motor neurons, resulting in spastic paresis or lower motor neuron signs. Combined motor and sensory lesions, such as Brown-Sequard syndrome, subacute combined degeneration of the spinal cord, Friedrich’s ataxia, anterior spinal artery occlusion, and syringomyelia, affect multiple tracts and result in a combination of spastic paresis, loss of proprioception and vibration sensation, limb ataxia, and loss of pain and temperature sensation. Multiple sclerosis can involve asymmetrical and varying spinal tracts and result in a combination of motor, sensory, and ataxia symptoms. Sensory lesions, such as neurosyphilis, affect the dorsal columns and result in loss of proprioception and vibration sensation.

    • This question is part of the following fields:

      • Neurological System
      19.3
      Seconds
  • Question 7 - You are working with a consultant paediatrician in an outpatient clinic and have...

    Incorrect

    • You are working with a consultant paediatrician in an outpatient clinic and have a 14-month-old patient who is failing to thrive. The GP suspects the presence of an audible murmur. The consultant informs you that this child has an atrial septal defect (ASD). What is the most prevalent form of ASD?

      Your Answer: Patent ductus arteriosus

      Correct Answer: Ostium secundum

      Explanation:

      Atrial Septal Defects

      Atrial septal defects (ASDs) are a type of congenital heart defect that occur when there is a hole in the wall separating the two upper chambers of the heart. The most common type of ASD is the ostium secundum defect, accounting for 75% of all cases. It is important to note that patent ductus arteriosus is not an ASD, but rather a connection between the aorta and pulmonary trunk that remains open after birth.

      Most patients with ASDs are asymptomatic, but symptoms may occur depending on the size of the defect and the resistance in the pulmonary and systemic circulation. Typically, there is shunting of blood from the left to the right atrium, causing an increase in pulmonary blood flow and diastolic overload of the right ventricle. This can lead to enlargement of the right atrium, right ventricle, and pulmonary arteries, as well as incompetence of the pulmonary and tricuspid valves. In severe cases, pulmonary arterial hypertension may develop, which can lead to cyanosis if the shunt reverses from right to left.

      It is important to note that right to left shunts cause cyanosis, while left to right shunts are generally not associated with cyanosis in the absence of other pathology. the pathophysiology of ASDs is crucial for proper diagnosis and management of this condition.

    • This question is part of the following fields:

      • Cardiovascular System
      12.8
      Seconds
  • Question 8 - Which type of bias are cohort studies particularly prone to? ...

    Correct

    • Which type of bias are cohort studies particularly prone to?

      Your Answer: Recall bias

      Explanation:

      Understanding Bias in Clinical Trials

      Bias refers to the systematic favoring of one outcome over another in a clinical trial. There are various types of bias, including selection bias, recall bias, publication bias, work-up bias, expectation bias, Hawthorne effect, late-look bias, procedure bias, and lead-time bias. Selection bias occurs when individuals are assigned to groups in a way that may influence the outcome. Sampling bias, volunteer bias, and non-responder bias are subtypes of selection bias. Recall bias refers to the difference in accuracy of recollections retrieved by study participants, which may be influenced by whether they have a disorder or not. Publication bias occurs when valid studies are not published, often because they showed negative or uninteresting results. Work-up bias is an issue in studies comparing new diagnostic tests with gold standard tests, where clinicians may be reluctant to order the gold standard test unless the new test is positive. Expectation bias occurs when observers subconsciously measure or report data in a way that favors the expected study outcome. The Hawthorne effect describes a group changing its behavior due to the knowledge that it is being studied. Late-look bias occurs when information is gathered at an inappropriate time, and procedure bias occurs when subjects in different groups receive different treatment. Finally, lead-time bias occurs when two tests for a disease are compared, and the new test diagnoses the disease earlier, but there is no effect on the outcome of the disease. Understanding these types of bias is crucial in designing and interpreting clinical trials.

    • This question is part of the following fields:

      • General Principles
      16.8
      Seconds
  • Question 9 - A young girl presents with thin grey discharge which has a fishy odour....

    Correct

    • A young girl presents with thin grey discharge which has a fishy odour. She is subsequently diagnosed with bacterial vaginosis. Her doctor explains that this is caused by an overgrowth of normal bacterial flora and that many bacteria can be responsible for this condition. The presence of which bacterium would call for a reconsideration of her diagnosis?

      Your Answer: Trichomonas vaginalis

      Explanation:

      Trichomonas vaginalis is not responsible for causing bacterial vaginosis. Instead, it causes trichomoniasis, a sexually transmitted infection that is characterized by yellow-green frothy vaginal discharge and vaginitis.

      Bacterial vaginosis (BV) is a condition where there is an overgrowth of anaerobic organisms, particularly Gardnerella vaginalis, in the vagina. This leads to a decrease in the amount of lactobacilli, which produce lactic acid, resulting in an increase in vaginal pH. BV is not a sexually transmitted infection, but it is commonly seen in sexually active women. Symptoms include a fishy-smelling vaginal discharge, although some women may not experience any symptoms at all. Diagnosis is made using Amsel’s criteria, which includes the presence of thin, white discharge, clue cells on microscopy, a vaginal pH greater than 4.5, and a positive whiff test. Treatment involves oral metronidazole for 5-7 days, with a cure rate of 70-80%. However, relapse rates are high, with over 50% of women experiencing a recurrence within 3 months. Topical metronidazole or clindamycin may be used as alternatives.

      Bacterial vaginosis during pregnancy can increase the risk of preterm labor, low birth weight, chorioamnionitis, and late miscarriage. It was previously recommended to avoid oral metronidazole in the first trimester and use topical clindamycin instead. However, recent guidelines suggest that oral metronidazole can be used throughout pregnancy. The British National Formulary (BNF) still advises against using high-dose metronidazole regimes. Clue cells, which are vaginal epithelial cells covered with bacteria, can be seen on microscopy in women with BV.

    • This question is part of the following fields:

      • General Principles
      10.6
      Seconds
  • Question 10 - A 30-year-old male is diagnosed with carcinoid syndrome. What hormone is secreted by...

    Incorrect

    • A 30-year-old male is diagnosed with carcinoid syndrome. What hormone is secreted by carcinoids?

      Your Answer: Dopamine

      Correct Answer: Serotonin

      Explanation:

      The rule of thirds for carcinoids is that one-third of cases involve multiple tumors, one-third affect the small bowel, and one-third result in metastasis or the development of a second tumor. It is important to note that carcinoids secrete serotonin, and carcinoid syndrome only occurs when there are liver metastases present, as the liver typically metabolizes the hormone released from primary lesions.

      Carcinoid tumours are a type of cancer that can cause a condition called carcinoid syndrome. This syndrome typically occurs when the cancer has spread to the liver and releases serotonin into the bloodstream. In some cases, it can also occur with lung carcinoid tumours, as the mediators are not cleared by the liver. The earliest symptom of carcinoid syndrome is often flushing, but it can also cause diarrhoea, bronchospasm, hypotension, and right heart valvular stenosis (or left heart involvement in bronchial carcinoid). Additionally, other molecules such as ACTH and GHRH may be secreted, leading to conditions like Cushing’s syndrome. Pellagra, a rare condition caused by a deficiency in niacin, can also develop as the tumour diverts dietary tryptophan to serotonin.

      To investigate carcinoid syndrome, doctors may perform a urinary 5-HIAA test or a plasma chromogranin A test. Treatment for the condition typically involves somatostatin analogues like octreotide, which can help manage symptoms like diarrhoea. Cyproheptadine may also be used to alleviate diarrhoea. Overall, early detection and treatment of carcinoid tumours can help prevent the development of carcinoid syndrome and improve outcomes for patients.

    • This question is part of the following fields:

      • Gastrointestinal System
      6.9
      Seconds
  • Question 11 - A 35-year-old woman seeking to become pregnant is worried about experiencing two miscarriages....

    Correct

    • A 35-year-old woman seeking to become pregnant is worried about experiencing two miscarriages. She is seeking guidance on how to improve her chances of a successful pregnancy. What factors are linked to miscarriage?

      Your Answer: Older paternal age

      Explanation:

      Miscarriage is not caused by a single factor, but rather by a combination of risk factors. Women over the age of 35 and men over the age of 40 are at a significantly higher risk of experiencing a miscarriage. It is important to note that activities such as exercise, emotional stress, consuming spicy foods, and engaging in sexual intercourse do not increase the risk of miscarriage.

      Miscarriage: Understanding the Epidemiology

      Miscarriage, also known as spontaneous abortion, refers to the natural expulsion of the products of conception before the 24th week of pregnancy. It is a common occurrence, with approximately 15-20% of diagnosed pregnancies ending in miscarriage during the early stages. To avoid any confusion, the term miscarriage is often used instead of abortion.

      Studies show that up to 50% of conceptions fail to develop into a blastocyst within 14 days. This highlights the importance of early detection and monitoring during pregnancy. Additionally, recurrent spontaneous miscarriage affects approximately 1% of women, which can be a distressing and emotionally challenging experience.

      Understanding the epidemiology of miscarriage is crucial in providing appropriate care and support for women who experience this loss. With proper medical attention and emotional support, women can navigate through this difficult time and move forward with hope and healing.

    • This question is part of the following fields:

      • Reproductive System
      6.5
      Seconds
  • Question 12 - An 80-year-old woman visits her doctor with complaints of moderate upper abdominal pain...

    Incorrect

    • An 80-year-old woman visits her doctor with complaints of moderate upper abdominal pain that is slightly relieved by eating. Despite taking ibuprofen, she has not experienced any relief. The doctor suspects a duodenal peptic ulcer and schedules an oesophagogastroduodenoscopy (OGD). Based on the location of the ulcer, which organ is derived from the same embryological region of the gut?

      Your Answer: Jejunum

      Correct Answer: Oesophagus

      Explanation:

      The major papilla located in the 2nd part of the duodenum marks the division between the foregut and the midgut, with the foregut encompassing structures from the mouth to the 2nd part of the duodenum where peptic ulcers are commonly found. It should be noted that the kidneys are not derived from gut embryology, but rather from the ureteric bud.

      The Three Embryological Layers and their Corresponding Gastrointestinal Structures and Blood Supply

      The gastrointestinal system is a complex network of organs responsible for the digestion and absorption of nutrients. During embryonic development, the gastrointestinal system is formed from three distinct layers: the foregut, midgut, and hindgut. Each layer gives rise to specific structures and is supplied by a corresponding blood vessel.

      The foregut extends from the mouth to the proximal half of the duodenum and is supplied by the coeliac trunk. The midgut encompasses the distal half of the duodenum to the splenic flexure of the colon and is supplied by the superior mesenteric artery. Lastly, the hindgut includes the descending colon to the rectum and is supplied by the inferior mesenteric artery.

      Understanding the embryological origin and blood supply of the gastrointestinal system is crucial in diagnosing and treating gastrointestinal disorders. By identifying the specific structures and blood vessels involved, healthcare professionals can better target their interventions and improve patient outcomes.

    • This question is part of the following fields:

      • Gastrointestinal System
      19.8
      Seconds
  • Question 13 - A 35-year-old male presents to the emergency department after experiencing a seizure. He...

    Correct

    • A 35-year-old male presents to the emergency department after experiencing a seizure. He reports a severe headache for the past several hours and feeling nauseous. Upon urgent MRI, oedema is observed in the temporal lobe. Antivirals are immediately initiated. What cells in the central nervous system act as phagocytes?

      Your Answer: Microglia

      Explanation:

      The central nervous system has a limited number of immune cells, but microglia are specialized phagocytes that play a crucial role in clearing extracellular debris and responding to bacterial or viral infections. The patient in the scenario likely had herpes simplex virus encephalitis, as indicated by the classic sign of temporal lobe edema. Oligodendrocytes are responsible for myelinating axons in the central nervous system, while Schwann cells perform this function in the peripheral nervous system. Astrocytes provide structural support and help regulate extracellular potassium levels.

      The nervous system is composed of various types of cells, each with their own unique functions. Oligodendroglia cells are responsible for producing myelin in the central nervous system (CNS) and are affected in multiple sclerosis. Schwann cells, on the other hand, produce myelin in the peripheral nervous system (PNS) and are affected in Guillain-Barre syndrome. Astrocytes provide physical support, remove excess potassium ions, help form the blood-brain barrier, and aid in physical repair. Microglia are specialised CNS phagocytes, while ependymal cells provide the inner lining of the ventricles.

      In summary, the nervous system is made up of different types of cells, each with their own specific roles. Oligodendroglia and Schwann cells produce myelin in the CNS and PNS, respectively, and are affected in certain diseases. Astrocytes provide physical support and aid in repair, while microglia are specialised phagocytes in the CNS. Ependymal cells line the ventricles. Understanding the functions of these cells is crucial in understanding the complex workings of the nervous system.

    • This question is part of the following fields:

      • Neurological System
      10.9
      Seconds
  • Question 14 - Mr. Johnson, a 68-year-old man visits his doctor with a complaint of experiencing...

    Incorrect

    • Mr. Johnson, a 68-year-old man visits his doctor with a complaint of experiencing dizzy spells for the past month. He mentions that he started taking a long-acting nitrate for heart failure about three weeks ago.

      The doctor takes his sitting blood pressure and compares it to his previous readings.

      Current BP 88/72mmHg
      BP two months ago 130/90mmHg

      The doctor concludes that the new medication has caused hypotension in Mr. Johnson.

      What molecular mechanism could be responsible for this change in blood pressure?

      Your Answer: Nitrate causing a decrease in intracellular potassium

      Correct Answer: Nitrate causing a decrease in intracellular calcium

      Explanation:

      The release of nitric oxide caused by nitrates can lead to a decrease in intracellular calcium. This occurs when nitric oxide activates guanylate cyclase, which converts GDP to cGMP. The resulting decrease in intracellular calcium within smooth muscle cells causes vasodilation and can result in hypotension as a side effect. Additionally, flushing may occur as a result of the vasodilation caused by decreased intracellular calcium. It is important to note that nitrates do not affect intracellular potassium or sodium, and do not cause an increase in intracellular calcium, which would lead to smooth muscle contraction and an increase in blood pressure.

      Understanding Nitrates and Their Effects on the Body

      Nitrates are a type of medication that can cause blood vessels to widen, which is known as vasodilation. They are commonly used to manage angina and treat heart failure. One of the most frequently prescribed nitrates is sublingual glyceryl trinitrate, which is used to relieve angina attacks in patients with ischaemic heart disease.

      The mechanism of action for nitrates involves the release of nitric oxide in smooth muscle, which activates guanylate cyclase. This enzyme then converts GTP to cGMP, leading to a decrease in intracellular calcium levels. In the case of angina, nitrates dilate the coronary arteries and reduce venous return, which decreases left ventricular work and reduces myocardial oxygen demand.

      However, nitrates can also cause side effects such as hypotension, tachycardia, headaches, and flushing. Additionally, many patients who take nitrates develop tolerance over time, which can reduce their effectiveness. To combat this, the British National Formulary recommends that patients who develop tolerance take the second dose of isosorbide mononitrate after 8 hours instead of 12 hours. This allows blood-nitrate levels to fall for 4 hours and maintains effectiveness. It’s important to note that this effect is not seen in patients who take modified release isosorbide mononitrate.

    • This question is part of the following fields:

      • Cardiovascular System
      27.3
      Seconds
  • Question 15 - A 26-year-old Afro-Caribbean woman comes to the Emergency Department complaining of dyspnoea and...

    Incorrect

    • A 26-year-old Afro-Caribbean woman comes to the Emergency Department complaining of dyspnoea and fatigue that has been going on for 2 days. She reports experiencing similar episodes repeatedly over the past few years. She has no other medical history.

      During the examination, you observe sporadic erythematous lesions on her shins and detect a pansystolic murmur. You request a chest x-ray, which reveals bilateral hilar lymphadenopathy and an enlarged heart.

      What additional symptom is linked to this ailment?

      Your Answer: Increased parathyroid hormone

      Correct Answer: Reduced ventricular ejection fraction

      Explanation:

      Patients with reduced ejection fraction heart failure (HF-rEF) usually experience systolic dysfunction, which refers to the impaired ability of the myocardium to contract during systole.

      Types of Heart Failure

      Heart failure is a clinical syndrome where the heart cannot pump enough blood to meet the body’s metabolic needs. It can be classified in multiple ways, including by ejection fraction, time, and left/right side. Patients with heart failure may have a normal or abnormal left ventricular ejection fraction (LVEF), which is measured using echocardiography. Reduced LVEF is typically defined as < 35 to 40% and is termed heart failure with reduced ejection fraction (HF-rEF), while preserved LVEF is termed heart failure with preserved ejection fraction (HF-pEF). Heart failure can also be described as acute or chronic, with acute heart failure referring to an acute exacerbation of chronic heart failure. Left-sided heart failure is more common and may be due to increased left ventricular afterload or preload, while right-sided heart failure is caused by increased right ventricular afterload or preload. High-output heart failure is another type of heart failure that occurs when a normal heart is unable to pump enough blood to meet the body's metabolic needs. By classifying heart failure in these ways, healthcare professionals can better understand the underlying causes and tailor treatment plans accordingly. It is important to note that many guidelines for the management of heart failure only cover HF-rEF patients and do not address the management of HF-pEF patients. Understanding the different types of heart failure can help healthcare professionals provide more effective care for their patients.

    • This question is part of the following fields:

      • Cardiovascular System
      30.5
      Seconds
  • Question 16 - A 58-year-old woman, previously healthy, visited her doctor complaining of a growing rubbery...

    Incorrect

    • A 58-year-old woman, previously healthy, visited her doctor complaining of a growing rubbery lump in her neck and night sweats. She was quickly referred to a haematologist who diagnosed her with lymphoma. The patient is currently undergoing chemotherapy for the lymphoma and has come to your clinic with glove-and-stocking distribution paraesthesia.

      What medication is the most probable cause of this symptom in this patient?

      Your Answer: Ondansetron

      Correct Answer: Vincristine

      Explanation:

      Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and potential adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin and anthracyclines, degrade preformed DNA and stabilize DNA-topoisomerase II complex, respectively. However, they can also cause lung fibrosis and cardiomyopathy. Antimetabolites, such as methotrexate and fluorouracil, inhibit dihydrofolate reductase and thymidylate synthesis, respectively. However, they can also cause myelosuppression, mucositis, and liver or lung fibrosis. Drugs that act on microtubules, like vincristine and docetaxel, inhibit the formation of microtubules and prevent microtubule depolymerisation & disassembly, respectively. However, they can also cause peripheral neuropathy, myelosuppression, and paralytic ileus. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I, which prevents relaxation of supercoiled DNA. However, they can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin and hydroxyurea, cause cross-linking in DNA and inhibit ribonucleotide reductase, respectively. However, they can also cause ototoxicity, peripheral neuropathy, hypomagnesaemia, and myelosuppression.

    • This question is part of the following fields:

      • Haematology And Oncology
      13
      Seconds
  • Question 17 - What is the most common method of assessing nutritional status in adults? ...

    Incorrect

    • What is the most common method of assessing nutritional status in adults?

      Your Answer: Skin fold thickness

      Correct Answer: Body mass index

      Explanation:

      The Body Mass Index as a Measure of Nutritional Status

      The measurement and assessment of nutritional status can be challenging, and there is no single test that can provide a complete picture. However, the body mass index (BMI) is a commonly used measurement in clinical practice. The BMI is calculated by dividing a person’s weight in kilograms by their height in meters squared. This measure is used to assess adiposity and nutritional status, and it is simple and quick to calculate and interpret.

      Although the BMI is a convenient measure, it has limitations for assessing obesity in individual patients. It is best used to track trends in an individual patient’s BMI over time. In some cases, the BMI may overestimate fat mass in patients who are very tall or have a high proportion of lean tissue due to an active lifestyle. Additionally, the BMI may not be accurate for athletes and children.

      Other measurements, such as skin fold thickness and weight, can also be useful, but the BMI is generally considered the better option. The ponderal index is used specifically for children. It is important to note that albumin is not a reliable marker of nutritional status, as it can also be affected by inflammation.

      Overall, the BMI is a widely used measure of nutritional status and is recommended by the World Health Organization. However, it is important to consider its limitations and use it in conjunction with other measurements to obtain a more complete picture of a patient’s nutritional status.

    • This question is part of the following fields:

      • Basic Sciences
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  • Question 18 - What is the cell type in the glomerulus that has a role in...

    Incorrect

    • What is the cell type in the glomerulus that has a role in phagocytosis?

      Your Answer: Podocytes

      Correct Answer: Mesangial cells

      Explanation:

      The Structure of the Glomerulus

      The glomerulus is composed of glomerular capillaries that are lined by a basement membrane and podocyte processes. Podocytes are connected to the epithelial cells of Bowman’s capsule, which are then connected to the cells of the proximal convoluted tubule. Supporting cells called mesangial cells are located between the capillary endothelial cells and podocytes. These cells produce the extracellular matrix that supports the structure of the glomerulus and remove dead cells through phagocytosis. Additionally, mesangial cells may play a role in regulating glomerular blood flow. Overall, the glomerulus is a complex structure that plays a crucial role in the filtration of blood in the kidneys.

    • This question is part of the following fields:

      • Histology
      3.4
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  • Question 19 - A patient presents at the clinic after experiencing head trauma. The physician conducts...

    Correct

    • A patient presents at the clinic after experiencing head trauma. The physician conducts a neurological assessment to evaluate for nerve damage. During the examination, the doctor observes a lack of pupil constriction when shining a flashlight into the patient's eyes.

      Which cranial nerve is accountable for this parasympathetic reaction?

      Your Answer: Oculomotor

      Explanation:

      The cranial nerves that carry parasympathetic fibers are the vagus nerve (X), glossopharyngeal nerve (IX), facial nerve (VII), and oculomotor nerve (III). The oculomotor nerve is responsible for the parasympathetic response of pupil constriction through innervating the iris sphincter muscle. The abducens nerve (VI) does not provide a parasympathetic response and only innervates the lateral rectus muscle of the eye for abduction. The ophthalmic nerve is a branch of the trigeminal nerve and does not provide any autonomic innervation. The optic nerve is responsible for vision and does not provide any autonomic or parasympathetic innervation.

      Cranial nerves are a set of 12 nerves that emerge from the brain and control various functions of the head and neck. Each nerve has a specific function, such as smell, sight, eye movement, facial sensation, and tongue movement. Some nerves are sensory, some are motor, and some are both. A useful mnemonic to remember the order of the nerves is Some Say Marry Money But My Brother Says Big Brains Matter Most, with S representing sensory, M representing motor, and B representing both.

      In addition to their specific functions, cranial nerves also play a role in various reflexes. These reflexes involve an afferent limb, which carries sensory information to the brain, and an efferent limb, which carries motor information from the brain to the muscles. Examples of cranial nerve reflexes include the corneal reflex, jaw jerk, gag reflex, carotid sinus reflex, pupillary light reflex, and lacrimation reflex. Understanding the functions and reflexes of the cranial nerves is important in diagnosing and treating neurological disorders.

    • This question is part of the following fields:

      • Neurological System
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  • Question 20 - A 40-year-old male presents with a six-month history of frequent diarrhoea. He describes...

    Incorrect

    • A 40-year-old male presents with a six-month history of frequent diarrhoea. He describes up to ten episodes a day of bloody stool. The patient denies any night sweats, fever, or weight loss, explains that he has not changed his diet recently.

      On examination he has;
      Normal vital signs
      No ulcerations in his mouth
      Mild lower abdominal tenderness
      Pain and blood noted on rectal examination

      What is the most probable finding on colonoscopy or biopsy?

      Your Answer: Non-caseating granulomas

      Correct Answer: Crypt abscesses

      Explanation:

      ASCA, also known as anti-Saccharomyces cerevisiae antibodies, can be abbreviated as 6.

      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
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  • Question 21 - A 6-year-old boy presents to the clinic after experiencing his seventh fracture. Upon...

    Incorrect

    • A 6-year-old boy presents to the clinic after experiencing his seventh fracture. Upon examination, his x-rays reveal dense bones with multiple cortical layers. He also has a mild normocytic anemia and low platelets, but his sclera appear white. What is the probable diagnosis?

      Your Answer: Osteogenesis imperfecta

      Correct Answer: Osteopetrosis

      Explanation:

      Osteopetrosis and its Distinction from Other Bone Disorders

      Osteopetrosis is a congenital condition that affects bone reabsorption, leading to the appearance of a ‘bone within a bone’ from multiple cortical layers. Despite the increased density, bones become brittle and prone to fracture, and there is no room for the marrow to grow, causing bone marrow failure and peripheral cytopenias. Additionally, bones expand and frequently cause neural compression symptoms.

      When diagnosing osteopetrosis, it is important to exclude non-accidental injury (NAI) due to the repeated bone injury, but NAI alone cannot account for the x-ray findings or the blood counts. However, a diagnosis of osteopetrosis does not rule out the possibility of NAI co-existing with the condition.

      Other bone disorders, such as acute lymphocytic leukemia and aplastic anemia, may present with peripheral cytopenias but not the x-ray appearances or multiple fractures. On the other hand, osteogenesis imperfecta (OI) is a congenital condition of brittle bones susceptible to multiple fractures due to a mutation in type I collagen. The most common form, type I OI, is inherited as an autosomal dominant condition and is associated with blue sclerae and neural deafness from bone overgrowth. X-rays show reduced bone density with cortical disorganization.

      In summary, the distinct features of osteopetrosis and its differentiation from other bone disorders is crucial in making an accurate diagnosis and providing appropriate treatment.

    • This question is part of the following fields:

      • Paediatrics
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  • Question 22 - A 65-year-old man is undergoing an upper GI endoscopy due to difficulty swallowing....

    Incorrect

    • A 65-year-old man is undergoing an upper GI endoscopy due to difficulty swallowing. During the procedure, a suspicious-looking blockage is found at 33 cm from the incisors. The endoscopist tries to widen the area with a balloon, but the tumor causes a rupture in the oesophageal wall. Where will the contents of the oesophagus now drain?

      Your Answer: Middle mediastinum

      Correct Answer: Posterior mediastinum

      Explanation:

      The oesophagus is expected to remain within the thoracic cavity and situated in the posterior mediastinum at this point.

      The mediastinum is the area located between the two pulmonary cavities and is covered by the mediastinal pleura. It extends from the thoracic inlet at the top to the diaphragm at the bottom. The mediastinum is divided into four regions: the superior mediastinum, middle mediastinum, posterior mediastinum, and anterior mediastinum.

      The superior mediastinum is the area between the manubriosternal angle and T4/5. It contains important structures such as the superior vena cava, brachiocephalic veins, arch of aorta, thoracic duct, trachea, oesophagus, thymus, vagus nerve, left recurrent laryngeal nerve, and phrenic nerve. The anterior mediastinum contains thymic remnants, lymph nodes, and fat. The middle mediastinum contains the pericardium, heart, aortic root, arch of azygos vein, and main bronchi. The posterior mediastinum contains the oesophagus, thoracic aorta, azygos vein, thoracic duct, vagus nerve, sympathetic nerve trunks, and splanchnic nerves.

      In summary, the mediastinum is a crucial area in the thorax that contains many important structures and is divided into four regions. Each region contains different structures that are essential for the proper functioning of the body.

    • This question is part of the following fields:

      • Respiratory System
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  • Question 23 - Which micro-organism can cause symptoms similar to achalasia of the esophagus in patients?...

    Incorrect

    • Which micro-organism can cause symptoms similar to achalasia of the esophagus in patients?

      Your Answer: Helicobacter Pylori

      Correct Answer: Trypanosoma Cruzi

      Explanation:

      The destruction of ganglion cells in the myenteric plexus caused by Trypanosoma Cruzi infection can lead to symptoms resembling those of achalasia.

      Understanding Trypanosomiasis

      Trypanosomiasis is a protozoal disease that comes in two main forms: African trypanosomiasis, also known as sleeping sickness, and American trypanosomiasis, or Chagas’ disease. The former has two types: Trypanosoma gambiense in West Africa and Trypanosoma rhodesiense in East Africa, both of which are spread by the tsetse fly. Trypanosoma rhodesiense tends to have a more acute course. Symptoms include a painless subcutaneous nodule at the site of infection, intermittent fever, enlargement of posterior cervical lymph nodes, and later, central nervous system involvement such as somnolence, headaches, mood changes, and meningoencephalitis.

      On the other hand, American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. In the acute phase, the vast majority of patients (95%) are asymptomatic, although a chagoma (an erythematous nodule at the site of infection) and periorbital oedema are sometimes seen. Chronic Chagas’ disease mainly affects the heart and gastrointestinal tract, with myocarditis leading to dilated cardiomyopathy (with apical atrophy) and arrhythmias, and gastrointestinal features including megaoesophagus and megacolon causing dysphagia and constipation.

      Early disease management for African trypanosomiasis involves IV pentamidine or suramin, while later disease or central nervous system involvement requires IV melarsoprol. Treatment for American trypanosomiasis is most effective in the acute phase using azole or nitroderivatives such as benznidazole or nifurtimox. Chronic disease management involves treating the complications, such as heart failure.

    • This question is part of the following fields:

      • General Principles
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  • Question 24 - A patient in their 50s complains of tenderness in the anatomical snuffbox following...

    Incorrect

    • A patient in their 50s complains of tenderness in the anatomical snuffbox following a fall. The tendons of the abductor pollicis longus are located along the radial (lateral) border of the anatomical snuffbox.

      What is the nerve that innervates this muscle?

      Your Answer: Median nerve

      Correct Answer: Radial nerve

      Explanation:

      The correct answer is that the posterior interosseous branch of the radial nerve supplies abductor pollicis longus, along with all the other extensor muscles of the forearm, including supinator. The main trunk of the radial nerve supplies triceps, anconeus, extensor carpi radialis, and brachioradialis. The anterior interosseous nerve supplies flexor digitorum profundus (radial half), flexor pollicis longus, and pronator quadratus. The median nerve supplies the LOAF muscles (lumbricals 1 and 2, opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis). The lateral cutaneous nerve of the forearm has no motor innervation, and the ulnar nerve supplies most of the intrinsic muscles of the hand and two muscles of the anterior forearm: the flexor carpi ulnaris and the medial flexor digitorum profundus.

      The Radial Nerve: Anatomy, Innervation, and Patterns of Damage

      The radial nerve is a continuation of the posterior cord of the brachial plexus, with root values ranging from C5 to T1. It travels through the axilla, posterior to the axillary artery, and enters the arm between the brachial artery and the long head of triceps. From there, it spirals around the posterior surface of the humerus in the groove for the radial nerve before piercing the intermuscular septum and descending in front of the lateral epicondyle. At the lateral epicondyle, it divides into a superficial and deep terminal branch, with the deep branch crossing the supinator to become the posterior interosseous nerve.

      The radial nerve innervates several muscles, including triceps, anconeus, brachioradialis, and extensor carpi radialis. The posterior interosseous branch innervates supinator, extensor carpi ulnaris, extensor digitorum, and other muscles. Denervation of these muscles can lead to weakness or paralysis, with effects ranging from minor effects on shoulder stability to loss of elbow extension and weakening of supination of prone hand and elbow flexion in mid prone position.

      Damage to the radial nerve can result in wrist drop and sensory loss to a small area between the dorsal aspect of the 1st and 2nd metacarpals. Axillary damage can also cause paralysis of triceps. Understanding the anatomy, innervation, and patterns of damage of the radial nerve is important for diagnosing and treating conditions that affect this nerve.

    • This question is part of the following fields:

      • Neurological System
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  • Question 25 - A 50-year-old previously healthy man presents with chest pain that is radiating to...

    Incorrect

    • A 50-year-old previously healthy man presents with chest pain that is radiating to his left arm and accompanied by nausea, vomiting, and sweating. Despite no ST-segment changes on the ECG, his troponin T level at six hours post-onset of pain is significantly elevated at 350 ng/L (<14). As a result, he is diagnosed with a non-ST elevation myocardial infarction and prescribed aspirin 300mg. What is the mechanism of action of this treatment?

      Your Answer: Decreases the formation of thromboxane A1 resulting in decreased platelet aggregation

      Correct Answer: Decreases the formation of thromboxane A2

      Explanation:

      How Aspirin Works and its Use in Cardiovascular Disease

      Aspirin is a medication that works by blocking the action of cyclooxygenase-1 and 2, which are responsible for the synthesis of prostaglandin, prostacyclin, and thromboxane. By blocking the formation of thromboxane A2 in platelets, aspirin reduces their ability to aggregate, making it a widely used medication in cardiovascular disease. However, recent trials have cast doubt on the use of aspirin in primary prevention of cardiovascular disease, and guidelines have not yet changed to reflect this. Aspirin should not be used in children under 16 due to the risk of Reye’s syndrome, except in cases of Kawasaki disease where the benefits outweigh the risks. As for its use in ischaemic heart disease, aspirin is recommended as a first-line treatment. It can also potentiate the effects of oral hypoglycaemics, warfarin, and steroids. It is important to note that recent guidelines recommend clopidogrel as a first-line treatment for ischaemic stroke and peripheral arterial disease, while the use of aspirin in TIAs remains a topic of debate among different guidelines.

      Overall, aspirin’s mechanism of action and its use in cardiovascular disease make it a valuable medication in certain cases. However, recent studies have raised questions about its effectiveness in primary prevention, and prescribers should be aware of the potential risks and benefits when considering its use.

    • This question is part of the following fields:

      • General Principles
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  • Question 26 - A 55-year-old patient visits his doctor with concerns about enlarged breast tissue causing...

    Incorrect

    • A 55-year-old patient visits his doctor with concerns about enlarged breast tissue causing him embarrassment. He has a medical history of hypertension, atrial fibrillation, bipolar disorder, and diabetes mellitus. He previously used cocaine and now takes methadone. He recently completed a course of amoxicillin for a chest infection. He has not gained weight and wonders if any of his medications could be responsible for his condition.

      Which medication is most likely responsible for the patient's complaint?

      Your Answer: Naproxen

      Correct Answer: Digoxin

      Explanation:

      Digoxin is a medication that can cause gynecomastia as a side effect. It belongs to the group of cardiac glycoside drugs and is commonly used to treat heart failure, atrial fibrillation, and atrial flutter.

      Amoxicillin, on the other hand, is an antibiotic that is not known to cause gynecomastia.

      Atenolol is a beta-blocker that is used to manage hypertension, angina, and acute myocardial infarction. It is a selective beta-1-adrenergic antagonist and can cause side effects such as bronchospasm, bradycardia, diarrhea, confusion, headache, erectile dysfunction, and peripheral coldness. However, it is not associated with gynecomastia, except for galactorrhea.

      Methadone, a medication used to treat opioid addiction, has been shown to increase plasma prolactin levels after administration. This effect is reversible with dopamine agonist administration, as pituitary prolactin release is inhibited by dopamine secreted from hypothalamic neurons.

      Understanding Digoxin and Its Toxicity

      Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure patients. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, it has a narrow therapeutic index and can cause toxicity even when the concentration is within the therapeutic range.

      Toxicity may present with symptoms such as lethargy, nausea, vomiting, confusion, and yellow-green vision. Arrhythmias and gynaecomastia may also occur. Hypokalaemia is a classic precipitating factor as it increases the inhibitory effects of digoxin. Other factors include increasing age, renal failure, myocardial ischaemia, and various electrolyte imbalances. Certain drugs, such as amiodarone and verapamil, can also contribute to toxicity.

      If toxicity is suspected, digoxin concentrations should be measured within 8 to 12 hours of the last dose. However, plasma concentration alone does not determine toxicity. Management includes the use of Digibind, correcting arrhythmias, and monitoring potassium levels.

      In summary, understanding the mechanism of action, monitoring, and potential toxicity of digoxin is crucial for its safe and effective use in clinical practice.

    • This question is part of the following fields:

      • General Principles
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  • Question 27 - A 60-year-old man with chronic kidney disease secondary to diabetes is scheduled to...

    Correct

    • A 60-year-old man with chronic kidney disease secondary to diabetes is scheduled to undergo a contrast-enhanced CT scan for a suspected brain lesion. His latest eGFR is 51ml/min/1.73m2. After a multidisciplinary team discussion, it was decided that using contrast in the scan was in the patient's best interests, despite the increased risk of contrast-induced acute kidney injury. What would be the most suitable approach to minimize the risk of contrast-induced acute kidney injury in this situation?

      Your Answer: Offer IV hydration before and after infusion

      Explanation:

      To reduce the risk of contrast-induced acute kidney injury in high-risk patients, NICE guidelines recommend administering sodium chloride at a rate of 1 mL/kg/hour for 12 hours before and after the procedure. While there is some evidence supporting the use of acetylcysteine via IV infusion, it is not strong enough to be recommended in the guidelines. In at-risk patients, it is important to discuss whether the contrast is necessary. Waiting for the patient’s eGFR to improve is not a realistic option in this scenario, as the patient has chronic kidney disease. While maintaining tight glycaemic control is important for long-term kidney function, it is less relevant in this setting. Potentially nephrotoxic medications such as NSAIDs should be temporarily stopped, and ACE inhibitor therapy should be considered for cessation in patients with an eGFR less than 40ml/min/1.73m2, according to NICE guidelines.

      Contrast media nephrotoxicity is characterized by a 25% increase in creatinine levels within three days of receiving intravascular contrast media. This condition typically occurs between two to five days after administration and is more likely to affect patients with pre-existing renal impairment, dehydration, cardiac failure, or those taking nephrotoxic drugs like NSAIDs. Procedures that may cause contrast-induced nephropathy include CT scans with contrast and coronary angiography or percutaneous coronary intervention (PCI). Around 5% of patients who undergo PCI experience a temporary increase in plasma creatinine levels of more than 88 µmol/L.

      To prevent contrast-induced nephropathy, intravenous 0.9% sodium chloride should be administered at a rate of 1 mL/kg/hour for 12 hours before and after the procedure. Isotonic sodium bicarbonate may also be used. While N-acetylcysteine was previously used, recent evidence suggests it is not effective. Patients at high risk for contrast-induced nephropathy should have metformin withheld for at least 48 hours and until their renal function returns to normal to avoid the risk of lactic acidosis.

    • This question is part of the following fields:

      • Renal System
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  • Question 28 - A 57-year-old man with a history of chronic myeloid leukaemia for which he...

    Correct

    • A 57-year-old man with a history of chronic myeloid leukaemia for which he has started receiving chemotherapy presents with left flank pain and oliguria. He has tenderness over his left renal angle. A working diagnosis of kidney stones is made. Both abdominal X-ray and CT scan are unremarkable and no stone is visible.

      What is the most likely composition of his kidney stone?

      Your Answer: Uric acid

      Explanation:

      Stones formed in the urinary tract due to infections with urease-positive bacteria, such as Proteus mirabilis, are known as struvite stones. These stones are caused by the hydrolysis of urea to ammonia, which alkalizes the urine. Struvite stones often take the shape of staghorn calculi and can be detected through radiography as they are radio-opaque.

      Renal stones can be classified into different types based on their composition. Calcium oxalate stones are the most common, accounting for 85% of all calculi. These stones are formed due to hypercalciuria, hyperoxaluria, and hypocitraturia. They are radio-opaque and may also bind with uric acid stones. Cystine stones are rare and occur due to an inherited recessive disorder of transmembrane cystine transport. Uric acid stones are formed due to purine metabolism and may precipitate when urinary pH is low. Calcium phosphate stones are associated with renal tubular acidosis and high urinary pH. Struvite stones are formed from magnesium, ammonium, and phosphate and are associated with chronic infections. The pH of urine can help determine the type of stone present, with calcium phosphate stones forming in normal to alkaline urine, uric acid stones forming in acidic urine, and struvate stones forming in alkaline urine. Cystine stones form in normal urine pH.

    • This question is part of the following fields:

      • Renal System
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  • Question 29 - Sophie is a 2-year-old child being cared for in a neonatal intensive care...

    Incorrect

    • Sophie is a 2-year-old child being cared for in a neonatal intensive care unit for multi-system organ failure, she is unlikely to see her fourth birthday.

      Her older brother, Jack, is a 9-year-old child who is healthy and doing well in school, except his PE teacher has noticed that Jack has mild difficulties with balance and coordination.

      Genetic testing identified both Sophie and Jack have the same disease affecting their mitochondria, which they inherited from their mother but not from their father.

      What is the most probable biological reason for why Sophie's condition is significantly more severe than Jack's?

      Your Answer: Genetic mosaicism

      Correct Answer: Mitochondrial heteroplasmy

      Explanation:

      Mitochondrial heteroplasmy is the presence of multiple types of mitochondrial DNA within an individual, which can result in variable expression of mitochondrial disease. It is likely that Tom and Emily’s mother has mitochondrial heteroplasmy, which caused her to produce eggs with mitochondria containing different genomes. If a mitochondrion contains unhealthy DNA, it may be poorly functional and result in symptoms such as poor balance and coordination, as seen in Emily. Tom, on the other hand, likely developed from an egg with a high proportion of unhealthy mitochondria, leading to multi-system organ failure and a short life expectancy.

      The condition cannot be autosomal recessive as Tom would need to inherit the condition from both parents, not just his mother. Genetic mosaicism is also unlikely as the question states that the condition was inherited from their mother. X-linked dominant inheritance is also ruled out as it only requires one affected chromosome to cause disease.

      It is important to note that mitochondrial disease severity can be influenced by various factors, including mitochondrial heteroplasmy, genetic mosaicism, and autosomal recessive mutations.

      Mitochondrial diseases are caused by a small amount of double-stranded DNA present in the mitochondria, which encodes protein components of the respiratory chain and some special types of RNA. These diseases are inherited only via the maternal line, as the sperm contributes no cytoplasm to the zygote. None of the children of an affected male will inherit the disease, while all of the children of an affected female will inherit it. Mitochondrial diseases generally encode rare neurological diseases, and there is poor genotype-phenotype correlation due to heteroplasmy, which means that within a tissue or cell, there can be different mitochondrial populations. Muscle biopsy typically shows red, ragged fibers due to an increased number of mitochondria. Examples of mitochondrial diseases include Leber’s optic atrophy, MELAS syndrome, MERRF syndrome, Kearns-Sayre syndrome, and sensorineural hearing loss.

    • This question is part of the following fields:

      • General Principles
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  • Question 30 - A 7-year-old boy is admitted to the paediatric ward and tests positive for...

    Incorrect

    • A 7-year-old boy is admitted to the paediatric ward and tests positive for influenzae A. He is taking immunosuppressants following a liver transplant he underwent 2 years ago. The doctor prescribes him oseltamivir to try and reduce his viral load, aiding recovery.

      What is the mechanism of action of oseltamivir?

      Your Answer: Inhibits viral DNA polymerase

      Correct Answer: Inhibits viral neuraminidase

      Explanation:

      Oseltamivir prevents replication of influenzae A and B viruses by inhibiting viral neuraminidase, an enzyme that alters the glycoproteins on the surface of an infected cell to enable the release of more viral particles. It is not an antiviral that works by inhibiting viral DNA polymerase, unlike foscarnet and acyclovir. Interferon-α is used to treat chronic hepatitis B and C by inhibiting mRNA synthesis. Ribavirin interferes with the capping of the viral mRNA by inhibiting specific dehydrogenase enzymes. Amantadine, an antiviral, can be used in Parkinson’s disease as well as influenzae, as it has a secondary action of releasing dopamine from nerve endings, but this action does not reduce viral load.

      Antiviral agents are drugs used to treat viral infections. They work by targeting specific mechanisms of the virus, such as inhibiting viral DNA polymerase or neuraminidase. Some common antiviral agents include acyclovir, ganciclovir, ribavirin, amantadine, oseltamivir, foscarnet, interferon-α, and cidofovir. Each drug has its own mechanism of action and indications for use, but they all aim to reduce the severity and duration of viral infections.

      In addition to these antiviral agents, there are also specific drugs used to treat HIV, a retrovirus. Nucleoside analogue reverse transcriptase inhibitors (NRTI), protease inhibitors (PI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) are all used to target different aspects of the HIV life cycle. NRTIs work by inhibiting the reverse transcriptase enzyme, which is needed for the virus to replicate. PIs inhibit a protease enzyme that is necessary for the virus to mature and become infectious. NNRTIs bind to and inhibit the reverse transcriptase enzyme, preventing the virus from replicating. These drugs are often used in combination to achieve the best possible outcomes for HIV patients.

    • This question is part of the following fields:

      • General Principles
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  • Question 31 - While working in a paediatric unit, a 15-year-old patient is diagnosed with acute...

    Correct

    • While working in a paediatric unit, a 15-year-old patient is diagnosed with acute lymphoblastic leukaemia. After his diagnosis you have a lengthy discussion with him and decide that he is competent to make the decision to begin treatment and that this is in his best interests. His parents ask to speak to you alone afterwards and they tell you that they do not want him to be treated as they have heard about the side-effects of treatment.

      What is the most appropriate advice you can give them?

      Your Answer: Tell them that because the treatment is in his best interests and because he is competent to give consent, they cannot overrule his decision

      Explanation:

      Even if parents disagree, a young person’s competent consent to treatment cannot be overridden if it is deemed to be in their best interests. This is according to the GMC’s guidance on 0-18 year olds.

      Guidelines for Obtaining Consent in Children

      When it comes to obtaining consent in children, the General Medical Council has provided guidelines. For children aged 16 and above, they can be treated as adults and are presumed to have the capacity to decide. However, for those under 16, their ability to understand what is involved determines their capacity to decide. If a competent child refuses treatment, a person with parental responsibility or the court may authorize investigation or treatment that is in the child’s best interests.

      In terms of providing contraceptives to patients under 16, the Fraser Guidelines must be followed. These guidelines state that the young person must understand the professional’s advice, cannot be persuaded to inform their parents, is likely to begin or continue having sexual intercourse with or without contraceptive treatment, and their physical or mental health is likely to suffer without contraceptive treatment. Additionally, the young person’s best interests require them to receive contraceptive advice or treatment with or without parental consent.

      Some doctors use the term Fraser competency for contraception and Gillick competency for general issues of consent in children. However, rumors that Victoria Gillick removed her permission to use her name or applied copyright have been debunked. It is important to note that in Scotland, those with parental responsibility cannot authorize procedures that a competent child has refused. For consistency over competence in children, it is crucial to follow these guidelines when obtaining consent.

    • This question is part of the following fields:

      • General Principles
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  • Question 32 - You are participating in a cardiology ward round with a senior consultant and...

    Incorrect

    • You are participating in a cardiology ward round with a senior consultant and encounter an 80-year-old patient. Your consultant requests that you auscultate the patient's heart and provide feedback.

      During your examination, you detect a very faint early-diastolic murmur. To identify additional indications, you palpate the patient's wrist and observe a collapsing pulse.

      What intervention could potentially amplify the intensity of the murmur?

      Your Answer: Asking the patient to breathe in

      Correct Answer: Asking patient to perform a handgrip manoeuvre

      Explanation:

      The intensity of an aortic regurgitation murmur can be increased by performing the handgrip manoeuvre, which raises afterload by contracting the arm muscles and compressing the arteries. Conversely, amyl nitrate is a vasodilator that reduces afterload by dilating peripheral arteries, while ACE inhibitors are used to treat aortic regurgitation by lowering afterload. Asking the patient to breathe in will not accentuate the murmur, but standing up or performing the Valsalva manoeuvre can decrease venous return to the heart and reduce the intensity of the murmur.

      Aortic regurgitation is a condition where the aortic valve of the heart leaks, causing blood to flow in the opposite direction during ventricular diastole. This can be caused by disease of the aortic valve or by distortion or dilation of the aortic root and ascending aorta. The most common causes of AR due to valve disease include rheumatic fever, calcific valve disease, and infective endocarditis. On the other hand, AR due to aortic root disease can be caused by conditions such as aortic dissection, hypertension, and connective tissue diseases like Marfan’s and Ehler-Danlos syndrome.

      The features of AR include an early diastolic murmur, a collapsing pulse, wide pulse pressure, Quincke’s sign, and De Musset’s sign. In severe cases, a mid-diastolic Austin-Flint murmur may also be present. Suspected AR should be investigated with echocardiography.

      Management of AR involves medical management of any associated heart failure and surgery in symptomatic patients with severe AR or asymptomatic patients with severe AR who have LV systolic dysfunction.

    • This question is part of the following fields:

      • Cardiovascular System
      13.6
      Seconds
  • Question 33 - What is the main role of cholecystokinin? ...

    Correct

    • What is the main role of cholecystokinin?

      Your Answer: Triggers gallbladder contraction

      Explanation:

      Hormones and their Functions in Digestion

      Cholecystokinin is a hormone that helps in digestion by neutralizing the partially digested food. It does this by stimulating the gallbladder to contract and the pancreas to release alkaline pancreatic fluid. This fluid helps to neutralize the acidic food and aids in the digestion process.

      Gastrin is another hormone that plays a crucial role in digestion. It increases the production of stomach acid and also increases the rate of gastric emptying. This helps to break down the food more efficiently and move it through the digestive system.

      Secretin is a hormone that reduces the production of stomach acid. It is released by the small intestine in response to the acidic food passing through it. This helps to prevent the stomach from becoming too acidic and causing discomfort.

      Leptin is a hormone that helps to regulate appetite. It is produced by fat cells and acts on the brain to suppress appetite. This helps to maintain a healthy weight and prevent overeating.

      In summary, hormones play a vital role in digestion by regulating the production of stomach acid, neutralizing acidic food, and suppressing appetite.

    • This question is part of the following fields:

      • Clinical Sciences
      4.4
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  • Question 34 - A 65-year-old man presents with abdominal tenderness, steatorrhoea, and jaundice. Upon investigation, a...

    Incorrect

    • A 65-year-old man presents with abdominal tenderness, steatorrhoea, and jaundice. Upon investigation, a somatostatinoma of the pancreas is discovered. What is the probable cell type from which this neoplasm originated?

      Your Answer: Alpha-cells

      Correct Answer: Delta-cells

      Explanation:

      Somatostatin is secreted by the delta cells located in the pancreas. These cells are also present in the stomach, duodenum, and jejunum. In the pancreas, somatostatin plays a role in inhibiting the release of exocrine enzymes, glucagon, and insulin. In rare cases of large somatostatinomas, patients may experience mild diabetes mellitus.

      The answer choices of alpha-cells, beta-cells, and S-cells are incorrect as they secrete glucagon, insulin, and secretin, respectively.

      Somatostatin: The Inhibitor Hormone

      Somatostatin, also known as growth hormone inhibiting hormone (GHIH), is a hormone produced by delta cells found in the pancreas, pylorus, and duodenum. Its main function is to inhibit the secretion of growth hormone, insulin, and glucagon. It also decreases acid and pepsin secretion, as well as pancreatic enzyme secretion. Additionally, somatostatin inhibits the trophic effects of gastrin and stimulates gastric mucous production.

      Somatostatin analogs are commonly used in the management of acromegaly, a condition characterized by excessive growth hormone secretion. These analogs work by inhibiting growth hormone secretion, thereby reducing the symptoms associated with acromegaly.

      The secretion of somatostatin is regulated by various factors. Its secretion increases in response to fat, bile salts, and glucose in the intestinal lumen, as well as glucagon. On the other hand, insulin decreases the secretion of somatostatin.

      In summary, somatostatin plays a crucial role in regulating the secretion of various hormones and enzymes in the body. Its inhibitory effects on growth hormone, insulin, and glucagon make it an important hormone in the management of certain medical conditions.

    • This question is part of the following fields:

      • Endocrine System
      11.4
      Seconds
  • Question 35 - Which one of the following structures does not pass anterior to the lateral...

    Incorrect

    • Which one of the following structures does not pass anterior to the lateral malleolus?

      Your Answer: Anterior tibial artery

      Correct Answer: Peroneus brevis

      Explanation:

      The lateral malleolus is located posterior to the path of the peroneus brevis.

      Anatomy of the Lateral Malleolus

      The lateral malleolus is a bony prominence on the outer side of the ankle joint. Posterior to the lateral malleolus and superficial to the superior peroneal retinaculum are the sural nerve and short saphenous vein. These structures are important for sensation and blood flow to the lower leg and foot.

      On the other hand, posterior to the lateral malleolus and deep to the superior peroneal retinaculum are the peroneus longus and peroneus brevis tendons. These tendons are responsible for ankle stability and movement.

      Additionally, the calcaneofibular ligament is attached at the lateral malleolus. This ligament is important for maintaining the stability of the ankle joint and preventing excessive lateral movement.

      Understanding the anatomy of the lateral malleolus is crucial for diagnosing and treating ankle injuries and conditions. Proper care and management of these structures can help prevent long-term complications and improve overall ankle function.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      6.4
      Seconds
  • Question 36 - A 75-year-old man with a long-standing history of type 2 diabetes mellitus presents...

    Incorrect

    • A 75-year-old man with a long-standing history of type 2 diabetes mellitus presents to his physician with an inability to walk. The patient has a history of chronic kidney disease, diabetic retinopathy and a prior myocardial infarction treated via a stent. The patient admits to a recent loss of sensation in the lower limbs and is found to also have associated motor neuropathy. Complications of his chronic disease are found to be the cause of his gait problems.

      What findings would be expected during examination of the lower limbs?

      Your Answer: Decreased tone, decreased reflexes, clonus

      Correct Answer: Decreased reflexes, fasciculations, decreased tone

      Explanation:

      When there is a lower motor neuron lesion, there is a reduction in everything, including reflexes, tone, and power. Fasciculations are also a common feature. Motor neuropathy caused by diabetes is a form of peripheral neuropathy, which typically presents with lower motor neuron symptoms. On the other hand, an upper motor neuron lesion is characterized by increased tone, reflexes, and weakness. A mixed picture may occur when there are both upper and lower motor neuron signs present. For example, Babinski positive, increased reflexes, and decreased tone indicate a combination of upper and lower motor neuron lesions. Similarly, decreased tone, decreased reflexes, and clonus suggest a mixed picture, with the clonus being an upper motor neuron sign. Conversely, increased tone, decreased reflexes, and clonus also indicate a mixed picture, with the increased tone and clonus being upper motor neuron signs and the decreased reflexes being a lower motor neuron sign.

      The spinal cord is a central structure located within the vertebral column that provides it with structural support. It extends rostrally to the medulla oblongata of the brain and tapers caudally at the L1-2 level, where it is anchored to the first coccygeal vertebrae by the filum terminale. The cord is characterised by cervico-lumbar enlargements that correspond to the brachial and lumbar plexuses. It is incompletely divided into two symmetrical halves by a dorsal median sulcus and ventral median fissure, with grey matter surrounding a central canal that is continuous with the ventricular system of the CNS. Afferent fibres entering through the dorsal roots usually terminate near their point of entry but may travel for varying distances in Lissauer’s tract. The key point to remember is that the anatomy of the cord will dictate the clinical presentation in cases of injury, which can be caused by trauma, neoplasia, inflammatory diseases, vascular issues, or infection.

      One important condition to remember is Brown-Sequard syndrome, which is caused by hemisection of the cord and produces ipsilateral loss of proprioception and upper motor neuron signs, as well as contralateral loss of pain and temperature sensation. Lesions below L1 tend to present with lower motor neuron signs. It is important to keep a clinical perspective in mind when revising CNS anatomy and to understand the ways in which the spinal cord can become injured, as this will help in diagnosing and treating patients with spinal cord injuries.

    • This question is part of the following fields:

      • Neurological System
      30.5
      Seconds
  • Question 37 - A 36-year-old man presents to his GP with symptoms of vertigo. He reports...

    Incorrect

    • A 36-year-old man presents to his GP with symptoms of vertigo. He reports that he has been experiencing constant dizziness for the past 2 days, which has prevented him from going to work. He also reports hearing difficulties and tinnitus in his right ear, as well as nausea and difficulty with balance. He notes that these symptoms are not related to changes in position. He has no significant medical history, except for a recent bout of flu that resolved on its own.

      During the examination, the man is observed to sway to the right while attempting to walk in a straight line. He also has a positive head thrust test to the right side. A complete neurological examination is performed, and aside from mild sensorineural hearing loss in the right ear, his neurological function is normal.

      Which structures are most likely involved in this man's condition?

      Your Answer: Facial nerve and vestibular nerve

      Correct Answer: Vestibular nerve and labyrinth

      Explanation:

      The patient is displaying symptoms of labyrinthitis, which affects both the vestibular nerve and labyrinth, resulting in vertigo and hearing impairment. In contrast, pure vestibular neuritis only causes vestibular symptoms without affecting hearing. Benign paroxysmal positional vertigo (BPPV) involves otolith displacement and is triggered by head position changes, which is not the case for this patient’s constant vertigo. Facial nerve palsy primarily causes facial drooping and does not affect hearing or vestibular function, making it an unlikely diagnosis for this patient.

      Understanding Viral Labyrinthitis

      Labyrinthitis is a condition that affects the membranous labyrinth, which includes the vestibular and cochlear end organs. It can be caused by a viral or bacterial infection, or it may be associated with systemic diseases. Viral labyrinthitis is the most common form of the condition.

      It’s important to distinguish labyrinthitis from vestibular neuritis, which only affects the vestibular nerve and doesn’t cause hearing impairment. Labyrinthitis, on the other hand, affects both the vestibular nerve and the labyrinth, resulting in both vertigo and hearing loss.

      The condition typically affects people between the ages of 40 and 70 and is characterized by an acute onset of symptoms, including vertigo, nausea and vomiting, hearing loss, and tinnitus. Patients may also experience gait disturbance and fall towards the affected side.

      Diagnosis is based on a patient’s history and examination, which may reveal spontaneous unidirectional horizontal nystagmus towards the unaffected side, sensorineural hearing loss, and an abnormal head impulse test.

      While episodes of labyrinthitis are usually self-limiting, medications like prochlorperazine or antihistamines may help reduce the sensation of dizziness. Understanding the symptoms and management of viral labyrinthitis can help patients seek appropriate treatment and manage their condition effectively.

    • This question is part of the following fields:

      • Respiratory System
      46.2
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  • Question 38 - A 45-year-old man arrives at the emergency department after being hit by a...

    Correct

    • A 45-year-old man arrives at the emergency department after being hit by a car while crossing the road. According to the paramedics, he was conscious at the scene but his level of consciousness deteriorated during transport. He is currently only responsive to voice and answering in single words. After stabilizing him, a CT scan of the head is urgently requested, which reveals an extradural hemorrhage. One of the common causes of this type of hemorrhage is the rupture of the middle meningeal artery. This artery runs along the deep surface of the cranium, with its anterior division located near which point on the cranium?

      Your Answer: Pterion

      Explanation:

      The pterion is the correct answer, as all of the options are anatomical points on the cranium. The pterion is located in the temporal fossa and marks the junction of four cranial bones. It is a weak area of the skull and a fracture at this site can cause a haemorrhage due to the middle meningeal artery running deep to it. The asterion is where three cranial bones meet, while the lambda is where two cranial bones meet and is the site of the posterior fontanelle in newborns. The bregma is where two cranial bones meet and is the site of the anterior fontanelle during infancy. The nasion is where the nasion bones meet the frontal bones. Extradural haemorrhage is bleeding between the dura mater and the skull, often caused by rupture of the middle meningeal artery following head trauma. It typically presents in older patients with a lucid interval between the head injury and neurological deterioration.

      The Middle Meningeal Artery: Anatomy and Clinical Significance

      The middle meningeal artery is a branch of the maxillary artery, which is one of the two terminal branches of the external carotid artery. It is the largest of the three arteries that supply the meninges, the outermost layer of the brain. The artery runs through the foramen spinosum and supplies the dura mater. It is located beneath the pterion, where the skull is thin, making it vulnerable to injury. Rupture of the artery can lead to an Extradural hematoma.

      In the dry cranium, the middle meningeal artery creates a deep indentation in the calvarium. It is intimately associated with the auriculotemporal nerve, which wraps around the artery. This makes the two structures easily identifiable in the dissection of human cadavers and also easily damaged in surgery.

      Overall, understanding the anatomy and clinical significance of the middle meningeal artery is important for medical professionals, particularly those involved in neurosurgery.

    • This question is part of the following fields:

      • Neurological System
      13.2
      Seconds
  • Question 39 - A 16-year-old male patient is experiencing an acute asthma attack and is struggling...

    Correct

    • A 16-year-old male patient is experiencing an acute asthma attack and is struggling to breathe. Which of the following options is not a correct description of anatomical dead space?

      Your Answer: Poorly perfused alveoli

      Explanation:

      Anatomical and Physiological Dead Space

      Anatomical dead space refers to the parts of the respiratory system that do not participate in gaseous exchange. These include the pharynx, larynx, trachea, bronchi, and bronchioles. Although these structures fill with air during inhalation, the air is exhaled without ever being available for circulation. On the other hand, physiological dead space includes not only the anatomical dead space but also regions of alveoli that do not participate in gaseous exchange due to a ventilation/perfusion mismatch.

      In simpler terms, anatomical dead space is the portion of the respiratory system that does not contribute to gas exchange, while physiological dead space includes both the anatomical dead space and areas of the lungs that are not functioning properly. these concepts is important in diagnosing and treating respiratory disorders, as well as in monitoring the effectiveness of respiratory therapies. By identifying and addressing dead space, healthcare professionals can help improve a patient’s breathing and overall respiratory function.

    • This question is part of the following fields:

      • Clinical Sciences
      15.7
      Seconds
  • Question 40 - A 40-year-old man with a diagnosis of chronic fatigue syndrome visits his GP...

    Incorrect

    • A 40-year-old man with a diagnosis of chronic fatigue syndrome visits his GP reporting a recent worsening of his symptoms following a strenuous workout. The GP decides to conduct routine blood tests.

      What are the most probable results that the GP will discover assuming that the patient's current condition is the cause of the exacerbation?

      Your Answer: Low ESR, normal haemoglobin

      Correct Answer: Normal ESR, normal haemoglobin

      Explanation:

      Graded exercise therapy is often recommended for chronic fatigue syndrome as symptoms can worsen after over-exercising. Routine blood tests are used to rule out other potential causes of the symptoms, such as anaemia or underlying inflammatory diseases, as chronic fatigue syndrome is a diagnosis of exclusion.

      Understanding Chronic Fatigue Syndrome

      Chronic fatigue syndrome is a condition that is diagnosed after at least four months of disabling fatigue that affects mental and physical function more than 50% of the time, in the absence of other diseases that may explain the symptoms. It is more common in females, and past psychiatric history has not been shown to be a risk factor. Fatigue is the central feature of this condition, and other recognized features include sleep problems, muscle and/or joint pains, headaches, painful lymph nodes without enlargement, sore throat, cognitive dysfunction, physical or mental exertion that makes symptoms worse, general malaise or ‘flu-like’ symptoms, dizziness, nausea, and palpitations.

      To diagnose chronic fatigue syndrome, a large number of screening blood tests are carried out to exclude other pathology, such as FBC, U&E, LFT, glucose, TFT, ESR, CRP, calcium, CK, ferritin*, coeliac screening, and urinalysis. The management of chronic fatigue syndrome includes cognitive behavior therapy, which is very effective, with a number needed to treat of 2. Graded exercise therapy is also recommended, which is a formal supervised program, not advice to go to the gym. ‘Pacing’ is another management technique, which involves organizing activities to avoid tiring. Low-dose amitriptyline may be useful for poor sleep, and referral to a pain management clinic is recommended if pain is a predominant feature. Children and young people have a better prognosis than adults.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      17.1
      Seconds
  • Question 41 - A 63-year-old man comes to the emergency department complaining of sudden onset of...

    Correct

    • A 63-year-old man comes to the emergency department complaining of sudden onset of right eye pain, headache, blurred vision, and vomiting. He has a history of hypertension and sickle cell anaemia.

      During the examination, you notice that he seems uneasy with a red right eye and a fixed dilated pupil. You suspect that he may be suffering from acute closed-angle glaucoma and decide to give him pilocarpine eye drops.

      What is the primary mode of action of this medication?

      Your Answer: Muscarinic agonist

      Explanation:

      Pilocarpine is a substance that activates muscarinic receptors, which are part of the parasympathetic nervous system. It can be used to treat certain eye conditions, like acute closed-angle glaucoma, by causing the pupil to constrict. It can also help alleviate dry mouth caused by head and neck radiotherapy or Sjogren’s disease.

      On the other hand, alpha agonists work by stimulating alpha adrenoreceptors. Examples of alpha-1 agonists include decongestants, while topical brimonidine is an alpha-2 agonist used in the treatment of glaucoma and acne rosacea.

      Muscarinic antagonists, on the other hand, block the parasympathetic nervous system. Medications with antimuscarinic properties include atropine, ipratropium bromide, and oxybutynin. Unlike muscarinic agonists, these drugs can cause side effects like dry mouth and dilated pupils.

      Finally, beta-1 agonists like dobutamine are inotropes, which means they increase the strength of heart contractions.

      Drugs Acting on Common Receptors

      The following table provides examples of drugs that act on common receptors in the body. These receptors include alpha, beta, dopamine, GABA, histamine, muscarinic, nicotinic, oxytocin, and serotonin. For each receptor, both agonists and antagonists are listed.

      For example, decongestants such as phenylephrine and oxymetazoline act as agonists on alpha-1 receptors, while topical brimonidine is an agonist on alpha-2 receptors. On the other hand, drugs used to treat benign prostatic hyperplasia, such as tamsulosin, act as antagonists on alpha-1 receptors.

      Similarly, inotropes like dobutamine act as agonists on beta-1 receptors, while beta-blockers such as atenolol and bisoprolol act as antagonists on both non-selective and selective beta receptors. Bronchodilators like salbutamol act as agonists on beta-2 receptors, while non-selective beta-blockers like propranolol and labetalol act as antagonists.

      Understanding the actions of drugs on common receptors is important in pharmacology and can help healthcare professionals make informed decisions when prescribing medications.

    • This question is part of the following fields:

      • General Principles
      19.4
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  • Question 42 - A 25-year-old man has been diagnosed with an abnormal electrical connection in his...

    Correct

    • A 25-year-old man has been diagnosed with an abnormal electrical connection in his heart, resulting in frequent palpitations, dizzy spells, and shortness of breath. Delta waves are also evident on his ECG. Would ablation of the coronary sinus be a viable treatment option for this condition?

      From which embryological structure is the target for this surgery derived?

      Your Answer: Left horn of the sinus venosus

      Explanation:

      The sinus venosus has two horns, left and right. The left horn gives rise to the coronary sinus, while the right horn forms the smooth part of the right atrium. In patients with Wolff-Parkinson-White syndrome, an abnormal conduction pathway exists in the heart. To eliminate this pathway, a treatment called ablation of the coronary sinus is used. This involves destroying the conducting pathway that runs through the coronary sinus, which is formed from the left horn of the sinus venosus during embryonic development.

      During cardiovascular embryology, the heart undergoes significant development and differentiation. At around 14 days gestation, the heart consists of primitive structures such as the truncus arteriosus, bulbus cordis, primitive atria, and primitive ventricle. These structures give rise to various parts of the heart, including the ascending aorta and pulmonary trunk, right ventricle, left and right atria, and majority of the left ventricle. The division of the truncus arteriosus is triggered by neural crest cell migration from the pharyngeal arches, and any issues with this migration can lead to congenital heart defects such as transposition of the great arteries or tetralogy of Fallot. Other structures derived from the primitive heart include the coronary sinus, superior vena cava, fossa ovalis, and various ligaments such as the ligamentum arteriosum and ligamentum venosum. The allantois gives rise to the urachus, while the umbilical artery becomes the medial umbilical ligaments and the umbilical vein becomes the ligamentum teres hepatis inside the falciform ligament. Overall, cardiovascular embryology is a complex process that involves the differentiation and development of various structures that ultimately form the mature heart.

    • This question is part of the following fields:

      • Cardiovascular System
      26.7
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  • Question 43 - A 61-year-old man is starting amiodarone for persistent atrial fibrillation. What blood tests...

    Correct

    • A 61-year-old man is starting amiodarone for persistent atrial fibrillation. What blood tests should be checked before beginning therapy?

      Your Answer: Liver function tests, thyroid function tests and renal function tests

      Explanation:

      Before and during amiodarone therapy, it is important to check thyroid and liver function tests.

      Drug monitoring is an essential aspect of patient care to ensure the safe and effective use of medications. The tables below provide basic guidelines for monitoring common drugs in different therapeutic categories. It is important to note that these guidelines do not relate to monitoring the effectiveness of treatment, such as checking lipid levels for patients taking statins.

      For cardiovascular drugs, statins require monitoring of liver function tests (LFTs) at baseline, 3 months, and 12 months. ACE inhibitors require monitoring of electrolytes (U&E) prior to treatment, after increasing the dose, and at least annually. Amiodarone requires monitoring of thyroid function tests (TFT), LFT, U&E, and chest X-ray prior to treatment, and TFT and LFT every 6 months.

      In rheumatology, methotrexate requires monitoring of full blood count (FBC), LFT, and U&E before starting treatment, with weekly monitoring until therapy stabilizes, and then every 2-3 months. Azathioprine requires monitoring of FBC and LFT before treatment, weekly for the first 4 weeks, and every 3 months thereafter.

      For neuropsychiatric drugs, lithium requires monitoring of lithium levels, TFT, and U&E prior to treatment, weekly until stabilized, and then every 3 months. TFT and U&E should be monitored every 6 months. Sodium valproate requires monitoring of LFT and FBC before treatment and periodically during the first 6 months.

      Finally, for endocrine drugs, glitazones require monitoring of LFT before treatment and regularly during treatment. These guidelines serve as a starting point for drug monitoring and may be adjusted based on individual patient needs and clinical judgment.

    • This question is part of the following fields:

      • General Principles
      15.5
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  • Question 44 - A 57-year-old man presents to the emergency department with acute, severe shortness of...

    Incorrect

    • A 57-year-old man presents to the emergency department with acute, severe shortness of breath.

      During the clinical examination, an elevated JVP is noted, and bilateral basal crackles are heard on auscultation. An S3 gallop is also heard on auscultation of his heart.

      The physician places him on high flow oxygen and positions him upright. You are asked to review the patient's medication chart and discontinue any medications that may be contraindicated in his current condition.

      Which medication should you discontinue?

      Your Answer: Nitrates

      Correct Answer: Nicorandil

      Explanation:

      Nicorandil is a medication that is commonly used to treat angina. It works by activating potassium channels, which leads to vasodilation. This process is achieved through the activation of guanylyl cyclase, which results in an increase in cGMP. However, there are some adverse effects associated with the use of nicorandil, including headaches, flushing, and the development of ulcers on the skin, mucous membranes, and eyes. Additionally, gastrointestinal ulcers, including anal ulceration, may also occur. It is important to note that nicorandil should not be used in patients with left ventricular failure.

    • This question is part of the following fields:

      • Cardiovascular System
      16.1
      Seconds
  • Question 45 - What characteristic might indicate the presence of high-grade dysplasia? ...

    Correct

    • What characteristic might indicate the presence of high-grade dysplasia?

      Your Answer: High Ki67 index

      Explanation:

      Dysplasia and its Association with Malignancy

      Dysplasia refers to the cellular changes that occur during the development of malignancy. The degree of dysplasia in a cell is directly proportional to its likelihood of being found in an invasive cancer. Cells with higher-grade dysplasia have more genetic abnormalities than those with low-grade dysplasia.

      Progressive dysplasia is characterized by variations in the appearance of cells and their nuclei, which is not typical in most tissues where cells appear similar. The nuclei of dysplastic cells are larger, and there is an increase in the number of nucleoli. The Ki67 index is a marker of proliferation, and a higher Ki67 index indicates a higher rate of cell turnover.

      In most tissues, mitoses are rare, but malignant tissues made up of dysplastic cells show visible mitoses. dysplasia and its association with malignancy is crucial in the early detection and treatment of cancer.

    • This question is part of the following fields:

      • Histology
      12.3
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  • Question 46 - What grade of evidence does a randomized controlled trial provide, as per the...

    Correct

    • What grade of evidence does a randomized controlled trial provide, as per the guidance of the Oxford Centre for Evidence-Based Medicine (CEBM)?

      Your Answer: 1

      Explanation:

      Levels and Grades of Evidence in Evidence-Based Medicine

      In order to evaluate the quality of evidence in evidence-based medicine, levels or grades are often used to organize the evidence. Traditional hierarchies placed systematic reviews or randomized control trials at the top and case-series/report at the bottom. However, this approach is overly simplistic as certain research questions cannot be answered using RCTs. To address this, the Oxford Centre for Evidence-Based Medicine introduced their 2011 Levels of Evidence system which separates the type of study questions and gives a hierarchy for each. On the other hand, the GRADE system is a grading approach that classifies the quality of evidence as high, moderate, low, or very low. The process begins by formulating a study question and identifying specific outcomes. Outcomes are then graded as critical or important, and the evidence is gathered and criteria are used to grade the evidence. Evidence can be promoted or downgraded based on certain circumstances. The use of levels and grades of evidence helps to evaluate the quality of evidence and make informed decisions in evidence-based medicine.

    • This question is part of the following fields:

      • General Principles
      7.9
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  • Question 47 - A 25-year-old man is intoxicated and falls, resulting in a transected median nerve...

    Incorrect

    • A 25-year-old man is intoxicated and falls, resulting in a transected median nerve by a shard of glass at the proximal border of the flexor retinaculum. Fortunately, his tendons remain unharmed. Which of the following features is unlikely to be present?

      Your Answer: Loss of power of opponens pollicis

      Correct Answer: Loss of sensation on the dorsal aspect of the thenar eminence

      Explanation:

      If the median nerve is damaged before reaching the flexor retinaculum, it can lead to the loss of certain muscles, including the abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, and the first and second lumbricals. When the patient is asked to slowly close their hand, there may be a delay in the movement of the index and middle fingers due to the impaired lumbrical muscle function. However, there are only minor sensory changes and no impact on the dorsal aspect of the thenar eminence. The abductor pollicis longus muscle, which is innervated by the posterior interosseous nerve, will still contribute to thumb abduction, but it may be weaker than before the injury.

      Anatomy and Function of the Median Nerve

      The median nerve is a nerve that originates from the lateral and medial cords of the brachial plexus. It descends lateral to the brachial artery and passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. The nerve then passes between the two heads of the pronator teres muscle and runs on the deep surface of flexor digitorum superficialis. Near the wrist, it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, passing deep to the flexor retinaculum to enter the palm.

      The median nerve has several branches that supply the upper arm, forearm, and hand. These branches include the pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor pollicis longus, and palmar cutaneous branch. The nerve also provides motor supply to the lateral two lumbricals, opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis muscles, as well as sensory supply to the palmar aspect of the lateral 2 ½ fingers.

      Damage to the median nerve can occur at the wrist or elbow, resulting in various symptoms such as paralysis and wasting of thenar eminence muscles, weakness of wrist flexion, and sensory loss to the palmar aspect of the fingers. Additionally, damage to the anterior interosseous nerve, a branch of the median nerve, can result in loss of pronation of the forearm and weakness of long flexors of the thumb and index finger. Understanding the anatomy and function of the median nerve is important in diagnosing and treating conditions that affect this nerve.

    • This question is part of the following fields:

      • Neurological System
      34.4
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  • Question 48 - A 4-year-old boy is presented to the GP by his father. He has...

    Correct

    • A 4-year-old boy is presented to the GP by his father. He has developed a rash around his mouth and nose over the past few days. It started as a flat red patch at the corner of his mouth but quickly progressed to a blistering rash that oozes fluid. During today's examination, the rash appears to have a crusty, golden appearance on the surface. The child is healthy otherwise and has no prior history of skin problems. Based on this history and examination, what is the most probable diagnosis?

      Your Answer: Impetigo

      Explanation:

      The most likely diagnosis based on the history and examination is impetigo or eczema herpeticum, which can have similar presentations and are difficult to differentiate clinically. However, since the child has no prior history of skin conditions, eczema herpeticum is less probable. Therefore, option 2 is the correct answer.

      Option 1: Atopic eczema would not manifest with a yellowish crust.

      Option 3: Chickenpox would not exhibit this particular progression.

      Understanding Impetigo: Causes, Symptoms, and Management

      Impetigo is a common bacterial skin infection that is caused by either Staphylococcus aureus or Streptococcus pyogenes. It can occur as a primary infection or as a complication of an existing skin condition such as eczema. Impetigo is most common in children, especially during warm weather. The infection can develop anywhere on the body, but it tends to occur on the face, flexures, and limbs not covered by clothing.

      The infection spreads through direct contact with discharges from the scabs of an infected person. The bacteria invade the skin through minor abrasions and then spread to other sites by scratching. Infection is spread mainly by the hands, but indirect spread via toys, clothing, equipment, and the environment may occur. The incubation period is between 4 to 10 days.

      Symptoms of impetigo include ‘golden’, crusted skin lesions typically found around the mouth. It is highly contagious, and children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment.

      Management of impetigo depends on the extent of the disease. Limited, localized disease can be treated with hydrogen peroxide 1% cream or topical antibiotic creams such as fusidic acid or mupirocin. MRSA is not susceptible to either fusidic acid or retapamulin, so topical mupirocin should be used in this situation. Extensive disease may require oral flucloxacillin or oral erythromycin if penicillin-allergic. The use of hydrogen peroxide 1% cream was recommended by NICE and Public Health England in 2020 to cut antibiotic resistance. The evidence base shows it is just as effective at treating non-bullous impetigo as a topical antibiotic.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      17.6
      Seconds
  • Question 49 - A 52-year-old man comes to the emergency department complaining of severe crushing chest...

    Correct

    • A 52-year-old man comes to the emergency department complaining of severe crushing chest pain that spreads to his left arm and jaw. He also feels nauseous. Upon conducting an ECG, you observe ST-segment elevation in several chest leads and diagnose him with ST-elevation MI. From which vessel do the coronary vessels arise?

      Your Answer: Ascending aorta

      Explanation:

      The left and right coronary arteries originate from the left and right aortic sinuses, respectively. The left aortic sinus is located on the left side of the ascending aorta, while the right aortic sinus is situated at the back.

      The coronary sinus is a venous vessel formed by the confluence of four coronary veins. It receives venous blood from the great, middle, small, and posterior cardiac veins and empties into the right atrium.

      The descending aorta is a continuation of the aortic arch and runs through the chest and abdomen before dividing into the left and right common iliac arteries. It has several branches along its path.

      The pulmonary veins transport oxygenated blood from the lungs to the left atrium and do not have any branches.

      The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. It splits into the left and right pulmonary arteries, which travel to the left and right lungs, respectively.

      The patient in the previous question has exhibited symptoms indicative of acute coronary syndrome, and the ECG results confirm an ST-elevation myocardial infarction.

      The walls of each cardiac chamber are made up of the epicardium, myocardium, and endocardium. The heart and roots of the great vessels are related anteriorly to the sternum and the left ribs. The coronary sinus receives blood from the cardiac veins, and the aortic sinus gives rise to the right and left coronary arteries. The left ventricle has a thicker wall and more numerous trabeculae carnae than the right ventricle. The heart is innervated by autonomic nerve fibers from the cardiac plexus, and the parasympathetic supply comes from the vagus nerves. The heart has four valves: the mitral, aortic, pulmonary, and tricuspid valves.

    • This question is part of the following fields:

      • Cardiovascular System
      11.5
      Seconds
  • Question 50 - What significance do linoleic and alpha-linolenic acids hold? ...

    Incorrect

    • What significance do linoleic and alpha-linolenic acids hold?

      Your Answer: They are omega-3 fatty acids

      Correct Answer: They are essential fatty acids

      Explanation:

      The Importance of Essential Fatty Acids in the Diet

      Essential fatty acids, such as linoleic and alpha-linolenic acids, are crucial components of a healthy diet. Although they are only required in small amounts, they play several important roles in the body. These fatty acids are necessary for the synthesis of phospholipids, which are essential components of cell membranes. They also help regulate cholesterol transport and synthesis, and serve as precursors for omega-3 fatty acids and arachidonic acid. Additionally, essential fatty acids are important for the synthesis of prostaglandins, leukotrienes, and thromboxanes.

      A lack of adequate essential fatty acids in the diet can have negative consequences, particularly for brain growth in infancy. It can also lead to alopecia, dermatitis, and fatty liver. Therefore, it is important to ensure that the diet includes sources of these essential fatty acids, such as certain types of fish, nuts, and seeds. By doing so, individuals can support their overall health and well-being.

    • This question is part of the following fields:

      • Basic Sciences
      6.8
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Haematology And Oncology (2/4) 50%
General Principles (6/12) 50%
Musculoskeletal System And Skin (1/4) 25%
Neurological System (4/7) 57%
Cardiovascular System (2/7) 29%
Gastrointestinal System (0/3) 0%
Reproductive System (1/1) 100%
Basic Sciences (0/2) 0%
Histology (1/2) 50%
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Respiratory System (0/2) 0%
Renal System (2/2) 100%
Clinical Sciences (2/2) 100%
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