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  • Question 1 - A teenage boy is brought in with clinical indications of Herpes Simplex Virus...

    Incorrect

    • A teenage boy is brought in with clinical indications of Herpes Simplex Virus (HSV) encephalitis. In an MRI, where would the lesions be typically observed?

      Your Answer:

      Correct Answer: Temporal lobes

      Explanation:

      HSV encephalitis is commonly linked with damage to the bitemporal lobes, but it can also affect the inferior frontal lobe. However, the parietal lobes, occipital lobes, and cerebellum are not typically affected by this condition.

      Herpes Simplex Encephalitis: Symptoms, Diagnosis, and Treatment

      Herpes simplex encephalitis is a common topic in medical exams. This viral infection affects the temporal lobes of the brain, causing symptoms such as fever, headache, seizures, and vomiting. Focal features like aphasia may also be present. It is important to note that peripheral lesions, such as cold sores, are not related to the presence of HSV encephalitis.

      HSV-1 is responsible for 95% of cases in adults and typically affects the temporal and inferior frontal lobes. Diagnosis is made through CSF analysis, PCR for HSV, and imaging studies like CT or MRI. EEG patterns may also show lateralized periodic discharges at 2 Hz.

      Early treatment with intravenous acyclovir is crucial for a good prognosis. Mortality rates can range from 10-20% with prompt treatment, but can approach 80% if left untreated. MRI is a better imaging modality for detecting changes in the medial temporal and inferior frontal lobes.

      In summary, herpes simplex encephalitis is a serious viral infection that affects the brain. It is important to recognize the symptoms and seek prompt medical attention for early diagnosis and treatment.

    • This question is part of the following fields:

      • Neurological System
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  • Question 2 - A 47-year-old male patient presented with complaints of fatigue and lethargy. He is...

    Incorrect

    • A 47-year-old male patient presented with complaints of fatigue and lethargy. He is health-conscious and likes to maintain his fitness.

      Upon examination, his blood work revealed a deficiency in vitamin D, for which he was prescribed calcitriol. He was advised to return for a follow-up appointment in two weeks to monitor his blood results.

      During his follow-up appointment, his blood work showed normal results, except for an electrolyte abnormality.

      What is the most likely electrolyte abnormality seen in his blood results?

      Your Answer:

      Correct Answer: High phosphate

      Explanation:

      The action of calcitriol on the body results in an increase in the reabsorption of phosphate by the kidneys, leading to an increase in plasma phosphate levels. Additionally, calcitriol promotes osteoclast activity, which further contributes to an increase in plasma calcium levels through bone resorption. It should be noted that calcitriol does not have any significant effect on potassium and magnesium levels. On the other hand, the hormone PTH has the opposite effect on plasma phosphate levels, causing a decrease in its concentration.

      Hormones Controlling Calcium Metabolism

      Calcium metabolism is primarily controlled by two hormones, parathyroid hormone (PTH) and 1,25-dihydroxycholecalciferol (calcitriol). Other hormones such as calcitonin, thyroxine, and growth hormone also play a role. PTH increases plasma calcium levels and decreases plasma phosphate levels. It also increases renal tubular reabsorption of calcium, osteoclastic activity, and renal conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol. On the other hand, 1,25-dihydroxycholecalciferol increases plasma calcium and plasma phosphate levels, renal tubular reabsorption and gut absorption of calcium, osteoclastic activity, and renal phosphate reabsorption. It is important to note that osteoclastic activity is increased indirectly by PTH as osteoclasts do not have PTH receptors. Understanding the actions of these hormones is crucial in maintaining proper calcium metabolism in the body.

    • This question is part of the following fields:

      • General Principles
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  • Question 3 - Which one of the following statements about the spleen is false? ...

    Incorrect

    • Which one of the following statements about the spleen is false?

      Your Answer:

      Correct Answer: The spleen is derived from endodermal tissue.

      Explanation:

      The spleen, which weighs 7oz (150-200g), is approximately 1 inch thick, 3 inches wide, and 5 inches long. It is located between the 9th and 11th ribs. While most of the gut is derived from endodermal tissue, the spleen is unique in that it originates from mesenchymal tissue.

      The Anatomy and Function of the Spleen

      The spleen is an organ located in the left upper quadrant of the abdomen. Its size can vary depending on the amount of blood it contains, but the typical adult spleen is 12.5cm long and 7.5cm wide, with a weight of 150g. The spleen is almost entirely covered by peritoneum and is separated from the 9th, 10th, and 11th ribs by both diaphragm and pleural cavity. Its shape is influenced by the state of the colon and stomach, with gastric distension causing it to resemble an orange segment and colonic distension causing it to become more tetrahedral.

      The spleen has two folds of peritoneum that connect it to the posterior abdominal wall and stomach: the lienorenal ligament and gastrosplenic ligament. The lienorenal ligament contains the splenic vessels, while the short gastric and left gastroepiploic branches of the splenic artery pass through the layers of the gastrosplenic ligament. The spleen is in contact with the phrenicocolic ligament laterally.

      The spleen has two main functions: filtration and immunity. It filters abnormal blood cells and foreign bodies such as bacteria, and produces properdin and tuftsin, which help target fungi and bacteria for phagocytosis. The spleen also stores 40% of platelets, reutilizes iron, and stores monocytes. Disorders of the spleen include massive splenomegaly, myelofibrosis, chronic myeloid leukemia, visceral leishmaniasis, malaria, Gaucher’s syndrome, portal hypertension, lymphoproliferative disease, haemolytic anaemia, infection, infective endocarditis, sickle-cell, thalassaemia, and rheumatoid arthritis.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 4 - A 54-year-old man is admitted to the coronary care unit after being hospitalized...

    Incorrect

    • A 54-year-old man is admitted to the coronary care unit after being hospitalized three weeks ago for an ST-elevation myocardial infarction. He reports chest pain again and is concerned it may be another infarction. The pain is described as sharp and worsens with breathing. The cardiology resident notes a fever and hears a rubbing sound and pansystolic murmur on auscultation, which were previously present. A 12-lead ECG shows no new ischemic changes. The patient has a history of diabetes, hypertension, and heavy smoking since his teenage years. What is the most likely cause of his current condition?

      Your Answer:

      Correct Answer: Autoimmune-mediated

      Explanation:

      Dressler’s syndrome is an autoimmune-mediated pericarditis that occurs 2-6 weeks after a myocardial infarction (MI). This patient, who has been admitted to the coronary care unit following an MI, is experiencing chest pain that is pleuritic in nature, along with fever and a friction rub sound upon examination. Given the timing of the symptoms at three weeks post-MI, Dressler’s syndrome is the most likely diagnosis. This condition results from an autoimmune-mediated inflammatory reaction to antigens following an MI, leading to inflammation of the pericardial sac and pericardial effusion. If left untreated, it can increase the risk of ventricular rupture. Treatment typically involves high-dose aspirin and corticosteroids if necessary.

      Myocardial infarction (MI) can lead to various complications, which can occur immediately, early, or late after the event. Cardiac arrest is the most common cause of death following MI, usually due to ventricular fibrillation. Cardiogenic shock may occur if a large part of the ventricular myocardium is damaged, and it is difficult to treat. Chronic heart failure may result from ventricular myocardium dysfunction, which can be managed with loop diuretics, ACE-inhibitors, and beta-blockers. Tachyarrhythmias, such as ventricular fibrillation and ventricular tachycardia, are common complications. Bradyarrhythmias, such as atrioventricular block, are more common following inferior MI. Pericarditis is common in the first 48 hours after a transmural MI, while Dressler’s syndrome may occur 2-6 weeks later. Left ventricular aneurysm and free wall rupture, ventricular septal defect, and acute mitral regurgitation are other complications that may require urgent medical attention.

    • This question is part of the following fields:

      • Cardiovascular System
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  • Question 5 - A nulliparous woman visits her obstetrician at 28 weeks of pregnancy. She has...

    Incorrect

    • A nulliparous woman visits her obstetrician at 28 weeks of pregnancy. She has a history of asthma and has noticed a deterioration in her asthma symptoms over the past few days. She is concerned that her asthma may affect her unborn child, as she has read online about the presence of extra antibodies in her blood due to asthma. Which immunoglobulin can be transmitted to her baby?

      Your Answer:

      Correct Answer: IgG

      Explanation:

      The immunoglobulin that fixes complement and is able to pass to the fetal circulation is IgG. This immunoglobulin is produced by plasma cells and is present in all body fluids, being the most abundant in the body. IgG is the only immunoglobulin that can provide immunity to a fetus by crossing the placenta. It indirectly promotes phagocytosis through complement activation. To remember this, you can associate the letter G with gestation.

      On the other hand, IgA is the predominant immunoglobulin found in breast milk and in the secretions of digestive, respiratory, and urogenital tracts and systems. However, it does not transmit to the fetus during pregnancy.

      IgD does not pass into the fetal circulation and is poorly understood. It is found on naive B cells and is involved in B cell activation, which in turn activates mast cell release. Mast cells produce antimicrobial factors involved in immune defense.

      Finally, IgE is involved in asthma and allergic reactions, as well as in protecting against parasitic worms and other allergens. It acts by binding to the allergen, activating mast cells and basophils. However, it does not pass into the fetal circulation.

      Immunoglobulins, also known as antibodies, are proteins produced by the immune system to help fight off infections and diseases. There are five types of immunoglobulins found in the body, each with their own unique characteristics.

      IgG is the most abundant type of immunoglobulin in blood serum and plays a crucial role in enhancing phagocytosis of bacteria and viruses. It also fixes complement and can be passed to the fetal circulation.

      IgA is the most commonly produced immunoglobulin in the body and is found in the secretions of digestive, respiratory, and urogenital tracts and systems. It provides localized protection on mucous membranes and is transported across the interior of the cell via transcytosis.

      IgM is the first immunoglobulin to be secreted in response to an infection and fixes complement, but does not pass to the fetal circulation. It is also responsible for producing anti-A, B blood antibodies.

      IgD’s role in the immune system is largely unknown, but it is involved in the activation of B cells.

      IgE is the least abundant type of immunoglobulin in blood serum and is responsible for mediating type 1 hypersensitivity reactions. It provides immunity to parasites such as helminths and binds to Fc receptors found on the surface of mast cells and basophils.

    • This question is part of the following fields:

      • General Principles
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  • Question 6 - A 67-year-old woman visits her general practitioner complaining of pelvic pain, weight loss,...

    Incorrect

    • A 67-year-old woman visits her general practitioner complaining of pelvic pain, weight loss, and vaginal bleeding that has persisted for 3 months. She has been menopausal for 15 years and is not currently taking any medication. Upon examination, no abnormalities are found in her abdomen or pelvis, and she is referred to a gynaecologist for urgent evaluation. Unfortunately, the patient is diagnosed with endometrial cancer that has spread to the fundus of her uterus.

      Which lymph node region is most likely to be affected by metastatic spread in this patient?

      Your Answer:

      Correct Answer: Para-aortic nodes

      Explanation:

      The para-aortic lymph nodes are responsible for draining the uterine fundus. This is because the ovaries develop in the abdomen and move down the posterior abdominal wall during fetal development, and their lymphatic drainage comes from the para-aortic nodes. Therefore, lymphatic spread is most likely to occur in this location.

      The inferior mesenteric nodes are not responsible for draining the uterine fundus, as they primarily drain hindgut structures from the transverse colon down to the rectum.

      Similarly, the internal iliac nodes are not responsible for draining the uterine fundus, as they primarily drain the inferior portion of the rectum, the anal canal above the pectinate line, and the pelvic viscera.

      The posterior mediastinal chain is also not responsible for draining the uterine fundus, as it primarily drains the oesophagus, mediastinum, and posterior surface of the diaphragm.

      Lymphatic Drainage of Female Reproductive Organs

      The lymphatic drainage of the female reproductive organs is a complex system that involves multiple nodal stations. The ovaries drain to the para-aortic lymphatics via the gonadal vessels. The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes. The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes. The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes. Understanding the lymphatic drainage of the female reproductive organs is important for the diagnosis and treatment of gynecological cancers.

    • This question is part of the following fields:

      • Haematology And Oncology
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  • Question 7 - During a parent-teacher conference, a student tells their teacher that 'all the older...

    Incorrect

    • During a parent-teacher conference, a student tells their teacher that 'all the older students are mean and unhelpful but the younger students are kind and friendly'. A few hours later they tell the complete opposite to one of the older students.

      This is an example of which of the following ego defence mechanisms?

      Your Answer:

      Correct Answer: Splitting

      Explanation:

      Splitting is a belief that individuals are either completely good or completely bad at different times, which stems from an inability to tolerate ambiguity. This behavior is frequently observed in individuals with borderline personality disorder. Other related behaviors include idealization, which involves expressing overly positive thoughts about oneself and others while disregarding negative thoughts, identification, which is the unconscious adoption of another person’s characteristics, qualities, or traits, and projection, which involves attributing an unacceptable internal impulse to an external source (as opposed to displacement).

      Understanding Ego Defenses

      Ego defenses are psychological mechanisms that individuals use to protect themselves from unpleasant emotions or thoughts. These defenses are classified into four levels, each with its own set of defense mechanisms. The first level, psychotic defenses, is considered pathological as it distorts reality to avoid dealing with it. The second level, immature defenses, includes projection, acting out, and projective identification. The third level, neurotic defenses, has short-term benefits but can lead to problems in the long run. These defenses include repression, rationalization, and regression. The fourth and most advanced level, mature defenses, includes altruism, sublimation, and humor.

      Despite the usefulness of understanding ego defenses, their classification and definitions can be inconsistent and frustrating to learn for exams. It is important to note that these defenses are not necessarily good or bad, but rather a natural part of human behavior. By recognizing and understanding our own ego defenses, we can better manage our emotions and thoughts in a healthy way.

    • This question is part of the following fields:

      • Psychiatry
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  • Question 8 - A 42-year-old man with a known history of poorly-controlled HIV presented to the...

    Incorrect

    • A 42-year-old man with a known history of poorly-controlled HIV presented to the emergency department with confusion and persistent headache. His partner brought him in and reported one episode of non-bloody, non-bilious vomiting. On examination, he had nuchal rigidity and a positive Kernig's sign. His vital signs were notable for a blood pressure of 130/103 mmHg, pulse of 100 beats per minute, and temperature of 39ºC. Cerebrospinal fluid India ink staining revealed encapsulated, spherical cells that grew colonies on Sabouraud agar. What is the most likely causative organism?

      Your Answer:

      Correct Answer: Cryptococcus meningitidis

      Explanation:

      Sabouraud agar is a culture medium that is specifically used for the cultivation of fungi.

      Based on the patient’s medical history of poorly-controlled HIV and the presence of fever, headache, and nuchal rigidity, it is highly likely that the patient is suffering from cryptococcus meningitis. This is further supported by the appearance of encapsulated, spherical cells on India ink staining and the growth of colonies on Sabouraud agar. The causative agent responsible for this condition is Cryptococcus meningitidis, which is a type of fungi.

      It is important to note that Neisseria meningitidis can also cause meningitis and present with similar symptoms of nuchal rigidity and positive Kernig’s sign. However, this is a Gram-negative bacterium that is unlikely to grow on Sabouraud agar. Instead, it can be cultured on Thayer-Martin agar.

      Mycoplasma pneumoniae is another possible cause of infection, but it typically presents with respiratory symptoms of atypical pneumonia, such as a dry cough, and has a milder course of illness. Additionally, it is unlikely to involve the cerebrospinal fluid (CSF) and would grow on Eaton agar rather than Sabouraud agar.

      Mycobacterium tuberculosis is a Gram-positive bacillus that is known to cause meningitis. However, it will not grow on Sabouraud agar and requires Lowenstein-Jensen agar for cultivation.

      Culture Requirements for Common Organisms

      Different microorganisms require specific culture conditions to grow and thrive. The table above lists some of the culture requirements for the more common organisms. For instance, Neisseria gonorrhoeae requires Thayer-Martin agar, which is a variant of chocolate agar, and the addition of Vancomycin, Polymyxin, and Nystatin to inhibit Gram-positive, Gram-negative, and fungal growth, respectively. Haemophilus influenzae, on the other hand, grows on chocolate agar with factors V (NAD+) and X (hematin).

      To remember the culture requirements for some of these organisms, some mnemonics can be used. For example, Nice Homes have chocolate can help recall that Neisseria and Haemophilus grow on chocolate agar. If I Tell-U the Corny joke Right, you’ll Laugh can be used to remember that Corynebacterium diphtheriae grows on tellurite agar or Loeffler’s media. Lactating pink monkeys can help recall that lactose fermenting bacteria, such as Escherichia coli, grow on MacConkey agar resulting in pink colonies. Finally, BORDETella pertussis can be used to remember that Bordetella pertussis grows on Bordet-Gengou (potato) agar.

    • This question is part of the following fields:

      • General Principles
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  • Question 9 - A preteen girl presents with vaginal discharge and itching. She is subsequently diagnosed...

    Incorrect

    • A preteen girl presents with vaginal discharge and itching. She is subsequently diagnosed with preadolescent atrophic vaginitis which her doctor explains is because she has not yet entered adolescence. What is the underlying pathophysiology of preadolescent atrophic vaginitis?

      Your Answer:

      Correct Answer: Lack of vaginal oestrogen causing infection-prone alkaline environment

      Explanation:

      The cause of prepubertal atrophic vaginitis is a deficiency of vaginal estrogen, making any response suggesting otherwise incorrect. This leads to an environment that is prone to infection due to its alkalinity, as estrogen boosts lactobacilli levels, which aid in the conversion of glucose to lactic acid. It is critical to consider this diagnosis when a prepubertal female patient complains of vaginal itching and discharge.

      Understanding Atrophic Vaginitis

      Atrophic vaginitis is a condition that commonly affects women who have gone through menopause. Its symptoms include vaginal dryness, painful intercourse, and occasional spotting. Upon examination, the vagina may appear dry and pale. The condition can be treated with vaginal lubricants and moisturizers. However, if these remedies do not provide relief, a topical estrogen cream may be prescribed.

    • This question is part of the following fields:

      • Reproductive System
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  • Question 10 - A 35-year-old missionary presents to the clinic with a history of fever, chills,...

    Incorrect

    • A 35-year-old missionary presents to the clinic with a history of fever, chills, and headache after working in clinics for 3 months in Nigeria and the Democratic Republic of Congo. Previous records indicate that 70% of patients who attend the clinic with these symptoms and a travel history to Sub-Saharan Africa have malaria.

      The malaria rapid test available has a sensitivity of 92% and specificity of 98%.

      What is the method to calculate the likelihood ratio for a positive malaria rapid test result?

      Your Answer:

      Correct Answer: Sensitivity / (1 - specificity)

      Explanation:

      Precision refers to the consistency of a test in producing the same results when repeated multiple times. It is an important aspect of test reliability and can impact the accuracy of the results. In order to assess precision, multiple tests are performed on the same sample and the results are compared. A test with high precision will produce similar results each time it is performed, while a test with low precision will produce inconsistent results. It is important to consider precision when interpreting test results and making clinical decisions.

    • This question is part of the following fields:

      • General Principles
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  • Question 11 - These thyroid function tests were obtained on a 55-year-old female who has recently...

    Incorrect

    • These thyroid function tests were obtained on a 55-year-old female who has recently been treated for hypertension:
      Free T4 28.5 pmol/L (9.8-23.1)
      TSH <0.02 mU/L (0.35-5.5)
      Free T3 10.8 pmol/L (3.5-6.5)
      She now presents with typical symptoms of hyperthyroidism.
      Which medication is likely to have caused this?

      Your Answer:

      Correct Answer: Amiodarone

      Explanation:

      Amiodarone and its Effects on Thyroid Function

      Amiodarone is a medication that can have an impact on thyroid function, resulting in both hypo- and hyperthyroidism. This is due to the high iodine content in the drug, which contributes to its antiarrhythmic effects. Atenolol, on the other hand, is a beta blocker that is commonly used to treat thyrotoxicosis. Warfarin is another medication that is used to treat atrial fibrillation.

      There are two types of thyrotoxicosis that can be caused by amiodarone. Type 1 results in excess thyroxine synthesis, while type 2 leads to the release of excess thyroxine but normal levels of synthesis. It is important for healthcare professionals to monitor thyroid function in patients taking amiodarone and adjust treatment as necessary to prevent complications.

    • This question is part of the following fields:

      • Pharmacology
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  • Question 12 - A man in his forties comes in with chest pain resembling a heart...

    Incorrect

    • A man in his forties comes in with chest pain resembling a heart attack and is diagnosed with a myocardial infarction. During his hospitalization, it is discovered that he has familial hypercholesterolemia but his triglyceride levels are normal. What is the underlying biochemical abnormality?

      Your Answer:

      Correct Answer: Defective LDL receptors

      Explanation:

      Lipid Metabolism and Transport in the Body

      The breakdown of triglycerides in the small intestine is facilitated by pancreatic lipase. These triglycerides are then transported to the liver and other parts of the body through chylomicrons.

      Very low-density lipoprotein (VLDL) is responsible for carrying triglycerides from the liver to peripheral tissues. When there is an overproduction of VLDL in the liver, it can lead to high levels of triglycerides in the body.

      Pure hypercholesterolaemia is a condition that arises due to a defect in the process of cholesterol uptake into cells. This process relies on apolipoprotein B-100 binding to LDL receptors and facilitating endocytosis. When this process is disrupted, it can lead to high levels of cholesterol in the body.

    • This question is part of the following fields:

      • Basic Sciences
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  • Question 13 - Which muscle is responsible for causing flexion of the distal interphalangeal joint of...

    Incorrect

    • Which muscle is responsible for causing flexion of the distal interphalangeal joint of the middle finger?

      Your Answer:

      Correct Answer: Flexor digitorum profundus

      Explanation:

      The flexor digitorum superficialis and flexor digitorum profundus muscles are accountable for inducing flexion. The tendons of the superficialis muscle attach to the bases of the middle phalanges, while the tendons of the profundus muscle attach to the bases of the distal phalanges. Both tendons are responsible for flexing the wrist, MCP, and PIP joints, but only the tendons of the profundus muscle are responsible for flexing the DIP joints.

      Anatomy of the Hand: Fascia, Compartments, and Tendons

      The hand is composed of bones, muscles, and tendons that work together to perform various functions. The bones of the hand include eight carpal bones, five metacarpals, and 14 phalanges. The intrinsic muscles of the hand include the interossei, which are supplied by the ulnar nerve, and the lumbricals, which flex the metacarpophalangeal joints and extend the interphalangeal joint. The thenar eminence contains the abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis, while the hypothenar eminence contains the opponens digiti minimi, flexor digiti minimi brevis, and abductor digiti minimi.

      The fascia of the palm is thin over the thenar and hypothenar eminences but relatively thick elsewhere. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The palmar fascia is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The hand is divided into compartments by fibrous septa, with the thenar compartment lying lateral to the lateral septum, the hypothenar compartment lying medial to the medial septum, and the central compartment containing the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch, and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis.

      The tendons of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths, extending from the heads of the metacarpals to the base of the distal phalanges.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 14 - What is the name of the intercellular junctional mechanism that allows cells to...

    Incorrect

    • What is the name of the intercellular junctional mechanism that allows cells to be electrically connected?

      Your Answer:

      Correct Answer: Gap junction

      Explanation:

      Cell Junctions: Types and Functions

      Gap junctions are found where two adjacent cell membranes meet, allowing for electrical communication between cells. Desmosomes are specialized proteins that help cells stick together, particularly in epithelial tissue. Tight junctions prevent water and solutes from leaking out of cells. Zonula adherens junctions are cell junctions that connect to the actin cytoskeleton. These different types of cell junctions play important roles in maintaining the structure and function of tissues in the body.

    • This question is part of the following fields:

      • Clinical Sciences
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  • Question 15 - A 57-year-old man comes to the clinic with complaints of dysuria, haematuria, and...

    Incorrect

    • A 57-year-old man comes to the clinic with complaints of dysuria, haematuria, and painful ejaculation. During digital rectal examination, his prostate gland is found to be intensely tender. The physician prescribes gentamicin for the treatment of prostatitis. What is the mechanism of action of this medication?

      Your Answer:

      Correct Answer: Inhibits protein synthesis by acting on the 30S ribosomal unit

      Explanation:

      Aminoglycosides hinder the process of protein synthesis by targeting the 30S ribosomal subunit. By binding to this subunit, they cause mRNA to be misread, leading to the production of abnormal peptides that accumulate within the cell and ultimately result in its death. These antibiotics are classified as bactericidal.

      Rifampicin, on the other hand, works by inhibiting DNA-dependent RNA polymerase, which leads to a suppression of RNA synthesis and ultimately causes cell death.

      Quinolones prevent bacterial DNA from unwinding and duplicating by inhibiting DNA topoisomerase.

      Trimethoprim binds to dihydrofolate reductase, which inhibits the reduction of dihydrofolic acid (DHF) to tetrahydrofolic acid (THF). THF is a crucial precursor in the thymidine synthesis pathway, and interference with this pathway inhibits bacterial DNA synthesis.

      Terbinafine inhibits squalene epoxidase, which blocks the biosynthesis of ergosterol, a vital component of fungal cell membranes.

      Antibiotics work in different ways to kill or inhibit the growth of bacteria. The commonly used antibiotics can be classified based on their gross mechanism of action. The first group inhibits cell wall formation by either preventing peptidoglycan cross-linking (penicillins, cephalosporins, carbapenems) or peptidoglycan synthesis (glycopeptides like vancomycin). The second group inhibits protein synthesis by acting on either the 50S subunit (macrolides, chloramphenicol, clindamycin, linezolid, streptogrammins) or the 30S subunit (aminoglycosides, tetracyclines) of the bacterial ribosome. The third group inhibits DNA synthesis (quinolones like ciprofloxacin) or damages DNA (metronidazole). The fourth group inhibits folic acid formation (sulphonamides and trimethoprim), while the fifth group inhibits RNA synthesis (rifampicin). Understanding the mechanism of action of antibiotics is important in selecting the appropriate drug for a particular bacterial infection.

    • This question is part of the following fields:

      • General Principles
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  • Question 16 - A 10-year-old boy comes to your clinic with a complaint of ear pain...

    Incorrect

    • A 10-year-old boy comes to your clinic with a complaint of ear pain that started last night and kept him awake. He missed school today because of the pain and reports muffled sounds on the affected side. During otoscopy, you observe a bulging tympanic membrane with visible fluid behind it, indicating a middle ear infection. Can you identify which nerves pass through the middle ear?

      Your Answer:

      Correct Answer: Chorda tympani

      Explanation:

      The chorda tympani is the correct answer. It is a branch of the seventh cranial nerve, the facial nerve, and carries parasympathetic and taste fibers. It passes through the middle ear before exiting and joining with the lingual nerve to reach the tongue and salivary glands.

      The vestibulocochlear nerve is the eighth cranial nerve and carries balance and hearing information.

      The maxillary nerve is the second division of the fifth cranial nerve and carries sensation from the upper teeth, nasal cavity, and skin.

      The mandibular nerve is the third division of the fifth cranial nerve and carries sensation from the lower teeth, tongue, mandible, and skin. It also carries motor fibers to certain muscles.

      The glossopharyngeal nerve is the ninth cranial nerve and carries taste and sensation from the posterior one-third of the tongue, as well as sensation from various areas. It also carries motor and parasympathetic fibers.

      The patient in the question has ear pain, likely due to otitis media, as evidenced by a bulging tympanic membrane and fluid level on otoscopy.

      Anatomy of the Ear

      The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.

    • This question is part of the following fields:

      • Respiratory System
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  • Question 17 - A 19-year-old male presents to the emergency department with complaints of breathing difficulty....

    Incorrect

    • A 19-year-old male presents to the emergency department with complaints of breathing difficulty. Upon examination, his chest appears normal, but his respiratory rate is 32 breaths per minute. The medical team suspects he may be experiencing a panic attack and subsequent hyperventilation. What impact will this have on his blood gas levels?

      Your Answer:

      Correct Answer: Respiratory alkalosis

      Explanation:

      The patient is experiencing a respiratory alkalosis due to their hyperventilation, which is causing a decrease in carbon dioxide levels and resulting in an alkaline state.

      Respiratory Alkalosis: Causes and Examples

      Respiratory alkalosis is a condition that occurs when the blood pH level rises above the normal range due to excessive breathing. This can be caused by various factors, including anxiety, pulmonary embolism, CNS disorders, altitude, and pregnancy. Salicylate poisoning can also lead to respiratory alkalosis, but it may also cause metabolic acidosis in the later stages. In this case, the respiratory centre is stimulated early, leading to respiratory alkalosis, while the direct acid effects of salicylates combined with acute renal failure may cause acidosis later on. It is important to identify the underlying cause of respiratory alkalosis to determine the appropriate treatment. Proper management can help prevent complications and improve the patient’s overall health.

    • This question is part of the following fields:

      • Respiratory System
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  • Question 18 - A 20-year-old female patient complains of fever and a sore throat that has...

    Incorrect

    • A 20-year-old female patient complains of fever and a sore throat that has been bothering her for two days. During the examination, the doctor notes that she has a temperature of 39°C, red fauces, cervical lymphadenopathy, and a slightly palpable spleen. What investigation would be most suitable for this patient?

      Your Answer:

      Correct Answer: Monospot test

      Explanation:

      Diagnosis of Glandular Fever with Monospot Test

      Glandular fever, caused by the Epstein-Barr virus, is suspected in a young girl based on her atypical lymphocytes in a full blood count. To confirm the diagnosis, a Monospot test is used. This test detects heterophile antibodies that are produced in response to an EBV infection. The antibodies are directed against horse red blood cells, and their presence in the blood indicates an active EBV infection. The Monospot test is a quick and reliable way to diagnose glandular fever, allowing for prompt treatment and management of symptoms.

    • This question is part of the following fields:

      • Infectious Diseases
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  • Question 19 - As a medical student in the memory clinic, I recently encountered an 84-year-old...

    Incorrect

    • As a medical student in the memory clinic, I recently encountered an 84-year-old female patient who was taking memantine. Can you explain the mechanism of action of this medication?

      Your Answer:

      Correct Answer: NMDA antagonist

      Explanation:

      Memantine, an NMDA receptor antagonist, is a drug commonly used in the treatment of various neurological disorders, such as Alzheimer’s disease. Its primary mode of action is thought to involve the inhibition of current flow through NMDA receptor channels, which are a type of glutamate receptor subfamily that plays a significant role in brain function.

      Management of Alzheimer’s Disease

      Alzheimer’s disease is a type of dementia that progressively affects the brain and is the most common form of dementia in the UK. There are both non-pharmacological and pharmacological management options available for patients with Alzheimer’s disease.

      Non-pharmacological management involves offering activities that promote wellbeing and are tailored to the patient’s preferences. Group cognitive stimulation therapy, group reminiscence therapy, and cognitive rehabilitation are some of the options that can be considered.

      Pharmacological management options include acetylcholinesterase inhibitors such as donepezil, galantamine, and rivastigmine for managing mild to moderate Alzheimer’s disease. Memantine, an NMDA receptor antagonist, is a second-line treatment option that can be used for patients with moderate Alzheimer’s who are intolerant of or have a contraindication to acetylcholinesterase inhibitors. It can also be used as an add-on drug to acetylcholinesterase inhibitors for patients with moderate or severe Alzheimer’s or as monotherapy in severe Alzheimer’s.

      When managing non-cognitive symptoms, NICE does not recommend the use of antidepressants for mild to moderate depression in patients with dementia. Antipsychotics should only be used for patients at risk of harming themselves or others or when the agitation, hallucinations, or delusions are causing them severe distress.

      It is important to note that donepezil is relatively contraindicated in patients with bradycardia, and adverse effects may include insomnia. Proper management of Alzheimer’s disease can improve the quality of life for patients and their caregivers.

    • This question is part of the following fields:

      • Neurological System
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  • Question 20 - A 73-year-old man comes to the clinic with complaints of increasing nocturia, a...

    Incorrect

    • A 73-year-old man comes to the clinic with complaints of increasing nocturia, a feeble urinary stream, and some weight loss in the past few months. Upon examination, an enlarged prostate with nodules is observed, and he is promptly referred for further testing, which reveals prostate cancer cells.

      During the local urology cancer multidisciplinary team meeting, his case is discussed, and the team recommends a course of bicalutamide. What is the mechanism of action of this medication?

      Your Answer:

      Correct Answer: Androgen receptor blocker

      Explanation:

      Bicalutamide, a non-steroidal drug, is utilized in the treatment of prostate cancer as an androgen receptor blocker. It is often used in combination with other approaches such as hormonal treatment, radiotherapy, chemotherapy, and prostatectomy. Abiraterone, on the other hand, is an androgen synthesis blocker that inhibits enzymes required for production. It is typically used for hormone-relapsed metastatic prostate cancer in patients who have no or mild symptoms after anti-androgen therapy has failed. Goserelin is a gonadotrophin-releasing hormone (GnRH) agonist that ultimately downregulates sex hormones. It is initially co-prescribed with an anti-androgen due to its potential to cause an initial flare in testosterone levels. More recently, GnRH antagonists like abarelix have been used to quickly suppress testosterone without the initial flare seen with agonists. Cyproterone acetate, which exhibits progestogenic activity and steroidal and antiandrogenic effects, is another drug used in prostate cancer management but is less commonly used due to the widespread use of non-steroidal drugs like bicalutamide.

      Prostate cancer management varies depending on the stage of the disease and the patient’s life expectancy and preferences. For localized prostate cancer (T1/T2), treatment options include active monitoring, watchful waiting, radical prostatectomy, and radiotherapy (external beam and brachytherapy). For localized advanced prostate cancer (T3/T4), options include hormonal therapy, radical prostatectomy, and radiotherapy. Patients may develop proctitis and are at increased risk of bladder, colon, and rectal cancer following radiotherapy for prostate cancer.

      In cases of metastatic prostate cancer, reducing androgen levels is a key aim of treatment. A combination of approaches is often used, including anti-androgen therapy, synthetic GnRH agonist or antagonists, bicalutamide, cyproterone acetate, abiraterone, and bilateral orchidectomy. GnRH agonists, such as Goserelin (Zoladex), initially cause a rise in testosterone levels before falling to castration levels. To prevent a rise in testosterone, anti-androgens are often used to cover the initial therapy. GnRH antagonists, such as degarelix, are being evaluated to suppress testosterone while avoiding the flare phenomenon. Chemotherapy with docetaxel is also an option for the treatment of hormone-relapsed metastatic prostate cancer in patients who have no or mild symptoms after androgen deprivation therapy has failed, and before chemotherapy is indicated.

    • This question is part of the following fields:

      • Renal System
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  • Question 21 - As a single-handed GP in a rural area, you come across a 35-year-old...

    Incorrect

    • As a single-handed GP in a rural area, you come across a 35-year-old woman named Sarah who is expecting her fourth child. She expresses her dissatisfaction with the care she received at the local hospital during her previous pregnancies, but there were no reported adverse events. Sarah lives in a remote farmhouse and is adamant about having a home birth. However, the midwives are too far away to reach her in time for the delivery, and she has no plans to contact them until she is in active labor. Her residence is located near your home. What would be the most appropriate course of action in this situation?

      Your Answer:

      Correct Answer: Discuss her past experiences in detail and try and persuade her to involve the community midwifery or hospital-based obstetric team in her birth. If she does not agree then ensure the risks of home birth are discussed and that her and her family know what the early signs of perinatal problems are and what to do. Offer ongoing support throughout her pregnancy and during the perinatal period

      Explanation:

      Balancing Autonomy and Risk in Home Birth Decision Making

      This is a complex situation where the GP needs to consider the autonomy of the patient, Marie, and the potential risks of home birth to her and her unborn child. The GP also needs to balance their responsibilities to Marie with their obligations to other patients. While parous women and their newborns are not at significantly increased risk with well-trained midwives present, Marie’s social circumstances may increase the risk of adverse outcomes. However, involving the child protection team would be inappropriate at this stage.

      As primary care services are not equipped to provide round-the-clock obstetric cover, guaranteeing 24-hour availability may not be feasible and could lead to inadequate care for other patients. Simply suggesting that Marie call 999 in case of problems would also not be sufficient. The best approach would be to discuss Marie’s past experiences and try to persuade her to involve the community midwifery or hospital-based obstetric team. If she refuses, the GP should ensure that the risks of home birth are discussed, and Marie and her family are aware of the early signs of perinatal problems and what to do. Ongoing support should be offered throughout the pregnancy and perinatal period. This approach balances Marie’s autonomy with the risks involved in a non-paternalistic manner, while providing adequate primary care.

    • This question is part of the following fields:

      • Ethics And Law
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  • Question 22 - A 50-year-old female patient presents to the vascular clinic for evaluation of varicose...

    Incorrect

    • A 50-year-old female patient presents to the vascular clinic for evaluation of varicose veins. During the assessment, a test is conducted to determine the site of incompetence. The patient is instructed to lie down, and her legs are raised to empty the veins. A constricting band is then placed below the sapheno-femoral junction, and the patient is asked to stand up to observe for varicose vein filling. What is the name of this test?

      Your Answer:

      Correct Answer: Tourniquet test

      Explanation:

      Tests for Varicose Veins and Arterial Insufficiency

      The Trendelenburg and tourniquet tests are both used to evaluate the site of incompetence in varicose veins at the sapheno-femoral junction. During the Trendelenburg test, the examiner applies pressure with their fingers over the junction, while in the tourniquet test, a tourniquet is placed just below the junction. If the veins fill rapidly upon standing, it suggests that the sapheno-femoral junction is not the source of the incompetence.

      Buerger’s test is used to assess the arterial circulation of the lower limb. The lower the angle at which blanching occurs, the more likely there is arterial insufficiency. This test is important in diagnosing peripheral artery disease.

      The ankle-brachial pressure index (ABPI) is another test used to assess arterial insufficiency. Blood pressure cuffs are used to measure the systolic blood pressure in the ankle and arm. The ratio of the two pressures is calculated, and a lower ratio indicates a higher degree of claudication.

      Finally, Perthe’s test is used to assess the patency of the deep femoral vein before varicose vein surgery. This test involves compressing the vein and observing the filling of the superficial veins. If the superficial veins fill quickly, it suggests that the deep femoral vein is patent and can be used for surgery.

      In summary, these tests are important in diagnosing and evaluating varicose veins and arterial insufficiency. They help healthcare professionals determine the best course of treatment for their patients.

    • This question is part of the following fields:

      • Basic Sciences
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  • Question 23 - At a rheumatology appointment, a 47-year-old woman with uncontrolled rheumatoid arthritis is prescribed...

    Incorrect

    • At a rheumatology appointment, a 47-year-old woman with uncontrolled rheumatoid arthritis is prescribed anakinra, an IL-1 receptor antagonist. What type of cell produces IL-1?

      Your Answer:

      Correct Answer: Macrophages

      Explanation:

      Macrophages are the primary source of IL-1, an acute inflammatory cytokine. This cytokine is mainly produced by innate immune cells, with macrophages being responsible for its production. While other innate immune cells such as basophils, neutrophils, and eosinophils also produce proinflammatory cytokines, they do so in lower quantities than macrophages. T cells, on the other hand, do not produce IL-1.

      Overview of Cytokines and Their Functions

      Cytokines are signaling molecules that play a crucial role in the immune system. Interleukins are a type of cytokine that are produced by various immune cells and have specific functions. IL-1, produced by macrophages, induces acute inflammation and fever. IL-2, produced by Th1 cells, stimulates the growth and differentiation of T cell responses. IL-3, produced by activated T helper cells, stimulates the differentiation and proliferation of myeloid progenitor cells. IL-4, produced by Th2 cells, stimulates the proliferation and differentiation of B cells. IL-5, also produced by Th2 cells, stimulates the production of eosinophils. IL-6, produced by macrophages and Th2 cells, stimulates the differentiation of B cells and induces fever. IL-8, produced by macrophages, promotes neutrophil chemotaxis. IL-10, produced by Th2 cells, inhibits Th1 cytokine production and is known as an anti-inflammatory cytokine. IL-12, produced by dendritic cells, macrophages, and B cells, activates NK cells and stimulates the differentiation of naive T cells into Th1 cells.

      In addition to interleukins, there are other cytokines with specific functions. Tumor necrosis factor-alpha, produced by macrophages, induces fever and promotes neutrophil chemotaxis. Interferon-gamma, produced by Th1 cells, activates macrophages. Understanding the functions of cytokines is important in developing treatments for various immune-related diseases.

    • This question is part of the following fields:

      • General Principles
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  • Question 24 - A 65-year-old woman comes to your clinic with symptoms of depression, weight gain,...

    Incorrect

    • A 65-year-old woman comes to your clinic with symptoms of depression, weight gain, and dry skin. You suspect that she might be experiencing hypothyroidism.

      What is the origin of the organ responsible for her symptoms, from an embryological perspective?

      Your Answer:

      Correct Answer: Endoderm

      Explanation:

      The thyroid, parathyroid, and thymus glands are all derived from the endodermal layer of the germ layer. Conversely, the ectoderm gives rise to the nails and lens of the eye, while the neural crest tissue is responsible for the development of the nervous system. Finally, the mesoderm is responsible for the formation of muscle and connective tissues.

      Embryological Layers and Their Derivatives

      Embryonic development involves the formation of three primary germ layers: ectoderm, mesoderm, and endoderm. Each layer gives rise to specific tissues and organs in the developing embryo. The ectoderm forms the surface ectoderm, which gives rise to the epidermis, mammary glands, and lens of the eye, as well as the neural tube, which gives rise to the central nervous system (CNS) and associated structures such as the posterior pituitary and retina. The neural crest, which arises from the neural tube, gives rise to a variety of structures including autonomic nerves, cranial nerves, facial and skull bones, and adrenal cortex. The mesoderm gives rise to connective tissue, muscle, bones (except facial and skull), and organs such as the kidneys, ureters, gonads, and spleen. The endoderm gives rise to the epithelial lining of the gastrointestinal tract, liver, pancreas, thyroid, parathyroid, and thymus.

    • This question is part of the following fields:

      • General Principles
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  • Question 25 - A 75-year-old female patient presents to the Emergency Department after experiencing a fall....

    Incorrect

    • A 75-year-old female patient presents to the Emergency Department after experiencing a fall. She has a medical history of hypertension and type 2 diabetes, and is a smoker with a BMI of 34 kg/m². Her family history includes high cholesterol in her father and older sister, who both passed away due to a heart attack.

      The patient denies any head trauma from the fall and has a regular pulse of 78 bpm. Upon conducting a full neurological examination, it is discovered that her left arm and left leg have a power of 3/5. Additionally, her smile is asymmetrical and droops on the left side.

      What is the most probable underlying cause of her symptoms?

      Your Answer:

      Correct Answer: Emboli caused by atherosclerosis

      Explanation:

      Intracerebral haemorrhage is not the most probable cause of all strokes. Hence, it is crucial to conduct a CT head scan to eliminate the possibility of haemorrhagic stroke before initiating treatment.

      A transient ischaemic attack (TIA) is a brief period of neurological deficit caused by a vascular issue, lasting less than an hour. The original definition of a TIA was based on time, but it is now recognized that even short periods of ischaemia can result in pathological changes to the brain. Therefore, a new ’tissue-based’ definition is now used. The clinical features of a TIA are similar to those of a stroke, but the symptoms resolve within an hour. Possible features include unilateral weakness or sensory loss, aphasia or dysarthria, ataxia, vertigo, or loss of balance, visual problems, sudden transient loss of vision in one eye (amaurosis fugax), diplopia, and homonymous hemianopia.

      NICE recommends immediate antithrombotic therapy, giving aspirin 300 mg immediately unless the patient has a bleeding disorder or is taking an anticoagulant. If aspirin is contraindicated, management should be discussed urgently with the specialist team. Specialist review is necessary if the patient has had more than one TIA or has a suspected cardioembolic source or severe carotid stenosis. Urgent assessment within 24 hours by a specialist stroke physician is required if the patient has had a suspected TIA in the last 7 days. Referral for specialist assessment should be made as soon as possible within 7 days if the patient has had a suspected TIA more than a week previously. The person should be advised not to drive until they have been seen by a specialist.

      Neuroimaging should be done on the same day as specialist assessment if possible. MRI is preferred to determine the territory of ischaemia or to detect haemorrhage or alternative pathologies. Carotid imaging is necessary as atherosclerosis in the carotid artery may be a source of emboli in some patients. All patients should have an urgent carotid doppler unless they are not a candidate for carotid endarterectomy.

      Antithrombotic therapy is recommended, with clopidogrel being the first-line treatment. Aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel. Carotid artery endarterectomy should only be considered if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled. It should only be recommended if carotid stenosis is greater

    • This question is part of the following fields:

      • Neurological System
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  • Question 26 - A 12-year-old boy has been experiencing recurrent and prolonged episodes of sinusitis and...

    Incorrect

    • A 12-year-old boy has been experiencing recurrent and prolonged episodes of sinusitis and bronchitis, as well as more frequent gastrointestinal infections compared to his peers. These symptoms have been ongoing for the past two years. Upon screening his immune system, a type of primary immunodeficiency is detected.

      What is the probable diagnosis?

      Your Answer:

      Correct Answer: Selective immunoglobulin A deficiency

      Explanation:

      There are several types of primary immunodeficiency disorders that can affect individuals. Common variable immunodeficiency (CVID) is a disorder that affects the production of immunoglobulins, which can lead to recurrent infections of the respiratory and gastrointestinal tracts. Symptoms can occur at any age.

      Bruton’s X-linked agammaglobulinaemia is a disorder that results in the complete absence or very low levels of all types of immunoglobulins. It typically presents in infants between 6-9 months of age with recurrent severe episodes of pneumonia, upper respiratory tract infections, gastrointestinal infections, and skin and joint infections.

      Severe combined immunodeficiency (SCID) is a disorder that impairs B and T cell function. It usually presents in infants at 6 months of age with recurrent severe bacterial, fungal, and viral infections. Common presenting conditions include ear infections, sinusitis, oral candidiasis, and Pneumocystis jirovecii pneumonia.

      Chronic granulomatous disease (CGD) is a neutrophil disorder that is typically diagnosed before the age of 5. It is characterized by recurrent infections by pus-forming (pyogenic) bacteria, especially Staphylococcus aureus. Commonly seen infections include abscesses of skin and organs, septic arthritis, and osteomyelitis.

      Immunoglobulins, also known as antibodies, are proteins produced by the immune system to help fight off infections and diseases. There are five types of immunoglobulins found in the body, each with their own unique characteristics.

      IgG is the most abundant type of immunoglobulin in blood serum and plays a crucial role in enhancing phagocytosis of bacteria and viruses. It also fixes complement and can be passed to the fetal circulation.

      IgA is the most commonly produced immunoglobulin in the body and is found in the secretions of digestive, respiratory, and urogenital tracts and systems. It provides localized protection on mucous membranes and is transported across the interior of the cell via transcytosis.

      IgM is the first immunoglobulin to be secreted in response to an infection and fixes complement, but does not pass to the fetal circulation. It is also responsible for producing anti-A, B blood antibodies.

      IgD’s role in the immune system is largely unknown, but it is involved in the activation of B cells.

      IgE is the least abundant type of immunoglobulin in blood serum and is responsible for mediating type 1 hypersensitivity reactions. It provides immunity to parasites such as helminths and binds to Fc receptors found on the surface of mast cells and basophils.

    • This question is part of the following fields:

      • General Principles
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  • Question 27 - You encounter a young patient on the haematology ward who has just received...

    Incorrect

    • You encounter a young patient on the haematology ward who has just received their first round of chemotherapy for high-grade non-Hodgkin's lymphoma. Upon reviewing their medical records, you discover that they have been prescribed allopurinol as a precaution against tumour lysis syndrome due to the size of the tumour. What is the mechanism of action of this medication?

      Your Answer:

      Correct Answer: Inhibition of xanthine oxidase

      Explanation:

      Allopurinol works by inhibiting xanthine oxidase, an enzyme that plays a role in the formation of uric acid. This medication is crucial for patients undergoing chemotherapy, as the breakdown of cells during treatment can lead to high levels of uric acid, which can cause kidney damage. By acting as a prophylactic measure, allopurinol helps prevent this from happening.

      The other options provided are incorrect. HMG-CoA reductase inhibition is the mechanism of action for statins, while colchicine acts as a mitotic spindle poison, and azathioprine works by inhibiting purine synthesis. It is important to note that allopurinol should never be combined with azathioprine, as this can increase the risk of toxicity.

      Allopurinol can interact with other medications such as azathioprine, cyclophosphamide, and theophylline. It can lead to high levels of 6-mercaptopurine when used with azathioprine, reduced renal clearance when used with cyclophosphamide, and an increase in plasma concentration of theophylline. Patients at a high risk of severe cutaneous adverse reaction should be screened for the HLA-B *5801 allele.

    • This question is part of the following fields:

      • General Principles
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  • Question 28 - Which of the following nerves is responsible for innervating the posterior belly of...

    Incorrect

    • Which of the following nerves is responsible for innervating the posterior belly of the digastric muscle?

      Your Answer:

      Correct Answer: Facial nerve

      Explanation:

      The facial nerve innervates the posterior belly of digastric, while the mylohoid nerve innervates the anterior belly.

      The Anterior Triangle of the Neck: Boundaries and Contents

      The anterior triangle of the neck is a region that is bounded by the anterior border of the sternocleidomastoid muscle, the lower border of the mandible, and the anterior midline. It is further divided into three sub-triangles by the digastric muscle and the omohyoid muscle. The muscular triangle contains the neck strap muscles, while the carotid triangle contains the carotid sheath, which houses the common carotid artery, the vagus nerve, and the internal jugular vein. The submandibular triangle, located below the digastric muscle, contains the submandibular gland, submandibular nodes, facial vessels, hypoglossal nerve, and other structures.

      The digastric muscle, which separates the submandibular triangle from the muscular triangle, is innervated by two different nerves. The anterior belly of the digastric muscle is supplied by the mylohyoid nerve, while the posterior belly is supplied by the facial nerve.

      Overall, the anterior triangle of the neck is an important anatomical region that contains many vital structures, including blood vessels, nerves, and glands. Understanding the boundaries and contents of this region is essential for medical professionals who work in this area.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 29 - A 67-year-old man is being evaluated on the ward. He was admitted with...

    Incorrect

    • A 67-year-old man is being evaluated on the ward. He was admitted with community-acquired pneumonia and required IV antibiotics. The results of his blood tests taken this morning are as follows:

      - Sodium (Na+): 143 mmol/L (135 - 145)
      - Potassium (K+): 6.5 mmol/L (3.5 - 5.0)
      - Bicarbonate: 25 mmol/L (22 - 29)
      - Urea: 5.5 mmol/L (2.0 - 7.0)
      - Creatinine: 115 µmol/L (55 - 120)

      An urgent ECG is ordered, which reveals peaked T waves and a loss of P waves.

      What is the immediate course of action for this patient?

      Your Answer:

      Correct Answer: IV calcium gluconate

      Explanation:

      The correct treatment for stabilizing the cardiac membrane in a patient with hyperkalaemia and ECG changes, such as peaked T waves and loss of P waves, is IV calcium gluconate. This is the first-line treatment option, as it can effectively stabilize the cardiac membrane and prevent arrhythmias. Other treatment options, such as calcium resonium, combined insulin/dextrose infusion, and nebulised salbutamol, can be used to treat hyperkalaemia, but only after IV calcium gluconate has been given.

      Managing Hyperkalaemia: A Step-by-Step Guide

      Hyperkalaemia is a serious condition that can lead to life-threatening arrhythmias if left untreated. To manage hyperkalaemia, it is important to address any underlying factors that may be contributing to the condition, such as acute kidney injury, and to stop any aggravating drugs, such as ACE inhibitors. Treatment can be categorised based on the severity of the hyperkalaemia, which is classified as mild, moderate, or severe based on the patient’s potassium levels.

      ECG changes are also important in determining the appropriate management for hyperkalaemia. Peaked or ‘tall-tented’ T waves, loss of P waves, broad QRS complexes, and a sinusoidal wave pattern are all associated with hyperkalaemia and should be evaluated in all patients with new hyperkalaemia.

      The principles of treatment modalities for hyperkalaemia include stabilising the cardiac membrane, shifting potassium from extracellular to intracellular fluid compartments, and removing potassium from the body. IV calcium gluconate is used to stabilise the myocardium, while insulin/dextrose infusion and nebulised salbutamol can be used to shift potassium from the extracellular to intracellular fluid compartments. Calcium resonium, loop diuretics, and dialysis can be used to remove potassium from the body.

      In practical terms, all patients with severe hyperkalaemia or ECG changes should receive emergency treatment, including IV calcium gluconate to stabilise the myocardium and insulin/dextrose infusion to shift potassium from the extracellular to intracellular fluid compartments. Other treatments, such as nebulised salbutamol, may also be used to temporarily lower serum potassium levels. Further management may involve stopping exacerbating drugs, treating any underlying causes, and lowering total body potassium through the use of calcium resonium, loop diuretics, or dialysis.

    • This question is part of the following fields:

      • Renal System
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  • Question 30 - A 56-year-old accountant presents to the hospital with severe abdominal pain that has...

    Incorrect

    • A 56-year-old accountant presents to the hospital with severe abdominal pain that has been ongoing for more than 3 hours. The pain is sharp and extends to his back, and he rates it as 8/10 on the pain scale. The pain subsides when he sits up. During the examination, he appears restless, cold, and clammy, with a pulse rate of 124 bpm and a blood pressure of 102/65. You notice some purple discoloration in his right flank, and his bowel sounds are normal. According to his social history, he has a history of excessive alcohol consumption. What is the most probable diagnosis?

      Your Answer:

      Correct Answer: Acute pancreatitis

      Explanation:

      Pancreatitis is the most probable diagnosis due to several reasons. Firstly, the patient’s history indicates that he is an alcoholic, which is a risk factor for pancreatitis. Secondly, the severe and radiating pain to the back is a typical symptom of pancreatitis. Additionally, the patient shows signs of jaundice and circulation collapse, with a purple discoloration known as Grey Turner’s sign caused by retroperitoneal hemorrhage. On the other hand, appendicitis pain is usually colicky, localized in the lower right quadrant, and moves up centrally. Although circulation collapse may indicate intestinal obstruction, the absence of vomiting/nausea makes it less likely. Chronic kidney disease can be ruled out as it presents with symptoms such as weight loss, tiredness, bone pain, and itchy skin, which are not present in this acute presentation. Lastly, if there was a significant history of recent surgery, ileus and obstruction would be more likely, and the absence of bowel sounds would support this diagnosis.

      Acute pancreatitis is a condition that is primarily caused by gallstones and alcohol consumption in the UK. However, there are other factors that can contribute to the development of this condition. A popular mnemonic used to remember these factors is GET SMASHED, which stands for gallstones, ethanol, trauma, steroids, mumps, autoimmune diseases, scorpion venom, hypertriglyceridaemia, hyperchylomicronaemia, hypercalcaemia, hypothermia, ERCP, and certain drugs. It is important to note that pancreatitis is seven times more common in patients taking mesalazine than sulfasalazine. CT scans can show diffuse parenchymal enlargement with oedema and indistinct margins in patients with acute pancreatitis.

    • This question is part of the following fields:

      • Gastrointestinal System
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SESSION STATS - PERFORMANCE PER SPECIALTY

Passmed