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  • Question 1 - The oxygen-haemoglobin dissociation curve is shifted to the right in which of the...

    Incorrect

    • The oxygen-haemoglobin dissociation curve is shifted to the right in which of the following situations?

      Your Answer: Low altitude

      Correct Answer: Chronic iron deficiency anaemia

      Explanation:

      A helpful mnemonic to remember the causes of a right shift in the oxygen dissociation curve is CADET face RIGHT. This stands for C O2, Acidosis, 2,3-DPG, Exercise, and Temperature. A right shift in the curve indicates an increased oxygen demand by the tissues, which can be caused by factors such as higher temperatures, acidosis, and increased levels of DPG. DPG is a molecule found in red blood cells that is elevated during glycolysis and can bind to hemoglobin, releasing oxygen to the tissues. Conditions associated with poor oxygen delivery, such as anemia and high altitude, can also lead to increased DPG levels.

      Oxygen Transport and Factors Affecting Haemoglobin Saturation

      Oxygen transport in the body is mainly carried out by erythrocytes, with only 1% of oxygen being transported as a solution due to its limited solubility. The amount of oxygen transported depends on the concentration of haemoglobin and its degree of saturation. Haemoglobin is a globular protein composed of four subunits, with two alpha and two beta subunits forming globin. Haem, which surrounds an iron atom in its ferrous state, can form two additional bonds with oxygen and a polypeptide chain. The oxygenation of haemoglobin is a reversible reaction, and the molecular shape of haemoglobin facilitates the binding of subsequent oxygen molecules.

      The oxygen dissociation curve describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood, and it is not affected by haemoglobin concentration. The curve can be shifted to the right or left by various factors. Chronic anaemia, for example, causes an increase in 2,3 DPG levels, which shifts the curve to the right, resulting in lower oxygen delivery. The Haldane effect causes a shift to the left, resulting in decreased oxygen delivery to tissues, while the Bohr effect causes a shift to the right, resulting in enhanced oxygen delivery to tissues. Factors that shift the curve to the left include low levels of H+, pCO2, 2,3-DPG, and temperature, as well as the presence of HbF, methaemoglobin, and carboxyhaemoglobin. Factors that shift the curve to the right include raised levels of H+, pCO2, and 2,3-DPG, as well as increased temperature.

    • This question is part of the following fields:

      • Haematology And Oncology
      20.4
      Seconds
  • Question 2 - A 32-year-old woman visits her doctor with complaints of vaginal bleeding, hot flashes,...

    Correct

    • A 32-year-old woman visits her doctor with complaints of vaginal bleeding, hot flashes, and diarrhea. She is extremely anxious as she coughed up blood earlier in the day. The patient had a successful delivery of a healthy baby boy two months ago and has no significant medical history except for a previous miscarriage. An X-ray shows multiple infiltrates in both lung fields, leading the physician to suspect a malignancy related to her recent pregnancy.

      What is likely to be elevated in this 32-year-old woman?

      Your Answer: Human chorionic gonadotropin

      Explanation:

      The patient’s symptoms of vaginal bleeding, hyperthyroidism, and chest pain suggest a possible diagnosis of choriocarcinoma, which is characterized by significantly elevated levels of human chorionic gonadotropin in the serum. Metastases to the lungs may explain the chest pain, while the hyperthyroidism may be due to cross-reactivity between hCG and TSH receptors. Alkaline phosphatase is a tumor marker associated with bone and liver metastases as well as germ cell tumors, while chromogranin is a marker for neuroendocrine tumors that can occur in various parts of the body.

      Gestational trophoblastic disorders refer to a range of conditions that originate from the placental trophoblast. These disorders include complete hydatidiform mole, partial hydatidiform mole, and choriocarcinoma. Complete hydatidiform mole is a benign tumor of trophoblastic material that occurs when an empty egg is fertilized by a single sperm that duplicates its own DNA, resulting in all 46 chromosomes being of paternal origin. Symptoms of this disorder include bleeding in the first or early second trimester, exaggerated pregnancy symptoms, a large uterus for dates, and high levels of human chorionic gonadotropin (hCG) in the blood. Hypertension and hyperthyroidism may also be present. Urgent referral to a specialist center is necessary, and evacuation of the uterus is performed. Effective contraception is recommended to avoid pregnancy in the next 12 months. About 2-3% of cases may progress to choriocarcinoma. In partial mole, a normal haploid egg may be fertilized by two sperms or one sperm with duplication of paternal chromosomes, resulting in DNA that is both maternal and paternal in origin. Fetal parts may be visible, and the condition is usually triploid.

    • This question is part of the following fields:

      • Reproductive System
      18.7
      Seconds
  • Question 3 - A 28-year-old presents to the hospital with severe wrist pain. He was playing...

    Correct

    • A 28-year-old presents to the hospital with severe wrist pain. He was playing basketball with his friends when he fell with his hand outstretched. On examination, there is significant tenderness at the anatomical snuffbox. Pain is elicited as the thumb is longitudinally compressed. His grip strength is also diminished.

      A posteroanterior and lateral x-ray of the wrist joint is performed which gives inconclusive results. The patient's wrist is immobilized with a splint and he is advised an MRI in a week’s time for further evaluation.

      The patient inquires about possible complications and the doctor expresses concern that if the blood supply is interrupted, the bone tissue may be compromised.

      Which of the following structures is most likely to be responsible for this complication?

      Your Answer: Dorsal carpal branch of radial artery

      Explanation:

      The primary neurovascular structure that can be affected by a scaphoid fracture is the dorsal carpal branch of the radial artery. This artery is responsible for supplying blood to the scaphoid bone, and a fracture can lead to a high risk of avascular necrosis in the proximal pole of the bone. Symptoms of a scaphoid fracture include tenderness in the anatomical snuffbox, pain when compressing the thumb longitudinally, and a loss of grip strength. While an X-ray may not provide a conclusive diagnosis, further imaging studies can confirm the presence of an occult fracture.

      The other answer choices are incorrect. The common digital arteries originate from the superficial palmar arch and supply the fingers. The deep palmar arch primarily supplies the thumb and index finger. The proper digital arteries arise from the common digital arteries and supply the fingers.

      A scaphoid fracture is a type of wrist fracture that usually occurs when a person falls onto an outstretched hand or during contact sports. It is important to identify scaphoid fractures as they can lead to avascular necrosis due to the unusual blood supply of the scaphoid bone. Patients with scaphoid fractures typically experience pain along the radial aspect of the wrist and loss of grip or pinch strength. Clinical examination involves checking for tenderness over the anatomical snuffbox, wrist joint effusion, pain on telescoping of the thumb, tenderness of the scaphoid tubercle, and pain on ulnar deviation of the wrist. Plain film radiographs and scaphoid views are used to diagnose scaphoid fractures, but MRI is considered the definitive investigation. Initial management involves immobilization with a splint or backslab and referral to orthopaedics. Orthopaedic management depends on the type of fracture, with undisplaced fractures typically treated with a cast and displaced fractures requiring surgical fixation. Complications of scaphoid fractures include non-union and avascular necrosis.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      18.1
      Seconds
  • Question 4 - Which one of the following mechanisms best explains the release of adrenaline? ...

    Incorrect

    • Which one of the following mechanisms best explains the release of adrenaline?

      Your Answer: Release from the adrenal medulla in response to increased angiotensin 1 levels

      Correct Answer: Release from the adrenal medulla in response to sympathetic stimulation from the splanchnic nerves

      Explanation:

      Adrenaline is released by the adrenal gland when the splanchnic nerves stimulate the chromaffin cells of the medulla to release preformed adrenaline through exocytosis. This stimulation is caused by an increase in sympathetic discharge.

      Understanding Adrenaline and Its Effects on the Body

      Adrenaline is a hormone that is responsible for the body’s fight or flight response. It is released by the adrenal glands and acts on both alpha and beta adrenergic receptors. Adrenaline has various effects on the body, including increasing cardiac output and total peripheral resistance, causing vasoconstriction in the skin and kidneys, and stimulating glycogenolysis and glycolysis in the liver and muscle.

      Adrenaline also has different actions on alpha and beta adrenergic receptors. It inhibits insulin secretion by the pancreas and stimulates glycogenolysis in the liver and muscle through alpha receptors. On the other hand, it stimulates glucagon secretion in the pancreas, ACTH, and lipolysis by adipose tissue through beta receptors. Adrenaline also acts on beta 2 receptors in skeletal muscle vessels, causing vasodilation.

      Adrenaline is used in emergency situations such as anaphylaxis and cardiac arrest. The recommended adult life support adrenaline doses for anaphylaxis are 0.5ml 1:1,000 IM, while for cardiac arrest, it is 10ml 1:10,000 IV or 1ml of 1:1000 IV. However, accidental injection of adrenaline can occur, and in such cases, local infiltration of phentolamine is recommended.

      In conclusion, adrenaline is a hormone that plays a crucial role in the body’s response to stress. It has various effects on the body, including increasing cardiac output and total peripheral resistance, causing vasoconstriction in the skin and kidneys, and stimulating glycogenolysis and glycolysis in the liver and muscle. Adrenaline is used in emergency situations such as anaphylaxis and cardiac arrest, and accidental injection can be managed through local infiltration of phentolamine.

    • This question is part of the following fields:

      • General Principles
      10.3
      Seconds
  • Question 5 - A 19-year-old male presents with a severe spreading sepsis in his hand. During...

    Incorrect

    • A 19-year-old male presents with a severe spreading sepsis in his hand. During surgical exploration of the palm, the flexor digiti minimi brevis muscle is mobilized to aid in drainage of the infection. Which of the following structures is not in close proximity to this muscle?

      Your Answer: Digital nerves arising from the ulnar nerve

      Correct Answer: Median nerve

      Explanation:

      The flexor digiti minimi brevis originates from the Hamate and is located beneath the ulnar contribution to the superficial palmar arterial arch and digital nerves. The median nerve is positioned over the flexor tendons.

      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
      17.1
      Seconds
  • Question 6 - During the repair of an atrial septal defect, the surgeons notice blood leakage...

    Incorrect

    • During the repair of an atrial septal defect, the surgeons notice blood leakage from the coronary sinus. What is the largest tributary of the coronary sinus?

      Your Answer: Thebesian veins

      Correct Answer: Great cardiac vein

      Explanation:

      The largest tributary of the coronary sinus is the great cardiac vein, which runs in the anterior interventricular groove. The heart is drained directly by the Thebesian veins.

      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
      11.4
      Seconds
  • Question 7 - A senior citizen trips and falls, injuring her hip. Upon examination, her hip...

    Incorrect

    • A senior citizen trips and falls, injuring her hip. Upon examination, her hip is sensitive to touch and x-rays are ordered to check for a possible intertrochanteric fracture. What is the typical degree of the angle between the femoral neck and shaft?

      Your Answer: 80o

      Correct Answer: 130o

      Explanation:

      The femoral head and shaft typically form an angle of 130 degrees, but any deviations from this angle may indicate underlying disease or pathology and require further examination.

      Anatomy of the Hip Joint

      The hip joint is formed by the articulation of the head of the femur with the acetabulum of the pelvis. Both of these structures are covered by articular hyaline cartilage. The acetabulum is formed at the junction of the ilium, pubis, and ischium, and is separated by the triradiate cartilage, which is a Y-shaped growth plate. The femoral head is held in place by the acetabular labrum. The normal angle between the femoral head and shaft is 130 degrees.

      There are several ligaments that support the hip joint. The transverse ligament connects the anterior and posterior ends of the articular cartilage, while the head of femur ligament (ligamentum teres) connects the acetabular notch to the fovea. In children, this ligament contains the arterial supply to the head of the femur. There are also extracapsular ligaments, including the iliofemoral ligament, which runs from the anterior iliac spine to the trochanteric line, the pubofemoral ligament, which connects the acetabulum to the lesser trochanter, and the ischiofemoral ligament, which provides posterior support from the ischium to the greater trochanter.

      The blood supply to the hip joint comes from the medial circumflex femoral and lateral circumflex femoral arteries, which are branches of the profunda femoris. The inferior gluteal artery also contributes to the blood supply. These arteries form an anastomosis and travel up the femoral neck to supply the head of the femur.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      8.8
      Seconds
  • Question 8 - A 56-year-old presents to his general physician with painless haematuria and is urgently...

    Incorrect

    • A 56-year-old presents to his general physician with painless haematuria and is urgently referred to urology due to a certain risk factor in his history. The urologist performs a flexible cystoscopy and discovers bladder cancer, which is later confirmed by a bladder biopsy. What could have prompted the general physician to make an urgent referral?

      Your Answer: Selenium

      Correct Answer: Exposure to 2-Naphthylamine

      Explanation:

      The primary intravesical immunotherapy for early-stage bladder cancer is Bacillus Calmette-Guerin (BCG), which does not pose a risk for bladder cancer. There is no evidence to suggest that aspirin has any impact on the risk of bladder cancer. However, exposure to hydrocarbons like 2-Naphthylamine is a known risk factor for bladder cancer.

      Bladder cancer is a common urological cancer that primarily affects males aged 50-80 years old. Smoking and exposure to hydrocarbons increase the risk of developing the disease. Chronic bladder inflammation from Schistosomiasis infection is also a common cause of squamous cell carcinomas in countries where the disease is endemic. Benign tumors of the bladder, such as inverted urothelial papilloma and nephrogenic adenoma, are rare. The most common bladder malignancies are urothelial (transitional cell) carcinoma, squamous cell carcinoma, and adenocarcinoma. Urothelial carcinomas may be solitary or multifocal, with papillary growth patterns having a better prognosis. The remaining tumors may be of higher grade and prone to local invasion, resulting in a worse prognosis.

      The TNM staging system is used to describe the extent of bladder cancer. Most patients present with painless, macroscopic hematuria, and a cystoscopy and biopsies or TURBT are used to provide a histological diagnosis and information on depth of invasion. Pelvic MRI and CT scanning are used to determine locoregional spread, and PET CT may be used to investigate nodes of uncertain significance. Treatment options include TURBT, intravesical chemotherapy, surgery (radical cystectomy and ileal conduit), and radical radiotherapy. The prognosis varies depending on the stage of the cancer, with T1 having a 90% survival rate and any T, N1-N2 having a 30% survival rate.

    • This question is part of the following fields:

      • Renal System
      11.9
      Seconds
  • Question 9 - Sarah, a 30-year-old woman presents to the emergency department with severe pain in...

    Incorrect

    • Sarah, a 30-year-old woman presents to the emergency department with severe pain in her left big toe. Her first MTP joint is swollen, hot, and red. She is seen biting her nails and hitting her head against the wall. Her caregiver informs you that this is her usual behavior.

      Upon joint aspiration, negative birefringent needle-shaped crystals are found. Sarah's medical history includes a learning disability, depression, and asthma. She takes sertraline for depression and frequently uses hydrocortisone cream for eczema. Sarah does not consume red meat and prefers a vegetable-based diet.

      What factors predispose Sarah to this type of crystalline arthritis?

      Your Answer: Lack of red meat in the diet

      Correct Answer: Lesch-Nyhan syndrome

      Explanation:

      If an individual with learning difficulties and a history of gout exhibits self-mutilating behaviors such as head-banging or nail-biting, it may indicate the presence of Lesch-Nyhan syndrome. However, risk factors for gout do not include sertraline, hydrocortisone, or asthma, but rather red meat consumption. Lesch-Nyhan syndrome is an X-linked recessive condition caused by a deficiency in hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) and is characterized by hyperuricemia, learning disability, self-mutilating behavior, gout, and renal failure.

      Predisposing Factors for Gout

      Gout is a type of synovitis caused by the accumulation of monosodium urate monohydrate in the synovium. This condition is triggered by chronic hyperuricaemia, which is characterized by uric acid levels exceeding 0.45 mmol/l. There are two main factors that contribute to the development of hyperuricaemia: decreased excretion of uric acid and increased production of uric acid.

      Decreased excretion of uric acid can be caused by various factors, including the use of diuretics, chronic kidney disease, and lead toxicity. On the other hand, increased production of uric acid can be triggered by myeloproliferative/lymphoproliferative disorders, cytotoxic drugs, and severe psoriasis.

      In rare cases, gout can also be caused by genetic disorders such as Lesch-Nyhan syndrome, which is characterized by hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency. This condition is x-linked recessive, which means it is only seen in boys. Lesch-Nyhan syndrome is associated with gout, renal failure, neurological deficits, learning difficulties, and self-mutilation.

      It is worth noting that aspirin in low doses (75-150mg) is not believed to have a significant impact on plasma urate levels. Therefore, the British Society for Rheumatology recommends that it should be continued if necessary for cardiovascular prophylaxis.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      14.4
      Seconds
  • Question 10 - A 56-year-old man presents to the emergency department with profuse haematemesis. Upon admission,...

    Incorrect

    • A 56-year-old man presents to the emergency department with profuse haematemesis. Upon admission, his vital signs include a temperature of 36.9ºC, oxygen saturation of 94% on air, heart rate of 124 beats per minute, respiratory rate of 26 breaths per minute, and blood pressure of 82/58 mmHg. An urgent endoscopy was performed to achieve haemostasis, revealing an ulcer on the posterior wall of the duodenum. Which artery is the most likely source of the gastrointestinal bleed?

      Your Answer: Inferior pancreaticoduodenal artery

      Correct Answer: Gastroduodenal artery

      Explanation:

      Duodenal ulcers on the posterior wall pose a risk to the gastroduodenal artery, which supplies blood to this area. The posterior wall is a common site for duodenal ulcers, and erosion of the ulcer through the duodenal wall can result in severe upper gastrointestinal bleeding. The inferior mesenteric artery, on the other hand, supplies blood to the hindgut (transverse colon, descending colon, and sigmoid colon) and does not include the duodenum. The inferior pancreaticoduodenal artery, which arises from the superior mesenteric artery, supplies the lower part of the duodenum but does not provide the majority of the blood supply to the posterior duodenal wall, which is mainly supplied by the gastroduodenal artery.

      Acute upper gastrointestinal bleeding is a common and significant medical issue that can be caused by various conditions, with oesophageal varices and peptic ulcer disease being the most common. The main symptoms include haematemesis (vomiting of blood), melena (passage of altered blood per rectum), and a raised urea level due to the protein meal of the blood. The diagnosis can be determined by identifying the specific features associated with a particular condition, such as stigmata of chronic liver disease for oesophageal varices or abdominal pain for peptic ulcer disease.

      The differential diagnosis for acute upper gastrointestinal bleeding includes oesophageal, gastric, and duodenal causes. Oesophageal varices may present with a large volume of fresh blood, while gastric ulcers may cause low volume bleeds that present as iron deficiency anaemia. Duodenal ulcers are usually posteriorly sited and may erode the gastroduodenal artery. Aorto-enteric fistula is a rare but important cause of major haemorrhage associated with high mortality in patients with previous abdominal aortic aneurysm surgery.

      The management of acute upper gastrointestinal bleeding involves risk assessment using the Glasgow-Blatchford score, which helps clinicians decide whether patients can be managed as outpatients or not. Resuscitation involves ABC, wide-bore intravenous access, and platelet transfusion if actively bleeding platelet count is less than 50 x 10*9/litre. Endoscopy should be offered immediately after resuscitation in patients with a severe bleed, and all patients should have endoscopy within 24 hours. Treatment options include repeat endoscopy, interventional radiology, and surgery for non-variceal bleeding, while terlipressin and prophylactic antibiotics should be given to patients with variceal bleeding. Band ligation should be used for oesophageal varices, and injections of N-butyl-2-cyanoacrylate for patients with gastric varices. Transjugular intrahepatic portosystemic shunts (TIPS) should be offered if bleeding from varices is not controlled with the above measures.

    • This question is part of the following fields:

      • Gastrointestinal System
      10.8
      Seconds
  • Question 11 - A 55-year-old man is having a radical gastrectomy for stomach cancer. What structure...

    Incorrect

    • A 55-year-old man is having a radical gastrectomy for stomach cancer. What structure must be divided to access the coeliac axis during the procedure?

      Your Answer: Greater omentum

      Correct Answer: Lesser omentum

      Explanation:

      The division of the lesser omentum is necessary during a radical gastrectomy as it constitutes one of the nodal stations that must be removed.

      The Coeliac Axis and its Branches

      The coeliac axis is a major artery that supplies blood to the upper abdominal organs. It has three main branches: the left gastric, hepatic, and splenic arteries. The hepatic artery further branches into the right gastric, gastroduodenal, right gastroepiploic, superior pancreaticoduodenal, and cystic arteries. Meanwhile, the splenic artery gives off the pancreatic, short gastric, and left gastroepiploic arteries. Occasionally, the coeliac axis also gives off one of the inferior phrenic arteries.

      The coeliac axis is located anteriorly to the lesser omentum and is related to the right and left coeliac ganglia, as well as the caudate process of the liver and the gastric cardia. Inferiorly, it is in close proximity to the upper border of the pancreas and the renal vein.

      Understanding the anatomy and branches of the coeliac axis is important in diagnosing and treating conditions that affect the upper abdominal organs, such as pancreatic cancer or gastric ulcers.

    • This question is part of the following fields:

      • Cardiovascular System
      68.8
      Seconds
  • Question 12 - A 23-year-old mother brings in her 6-week-old child worried about a 'growth' in...

    Incorrect

    • A 23-year-old mother brings in her 6-week-old child worried about a 'growth' in the child's abdomen. The mother is a carrier for Cori's disease.

      During the clinical examination, the healthcare provider observes hepatomegaly and a characteristic sign of Cori's disease.

      What is the distinctive sign observed?

      Your Answer: Macroglossia

      Correct Answer: Hypotonia

      Explanation:

      Cori’s disease is characterized by muscle hypotonia as a prominent feature. However, the Finkelstein sign, which is present in De Quervain’s tenosynovitis, is not observed in Cori’s disease. Additionally, hyperventilation due to lactic acidosis is a distinguishing feature of von Gierke disease rather than Cori’s disease.

      Inherited Metabolic Disorders: Types and Deficiencies

      Inherited metabolic disorders are a group of genetic disorders that affect the body’s ability to process certain substances. These disorders can be categorized into different types based on the specific substance that is affected. One type is glycogen storage disease, which is caused by deficiencies in enzymes involved in glycogen metabolism. This can lead to the accumulation of glycogen in various organs, resulting in symptoms such as hypoglycemia, lactic acidosis, and hepatomegaly.

      Another type is lysosomal storage disease, which is caused by deficiencies in enzymes involved in lysosomal metabolism. This can lead to the accumulation of various substances within lysosomes, resulting in symptoms such as hepatosplenomegaly, developmental delay, and optic atrophy. Examples of lysosomal storage diseases include Gaucher’s disease, Tay-Sachs disease, and Fabry disease.

      Finally, mucopolysaccharidoses are a group of disorders caused by deficiencies in enzymes involved in the breakdown of glycosaminoglycans. This can lead to the accumulation of these substances in various organs, resulting in symptoms such as coarse facial features, short stature, and corneal clouding. Examples of mucopolysaccharidoses include Hurler syndrome and Hunter syndrome.

      Overall, inherited metabolic disorders can have a wide range of symptoms and can affect various organs and systems in the body. Early diagnosis and treatment are important in managing these disorders and preventing complications.

    • This question is part of the following fields:

      • General Principles
      10.8
      Seconds
  • Question 13 - As a doctor in the emergency department, you are presented with a 72-year-old...

    Incorrect

    • As a doctor in the emergency department, you are presented with a 72-year-old woman who has been brought in by her carers due to a large erythematous area on her lower leg. Upon questioning, the patient reveals that she scratched her leg while gardening at her assisted living facility last week.

      Upon examination, you notice a clearly demarcated erythematous area on the lateral aspect of her right lower leg. The area is hot to touch, but the patient is comfortable at rest and not experiencing any breathlessness. Upon auscultation, her chest is clear. Her chart shows a temperature of 37.6ºC.

      The carers inform you that the patient has no allergies but has a history of type 2 diabetes. Based on the likely diagnosis, what medication should you administer immediately?

      Your Answer: Adrenaline

      Correct Answer: Flucloxacillin

      Explanation:

      It is highly unlikely that the patient has a pulmonary embolism as acute-onset breathlessness is not a common symptom of individuals with a PE. Additionally, the presence of a well-demarcated lesion on the calf and a history of skin trauma supports a diagnosis of cellulitis instead. Therefore, treatment with apixaban is not appropriate. Azithromycin would be a suitable alternative if the patient is allergic to penicillin. Although cellulitis can cause pain, providing analgesia such as paracetamol is not a primary concern.

      Understanding Cellulitis: Symptoms, Diagnosis, and Treatment

      Cellulitis is a common skin infection caused by Streptococcus pyogenes or Staphylococcus aureus. It is characterized by inflammation of the skin and subcutaneous tissues, usually on the shins, accompanied by erythema, pain, swelling, and sometimes fever. The diagnosis of cellulitis is based on clinical features, and no further investigations are required in primary care. However, bloods and blood cultures may be requested if the patient is admitted and septicaemia is suspected.

      To guide the management of patients with cellulitis, NICE Clinical Knowledge Summaries recommend using the Eron classification. Patients with Eron Class III or Class IV cellulitis, severe or rapidly deteriorating cellulitis, very young or frail patients, immunocompromised patients, patients with significant lymphoedema, or facial or periorbital cellulitis (unless very mild) should be admitted for intravenous antibiotics. Patients with Eron Class II cellulitis may not require admission if the facilities and expertise are available in the community to give intravenous antibiotics and monitor the patient.

      The first-line treatment for mild/moderate cellulitis is flucloxacillin, while clarithromycin, erythromycin (in pregnancy), or doxycycline is recommended for patients allergic to penicillin. Patients with severe cellulitis should be offered co-amoxiclav, cefuroxime, clindamycin, or ceftriaxone. Understanding the symptoms, diagnosis, and treatment of cellulitis is crucial for effective management and prevention of complications.

    • This question is part of the following fields:

      • General Principles
      9.7
      Seconds
  • Question 14 - A 32-year-old woman is being evaluated for an abdominal mass. She delivered her...

    Incorrect

    • A 32-year-old woman is being evaluated for an abdominal mass. She delivered her first child vaginally and without any issues. Biopsy results indicate the presence of differentiated fibroblasts in sheets, which is indicative of a desmoid tumor. What is a potential risk factor for this type of tumor?

      Your Answer: RET oncogene

      Correct Answer: APC mutations

      Explanation:

      Desmoid tumours are more likely to occur in individuals with APC mutations.

      Pancreatic and hepatic cancer have been linked to CA-199.

      Breast cancer is strongly linked to BRCA1 and BRCA2 mutations.

      Burkitt’s lymphoma, a high-grade B-cell neoplasm, is associated with translocation of the C-myc gene.

      Desmoid tumours are growths that arise from musculoaponeurotic structures and are made up of clonal proliferations of myofibroblasts. They are typically firm and have a tendency to infiltrate surrounding tissue. These tumours are often seen in patients with familial adenomatous polyposis coli, and are most commonly found in women after childbirth in the rectus abdominis muscle. Bi allelic APC mutations are usually present in desmoid tumours.

      The preferred treatment for desmoid tumours is radical surgical resection, although radiotherapy and chemotherapy may be considered in some cases. Non-surgical therapy is generally less effective than surgical resection. In certain cases of abdominal desmoids, observation may be preferred as some tumours may spontaneously regress. However, desmoids have a high likelihood of local recurrence. These tumours consist of sheets of differentiated fibroblasts.

    • This question is part of the following fields:

      • Gastrointestinal System
      12.8
      Seconds
  • Question 15 - A 50-year-old male presents with yellow discoloration of his nails. Upon examination, he...

    Correct

    • A 50-year-old male presents with yellow discoloration of his nails. Upon examination, he has thickened yellow toenails. Your plan of action is to treat him with terbinafine.

      What is the mechanism of action for terbinafine?

      Your Answer: Inhibits the fungal enzyme squalene epoxidase

      Explanation:

      Terbinafine causes cellular death by inhibiting the fungal enzyme squalene epoxidase and is used to treat fungal nail infections, ringworm, and pityriasis versicolor.

      Griseofulvin disrupts the mitotic spindle by interacting with microtubules.

      Amphotericin B forms a transmembrane channel by binding with ergosterol.

      Flucytosine is converted to 5-fluorouracil by cytosine deaminase, which disrupts fungal protein synthesis by inhibiting thymidylate synthase.

      Caspofungin inhibits the synthesis of beta-glucan, a major component of the fungal cell wall.

      Antifungal agents are drugs used to treat fungal infections. There are several types of antifungal agents, each with a unique mechanism of action and potential adverse effects. Azoles work by inhibiting 14α-demethylase, an enzyme that produces ergosterol, a component of fungal cell membranes. However, they can also inhibit the P450 system in the liver, leading to potential liver toxicity. Amphotericin B binds with ergosterol to form a transmembrane channel that causes leakage of monovalent ions, but it can also cause nephrotoxicity and flu-like symptoms. Terbinafine inhibits squalene epoxidase, while griseofulvin interacts with microtubules to disrupt mitotic spindle. However, griseofulvin can induce the P450 system and is teratogenic. Flucytosine is converted by cytosine deaminase to 5-fluorouracil, which inhibits thymidylate synthase and disrupts fungal protein synthesis, but it can cause vomiting. Caspofungin inhibits the synthesis of beta-glucan, a major fungal cell wall component, and can cause flushing. Nystatin binds with ergosterol to form a transmembrane channel that causes leakage of monovalent ions, but it is very toxic and can only be used topically, such as for oral thrush.

    • This question is part of the following fields:

      • General Principles
      24.1
      Seconds
  • Question 16 - A 16-year old girl comes to the clinic with a complaint of fever....

    Correct

    • A 16-year old girl comes to the clinic with a complaint of fever. Upon examination, Gram negative diplococci are observed in her blood cultures. What is the probable causative agent?

      Your Answer: Neisseria meningitidis

      Explanation:

      Meningococcus: A Unique Gram Negative Diplococcus

      Meningococcus, also known as Neisseria meningitidis, is a rare Gram negative organism that presents itself as diplococci. This means that the bacteria are paired together, forming two spherical shapes that resemble a pair of eyes. While other Neisseria species and Diphtheria are also Gram negative organisms, meningococcus is the only possible organism that presents as diplococci.

      Meningococcus is a dangerous pathogen that can cause meningitis, septicaemia, or both. It is important to note that meningococcus is not the only organism that can cause these illnesses, but it is one of the most common culprits.

      In contrast, Escherichia coli is a Gram negative rod-shaped bacterium that is not present as diplococci. It is a single organism that does not form pairs. Haemophilus influenzae are Gram negative coccobacilli, but they do not present as paired organisms. Staphylococcus aureus and Streptococcus pyogenes are both Gram positive bacteria and are not related to meningococcus.

    • This question is part of the following fields:

      • Microbiology
      19.6
      Seconds
  • Question 17 - A 68-year-old woman has a left ankle ulcer that has been present for...

    Correct

    • A 68-year-old woman has a left ankle ulcer that has been present for nine months. She had a DVT in her right leg five years ago. Upon examination, there is a 6 cm diameter slough-based ulcer on the medial malleolus without cellulitis. What investigation is required before applying compression bandaging?

      Your Answer: Ankle-brachial pressure index

      Explanation:

      Venous Ulceration and the Importance of Identifying Arterial Disease

      Venous ulcerations are a common type of ulcer that affects the lower extremities. The underlying cause of venous congestion, which can promote ulceration, is venous insufficiency. The treatment for venous ulceration involves controlling oedema, treating any infection, and compression. However, compressive dressings or devices should not be applied if the arterial circulation is impaired. Therefore, it is crucial to identify any arterial disease, and the ankle-brachial pressure index is a simple way of doing this. If indicated, one may progress to a lower limb arteriogram.

      It is important to note that there is no clinical sign of infection, and although a bacterial swab would help to rule out pathogens within the ulcer, arterial insufficiency is the more important issue. If there is a clinical suspicion of DVT, then duplex (or rarely a venogram) is indicated to decide on the indication for anticoagulation. By identifying arterial disease, healthcare professionals can ensure that appropriate treatment is provided and avoid potential complications from compressive dressings or devices.

    • This question is part of the following fields:

      • Haematology And Oncology
      15.9
      Seconds
  • Question 18 - A general practitioner wants to conduct a clinical audit on the appropriate prescription...

    Incorrect

    • A general practitioner wants to conduct a clinical audit on the appropriate prescription of aspirin for patients after a heart attack.

      Which of the following details is crucial for this audit?

      Your Answer: Literature review of existing clinical audits in the correct use of aspirin

      Correct Answer: National guidelines for correct prescription of aspirin

      Explanation:

      Clinical audit aims to enhance patient care and outcomes by systematically reviewing care against specific criteria and implementing changes accordingly.

      The process of clinical audits typically involves the following steps:

      1) Obtaining explicit criteria/standards for the issue at hand
      2) Collecting data and comparing it to the criteria
      3) Implementing changes to improve performance and compliance with the criteria
      4) Re-auditing the results to assess the effectiveness of the changes made

      To conduct a successful clinical audit, healthcare professionals need to have access to national guidelines that outline the correct prescription of aspirin, which serves as the standard for comparison.

      While a literature review of previous clinical audits can be helpful in designing an audit, it is not a necessary component of the process. Similarly, while comparing local performance against national standards can be useful, it is not a requirement for conducting a clinical audit. Finally, while staff opinions can be valuable in implementing improvement strategies, they are not the most critical piece of information for a clinical audit, which can be conducted without consulting staff.

      Understanding Clinical Audit

      Clinical audit is a process that aims to improve the quality of patient care and outcomes by systematically reviewing care against specific criteria and implementing changes. It is a quality improvement process that involves the collection and analysis of data to identify areas where improvements can be made. The process involves reviewing current practices, identifying areas for improvement, and implementing changes to improve patient care and outcomes.

      Clinical audit is an essential tool for healthcare professionals to ensure that they are providing the best possible care to their patients. It helps to identify areas where improvements can be made and provides a framework for implementing changes. The process involves a team of healthcare professionals working together to review current practices and identify areas for improvement. Once areas for improvement have been identified, changes can be implemented to improve patient care and outcomes.

      In summary, clinical audit is a quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and the implementation of change. It is an essential tool for healthcare professionals to ensure that they are providing the best possible care to their patients. By identifying areas for improvement and implementing changes, clinical audit helps to improve patient care and outcomes.

    • This question is part of the following fields:

      • General Principles
      11.1
      Seconds
  • Question 19 - A 32-year-old woman arrived at the emergency department after being bitten by a...

    Incorrect

    • A 32-year-old woman arrived at the emergency department after being bitten by a stray dog. She is worried about the possibility of developing a severe infection from the bite.

      Which organism is commonly associated with this type of injury?

      Your Answer: Staphylococcus spp

      Correct Answer: Pasteurella multocida

      Explanation:

      Polymicrobial infections are common in animal bites, with Pasteurella multocida being the most frequently isolated organism. Other organisms found in the oral cavity of animals, such as Staphylococcus spp, can also contribute to these infections.

      Animal bites are a common occurrence in everyday practice, with dogs and cats being the most frequent culprits. These bites are usually caused by multiple types of bacteria, with Pasteurella multocida being the most commonly isolated organism. To manage these bites, it is important to cleanse the wound thoroughly. Puncture wounds should not be sutured unless there is a risk of cosmesis. The current recommendation is to use co-amoxiclav, but if the patient is allergic to penicillin, doxycycline and metronidazole are recommended.

      On the other hand, human bites can cause infections from a variety of bacteria, including both aerobic and anaerobic types. Common organisms include Streptococci spp., Staphylococcus aureus, Eikenella, Fusobacterium, and Prevotella. To manage these bites, co-amoxiclav is also recommended. It is important to consider the risk of viral infections such as HIV and hepatitis C when dealing with human bites.

    • This question is part of the following fields:

      • General Principles
      69.7
      Seconds
  • Question 20 - Which of the following medications used in the treatment of hyperlipidemia is most...

    Incorrect

    • Which of the following medications used in the treatment of hyperlipidemia is most likely to cause flushing?

      Your Answer: Atorvastatin

      Correct Answer: Nicotinic acid

      Explanation:

      Side-effects of drugs used in hyperlipidaemia

      Hyperlipidaemia is a condition characterized by high levels of lipids in the blood. Drugs used to treat this condition have different mechanisms of action and can cause various adverse effects. Statins, which are HMG CoA reductase inhibitors, work by reducing the production of cholesterol in the liver. However, they can cause myositis (muscle inflammation) and deranged liver function tests (LFTs). Ezetimibe, on the other hand, decreases cholesterol absorption in the small intestine, but it can cause headaches. Nicotinic acid decreases hepatic VLDL secretion, but it can cause flushing and myositis. Fibrates, which are agonists of PPAR-alpha and increase lipoprotein lipase expression, can cause myositis, pruritus, and cholestasis. Cholestyramine decreases bile acid reabsorption in the small intestine, upregulating the amount of cholesterol that is converted to bile acid, but it can cause gastrointestinal side-effects. It is important to weigh the benefits and risks of each drug when choosing a treatment for hyperlipidaemia.

      Overall, the table above summarizes the different mechanisms of action and adverse effects of drugs used in hyperlipidaemia. It is important to note that each drug has its own set of benefits and risks, and patients should discuss their options with their healthcare provider to determine the best course of treatment. Proper monitoring and management of adverse effects can help ensure the safety and effectiveness of these medications.

    • This question is part of the following fields:

      • General Principles
      34.7
      Seconds
  • Question 21 - A 67-year-old female smoker with a two-month history of worsening shortness of breath...

    Incorrect

    • A 67-year-old female smoker with a two-month history of worsening shortness of breath presents for evaluation. On examination, she appears comfortable at rest with a regular pulse of 72 bpm, respiratory rate of 16/min, and blood pressure of 128/82 mmHg. Physical findings include reduced expansion on the left lower zone, dullness to percussion over this area, and absent breath sounds over the left lower zone with bronchial breath sounds just above this region. What is the likely clinical diagnosis?

      Your Answer: Pulmonary fibrosis

      Correct Answer: Pleural effusion

      Explanation:

      Pleural Effusion and its Investigation

      Pleural effusion is a condition where there is an abnormal accumulation of fluid in the pleural space, which is the space between the lungs and the chest wall. This can be caused by various factors such as post-infection, carcinoma, or emboli. To determine the cause of the pleural effusion, a pleural tap is the most appropriate investigation. The sample obtained from the pleural tap is sent for cytology, protein concentration, and culture.

      A normal pleural tap would have clear appearance, pH of 7.60-7.64, protein concentration of less than 2%, white blood cells count of less than 1000/mm³, glucose level similar to that of plasma, LDH level of less than 50% of plasma concentration, amylase level of 30-110 U/L, triglycerides level of less than 2 mmol/l, and cholesterol level of 3.5-6.5 mmol/l.

      A transudative tap is associated with conditions such as congestive heart failure, liver cirrhosis, severe hypoalbuminemia, and nephrotic syndrome. On the other hand, an exudative tap is associated with malignancy, infection (such as empyema due to bacterial pneumonia), trauma, pulmonary infarction, and pulmonary embolism.

      In summary, pleural effusion can be caused by various factors and a pleural tap is the most appropriate investigation to determine the cause. The results of the pleural tap can help differentiate between transudative and exudative effusions, which can provide important information for diagnosis and treatment.

    • This question is part of the following fields:

      • Respiratory System
      14.7
      Seconds
  • Question 22 - At what stage does the sciatic nerve typically divide into the tibial and...

    Correct

    • At what stage does the sciatic nerve typically divide into the tibial and common peroneal nerves?

      Your Answer: At the superior aspect of the popliteal fossa

      Explanation:

      The path of the sciatic nerve begins at the posterior surface of the obturator internus and quadratus femoris, where it descends vertically towards the hamstring compartment of the thigh. As it reaches this area, it is crossed by the long head of biceps femoris. Moving towards the buttock, the nerve is covered by the gluteus maximus. Finally, it splits into its tibial and common peroneal components at the upper part of the popliteal fossa.

      Understanding the Sciatic Nerve

      The sciatic nerve is the largest nerve in the body, formed from the sacral plexus and arising from spinal nerves L4 to S3. It passes through the greater sciatic foramen and emerges beneath the piriformis muscle, running under the cover of the gluteus maximus muscle. The nerve provides cutaneous sensation to the skin of the foot and leg, as well as innervating the posterior thigh muscles and lower leg and foot muscles. Approximately halfway down the posterior thigh, the nerve splits into the tibial and common peroneal nerves. The tibial nerve supplies the flexor muscles, while the common peroneal nerve supplies the extensor and abductor muscles.

      The sciatic nerve also has articular branches for the hip joint and muscular branches in the upper leg, including the semitendinosus, semimembranosus, biceps femoris, and part of the adductor magnus. Cutaneous sensation is provided to the posterior aspect of the thigh via cutaneous nerves, as well as the gluteal region and entire lower leg (except the medial aspect). The nerve terminates at the upper part of the popliteal fossa by dividing into the tibial and peroneal nerves. The nerve to the short head of the biceps femoris comes from the common peroneal part of the sciatic, while the other muscular branches arise from the tibial portion. The tibial nerve goes on to innervate all muscles of the foot except the extensor digitorum brevis, which is innervated by the common peroneal nerve.

    • This question is part of the following fields:

      • Neurological System
      111.8
      Seconds
  • Question 23 - A 6-year-old girl trips and obtains a significant abrasion on her knee. Can...

    Incorrect

    • A 6-year-old girl trips and obtains a significant abrasion on her knee. Can you provide the correct sequence of vascular changes that occur in her knee after the injury?

      Your Answer: Vasodilation, vasoconstriction, increased permeability of vessels, stasis of red blood cells, eosinophil margination

      Correct Answer: Vasoconstriction, vasodilation, increased permeability of vessels, stasis of red blood cells, neutrophil margination

      Explanation:

      Acute inflammation is a response to cell injury in vascularized tissue. It is triggered by chemical factors produced in response to a stimulus, such as fibrin, antibodies, bradykinin, and the complement system. The goal of acute inflammation is to neutralize the offending agent and initiate the repair process. The main characteristics of inflammation are fluid exudation, exudation of plasma proteins, and migration of white blood cells.

      The vascular changes that occur during acute inflammation include transient vasoconstriction, vasodilation, increased permeability of vessels, RBC concentration, and neutrophil margination. These changes are followed by leukocyte extravasation, margination, rolling, and adhesion of neutrophils, transmigration across the endothelium, and migration towards chemotactic stimulus.

      Leukocyte activation is induced by microbes, products of necrotic cells, antigen-antibody complexes, production of prostaglandins, degranulation and secretion of lysosomal enzymes, cytokine secretion, and modulation of leukocyte adhesion molecules. This leads to phagocytosis and termination of the acute inflammatory response.

    • This question is part of the following fields:

      • General Principles
      10
      Seconds
  • Question 24 - A 35-year-old man arrives at the emergency department with chest pain. He confesses...

    Incorrect

    • A 35-year-old man arrives at the emergency department with chest pain. He confesses to using cocaine. Upon examination, his heart rate is 110 bpm and his blood pressure is 118/76 mmHg. An ECG reveals T wave inversion in leads V3-V6. What part of his heart has been impacted?

      Your Answer: Inferior

      Correct Answer: Anterolateral

      Explanation:

      ECG Leads and Myocardial Infarction

      The T wave inversion on an electrocardiogram (ECG) can indicate a non-ST elevation myocardial infarction (MI) caused by cocaine abuse. The ECG has different leads that correspond to different areas of the heart. The septal leads are V1-V2, the anterior leads are V3-V4, the lateral leads are V5-V6, I, and aVL, and the inferior leads are II, III, and aVF. However, detecting posterior infarcts on a 12-lead ECG can be challenging. Some medical centers use additional ECG leads V7-9 to help identify posterior infarcts.

    • This question is part of the following fields:

      • Clinical Sciences
      38.7
      Seconds
  • Question 25 - A 10-month-old girl arrives at the emergency department with cough and nasal congestion....

    Incorrect

    • A 10-month-old girl arrives at the emergency department with cough and nasal congestion. The triage nurse records a temperature of 38.2ºC. Which area of the brain is accountable for the observed physiological anomaly in this infant?

      Your Answer: Thalamus

      Correct Answer: Hypothalamus

      Explanation:

      The hypothalamus is responsible for regulating body temperature, as it controls thermoregulation. It responds to pyrogens produced during infections, which induce the synthesis of prostaglandins that bind to receptors in the hypothalamus and raise body temperature. The cerebellum, limbic system, and pineal gland are not involved in temperature control.

      The hypothalamus is a part of the brain that plays a crucial role in maintaining the body’s internal balance, or homeostasis. It is located in the diencephalon and is responsible for regulating various bodily functions. The hypothalamus is composed of several nuclei, each with its own specific function. The anterior nucleus, for example, is involved in cooling the body by stimulating the parasympathetic nervous system. The lateral nucleus, on the other hand, is responsible for stimulating appetite, while lesions in this area can lead to anorexia. The posterior nucleus is involved in heating the body and stimulating the sympathetic nervous system, and damage to this area can result in poikilothermia. Other nuclei include the septal nucleus, which regulates sexual desire, the suprachiasmatic nucleus, which regulates circadian rhythm, and the ventromedial nucleus, which is responsible for satiety. Lesions in the paraventricular nucleus can lead to diabetes insipidus, while lesions in the dorsomedial nucleus can result in savage behavior.

    • This question is part of the following fields:

      • Neurological System
      12.9
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  • Question 26 - What is the term used to describe a drug that binds to the...

    Correct

    • What is the term used to describe a drug that binds to the same receptor as an agonist but is unable to produce a comparable effect even with increasing doses?

      Your Answer: Partial agonist

      Explanation:

      Agonists, Antagonists, and Partial Agonists

      Agonists, antagonists, and partial agonists are terms used to describe drugs that interact with receptors in the body. Competitive antagonists work by binding to the same receptor site as the agonist, preventing it from binding and producing its effect. However, increasing the concentration of the agonist can overcome this effect.

      Allosteric drugs, on the other hand, act at a site separate from the receptor site of the agonist. This can either enhance or inhibit the effect of the agonist. Partial agonists, like buprenorphine, produce a weaker effect than a full agonist. When combined with a full agonist, like morphine, the overall effect is decreased, leading to poor pain control.

      the differences between agonists, antagonists, and partial agonists is important in the development and use of drugs for various medical conditions. By targeting specific receptors in the body, these drugs can produce a desired effect or block unwanted effects. Proper dosing and combination of these drugs can lead to effective treatment and management of various conditions.

    • This question is part of the following fields:

      • Pharmacology
      18
      Seconds
  • Question 27 - A 35-year-old man is diagnosed with a DVT in his right leg, which...

    Incorrect

    • A 35-year-old man is diagnosed with a DVT in his right leg, which is determined to be caused by a genetic disorder. What is the most prevalent hereditary factor leading to DVT?

      Your Answer: Von Willebrand disease

      Correct Answer: Factor V Leiden

      Explanation:

      Deep vein thrombosis is a condition that occurs more frequently in Caucasians than in people of black African, Far East Asian, native Australian, and native American origin. The most common heritable causes of DVT, in descending order, are Factor V Leiden, Prothrombin G20210A variant, Protein C deficiency, Protein S deficiency, and Antithrombin deficiency. However, Von Willebrand disease and thalassaemia are not associated with DVT.

      Understanding Factor V Leiden

      Factor V Leiden is a common inherited thrombophilia, affecting around 5% of the UK population. It is caused by a mutation in the Factor V Leiden protein, resulting in activated factor V being inactivated 10 times more slowly by activated protein C than normal. This leads to activated protein C resistance, which increases the risk of venous thrombosis. Heterozygotes have a 4-5 fold risk of venous thrombosis, while homozygotes have a 10 fold risk, although the prevalence of homozygotes is much lower at 0.05%.

      Despite its prevalence, screening for Factor V Leiden is not recommended, even after a venous thromboembolism. This is because a previous thromboembolism itself is a risk factor for further events, and specific management should be based on this rather than the particular thrombophilia identified.

      Other inherited thrombophilias include Prothrombin gene mutation, Protein C deficiency, Protein S deficiency, and Antithrombin III deficiency. The table below shows the prevalence and relative risk of venous thromboembolism for each of these conditions.

      Overall, understanding Factor V Leiden and other inherited thrombophilias can help healthcare professionals identify individuals at higher risk of venous thrombosis and provide appropriate management to prevent future events.

      Condition | Prevalence | Relative risk of VTE
      — | — | —
      Factor V Leiden (heterozygous) | 5% | 4
      Factor V Leiden (homozygous) | 0.05% | 10
      Prothrombin gene mutation (heterozygous) | 1.5% | 3
      Protein C deficiency | 0.3% | 10
      Protein S deficiency | 0.1% | 5-10
      Antithrombin III deficiency | 0.02% | 10-20

    • This question is part of the following fields:

      • Haematology And Oncology
      10.6
      Seconds
  • Question 28 - In a 70 Kg person, what percentage of the entire body fluid will...

    Correct

    • In a 70 Kg person, what percentage of the entire body fluid will be provided by plasma?

      Your Answer: 5%

      Explanation:

      Understanding the Physiology of Body Fluid Compartments

      Body fluid compartments are essential components of the human body, consisting of intracellular and extracellular compartments. The extracellular compartment is further divided into interstitial fluid, plasma, and transcellular fluid. In a typical 70 Kg male, the intracellular compartment comprises 60-65% of the total body fluid volume, while the extracellular compartment comprises 35-40%. The plasma volume is approximately 5%, while the interstitial fluid volume is 24%. The transcellular fluid volume is approximately 3%. These figures are only approximate and may vary depending on the individual’s weight and other factors. Understanding the physiology of body fluid compartments is crucial in maintaining proper fluid balance and overall health.

    • This question is part of the following fields:

      • Renal System
      19.4
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  • Question 29 - A 28-year-old woman, who is 12 weeks pregnant, arrives at the Emergency Department...

    Correct

    • A 28-year-old woman, who is 12 weeks pregnant, arrives at the Emergency Department complaining of severe nausea and general malaise. She has not undergone a booking scan. After conducting an ultrasound, you observe that her uterus appears larger than expected for her gestational age. What is the probable diagnosis?

      Your Answer: Molar pregnancy

      Explanation:

      A uterus that is larger than expected for the stage of pregnancy is a strong indication of a molar pregnancy. The patient is experiencing hyperemesis and overall discomfort, which can be attributed to the elevated levels of B-hcG in her bloodstream, as confirmed by a blood test.

      Gestational trophoblastic disorders refer to a range of conditions that originate from the placental trophoblast. These disorders include complete hydatidiform mole, partial hydatidiform mole, and choriocarcinoma. Complete hydatidiform mole is a benign tumor of trophoblastic material that occurs when an empty egg is fertilized by a single sperm that duplicates its own DNA, resulting in all 46 chromosomes being of paternal origin. Symptoms of this disorder include bleeding in the first or early second trimester, exaggerated pregnancy symptoms, a large uterus for dates, and high levels of human chorionic gonadotropin (hCG) in the blood. Hypertension and hyperthyroidism may also be present. Urgent referral to a specialist center is necessary, and evacuation of the uterus is performed. Effective contraception is recommended to avoid pregnancy in the next 12 months. About 2-3% of cases may progress to choriocarcinoma. In partial mole, a normal haploid egg may be fertilized by two sperms or one sperm with duplication of paternal chromosomes, resulting in DNA that is both maternal and paternal in origin. Fetal parts may be visible, and the condition is usually triploid.

    • This question is part of the following fields:

      • Reproductive System
      80.4
      Seconds
  • Question 30 - A 68-year-old male comes to the emergency department complaining of double vision. He...

    Incorrect

    • A 68-year-old male comes to the emergency department complaining of double vision. He has a history of diabetes. During the examination, it is observed that his left eye is pointing downwards and outwards, and he is unable to move it. What is the probable cause of this?

      Your Answer: Optic nerve palsy

      Correct Answer: Oculomotor nerve palsy

      Explanation:

      The eye can move in three different planes – vertical, horizontal, and torsional. Torsion can be further divided into intorsion and extorsion. The six extraocular muscles are responsible for these movements. The medial rectus adducts, while the lateral rectus abducts. The superior rectus primarily elevates and controls intorsion, while the inferior rectus primarily depresses and controls extorsion.

      The superior and inferior oblique muscles are responsible for torsion movements. The superior oblique controls intorsion and depression, while the inferior oblique controls extorsion.

      Most of the extraocular muscles are innervated by the oculomotor nerve, except for the superior oblique (innervated by the trochlear nerve) and the lateral rectus (innervated by the abducens nerve).

      When considering the options for a question, we can exclude the optic nerve and long ciliary nerve as they are not involved in eye movement. Trochlear nerve palsy would result in impaired intorsion, while abducens nerve palsy would result in impaired abduction. However, a down and out eye is typically associated with oculomotor nerve palsy.

      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
      18.9
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SESSION STATS - PERFORMANCE PER SPECIALTY

Haematology And Oncology (1/3) 33%
Reproductive System (2/2) 100%
Musculoskeletal System And Skin (1/4) 25%
General Principles (1/8) 13%
Cardiovascular System (0/2) 0%
Renal System (1/2) 50%
Gastrointestinal System (0/2) 0%
Microbiology (1/1) 100%
Respiratory System (0/1) 0%
Neurological System (1/3) 33%
Clinical Sciences (0/1) 0%
Pharmacology (1/1) 100%
Passmed