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  • Question 1 - A new medication is being tested for its potential benefits in improving 30-day...

    Incorrect

    • A new medication is being tested for its potential benefits in improving 30-day survival rates after a heart attack in patients over the age of 60. In a study of 1500 patients over the age of 60 who have had a heart attack, 600 are given the new medication and 900 are given a placebo.

      Among the group given the new medication, 20 patients die within 30 days. Among the group given the placebo, 80 patients die within 30 days.

      What is the number needed to treat?

      Your Answer: 3

      Correct Answer: 20

      Explanation:

      Numbers needed to treat (NNT) is a measure that determines how many patients need to receive a particular intervention to reduce the expected number of outcomes by one. To calculate NNT, you divide 1 by the absolute risk reduction (ARR) and round up to the nearest whole number. ARR can be calculated by finding the absolute difference between the control event rate (CER) and the experimental event rate (EER). There are two ways to calculate ARR, depending on whether the outcome of the study is desirable or undesirable. If the outcome is undesirable, then ARR equals CER minus EER. If the outcome is desirable, then ARR is equal to EER minus CER. It is important to note that ARR may also be referred to as absolute benefit increase.

    • This question is part of the following fields:

      • General Principles
      63.7
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  • Question 2 - A 28-year-old woman presents to the Emergency Department complaining of a headache and...

    Incorrect

    • A 28-year-old woman presents to the Emergency Department complaining of a headache and blurred vision. The headache began 2 days ago and is aggravated by coughing and changing position. The blurred vision started 5 hours ago. She has no history of head injuries and has never experienced these symptoms before. Her BMI is 27 kg/m² and she is currently taking the combined oral contraceptive pill.

      Upon examination, the patient has difficulty abducting her left eye. Fundoscopy reveals bilateral papilloedema.

      Vital signs:
      Blood pressure: 130/90 mmHg
      Heart rate: 80 bpm
      Respiratory rate: 16/min

      What is the most probable diagnosis?

      Your Answer: Acute-angle closure glaucoma

      Correct Answer: Idiopathic intracranial hypertension

      Explanation:

      The patient’s difficulty in abducting the right eye and accompanying 6th nerve palsy, along with papilloedema, are indicative of idiopathic intracranial hypertension. This is further supported by the patient’s age, BMI, and COCP use, which are common risk factors for this condition. Acute-angle closure glaucoma, meningitis, and migraine are less likely explanations as they do not fully align with the patient’s symptoms and history.

      Understanding Idiopathic Intracranial Hypertension

      Idiopathic intracranial hypertension, also known as pseudotumour cerebri, is a medical condition that is commonly observed in young, overweight females. The condition is characterized by a range of symptoms, including headache, blurred vision, and papilloedema, which is usually present. Other symptoms may include an enlarged blind spot and sixth nerve palsy.

      There are several risk factors associated with idiopathic intracranial hypertension, including obesity, female sex, pregnancy, and certain drugs such as the combined oral contraceptive pill, steroids, tetracyclines, vitamin A, and lithium.

      Management of idiopathic intracranial hypertension may involve weight loss, diuretics such as acetazolamide, and topiramate, which can also cause weight loss in most patients. Repeated lumbar puncture may also be necessary, and surgery may be required to prevent damage to the optic nerve. This may involve optic nerve sheath decompression and fenestration, or a lumboperitoneal or ventriculoperitoneal shunt to reduce intracranial pressure.

      It is important to note that if intracranial hypertension is thought to occur secondary to a known cause, such as medication, it is not considered idiopathic. Understanding the risk factors and symptoms associated with idiopathic intracranial hypertension can help individuals seek appropriate medical attention and management.

    • This question is part of the following fields:

      • Neurological System
      23.4
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  • Question 3 - A 12-year-old girl comes to the clinic with an itchy rash on her...

    Incorrect

    • A 12-year-old girl comes to the clinic with an itchy rash on her knees. The rash appears red and there are marks from scratching. She has a history of seasonal allergies and tends to have dry skin. The doctor diagnoses her with eczema and prescribes hydrocortisone. The doctor also informs her that there are specific triggers that she may be hypersensitive to, such as dust. What is the antibody responsible for mediating type 1 hypersensitivity?

      Your Answer: IgA

      Correct Answer: IgE

      Explanation:

      Type 1 hypersensitivity is mediated by IgE, which binds to the Fc receptors of Mast cells, resulting in their activation. IgG and other antibodies do not play a significant role in this type of hypersensitivity reaction.

      Classification of Hypersensitivity Reactions

      Hypersensitivity reactions are classified into four types according to the Gell and Coombs classification. Type I, also known as anaphylactic hypersensitivity, occurs when an antigen reacts with IgE bound to mast cells. This type of reaction is commonly seen in atopic conditions such as asthma, eczema, and hay fever. Type II hypersensitivity occurs when cell-bound IgG or IgM binds to an antigen on the cell surface, leading to autoimmune conditions such as autoimmune hemolytic anemia, ITP, and Goodpasture’s syndrome. Type III hypersensitivity occurs when free antigen and antibody (IgG, IgA) combine to form immune complexes, leading to conditions such as serum sickness, systemic lupus erythematosus, and post-streptococcal glomerulonephritis. Type IV hypersensitivity is T-cell mediated and includes conditions such as tuberculosis, graft versus host disease, and allergic contact dermatitis.

      In recent times, a fifth category has been added to the classification of hypersensitivity reactions. Type V hypersensitivity occurs when antibodies recognize and bind to cell surface receptors, either stimulating them or blocking ligand binding. This type of reaction is seen in conditions such as Graves’ disease and myasthenia gravis. Understanding the classification of hypersensitivity reactions is important in the diagnosis and management of these conditions.

    • This question is part of the following fields:

      • General Principles
      17.3
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  • Question 4 - Sarah is a 65-year-old patient with decompensated liver cirrhosis. Two years ago she...

    Incorrect

    • Sarah is a 65-year-old patient with decompensated liver cirrhosis. Two years ago she had variceal bleed, for which she has been taking propranolol and received endoscopic variceal ligation. Sarah presents to the emergency department with haematemesis and a recurrent oesophageal variceal bleed is suspected.

      What emergency surgery is necessary in this case?

      Your Answer: Oesophagectomy

      Correct Answer: Transjugular intrahepatic portosystemic shunt (TIPS) procedure

      Explanation:

      To address recurrent variceal haemorrhage despite optimal medical therapy, a TIPS procedure may be performed. This involves linking the hepatic vein to the portal vein, which helps to alleviate the complications associated with portal hypertension.

      Variceal haemorrhage is a serious condition that requires prompt and effective management. The initial treatment involves resuscitation of the patient, correction of clotting abnormalities, and administration of vasoactive agents such as terlipressin or octreotide. Prophylactic IV antibiotics are also recommended to reduce mortality in patients with liver cirrhosis. Endoscopic variceal band ligation is the preferred method for controlling bleeding, and the use of a Sengstaken-Blakemore tube or Transjugular Intrahepatic Portosystemic Shunt (TIPSS) may be necessary if bleeding cannot be controlled. However, TIPSS can lead to exacerbation of hepatic encephalopathy, which is a common complication.

      To prevent variceal haemorrhage, prophylactic measures such as propranolol and endoscopic variceal band ligation (EVL) are recommended. Propranolol has been shown to reduce rebleeding and mortality compared to placebo. EVL is superior to endoscopic sclerotherapy and should be performed at two-weekly intervals until all varices have been eradicated. Proton pump inhibitor cover is given to prevent EVL-induced ulceration. NICE guidelines recommend offering endoscopic variceal band ligation for the primary prevention of bleeding for people with cirrhosis who have medium to large oesophageal varices.

    • This question is part of the following fields:

      • Gastrointestinal System
      64.3
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  • Question 5 - Which one of the following triggers the production of stomach acid? ...

    Incorrect

    • Which one of the following triggers the production of stomach acid?

      Your Answer: Somatostatin

      Correct Answer: Histamine

      Explanation:

      Gastrin is produced by G cells and stimulates the production of gastric acid. Pepsin is responsible for digesting protein and is secreted simultaneously with gastrin. Secretin, produced by mucosal cells in the duodenum and jejunum, inhibits gastric acid production and stimulates the production of bile and pancreatic juice. Gastric inhibitory peptide, produced in response to fatty acids, inhibits the release of gastrin and acid secretion from parietal cells. Cholecystokinin, also produced by mucosal cells in the duodenum and jejunum in response to fatty acids, inhibits acid secretion from parietal cells and causes the gallbladder to contract while relaxing the sphincter of Oddi.

      Overview of Gastrointestinal Hormones

      Gastrointestinal hormones play a crucial role in the digestion and absorption of food. These hormones are secreted by various cells in the stomach and small intestine in response to different stimuli such as the presence of food, pH changes, and neural signals.

      One of the major hormones involved in food digestion is gastrin, which is secreted by G cells in the antrum of the stomach. Gastrin increases acid secretion by gastric parietal cells, stimulates the secretion of pepsinogen and intrinsic factor, and increases gastric motility. Another hormone, cholecystokinin (CCK), is secreted by I cells in the upper small intestine in response to partially digested proteins and triglycerides. CCK increases the secretion of enzyme-rich fluid from the pancreas, contraction of the gallbladder, and relaxation of the sphincter of Oddi. It also decreases gastric emptying and induces satiety.

      Secretin is another hormone secreted by S cells in the upper small intestine in response to acidic chyme and fatty acids. Secretin increases the secretion of bicarbonate-rich fluid from the pancreas and hepatic duct cells, decreases gastric acid secretion, and has a trophic effect on pancreatic acinar cells. Vasoactive intestinal peptide (VIP) is a neural hormone that stimulates secretion by the pancreas and intestines and inhibits acid secretion.

      Finally, somatostatin is secreted by D cells in the pancreas and stomach in response to fat, bile salts, and glucose in the intestinal lumen. Somatostatin decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion, and decreases insulin and glucagon secretion. It also inhibits the trophic effects of gastrin and stimulates gastric mucous production.

      In summary, gastrointestinal hormones play a crucial role in regulating the digestive process and maintaining homeostasis in the gastrointestinal tract.

    • This question is part of the following fields:

      • Gastrointestinal System
      7.9
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  • Question 6 - A 26-year-old female presents to her physician complaining of tingling in her left...

    Incorrect

    • A 26-year-old female presents to her physician complaining of tingling in her left arm and double vision for the past three days. She reports feeling fatigued for the past six months. She has no significant medical history and is not taking any medications. She smokes five cigarettes per day, drinks one bottle of wine per week, and works as a journalist.

      During the neurological examination, the physician observed reduced sensation in the patient's left upper limb. Additionally, the patient's right eye failed to adduct and her left eye demonstrated nystagmus on left lateral gaze. Based on these findings, where is the anatomical location of the lesion causing the eye signs on examination likely to be?

      Your Answer: Mamillary bodies

      Correct Answer: Medial longitudinal fasciculus

      Explanation:

      The correct answer is the medial longitudinal fasciculus, which is a myelinated structure located in the brainstem responsible for conjugate eye movements. In this case, the patient’s symptoms and examination findings suggest a diagnosis of internuclear ophthalmoplegia, which is a disorder of conjugate lateral gaze caused by a lesion in the medial longitudinal fasciculus. This is often associated with multiple sclerosis. The affected eye fails to adduct when attempting to look contralaterally, and the contralateral eye demonstrates nystagmus. Mamillary bodies, neuromuscular junction, and optic nerve are not the likely causes of the patient’s symptoms.

      Understanding Internuclear Ophthalmoplegia

      Internuclear ophthalmoplegia is a condition that affects the horizontal movement of the eyes. It is caused by a lesion in the medial longitudinal fasciculus (MLF), which is responsible for interconnecting the IIIrd, IVth, and VIth cranial nuclei. This area is located in the paramedian region of the midbrain and pons. The main feature of this condition is impaired adduction of the eye on the same side as the lesion, along with horizontal nystagmus of the abducting eye on the opposite side.

      The most common causes of internuclear ophthalmoplegia are multiple sclerosis and vascular disease. It is important to note that this condition can also be a sign of other underlying neurological disorders.

    • This question is part of the following fields:

      • Neurological System
      38.4
      Seconds
  • Question 7 - A 58-year-old woman arrives at the emergency department complaining of persistent nausea and...

    Incorrect

    • A 58-year-old woman arrives at the emergency department complaining of persistent nausea and vomiting for the past 4 days. Despite taking cyclizine and metoclopramide, she has not experienced any relief. The patient is currently under palliative care for lung cancer with cerebral metastases.

      Upon consultation with the palliative care team, it is decided to administer a steroid with potent glucocorticoid activity and minimal mineralocorticoid activity.

      What medication is the patient expected to receive?

      Your Answer: Methylprednisolone

      Correct Answer: Dexamethasone

      Explanation:

      Dexamethasone is the most suitable example of a steroid that has very high glucocorticoid activity and minimal mineralocorticoid activity among the given options.

      Corticosteroids are commonly prescribed medications that can be taken orally or intravenously, or applied topically. They mimic the effects of natural steroids in the body and can be used to replace or supplement them. However, the use of corticosteroids is limited by their numerous side effects, which are more common with prolonged and systemic use. These side effects can affect various systems in the body, including the endocrine, musculoskeletal, gastrointestinal, ophthalmic, and psychiatric systems. Some of the most common side effects include impaired glucose regulation, weight gain, osteoporosis, and increased susceptibility to infections. Patients on long-term corticosteroids should have their doses adjusted during intercurrent illness, and the medication should not be abruptly withdrawn to avoid an Addisonian crisis. Gradual withdrawal is recommended for patients who have received high doses or prolonged treatment.

    • This question is part of the following fields:

      • Endocrine System
      22.8
      Seconds
  • Question 8 - A 70-year-old man comes to the Parkinson clinic for a levodopa review. In...

    Correct

    • A 70-year-old man comes to the Parkinson clinic for a levodopa review. In Parkinson's disease, which region of the basal ganglia is most affected?

      Your Answer: Substantia nigra pars compacta

      Explanation:

      Parkinson’s disease primarily affects the basal ganglia, which is responsible for movement. Within the basal ganglia, the substantia nigra is a crucial component that plays a significant role in movement and reward. The dopaminergic neurons in the substantia nigra, which contain high levels of neuromelanin, function through the indirect pathway to facilitate movement. However, these neurons are the ones most impacted by Parkinson’s disease. The substantia nigra gets its name from its dark appearance, which is due to the abundance of neuromelanin in its neurons.

      Parkinson’s disease is a progressive neurodegenerative disorder that occurs due to the degeneration of dopaminergic neurons in the substantia nigra. This leads to a classic triad of symptoms, including bradykinesia, tremor, and rigidity, which are typically asymmetrical. The disease is more common in men and is usually diagnosed around the age of 65. Bradykinesia is characterized by a poverty of movement, shuffling steps, and difficulty initiating movement. Tremors are most noticeable at rest and typically occur in the thumb and index finger. Rigidity can be either lead pipe or cogwheel, and other features include mask-like facies, flexed posture, and drooling of saliva. Psychiatric features such as depression, dementia, and sleep disturbances may also occur. Diagnosis is usually clinical, but if there is difficulty differentiating between essential tremor and Parkinson’s disease, 123I‑FP‑CIT single photon emission computed tomography (SPECT) may be considered.

    • This question is part of the following fields:

      • Neurological System
      5
      Seconds
  • Question 9 - A 75-year-old man with a long-standing history of type 2 diabetes mellitus presents...

    Incorrect

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

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

      Your Answer: Increased tone, decreased reflexes, clonus

      Correct Answer: Decreased reflexes, fasciculations, decreased tone

      Explanation:

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

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

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

    • This question is part of the following fields:

      • Neurological System
      3
      Seconds
  • Question 10 - A 30-year-old woman visits her GP complaining of left thigh pain, tingling, and...

    Incorrect

    • A 30-year-old woman visits her GP complaining of left thigh pain, tingling, and numbness that have been gradually worsening for the past 2 months. She points to the lateral and posterior aspects of her left thigh when asked to indicate the affected area. There is no history of leg or hip injury. During the examination, she demonstrates full range of motion in both hips, and her power is 5/5.

      What nerve is the most probable cause of her injury?

      Your Answer:

      Correct Answer: Lateral cutaneous nerve of the thigh

      Explanation:

      The correct answer is the lateral cutaneous nerve of the thigh. The patient’s symptoms suggest meralgia paraesthetica, which is caused by compression of the nerve near the ASIS. The location of the tingling and numbness, as well as the absence of motor symptoms, point towards this diagnosis.

      The femoral nerve, obturator nerve, and sciatic nerve are not the correct answers. Each of these nerves would cause different symptoms and are typically injured in different ways.

      Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteral lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 11 - A 15-year-old male arrives at the emergency department with complaints of abdominal pain,...

    Incorrect

    • A 15-year-old male arrives at the emergency department with complaints of abdominal pain, nausea, and shortness of breath. He has a history of insulin-dependent diabetes and is diagnosed with diabetic ketoacidosis after undergoing tests. During treatment, which electrolyte should you be particularly cautious of, as it may become depleted in the body despite appearing normal in plasma concentrations?

      Your Answer:

      Correct Answer: Potassium

      Explanation:

      Insulin normally helps to move potassium into cells, but in a state of ketoacidosis, there is a lack of insulin to perform this function. As a result, potassium leaks out of cells. Additionally, high levels of glucose in the blood lead to glycosuria in the urine, causing potassium loss through the kidneys.

      Even though patients in a ketoacidotic state may have normal levels of potassium in their blood, their overall potassium levels in the body are often depleted. When insulin is administered to these patients, it can cause a dangerous drop in potassium levels as the minimal amount of potassium left in the body is driven into cells.

      Diabetic ketoacidosis (DKA) is a serious complication of type 1 diabetes mellitus, accounting for around 6% of cases. It can also occur in rare cases of extreme stress in patients with type 2 diabetes mellitus. DKA is caused by uncontrolled lipolysis, resulting in an excess of free fatty acids that are converted to ketone bodies. The most common precipitating factors of DKA are infection, missed insulin doses, and myocardial infarction. Symptoms include abdominal pain, polyuria, polydipsia, dehydration, Kussmaul respiration, and breath that smells like acetone. Diagnostic criteria include glucose levels above 11 mmol/l or known diabetes mellitus, pH below 7.3, bicarbonate below 15 mmol/l, and ketones above 3 mmol/l or urine ketones ++ on dipstick.

      Management of DKA involves fluid replacement, insulin, and correction of electrolyte disturbance. Fluid replacement is necessary as most patients with DKA are deplete around 5-8 litres. Isotonic saline is used initially, even if the patient is severely acidotic. Insulin is administered through an intravenous infusion, and correction of electrolyte disturbance is necessary. Long-acting insulin should be continued, while short-acting insulin should be stopped. Complications may occur from DKA itself or the treatment, such as gastric stasis, thromboembolism, arrhythmias, acute respiratory distress syndrome, acute kidney injury, and cerebral edema. Children and young adults are particularly vulnerable to cerebral edema following fluid resuscitation in DKA and often need 1:1 nursing to monitor neuro-observations, headache, irritability, visual disturbance, focal neurology, etc.

    • This question is part of the following fields:

      • Endocrine System
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  • Question 12 - Liam is a 5-year-old boy playing outside in the park on his scooter....

    Incorrect

    • Liam is a 5-year-old boy playing outside in the park on his scooter. He accidentally falls off his scooter and scrapes his elbow, causing a small amount of bleeding. After a few days, a scab forms and eventually falls off, leaving the skin healed. What is the outermost layer of the epidermis?

      Your Answer:

      Correct Answer: Stratum corneum

      Explanation:

      The epidermis comprises five distinct layers that consist of various cell types and perform different functions. These layers, listed from outermost to innermost, are the stratum corneum, stratum lucidum*, and stratum granulosum.

      The Layers of the Epidermis

      The epidermis is the outermost layer of the skin and is made up of a stratified squamous epithelium with a basal lamina underneath. It can be divided into five layers, each with its own unique characteristics. The first layer is the stratum corneum, which is made up of flat, dead, scale-like cells filled with keratin. These cells are continually shed and replaced with new ones. The second layer, the stratum lucidum, is only present in thick skin and is a clear layer. The third layer, the stratum granulosum, is where cells form links with their neighbors. The fourth layer, the stratum spinosum, is the thickest layer of the epidermis and is where squamous cells begin keratin synthesis. Finally, the fifth layer is the stratum germinativum, which is the basement membrane and is made up of a single layer of columnar epithelial cells. This layer gives rise to keratinocytes and contains melanocytes. Understanding the layers of the epidermis is important for understanding the structure and function of the skin.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 13 - A 65-year-old woman presented with pain, weakness, and numbness in her right arm...

    Incorrect

    • A 65-year-old woman presented with pain, weakness, and numbness in her right arm one day after undergoing surgery on her right shoulder. Upon neurological examination, it was found that the patient had full power in all upper limb movements except for a 4/5 power in right elbow flexion. Sensation was normal throughout the upper limbs except for a specific area on the lateral part of the forearm. The surgeon suspects that the nerve supplying the biceps brachii in the right arm was damaged during the surgical procedure. Which nerve is most likely to have been affected?

      Your Answer:

      Correct Answer: Musculocutaneous nerve

      Explanation:

      If a person experiences weakness in elbow flexion, it may be due to an injury to the musculocutaneous nerve. This nerve is responsible for supplying the biceps brachii, coracobrachialis, and brachialis muscles, as well as the skin on the lateral aspect of the forearm.

      Other nerves in the arm include the axillary nerve, which supplies the teres minor and deltoid muscles, as well as skin over the lower half of the deltoid and adjacent areas of the arm. The median nerve supplies most of the muscles in the anterior part of the forearm, as well as skin over the lateral portion of the palm, the palmar surface of the thumb, and the lateral two and a half fingers. The radial nerve supplies the supinator and extensor muscles in the forearm, as well as skin on the posterior side of the lateral aspect of the hand, the dorsum of the thumb, and the proximal part of the lateral two and a half fingers. Finally, the ulnar nerve supplies one and a half muscles in the anterior part of the forearm, as well as skin over the medial portion of the palm and the posterior surface of the medial part of the hand.

      The shoulder joint is a shallow synovial ball and socket joint that is inherently unstable but capable of a wide range of movement. Stability is provided by the muscles of the rotator cuff. The glenoid labrum is a fibrocartilaginous rim attached to the free edge of the glenoid cavity. The fibrous capsule attaches to the scapula, humerus, and tendons of various muscles. Movements of the shoulder joint are controlled by different muscles. The joint is closely related to important anatomical structures such as the brachial plexus, axillary artery and vein, and various nerves and vessels.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 14 - You are observing a tarsal tunnel release surgery on a patient you had...

    Incorrect

    • You are observing a tarsal tunnel release surgery on a patient you had interviewed earlier that afternoon. Upon incision of the flexor retinaculum, you notice several structures that are visible.

      Can you list the structural contents in order from anterior to posterior?

      Your Answer:

      Correct Answer: Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and vein, tibial nerve, flexor hallucis longus tendon

      Explanation:

      The correct order of contents in the tarsal tunnel, from anterior to posterior, is as follows: tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and vein, tibial nerve, and flexor hallucis longus tendon. Therefore, the correct answer is 3. Answers 1 and 2 are incorrect as they include the tibialis anterior tendon, which is not located in the tarsal tunnel.

      The foot has two arches: the longitudinal arch and the transverse arch. The longitudinal arch is higher on the medial side and is supported by the posterior pillar of the calcaneum and the anterior pillar composed of the navicular bone, three cuneiforms, and the medial three metatarsal bones. The transverse arch is located on the anterior part of the tarsus and the posterior part of the metatarsus. The foot has several intertarsal joints, including the sub talar joint, talocalcaneonavicular joint, calcaneocuboid joint, transverse tarsal joint, cuneonavicular joint, intercuneiform joints, and cuneocuboid joint. The foot also has various ligaments, including those of the ankle joint and foot. The foot is innervated by the lateral plantar nerve and medial plantar nerve, and it receives blood supply from the plantar arteries and dorsalis pedis artery. The foot has several muscles, including the abductor hallucis, flexor digitorum brevis, abductor digit minimi, flexor hallucis brevis, adductor hallucis, and extensor digitorum brevis.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
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  • Question 15 - A 30-year-old male comes to the clinic complaining of toothache that has been...

    Incorrect

    • A 30-year-old male comes to the clinic complaining of toothache that has been bothering him for two days. He is prescribed a new anti-inflammatory medication that works by preventing the conversion of arachidonic acid to endoperoxides.

      What specific enzyme is likely being inhibited by this drug?

      Your Answer:

      Correct Answer: Cyclooxygenase

      Explanation:

      The metabolism of arachidonic acid involves several steps, with cyclooxygenase playing a key role in converting it to endoperoxides. Additionally, lipoxygenase is responsible for the conversion of arachidonic acid to hydroperoxyeicosatetraenoic acid (HPETEs), while phospholipase A breaks down phospholipids to release arachidonic acid. The end products of arachidonic acid metabolism include leukotrienes A4, B4, C4, D4, and E4.

      Arachidonic Acid Metabolism: The Role of Leukotrienes and Endoperoxides

      Arachidonic acid is a fatty acid that plays a crucial role in the body’s inflammatory response. The metabolism of arachidonic acid involves the production of various compounds, including leukotrienes and endoperoxides. Leukotrienes are produced by leukocytes and can cause constriction of the lungs. LTB4 is produced before leukocytes arrive, while the rest of the leukotrienes (A, C, D, and E) cause lung constriction.

      Endoperoxides, on the other hand, are produced by the cyclooxygenase enzyme and can lead to the formation of thromboxane and prostacyclin. Thromboxane is associated with platelet aggregation and vasoconstriction, which can lead to thrombosis. Prostacyclin, on the other hand, has the opposite effect and can cause vasodilation and inhibit platelet aggregation.

      Understanding the metabolism of arachidonic acid and the role of these compounds can help in the development of treatments for inflammatory conditions and cardiovascular diseases.

    • This question is part of the following fields:

      • General Principles
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  • Question 16 - You have recently learned about the embryological origin of the palatine tonsils after...

    Incorrect

    • You have recently learned about the embryological origin of the palatine tonsils after being treated with antibiotics for a bacterial infection. Can you share where they are derived from?

      Your Answer:

      Correct Answer: 2nd pharyngeal pouch

      Explanation:

      The 2nd pharyngeal pouch gives rise to the palatine tonsils, while the 1st pharyngeal pouch gives rise to the auditory tube, middle ear, and mastoid antrum. The 3rd pharyngeal pouch gives rise to the inferior parathyroid glands and thymus, while the 4th pharyngeal pouch gives rise to the superior parathyroid glands and the musculature of the larynx.

      Embryology of Branchial (Pharyngeal) Pouches

      During embryonic development, the branchial (pharyngeal) pouches give rise to various structures in the head and neck region. The first pharyngeal pouch forms the Eustachian tube, middle ear cavity, and mastoid antrum. The second pharyngeal pouch gives rise to the palatine tonsils. The third pharyngeal pouch divides into dorsal and ventral wings, with the dorsal wings forming the inferior parathyroid glands and the ventral wings forming the thymus. Finally, the fourth pharyngeal pouch gives rise to the superior parathyroid glands.

      Understanding the embryology of the branchial pouches is important in the diagnosis and treatment of certain congenital abnormalities and diseases affecting these structures. By knowing which structures arise from which pouches, healthcare professionals can better understand the underlying pathophysiology and develop appropriate management strategies. Additionally, knowledge of the embryology of these structures can aid in the development of new treatments and therapies for related conditions.

    • This question is part of the following fields:

      • General Principles
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  • Question 17 - A 45-year-old woman with a history of endometriosis is having a hysterectomy. During...

    Incorrect

    • A 45-year-old woman with a history of endometriosis is having a hysterectomy. During the procedure, the gynaecology registrar observes the position of the ureter in relation to the uterus. Can you describe the location of the ureter in relation to the nearby blood vessels?

      Your Answer:

      Correct Answer: Ureter passes underneath uterine artery

      Explanation:

      Long Term Complications of Vaginal Hysterectomy

      Vaginal hysterectomy with antero-posterior repair can lead to enterocoele and vaginal vault prolapse as common long term complications. While urinary retention may occur immediately after the procedure, it is not typically a chronic complication. These complications can cause discomfort and affect the quality of life of the patient. It is important for healthcare providers to monitor patients for these complications and provide appropriate treatment if necessary. Additionally, patients should be educated on the potential risks and benefits of the procedure before undergoing a vaginal hysterectomy. Proper postoperative care and follow-up can help prevent or manage these complications.

    • This question is part of the following fields:

      • Reproductive System
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  • Question 18 - A 45-year-old patient visits his GP with complaints of fatigue and weight loss....

    Incorrect

    • A 45-year-old patient visits his GP with complaints of fatigue and weight loss. He reports pain in his right shoulder area and tingling sensations in his fourth and fifth fingers on the right hand. Upon diagnosis, it is revealed that he has an apical lung tumor that is pressing on the C8-T1 nerve roots of the brachial plexus. Which nerve in the upper limb is primarily affected?

      Your Answer:

      Correct Answer: Ulnar nerve

      Explanation:

      The pressure applied by the tumour on the inferior roots of the brachial plexus (C8-T1) explains the pain in the shoulder region, as the ulnar nerve, which innervates the palmar surface of the fifth digit and medial part of the fourth digit, originates from these roots.

      The axillary nerve’s cutaneous branches supply the skin surrounding the inferior part of the deltoid muscle around the shoulder joint.

      The lateral cutaneous nerve of the forearm is the only sensory branch of the musculoskeletal nerve and innervates the lateral aspect of the forearm.

      Although the radial nerve has the most extensive cutaneous innervation of the nerves in the upper limb, it does not supply the palmar surface of the hand but rather its dorsal side.

      The median nerve supplies the lateral part of the palm and the palmar surface of the three most lateral fingers, and is partially comprised of the C8-T1 roots of the brachial plexus. Therefore, altered sensations of the thumb or index finger would be more typical of median nerve impairment than the fourth or fifth digits.

      The ulnar nerve originates from the medial cord of the brachial plexus, specifically from the C8 and T1 nerve roots. It provides motor innervation to various muscles in the hand, including the medial two lumbricals, adductor pollicis, interossei, hypothenar muscles (abductor digiti minimi, flexor digiti minimi), and flexor carpi ulnaris. Sensory innervation is also provided to the medial 1 1/2 fingers on both the palmar and dorsal aspects. The nerve travels through the posteromedial aspect of the upper arm and enters the palm of the hand via Guyon’s canal, which is located superficial to the flexor retinaculum and lateral to the pisiform bone.

      The ulnar nerve has several branches that supply different muscles and areas of the hand. The muscular branch provides innervation to the flexor carpi ulnaris and the medial half of the flexor digitorum profundus. The palmar cutaneous branch arises near the middle of the forearm and supplies the skin on the medial part of the palm, while the dorsal cutaneous branch supplies the dorsal surface of the medial part of the hand. The superficial branch provides cutaneous fibers to the anterior surfaces of the medial one and one-half digits, and the deep branch supplies the hypothenar muscles, all the interosseous muscles, the third and fourth lumbricals, the adductor pollicis, and the medial head of the flexor pollicis brevis.

      Damage to the ulnar nerve at the wrist can result in a claw hand deformity, where there is hyperextension of the metacarpophalangeal joints and flexion at the distal and proximal interphalangeal joints of the 4th and 5th digits. There may also be wasting and paralysis of intrinsic hand muscles (except for the lateral two lumbricals), hypothenar muscles, and sensory loss to the medial 1 1/2 fingers on both the palmar and dorsal aspects. Damage to the nerve at the elbow can result in similar symptoms, but with the addition of radial deviation of the wrist. It is important to diagnose and treat ulnar nerve damage promptly to prevent long-term complications.

    • This question is part of the following fields:

      • Neurological System
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  • Question 19 - A 60-year-old man comes to the hospital complaining of intense upper abdominal pain,...

    Incorrect

    • A 60-year-old man comes to the hospital complaining of intense upper abdominal pain, fever, and vomiting. After diagnosis, he is found to have acute pancreatitis. Among the liver function tests, which one is significantly elevated in cases of pancreatitis?

      Your Answer:

      Correct Answer: Amylase

      Explanation:

      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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  • Question 20 - A 39-year-old male presents to an endocrine clinic with acromegaly caused by a...

    Incorrect

    • A 39-year-old male presents to an endocrine clinic with acromegaly caused by a growth hormone-secreting tumor. The patient is prescribed Octreotide, a somatostatin analogue, to suppress growth hormone release.

      What additional hormonal effects can be attributed to somatostatin?

      Your Answer:

      Correct Answer: Decreases secretion of glucagon

      Explanation:

      Somatostatin has an inhibitory effect on the secretion of glucagon, but it does not affect the secretion of estrogen. It also decreases the secretion of insulin, and overproduction of somatostatin can lead to diabetes mellitus. Additionally, somatostatin reduces the secretion of gastrin, which in turn decreases the production of gastric acid by parietal cells. It also decreases the secretion of thyroid stimulating hormone (TSH), resulting in a decrease in the production of thyroxine in the thyroid.

      Somatostatin: The Inhibitor Hormone

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

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

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

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

    • This question is part of the following fields:

      • Endocrine System
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