-
Question 1
Correct
-
You are participating in a seminar about eating disorders. What renal alteration is common in individuals with extreme malnourishment?
Your Answer: Reduced glomerular filtration rate
Explanation:Renal Physiology Changes in Severe Malnutrition
Patients with severe malnutrition experience changes in their renal physiology due to reduced food intake. These changes include an increased secretion of aldosterone and a reduced glomerular filtration rate (GFR), which alters the excretion patterns of many solutes, electrolytes, and drugs. As a result, there is an increased urinary excretion of potassium, calcium, magnesium, and phosphate, leading to a tendency for hypokalaemia, hypocalcaemia, hypomagnesaemia, and hypophosphataemia over time.
Furthermore, the reduced muscle bulk in individuals with severe malnutrition causes low levels of production of urea and creatinine. However, reduced excretion causes plasma levels to remain normal or only slightly reduced. As muscle is broken down to provide substrates for gluconeogenesis, a negative nitrogen balance ensues. Additionally, urate excretion is reduced, causing a relative hyperuricaemia.
In summary, severe malnutrition affects renal physiology, leading to altered excretion patterns of various solutes, electrolytes, and drugs. These changes can result in imbalances in potassium, calcium, magnesium, and phosphate levels. Furthermore, the breakdown of muscle tissue can cause a negative nitrogen balance, while reduced urate excretion can lead to hyperuricaemia.
-
This question is part of the following fields:
- Clinical Sciences
-
-
Question 2
Correct
-
A 63-year-old man visits his GP complaining of worsening shortness of breath. He was diagnosed with COPD six years ago and has been frequently admitted to the emergency department due to lower respiratory tract infections, especially in the past year. He has a smoking history of 50 pack-years and currently smokes 20 cigarettes per day.
During the examination, the patient appears to be struggling to breathe even at rest and is in the tripod position. His heart rate is 78/min, blood pressure is 140/88 mmHg, oxygen saturation is 88% on air, respiratory rate is 26 breaths per minute, and temperature is 36.4ºC. His chest expansion is symmetrical, and breath sounds are equal throughout the lung fields.
Recent spirometry results show that his FEV1 was 47% a week ago, 53% a month ago, and 67% six months ago. What intervention would be most effective in slowing the decline of his FEV1?Your Answer: Smoking cessation
Explanation:Slowing the decrease in FEV1 in COPD can be most effectively achieved by quitting smoking.
The National Institute for Health and Care Excellence (NICE) updated its guidelines on the management of chronic obstructive pulmonary disease (COPD) in 2018. The guidelines recommend general management strategies such as smoking cessation advice, annual influenzae vaccination, and one-off pneumococcal vaccination. Pulmonary rehabilitation is also recommended for patients who view themselves as functionally disabled by COPD.
Bronchodilator therapy is the first-line treatment for patients who remain breathless or have exacerbations despite using short-acting bronchodilators. The next step is determined by whether the patient has asthmatic features or features suggesting steroid responsiveness. NICE suggests several criteria to determine this, including a previous diagnosis of asthma or atopy, a higher blood eosinophil count, substantial variation in FEV1 over time, and substantial diurnal variation in peak expiratory flow.
If the patient does not have asthmatic features or features suggesting steroid responsiveness, a long-acting beta2-agonist (LABA) and long-acting muscarinic antagonist (LAMA) should be added. If the patient is already taking a short-acting muscarinic antagonist (SAMA), it should be discontinued and switched to a short-acting beta2-agonist (SABA). If the patient has asthmatic features or features suggesting steroid responsiveness, a LABA and inhaled corticosteroid (ICS) should be added. If the patient remains breathless or has exacerbations, triple therapy (LAMA + LABA + ICS) should be offered.
NICE only recommends theophylline after trials of short and long-acting bronchodilators or to people who cannot use inhaled therapy. Azithromycin prophylaxis is recommended in select patients who have optimised standard treatments and continue to have exacerbations. Mucolytics should be considered in patients with a chronic productive cough and continued if symptoms improve.
Cor pulmonale features include peripheral oedema, raised jugular venous pressure, systolic parasternal heave, and loud P2. Loop diuretics should be used for oedema, and long-term oxygen therapy should be considered. Smoking cessation, long-term oxygen therapy in eligible patients, and lung volume reduction surgery in selected patients may improve survival in patients with stable COPD. NICE does not recommend the use of ACE-inhibitors, calcium channel blockers, or alpha blockers
-
This question is part of the following fields:
- Respiratory System
-
-
Question 3
Incorrect
-
At which of the following sites is the development of diverticulosis least likely in individuals over 60 years of age?
Your Answer: Transverse colon
Correct Answer: Rectum
Explanation:It is extremely rare for diverticular disease to affect the rectum due to the circular muscle coat present in this area, which is a result of the blending of the tenia at the recto-sigmoid junction. While left-sided colonic diverticular disease is more common, right-sided colonic diverticular disease is also acknowledged.
Understanding Diverticular Disease
Diverticular disease is a common condition that involves the protrusion of the colon’s mucosa through its muscular wall. This typically occurs between the taenia coli, where vessels penetrate the muscle to supply the mucosa. Symptoms of diverticular disease include altered bowel habits, rectal bleeding, and abdominal pain. Complications can arise, such as diverticulitis, haemorrhage, fistula development, perforation and faecal peritonitis, abscess formation, and diverticular phlegmon.
To diagnose diverticular disease, patients may undergo a colonoscopy, CT cologram, or barium enema. However, it can be challenging to rule out cancer, especially in diverticular strictures. Acutely unwell surgical patients require a systematic investigation, including plain abdominal films and an erect chest x-ray to identify perforation. An abdominal CT scan with oral and intravenous contrast can help identify acute inflammation and local complications.
Treatment for diverticular disease includes increasing dietary fibre intake and managing mild attacks with antibiotics. Peri colonic abscesses require drainage, either surgically or radiologically. Recurrent episodes of acute diverticulitis requiring hospitalisation may indicate a segmental resection. Hinchey IV perforations, which involve generalised faecal peritonitis, require a resection and usually a stoma. This group has a high risk of postoperative complications and typically requires HDU admission. Less severe perforations may be managed by laparoscopic washout and drain insertion.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 4
Correct
-
By what means do viruses enter human cells?
Your Answer: Specific surface protein-protein interaction
Explanation:How Viruses Enter Cells
Viruses have specific proteins on their surface that bind to cell surface proteins, allowing them to enter the cell and release their genomic material. Sometimes, the viral genomic material is injected through a protein channel, while the capsid remains outside the cell. In other cases, the entire virus enters the cell. Viruses only cause membrane lysis when they have multiplied inside cells and kill them to release viral particles.
The viral envelope is formed when virus particles bud off from cells, taking some membrane with them. While it can play a role in permitting viral entry, a protein-protein interaction must still occur for the capsid and genome to enter. Viruses are too large to pass through cell membrane pores.
-
This question is part of the following fields:
- Microbiology
-
-
Question 5
Incorrect
-
A 47-year-old male presents to the emergency department with an acute flare-up of his ulcerative colitis. This is his 5th flare-up in 4 weeks.
He has a past medical history of hypertension, adhesive capsulitis and gout.
His regular medications include lisinopril, paracetamol, ibuprofen, allopurinol and simvastatin.
The doctor starts him on azathioprine and considers switching one of his current drugs.
Which one of the following drugs does he wish to switch?Your Answer: Ibuprofen
Correct Answer: Allopurinol
Explanation:Taking allopurinol while on azathioprine therapy can increase the risk of toxicity. This is because allopurinol inhibits the enzyme xanthine oxidase, which is responsible for inactivating the active form of azathioprine. As a result, 6-mercaptopurine is shunted down to form metabolites that can be incorporated into DNA, leading to a reduction in white blood cell replication and activation, as well as increased apoptosis of white blood cells. There is no known interaction between azathioprine and the other drugs mentioned.
Allopurinol can interact with other medications such as azathioprine, cyclophosphamide, and theophylline. It can lead to high levels of 6-mercaptopurine when used with azathioprine, reduced renal clearance when used with cyclophosphamide, and an increase in plasma concentration of theophylline. Patients at a high risk of severe cutaneous adverse reaction should be screened for the HLA-B *5801 allele.
-
This question is part of the following fields:
- General Principles
-
-
Question 6
Correct
-
A 45-year-old man with epilepsy has been prescribed carbamazepine. As time passes, the dosage of carbamazepine required by him has been gradually increasing. He only takes paracetamol occasionally and no other medications. What type of drug reaction is this indicative of?
Your Answer: Induction of metabolism
Explanation:Medications and their effects on metabolism
Some medications can affect the metabolism of other drugs. For instance, carbamazepine is a medication that induces liver enzymes, which can increase the metabolism of certain drugs that rely on those pathways. It is worth noting that carbamazepine is an auto-inducer, meaning that the amount of carbamazepine required can increase over time. This can lead to changes in the dosage required to achieve the desired therapeutic effect. Therefore, it is important to monitor patients who are taking carbamazepine or any other medication that can affect the metabolism of other drugs. By doing so, healthcare providers can ensure that patients receive the appropriate dosage of medication to achieve the desired therapeutic effect.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 7
Incorrect
-
A 78-year-old woman is diagnosed with a femoral hernia and requires surgery. What structure forms the posterior wall of the femoral canal?
Your Answer: Inguinal ligament
Correct Answer: Pectineal ligament
Explanation:Understanding the Femoral Canal
The femoral canal is a fascial tunnel located at the medial aspect of the femoral sheath. It contains both the femoral artery and femoral vein, with the canal lying medial to the vein. The borders of the femoral canal include the femoral vein laterally, the lacunar ligament medially, the inguinal ligament anteriorly, and the pectineal ligament posteriorly.
The femoral canal plays a significant role in allowing the femoral vein to expand, which facilitates increased venous return to the lower limbs. However, it can also be a site of femoral hernias, which occur when abdominal contents protrude through the femoral canal. The relatively tight neck of the femoral canal places these hernias at high risk of strangulation, making it important to understand the anatomy and function of this structure. Overall, understanding the femoral canal is crucial for medical professionals in diagnosing and treating potential issues related to this area.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 8
Correct
-
A 59-year-old male patient visits his physician complaining of a recent cough that is producing green sputum. The doctor suspects a lower respiratory tract infection and initiates treatment with ceftriaxone. What is the mode of action of this medication?
Your Answer: Inhibits cell wall formation
Explanation:Ceftriaxone is a cephalosporin antibiotic that works by inhibiting cell wall formation through the prevention of peptidoglycan cross-linking. This mechanism is similar to other beta-lactam antibiotics like penicillins and carbapenems. It is important to note that cephalosporins do not inhibit RNA synthesis, folic acid synthesis, protein synthesis, or DNA synthesis, which are mechanisms of action for other types of antibiotics such as Rifampicin, sulphonamides and trimethoprim, macrolides, aminoglycosides, tetracyclines, and quinolones, respectively.
Antibiotics work in different ways to kill or inhibit the growth of bacteria. The commonly used antibiotics can be classified based on their gross mechanism of action. The first group inhibits cell wall formation by either preventing peptidoglycan cross-linking (penicillins, cephalosporins, carbapenems) or peptidoglycan synthesis (glycopeptides like vancomycin). The second group inhibits protein synthesis by acting on either the 50S subunit (macrolides, chloramphenicol, clindamycin, linezolid, streptogrammins) or the 30S subunit (aminoglycosides, tetracyclines) of the bacterial ribosome. The third group inhibits DNA synthesis (quinolones like ciprofloxacin) or damages DNA (metronidazole). The fourth group inhibits folic acid formation (sulphonamides and trimethoprim), while the fifth group inhibits RNA synthesis (rifampicin). Understanding the mechanism of action of antibiotics is important in selecting the appropriate drug for a particular bacterial infection.
-
This question is part of the following fields:
- General Principles
-
-
Question 9
Incorrect
-
A patient in their mid-30s has suffered a carotid canal fracture due to a traffic collision resulting in severe head trauma. The medical team must evaluate the potential damage to the adjacent structures. What structure is located directly posterior to the fracture?
Your Answer: Foramen magnum
Correct Answer: Jugular foramen
Explanation:The jugular foramen is situated at the back of the carotid canal, while the foramen magnum is even further posterior within the skull. The mental foramen can be found on the front surface of the mandible, while the optic canal is located in the sphenoid bone and serves as a passage for the optic nerve. The femoral canal is not relevant to the skull and is therefore an inappropriate answer to this question.
Foramina of the Skull
The foramina of the skull are small openings in the bones that allow for the passage of nerves and blood vessels. These foramina are important for the proper functioning of the body and can be tested on exams. Some of the major foramina include the optic canal, superior and inferior orbital fissures, foramen rotundum, foramen ovale, and jugular foramen. Each of these foramina has specific vessels and nerves that pass through them, such as the ophthalmic artery and optic nerve in the optic canal, and the mandibular nerve in the foramen ovale. It is important to have a basic understanding of these foramina and their contents in order to understand the anatomy and physiology of the head and neck.
-
This question is part of the following fields:
- Neurological System
-
-
Question 10
Correct
-
A 65-year-old male patient complains of a persistent cough that has been bothering him for the past three months. He has a medical history of hypertension and type 2 diabetes, which he manages with medication. Which of the following drugs is the most probable cause of his cough?
Your Answer: ACE inhibitors
Explanation:ACE Inhibitors and Coughing: the Mechanism
Angiotensin-converting enzyme (ACE) inhibitors are known to cause coughing in almost a third of the people who use them. However, angiotensin blockers, which have similar benefits to ACE inhibitors, do not cause coughing and are often prescribed to patients who cannot tolerate ACE inhibitors. The reason behind this difference lies in the mechanism of action of these drugs. ACE inhibitors lead to the accumulation of bradykinin in the bronchial tissue, which triggers coughing. On the other hand, angiotensin blockers do not affect bradykinin levels and hence do not cause coughing. this mechanism is crucial in selecting the right medication for patients who are intolerant to ACE inhibitors.
-
This question is part of the following fields:
- Pharmacology
-
-
Question 11
Incorrect
-
Which muscle is innervated by the superficial peroneal nerve?
Your Answer: Peroneus tertius
Correct Answer: Peroneus brevis
Explanation:Anatomy of the Superficial Peroneal Nerve
The superficial peroneal nerve is responsible for supplying the lateral compartment of the leg, specifically the peroneus longus and peroneus brevis muscles which aid in eversion and plantar flexion. It also provides sensation over the dorsum of the foot, excluding the first web space which is innervated by the deep peroneal nerve.
The nerve passes between the peroneus longus and peroneus brevis muscles along the proximal one-third of the fibula. Approximately 10-12 cm above the tip of the lateral malleolus, the nerve pierces the fascia. It then bifurcates into intermediate and medial dorsal cutaneous nerves about 6-7 cm distal to the fibula.
Understanding the anatomy of the superficial peroneal nerve is important in diagnosing and treating conditions that affect the lateral compartment of the leg and dorsum of the foot. Injuries or compression of the nerve can result in weakness or numbness in the affected areas.
-
This question is part of the following fields:
- Neurological System
-
-
Question 12
Incorrect
-
The following result is obtained on a 48-year-old male who is admitted with acute onset chest pain:
Serum Cholesterol 7.3 mmol/L (<5.2)
He has a strong family history of ischaemic heart disease.
What abnormalities might be expected upon examination of this man?Your Answer: Ejection systolic murmur
Correct Answer: Tendon nodules
Explanation:Familial Hypercholesterolaemia and its Manifestations
Familial hypercholesterolaemia is a condition characterized by high levels of cholesterol in the blood. This condition is often indicated by the deposition of cholesterol in various parts of the body. The history of the patient suggests that they may be suffering from familial hypercholesterolaemia. The deposition of cholesterol can be observed around the corneal arcus, around the eye itself (xanthelasma), and in tendons such as achilles, knuckles or triceps tendons (tendon xanthomas).
While dietary and lifestyle modifications are recommended, they are usually not enough to manage the condition. High dose lifelong statin therapy is often necessary to control the levels of cholesterol in the blood. It is important to seek medical attention and follow the recommended treatment plan to prevent further complications associated with familial hypercholesterolaemia. The National Institute for Health and Care Excellence (NICE) recommends the use of statin therapy in conjunction with lifestyle modifications for the management of familial hypercholesterolaemia.
-
This question is part of the following fields:
- Cardiovascular System
-
-
Question 13
Incorrect
-
In the Vaughan Williams classification of antihypertensives, lisinopril is an example of a:
Your Answer: Class IV agent
Correct Answer: Class Ib agent
Explanation:The Vaughan Williams Classification of Antiarrhythmics
The Vaughan Williams classification is a widely used system for categorizing antiarrhythmic drugs based on their mechanism of action. The classification system is divided into four classes, each with a different mechanism of action. Class I drugs block sodium channels, Class II drugs are beta-adrenoceptor antagonists, Class III drugs block potassium channels, and Class IV drugs are calcium channel blockers.
Class Ia drugs, such as quinidine and procainamide, increase the duration of the action potential by blocking sodium channels. However, quinidine toxicity can cause cinchonism, which is characterized by symptoms such as headache, tinnitus, and thrombocytopenia. Procainamide may also cause drug-induced lupus.
Class Ib drugs, such as lidocaine and mexiletine, decrease the duration of the action potential by blocking sodium channels. Class Ic drugs, such as flecainide and propafenone, have no effect on the duration of the action potential but still block sodium channels.
Class II drugs, such as propranolol and metoprolol, are beta-adrenoceptor antagonists that decrease the heart rate and contractility of the heart.
Class III drugs, such as amiodarone and sotalol, block potassium channels, which prolongs the duration of the action potential.
Class IV drugs, such as verapamil and diltiazem, are calcium channel blockers that decrease the influx of calcium ions into the heart, which slows down the heart rate and reduces contractility.
It should be noted that some common antiarrhythmic drugs, such as adenosine, atropine, digoxin, and magnesium, are not included in the Vaughan Williams classification.
-
This question is part of the following fields:
- General Principles
-
-
Question 14
Incorrect
-
A 14-year-old boy comes to the clinic complaining of ear pain. He mentions having some crusty discharge at the entrance of his ear canal when he woke up this morning. He denies any hearing loss, dizziness, or other symptoms. He swims twice a week. Upon examination, he has no fever. The auricle of his ear appears red, and pressing on the tragus causes discomfort. Otoscopy reveals an erythematous canal with a small amount of yellow discharge. The superior edge of the tympanic membrane is also red, but there is no bulging or fluid in the middle ear. Which bone articulates with the bone that is typically seen pressing against the tympanic membrane?
Your Answer: Stapes
Correct Answer: Incus
Explanation:The middle bone of the 3 ossicles is known as the incus. During otoscopy, the malleus can be observed in contact with the tympanic membrane and it connects with the incus medially.
The ossicles, which are the 3 bones in the middle ear, are arranged from lateral to medial as follows:
Malleus: This is the most lateral of the ossicles. The handle and lateral process of the malleus attach to the tympanic membrane, making it visible during otoscopy. The head of the malleus connects with the incus. The term ‘malleus’ is derived from the Latin word for ‘hammer’.
Incus: The incus is positioned between and connects with the other two ossicles. The body of the incus connects with the malleus, while the long limb of the bone connects with the stapes. The term ‘incus’ is derived from the Latin word for ‘anvil’.Anatomy of the Ear
The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 15
Incorrect
-
A 82-year-old man arrives at the emergency department complaining of bone and abdominal pain. He appears confused, and his wife reports that he has been experiencing low mood lately. Upon conducting blood tests, it is discovered that he has elevated levels of calcium and parathyroid hormone. What is the probable cause of his hypercalcaemia?
Your Answer: Decreased activity of vitamin D
Correct Answer: Increased activity of osteoclasts
Explanation:Primary hyperparathyroidism is the likely diagnosis for this patient, which is typically caused by a single adenoma in the parathyroid gland. The hormone PTH plays a key role in increasing plasma calcium levels while decreasing phosphate levels. This is achieved through increased absorption of calcium in the bowel and kidneys, as well as increased bone resorption through the activity of osteoclasts.
If osteoblast activity were increased, it would actually decrease plasma calcium levels. Conversely, decreased resorption in the kidneys would result in more calcium being lost in the urine, leading to lower plasma calcium levels. Lower levels of plasma calcium would also result from decreased activity of vitamin D.
It’s important to note that PTH has no direct effect on calcitonin secretion, which is controlled by plasma calcium levels as well as the hormones gastrin and pentagastrin.
Maintaining Calcium Balance in the Body
Calcium ions are essential for various physiological processes in the body, and the largest store of calcium is found in the skeleton. The levels of calcium in the body are regulated by three hormones: parathyroid hormone (PTH), vitamin D, and calcitonin.
PTH increases calcium levels and decreases phosphate levels by increasing bone resorption and activating osteoclasts. It also stimulates osteoblasts to produce a protein signaling molecule that activates osteoclasts, leading to bone resorption. PTH increases renal tubular reabsorption of calcium and the synthesis of 1,25(OH)2D (active form of vitamin D) in the kidney, which increases bowel absorption of calcium. Additionally, PTH decreases renal phosphate reabsorption.
Vitamin D, specifically the active form 1,25-dihydroxycholecalciferol, increases plasma calcium and plasma phosphate levels. It increases renal tubular reabsorption and gut absorption of calcium, as well as osteoclastic activity. Vitamin D also increases renal phosphate reabsorption in the proximal tubule.
Calcitonin, secreted by C cells of the thyroid, inhibits osteoclast activity and renal tubular absorption of calcium.
Although growth hormone and thyroxine play a small role in calcium metabolism, the primary regulation of calcium levels in the body is through PTH, vitamin D, and calcitonin. Maintaining proper calcium balance is crucial for overall health and well-being.
-
This question is part of the following fields:
- Neurological System
-
-
Question 16
Correct
-
A 28-year-old man with schizophrenia who began taking clozapine 2 weeks ago visits for his routine blood test. What is a known severe side effect of clozapine?
Your Answer: Agranulocytosis
Explanation:Clozapine, an antipsychotic medication used to treat refractory schizophrenia, requires continuous monitoring for patients taking it. This involves weekly blood tests for the first 18 weeks, followed by bi-weekly tests until the first year, and then monthly tests thereafter.
Atypical antipsychotics are now recommended as the first-line treatment for patients with schizophrenia, as per the 2005 NICE guidelines. These agents have a significant advantage over traditional antipsychotics in that they cause fewer extrapyramidal side-effects. However, atypical antipsychotics can still cause adverse effects such as weight gain, hyperprolactinaemia, and clozapine-associated agranulocytosis. Elderly patients who take antipsychotics are at an increased risk of stroke and venous thromboembolism, according to the Medicines and Healthcare products Regulatory Agency.
Clozapine is one of the first atypical antipsychotics to be developed, but it carries a significant risk of agranulocytosis. Therefore, full blood count monitoring is essential during treatment. Clozapine should only be used in patients who are resistant to other antipsychotic medication. The BNF recommends introducing clozapine if schizophrenia is not controlled despite the sequential use of two or more antipsychotic drugs, one of which should be a second-generation antipsychotic drug, each for at least 6-8 weeks. Clozapine can cause adverse effects such as reduced seizure threshold, constipation, myocarditis, and hypersalivation. Dose adjustment of clozapine may be necessary if smoking is started or stopped during treatment.
-
This question is part of the following fields:
- Psychiatry
-
-
Question 17
Incorrect
-
An asymptomatic 75-year-old patient is scheduled for an elective laparoscopic cholecystectomy and undergoes routine pre-operative blood tests. The results show a white cell count of 25 ×109/ml, with lymphocytes at 22 ×109/ml. What would be an unfavorable prognostic indicator for this patient?
Your Answer: His age
Correct Answer: Trisomy 12
Explanation:Chronic Lymphocytic Leukaemia (CLL) Prognostic Indicators
Chronic lymphocytic leukaemia (CLL) is a type of cancer that affects the blood and bone marrow. Patients with CLL often have genetic mutations, with trisomy 12 being a bad prognostic indicator. ZAP-70, a tyrosine kinase involved in cell signalling, is also measured in CLL patients, and high expression is associated with a poor prognosis. On the other hand, lactate dehydrogenase (LDH) is a marker of tumour burden, and a normal level suggests less tumour bulk, which is a good prognostic marker.
Many patients with CLL may not require treatment and may die with the disease rather than from it. It is often diagnosed in asymptomatic patients who undergo blood tests for other reasons. Treating the disease too early may actually lead to a worse outcome than monitoring the patient initially. Therefore, patients who do not need to start treatment immediately have a more favourable outlook.
B cells in secondary lymphoid tissue undergo somatic hypermutation when they recognise an antigen. This process fine-tunes antibody specificity, and cells that have undergone somatic hypermutation are more mature. If CLL arises from one of these cells, it is associated with a more favourable prognosis. these prognostic indicators can help healthcare professionals determine the best course of treatment for patients with CLL.
-
This question is part of the following fields:
- Haematology And Oncology
-
-
Question 18
Incorrect
-
A new blood test to screen patients for dementia is trialled on 500 patients. The test was positive in 60 of the 70 patients shown to have dementia by cognitive assessment. It was also positive in 30 patients who were shown not to have dementia. What is the positive predictive value of the test?
Your Answer: 0.8
Correct Answer: 0.66
Explanation:The positive predictive value can be calculated using the formula TP / (TP + FP), where TP represents true positives and FP represents false positives. Based on the given data, a contingency table can be created with the following values:
Heart failure No heart failure
Test positive 40 20
Test negative 10 430Using the formula, the positive predictive value can be calculated as 40 / (40 + 20) = 0.66.
Precision refers to the consistency of a test in producing the same results when repeated multiple times. It is an important aspect of test reliability and can impact the accuracy of the results. In order to assess precision, multiple tests are performed on the same sample and the results are compared. A test with high precision will produce similar results each time it is performed, while a test with low precision will produce inconsistent results. It is important to consider precision when interpreting test results and making clinical decisions.
-
This question is part of the following fields:
- General Principles
-
-
Question 19
Correct
-
A 25-year-old regular gym attendee has been using growth hormone injections to enhance his muscle mass. What potential risks is he now more susceptible to?
Your Answer: Diabetes mellitus type II
Explanation:Excessive growth hormone can elevate the likelihood of developing type II diabetes mellitus. This is due to the hormone’s ability to release glucose from fat reserves, which raises its concentration in the bloodstream. As a result, the pancreas must produce more insulin to counteract the heightened glucose levels.
Additional indications of surplus growth hormone may involve thickened skin, enlarged extremities, a protruding jaw, carpal tunnel syndrome, fatigue, muscle frailty, and high blood pressure.
Understanding Growth Hormone and Its Functions
Growth hormone (GH) is a hormone produced by the somatotroph cells in the anterior pituitary gland. It plays a crucial role in postnatal growth and development, as well as in regulating protein, lipid, and carbohydrate metabolism. GH acts on a transmembrane receptor for growth factor, leading to receptor dimerization and direct or indirect effects on tissues via insulin-like growth factor 1 (IGF-1), which is primarily secreted by the liver.
GH secretion is regulated by various factors, including growth hormone releasing hormone (GHRH), fasting, exercise, and sleep. Conversely, glucose and somatostatin can decrease GH secretion. Disorders associated with GH include acromegaly, which results from excess GH, and GH deficiency, which can lead to short stature.
In summary, GH is a vital hormone that plays a significant role in growth and metabolism. Understanding its functions and regulation can help in the diagnosis and treatment of GH-related disorders.
-
This question is part of the following fields:
- Endocrine System
-
-
Question 20
Correct
-
A 25-year-old woman is stabbed in the buttock and receives sutures in the emergency department. When she visits the clinic eight weeks later, she presents with a waddling gait and difficulty with thigh abduction. Upon examination, she exhibits buttock muscle wasting. Which nerve was damaged in the injury?
Your Answer: Superior gluteal nerve
Explanation:If the superior gluteal nerve is damaged, it will cause a Trendelenburg gait.
The Trendelenburg Test: Assessing Gluteal Nerve Function
The Trendelenburg test is a diagnostic tool used to assess the function of the superior gluteal nerve. This nerve is responsible for the contraction of the gluteus medius muscle, which is essential for maintaining balance and stability while standing on one leg.
When the superior gluteal nerve is injured or damaged, the gluteus medius muscle is weakened, resulting in a compensatory shift of the body towards the unaffected side. This shift is characterized by a gravitational shift, which causes the body to be supported on the unaffected limb.
To perform the Trendelenburg test, the patient is asked to stand on one leg while the physician observes the position of the pelvis. In a healthy individual, the gluteus medius muscle contracts as soon as the contralateral leg leaves the floor, preventing the pelvis from dipping towards the unsupported side. However, in a person with paralysis of the superior gluteal nerve, the pelvis on the unsupported side descends, indicating that the gluteus medius on the affected side is weak or non-functional. This is known as a positive Trendelenburg test.
It is important to note that the Trendelenburg test is also used in vascular investigations to determine the presence of saphenofemoral incompetence. In this case, tourniquets are placed around the upper thigh to assess blood flow. However, in the context of assessing gluteal nerve function, the Trendelenburg test is a valuable tool for diagnosing and treating motor deficits and gait abnormalities.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 21
Incorrect
-
You are conducting a study to compare the sensitivity and specificity of mammograms to detect breast cancer. In your study, 200 women had a positive mammogram result, however, 50 of those women were then diagnosed with breast cancer on further testing. A further 500 women had a negative mammogram result, with 20 women being diagnosed with breast cancer from this group.
What is the positive predictive value of a positive mammogram result?Your Answer: 0.15
Correct Answer: 0.6
Explanation:Precision refers to the consistency of a test in producing the same results when repeated multiple times. It is an important aspect of test reliability and can impact the accuracy of the results. In order to assess precision, multiple tests are performed on the same sample and the results are compared. A test with high precision will produce similar results each time it is performed, while a test with low precision will produce inconsistent results. It is important to consider precision when interpreting test results and making clinical decisions.
-
This question is part of the following fields:
- General Principles
-
-
Question 22
Correct
-
A 32-year-old man is referred to the gastroenterologist for ongoing nausea and epigastric pain. He recently returned from a trip to southeast Asia. Blood tests show he has iron deficiency anemia, and faecal microscopy reveals hookworm eggs. What type of immune cell is responsible for protecting against helminths?
Your Answer: Eosinophils
Explanation:The defence against parasites, including helminths and protozoa, is carried out by eosinophils, which are innate cells. The role of basophils in the immune system is not well understood, but they are closely linked to mast cells. Neutrophils, on the other hand, are crucial phagocytic cells present in acute inflammation.
Innate Immune Response: Cells Involved
The innate immune response is the first line of defense against invading pathogens. It involves a variety of cells that work together to quickly recognize and eliminate foreign invaders. The following cells are primarily involved in the innate immune response:
Neutrophils are the most common type of white blood cell and are the primary phagocytic cell in acute inflammation. They contain granules that contain myeloperoxidase and lysozyme, which help to break down and destroy pathogens.
Basophils and mast cells are similar in function and both release histamine during an allergic response. They also contain granules that contain histamine and heparin, and express IgE receptors on their cell surface.
Eosinophils defend against protozoan and helminthic infections, and have a bi-lobed nucleus.
Monocytes differentiate into macrophages, which are involved in phagocytosis of cellular debris and pathogens. They also act as antigen-presenting cells and are a major source of IL-1.
Natural killer cells induce apoptosis in virally infected and tumor cells, while dendritic cells act as antigen-presenting cells.
Overall, these cells work together to provide a rapid and effective response to invading pathogens, helping to protect the body from infection and disease.
-
This question is part of the following fields:
- General Principles
-
-
Question 23
Incorrect
-
A 14-year-old girl presents to the paediatric emergency department with fever, vomiting, and abdominal pain. During the abdominal examination, the right lower quadrant is tender upon palpation of the left lower quadrant. What is the term for this sign?
Your Answer: Murphy's sign
Correct Answer: Rovsing's sign
Explanation:Rovsing’s sign is a sign that may indicate the presence of appendicitis. It is considered positive when pressure applied to the left lower quadrant of the abdomen causes pain in the right lower quadrant.
Murphy’s sign is a sign that may indicate inflammation of the gallbladder. It is considered positive when pressure applied to the right upper quadrant of the abdomen, just below the rib cage, causes pain when the patient inhales.
Cullen’s sign is a sign that may indicate ectopic pregnancy or acute pancreatitis. It is characterized by bruising around the belly button.
Tinel’s sign is a sign that may indicate carpal tunnel syndrome. It is considered positive when tapping the median nerve over the flexor retinaculum causes tingling or numbness in the distribution of the median nerve.
Battles sign is a sign that may indicate a basal skull fracture of the posterior cranial fossa. It is characterized by bruising behind the ear.
Acute appendicitis is a common condition that requires surgery and can occur at any age, but is most prevalent in young people aged 10-20 years. The pathogenesis of acute appendicitis involves lymphoid hyperplasia or a faecolith, which leads to obstruction of the appendiceal lumen. This obstruction causes gut organisms to invade the appendix wall, resulting in oedema, ischaemia, and possibly perforation.
The most common symptom of acute appendicitis is abdominal pain, which is typically peri-umbilical and radiates to the right iliac fossa due to localised peritoneal inflammation. Other symptoms include mild pyrexia, anorexia, and nausea. Examination may reveal generalised or localised peritonism, rebound and percussion tenderness, guarding and rigidity, and classical signs such as Rovsing’s sign and psoas sign.
Diagnosis of acute appendicitis is typically based on raised inflammatory markers and compatible history and examination findings. Imaging may be used in certain cases, such as ultrasound in females where pelvic organ pathology is suspected. Management of acute appendicitis involves appendicectomy, which can be performed via an open or laparoscopic approach. Patients with perforated appendicitis require copious abdominal lavage, while those without peritonitis who have an appendix mass should receive broad-spectrum antibiotics and consideration given to performing an interval appendicectomy. Intravenous antibiotics alone have been trialled as a treatment for appendicitis, but evidence suggests that this is associated with a longer hospital stay and up to 20% of patients go on to have an appendicectomy within 12 months.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 24
Incorrect
-
A 20-year-old male comes to the clinic complaining of fatigue and a sore throat. During the examination, the doctor observes cervical lymphadenopathy and splenomegaly. Mono is suspected as the diagnosis. Which type of cancer is most commonly linked to Epstein-Barr Virus?
Your Answer: Hepatocellular carcinoma
Correct Answer: Burkitt's lymphoma
Explanation:Epstein-Barr Virus is linked to Burkitt’s lymphoma.
Hepatitis C is linked to hepatocellular carcinoma.
Alcohol excess and smoking are linked to oesophageal cancer.
Individuals with Down’s syndrome have a higher incidence of acute lymphoblastic leukaemia.
Conditions Linked to Epstein-Barr Virus
Epstein-Barr virus (EBV) is associated with various conditions, including malignancies and non-malignant conditions. Malignancies linked to EBV infection include Burkitt’s lymphoma, Hodgkin’s lymphoma, nasopharyngeal carcinoma, and HIV-associated central nervous system lymphomas. Burkitt’s lymphoma is currently believed to be associated with both African and sporadic cases.
Apart from malignancies, EBV infection is also linked to non-malignant conditions such as hairy leukoplakia. This condition is characterized by white patches on the tongue and inside of the cheeks, and it is often seen in people with weakened immune systems.
In summary, EBV infection is associated with various conditions, including malignancies and non-malignant conditions. Understanding the link between EBV and these conditions can help in the development of effective prevention and treatment strategies.
-
This question is part of the following fields:
- General Principles
-
-
Question 25
Incorrect
-
Which human herpesvirus causes a childhood exanthem?
Your Answer: Measles
Correct Answer: Roseola infantum
Explanation:Exanthema: Common Childhood Illnesses
An exanthema is a childhood illness that is characterized by a fever and a rash that blanches when pressure is applied. These illnesses are quite common in childhood and are usually mild and self-limiting. There are several types of exanthema, and some of them have been numbered for easy identification.
The first disease is measles, which is caused by a virus called paramyxoviridae. The second disease is scarlet fever, which is caused by a bacterium called Streptococcus pyogenes. The third disease is rubella, also known as German measles, which is caused by a virus called togaviridae. The fifth disease is erythema infectiosum, also known as slapped cheek disease, which is caused by a virus called parvoviridae. The sixth disease is roseola infantum, which is caused by two viruses called HHV6 and HHV7. The fourth disease is no longer recognized.
In addition to these numbered diseases, there are other viruses that can cause an exanthematous rash, including rhinovirus, mumps, and varicella zoster virus. Despite their prevalence, most exanthema illnesses are mild and do not require medical intervention.
-
This question is part of the following fields:
- Microbiology
-
-
Question 26
Correct
-
A 54-year-old man undergoes an abdomino-perineal excision of the colon and rectum and is now experiencing impotence. What is the probable cause?
Your Answer: Damage to the hypogastric plexus during mobilisation of the inferior mesenteric artery
Explanation:The most frequent cause is injury to the autonomic nerves.
During surgical procedures, there is a risk of nerve injury caused by the surgery itself. This is not only important for the patient’s well-being but also from a legal perspective. There are various operations that carry the risk of nerve damage, such as posterior triangle lymph node biopsy, Lloyd Davies stirrups, thyroidectomy, anterior resection of rectum, axillary node clearance, inguinal hernia surgery, varicose vein surgery, posterior approach to the hip, and carotid endarterectomy. Surgeons must have a good understanding of the anatomy of the area they are operating on to minimize the incidence of nerve lesions. Blind placement of haemostats is not recommended as it can also cause nerve damage.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 27
Correct
-
Which of the following is involved in the breakdown of polypeptides?
Your Answer: Proteasome
Explanation:Functions of Cell Organelles
The functions of major cell organelles can be summarized in a table. The rough endoplasmic reticulum (RER) is responsible for the translation and folding of new proteins, as well as the manufacture of lysosomal enzymes. It is also the site of N-linked glycosylation. Cells such as pancreatic cells, goblet cells, and plasma cells have extensive RER. On the other hand, the smooth endoplasmic reticulum (SER) is involved in steroid and lipid synthesis. Cells of the adrenal cortex, hepatocytes, and reproductive organs have extensive SER.
The Golgi apparatus modifies, sorts, and packages molecules that are destined for cell secretion. The addition of mannose-6-phosphate to proteins designates transport to lysosome. The mitochondrion is responsible for aerobic respiration and contains mitochondrial genome as circular DNA. The nucleus is involved in DNA maintenance, RNA transcription, and RNA splicing, which removes the non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons).
The lysosome is responsible for the breakdown of large molecules such as proteins and polysaccharides. The nucleolus produces ribosomes, while the ribosome translates RNA into proteins. The peroxisome is involved in the catabolism of very long chain fatty acids and amino acids, resulting in the formation of hydrogen peroxide. Lastly, the proteasome, along with the lysosome pathway, is involved in the degradation of protein molecules that have been tagged with ubiquitin.
-
This question is part of the following fields:
- General Principles
-
-
Question 28
Correct
-
A 50-year-old man presents to the Emergency Department complaining of abdominal pain, malaise, and visible jaundice. Upon taking his history, a junior doctor notes that the pain began after breakfast and has been worsening throughout the day. The patient's partner noticed his jaundice a few days ago, but he did not seek medical attention. The man has type II diabetes, which is well controlled with metformin, and he does not smoke. He drinks 16 units of alcohol per week and had unprotected sexual intercourse with a casual partner three days ago. He recently returned from a business trip to India, where he ate at a hotel and a client's home. One week ago, he experienced vomiting and diarrhea after eating undercooked chicken at a local restaurant. Based on this history, the junior doctor suspects hepatitis A. What aspect of the patient's history is most supportive of this diagnosis?
Your Answer: Trip to India three weeks ago
Explanation:Hepatitis A typically has a 2-4 week incubation period and is usually a mild, self-limiting illness. Symptoms may include jaundice, abdominal pain, and tender hepatomegaly. The virus is spread through the faecal-oral route, making it important to obtain a detailed history going back several weeks. India is an endemic area for hepatitis A, and eating at a local’s house may increase the risk of exposure.
While contaminated shellfish is a common source of hepatitis A, it is unlikely to be transmitted through chicken in the UK. Unprotected sex is a risk factor for hepatitis B and C, but not for hepatitis A. Type II diabetes is associated with non-alcoholic fatty liver disease, but not with an increased risk of viral hepatitis. Chronic hepatitis C infection may increase the risk of developing diabetes.
Although the patient’s alcohol consumption is slightly above the recommended limit of 14 units per week, it is not directly associated with an increased risk of viral hepatitis. However, it may be worth discussing reducing alcohol intake to promote overall liver health.
Understanding Hepatitis A: Symptoms, Transmission, and Prevention
Hepatitis A is a viral infection that affects the liver. It is usually a mild illness that resolves on its own, with serious complications being rare. The virus is transmitted through the faecal-oral route, often in institutions. The incubation period is typically 2-4 weeks, and symptoms include a flu-like prodrome, abdominal pain (usually in the right upper quadrant), tender hepatomegaly, jaundice, and deranged liver function tests.
While complications are rare, there is no increased risk of hepatocellular cancer. An effective vaccine is available, and it is recommended for people travelling to or residing in areas of high or intermediate prevalence, those with chronic liver disease, patients with haemophilia, men who have sex with men, injecting drug users, and individuals at occupational risk (such as laboratory workers, staff of large residential institutions, sewage workers, and people who work with primates).
It is important to note that the vaccine requires a booster dose 6-12 months after the initial dose. By understanding the symptoms, transmission, and prevention of hepatitis A, individuals can take steps to protect themselves and others from this viral infection.
-
This question is part of the following fields:
- General Principles
-
-
Question 29
Correct
-
A 38-year-old male patient complains of a painless lump in his left testicle that he discovered during self-examination. Upon examination, a solid nodule is palpable in the left testicle, and ultrasound imaging reveals an irregular mass lesion. The patient's serum AFP and HCG levels are both normal. What is the probable diagnosis?
Your Answer: Seminoma
Explanation:A seminoma is the most probable diagnosis for this man based on his age, symptoms, and normal levels of tumour markers. Teratomas and yolk sac tumours usually result in elevated AFP and HCG levels, which are not present in seminomas. Epididymo-orchitis does not cause painless irregular mass lesions.
Overview of Testicular Disorders
Testicular disorders can range from benign conditions to malignant tumors. Testicular cancer is the most common malignancy in men aged 20-30 years, with germ-cell tumors accounting for 95% of cases. Seminomas are the most common subtype, while non-seminomatous germ cell tumors include teratoma, yolk sac tumor, choriocarcinoma, and mixed germ cell tumors. Risk factors for testicular cancer include cryptorchidism, infertility, family history, Klinefelter’s syndrome, and mumps orchitis. The most common presenting symptom is a painless lump, but pain, hydrocele, and gynecomastia may also be present.
Benign testicular disorders include epididymo-orchitis, which is an acute inflammation of the epididymis often caused by bacterial infection. Testicular torsion, which results in testicular ischemia and necrosis, is most common in males aged between 10 and 30. Hydrocele presents as a mass that transilluminates and may occur as a result of a patent processus vaginalis in children. Treatment for these conditions varies, with orchidectomy being the primary treatment for testicular cancer. Surgical exploration is necessary for testicular torsion, while epididymo-orchitis and hydrocele may require medication or surgical procedures depending on the severity of the condition.
-
This question is part of the following fields:
- Renal System
-
-
Question 30
Incorrect
-
Mobilization of the left lobe of the liver will aid in accessing which surgical area?
Your Answer: Right kidney
Correct Answer: Abdominal oesophagus
Explanation:The posterior fundus of the stomach is located while the inferolateral position is occupied by the pylorus. In order to access the proximal stomach and abdominal esophagus during a total gastrectomy, it is helpful to divide the ligaments that hold the left lobe of the liver. However, this maneuver is not usually necessary during a distal gastrectomy.
Structure and Relations of the Liver
The liver is divided into four lobes: the right lobe, left lobe, quadrate lobe, and caudate lobe. The right lobe is supplied by the right hepatic artery and contains Couinaud segments V to VIII, while the left lobe is supplied by the left hepatic artery and contains Couinaud segments II to IV. The quadrate lobe is part of the right lobe anatomically but functionally is part of the left, and the caudate lobe is supplied by both right and left hepatic arteries and lies behind the plane of the porta hepatis. The liver lobules are separated by portal canals that contain the portal triad: the hepatic artery, portal vein, and tributary of bile duct.
The liver has various relations with other organs in the body. Anteriorly, it is related to the diaphragm, esophagus, xiphoid process, stomach, duodenum, hepatic flexure of colon, right kidney, gallbladder, and inferior vena cava. The porta hepatis is located on the postero-inferior surface of the liver and transmits the common hepatic duct, hepatic artery, portal vein, sympathetic and parasympathetic nerve fibers, and lymphatic drainage of the liver and nodes.
The liver is supported by ligaments, including the falciform ligament, which is a two-layer fold of peritoneum from the umbilicus to the anterior liver surface and contains the ligamentum teres (remnant of the umbilical vein). The ligamentum venosum is a remnant of the ductus venosus. The liver is supplied by the hepatic artery and drained by the hepatic veins and portal vein. Its nervous supply comes from the sympathetic and parasympathetic trunks of the coeliac plexus.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 31
Correct
-
A 53-year-old male presents to an endocrinology clinic with recurring symptoms of painful fingers and hands that seem to be enlarging. He was previously diagnosed with acromegaly eight months ago and underwent transsphenoidal surgery six months ago to remove the pituitary adenoma responsible. During examination, his facial features appear rough, and his hands are large and spade-like. You opt to manage this patient's symptoms with medication and initiate a trial of octreotide.
What physiological function is linked to this medication?Your Answer: Inhibition of glucagon secretion from the pancreas
Explanation:Somatostatin analogues, such as octreotide, are used to treat acromegaly in patients who have not responded well to surgery. Somatostatin is a hormone that has various functions, including inhibiting the secretion of growth hormone from the anterior pituitary gland and insulin and glucagon from the pancreas. Therefore, the correct answer is that somatostatin inhibits the secretion of glucagon.
The secretion of ACTH by the pancreas is regulated by a negative feedback loop involving cortisol and corticotropin-releasing hormone (CRH). When blood cortisol levels decrease, CRH is secreted from the hypothalamus, which then stimulates the secretion of ACTH from the anterior pituitary gland.
Somatostatin analogues typically do not affect the secretion of aldosterone from the pancreas, which is primarily stimulated by angiotensin-II.
Somatostatin analogues inhibit the secretion of growth hormone from the anterior pituitary gland. The hormone responsible for stimulating the secretion of growth hormone is growth hormone-releasing hormone (GHRH).
The secretion of insulin by pancreatic β-cells is inhibited by somatostatin analogues. The primary stimulus for insulin secretion is low blood glucose levels, but other substances such as arginine and leucine, acetylcholine, sulfonylurea, cholecystokinin, and incretins can also stimulate insulin release.
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
-
-
Question 32
Correct
-
An eager nursing student comes to you with a set of inquiries regarding blood transfusion reactions. Which of her subsequent statements is inaccurate?
Your Answer: Graft versus host disease involves neutrophil proliferation
Explanation:A helpful mnemonic for remembering transfusion reactions is Got a bad unit. Each letter represents a potential complication:
G – Graft vs. Host disease
O – Overload
T – Thrombocytopenia
A – Alloimmunization
B – Blood pressure unstable
A – Acute hemolytic reaction
D – Delayed hemolytic reaction
U – Urticaria
N – Neutrophilia
I – Infection
T – Transfusion-associated lung injuryGraft vs. Host disease occurs when the patient’s own lymphocytes are similar to the donor’s lymphocytes, causing severe complications. Thrombocytopenia may occur a few days after transfusion and may resolve on its own. Patients with IGA antibodies require IgA deficient blood transfusions.
Blood product transfusion complications can be categorized into immunological, infective, and other complications. Immunological complications include acute haemolytic reactions, non-haemolytic febrile reactions, and allergic/anaphylaxis reactions. Infective complications may arise due to transmission of vCJD, although measures have been taken to minimize this risk. Other complications include transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), hyperkalaemia, iron overload, and clotting.
Non-haemolytic febrile reactions are thought to be caused by antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage. These reactions may occur in 1-2% of red cell transfusions and 10-30% of platelet transfusions. Minor allergic reactions may also occur due to foreign plasma proteins, while anaphylaxis may be caused by patients with IgA deficiency who have anti-IgA antibodies.
Acute haemolytic transfusion reaction is a serious complication that results from a mismatch of blood group (ABO) which causes massive intravascular haemolysis. Symptoms begin minutes after the transfusion is started and include a fever, abdominal and chest pain, agitation, and hypotension. Treatment should include immediate transfusion termination, generous fluid resuscitation with saline solution, and informing the lab. Complications include disseminated intravascular coagulation and renal failure.
TRALI is a rare but potentially fatal complication of blood transfusion that is characterized by the development of hypoxaemia/acute respiratory distress syndrome within 6 hours of transfusion. On the other hand, TACO is a relatively common reaction due to fluid overload resulting in pulmonary oedema. As well as features of pulmonary oedema, the patient may also be hypertensive, a key difference from patients with TRALI.
-
This question is part of the following fields:
- Haematology And Oncology
-
-
Question 33
Incorrect
-
A 25-day-old girl is brought in with jaundice and inadequate weight gain. She presents with a swollen tongue, thick skin, and elevated unconjugated bilirubin levels. It is noted that she did not receive the heel prick blood test on day 5.
What condition is the most probable diagnosis?Your Answer: MCAD deficiency
Correct Answer: Hypothyroidism
Explanation:Congenital Hypothyroidism and Other Conditions Screened for in the UK
Congenital hypothyroidism is a rare condition in the United Kingdom, often caused by inherited metabolic defects. It is important to diagnose and treat early, as untreated cases can lead to serious long-term consequences such as learning difficulties and growth restriction. Symptoms of congenital hypothyroidism include poor weight gain, a large tongue, thick skin, constipation, and coarse facies.
In the UK, the Guthrie test is used to screen for five conditions on days four to five after birth. These conditions include cystic fibrosis, sickle cell disease, phenylketonuria (PKU), MCAD deficiency, and congenital hypothyroidism. Galactosaemia is another severe metabolic condition that affects neonates from their first milk feed.
Cystic fibrosis is an autosomal recessive condition that results in thick bodily secretions due to a mutation in the chloride ion channel transporter proteins. MCAD deficiency leads to symptoms of hypotonia, hypoglycemia, and vomiting. PKU leads to symptoms of cognitive dysfunction, learning disability, and seizures. By screening for these conditions, healthcare professionals can identify and treat affected infants early, improving their long-term outcomes.
-
This question is part of the following fields:
- Paediatrics
-
-
Question 34
Correct
-
A 56-year-old male patient comes to the clinic with a history of dyspepsia that he has ignored for a long time. He reports no symptoms of dysphagia or haematemesis. During an oesophagoduodenoscopy (OGD), mucosal changes are observed in the lower part of the oesophagus near the sphincter, and a biopsy is taken from this area. What is the probable result of the biopsy?
Your Answer: Columnar epithelial cells
Explanation:The patient has Barrett’s oesophagus, which is a metaplastic condition where the normal oesophageal epithelium is replaced by columnar cells. This increases the risk of adenocarcinoma.
Barrett’s oesophagus is a condition where the lower oesophageal mucosa is replaced by columnar epithelium, which increases the risk of oesophageal adenocarcinoma by 50-100 fold. It is usually identified during an endoscopy for upper gastrointestinal symptoms such as dyspepsia, as there are no screening programs for it. The length of the affected segment determines the chances of identifying metaplasia, with short (<3 cm) and long (>3 cm) subtypes. The prevalence of Barrett’s oesophagus is estimated to be around 1 in 20, and it is identified in up to 12% of those undergoing endoscopy for reflux.
The columnar epithelium in Barrett’s oesophagus may resemble that of the cardiac region of the stomach or that of the small intestine, with goblet cells and brush border. The single strongest risk factor for Barrett’s oesophagus is gastro-oesophageal reflux disease (GORD), followed by male gender, smoking, and central obesity. Alcohol is not an independent risk factor for Barrett’s, but it is associated with both GORD and oesophageal cancer. Patients with Barrett’s oesophagus often have coexistent GORD symptoms.
The management of Barrett’s oesophagus involves high-dose proton pump inhibitor, although the evidence base for its effectiveness in reducing the progression to dysplasia or inducing regression of the lesion is limited. Endoscopic surveillance with biopsies is recommended every 3-5 years for patients with metaplasia but not dysplasia. If dysplasia of any grade is identified, endoscopic intervention is offered, such as radiofrequency ablation, which is the preferred first-line treatment, particularly for low-grade dysplasia, or endoscopic mucosal resection.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 35
Correct
-
A 43-year-old female comes to the ENT clinic with a history of constant vertigo and right-sided deafness for the past year. She has no significant medical history. Upon conducting an audiogram, it is discovered that her right ear has reduced hearing to both bone and air conduction. During a cranial nerve exam, an absent corneal reflex is observed on the right side, and she has poor balance. Otoscopy of both ears is normal. What is the probable underlying pathology responsible for this patient's symptoms and signs?
Your Answer: Vestibular schwannoma (acoustic neuroma)
Explanation:If a patient presents with loss of the corneal reflex, the likely diagnosis is vestibular schwannoma (acoustic neuroma). This is a noncancerous tumor that affects the vestibular portion of the 8th cranial nerve, leading to sensorineural deafness, tinnitus, and vertigo. As the tumor grows, it can also press on other cranial nerves. Loss of the corneal reflex is a classic sign of early trigeminal (cranial nerve 5) involvement, which is unlikely in any of the other listed conditions.
Meniere’s disease is not the correct answer. This is a disorder of the middle ear that causes episodic vertigo, sensorineural hearing loss, and a sensation of aural fullness or pressure.
Otosclerosis is also incorrect. This is an inherited condition that causes conductive deafness and tinnitus, typically presenting in patients aged 20-40 years.
Vestibular mononeuritis is not the correct answer either. This condition is caused by inflammation of the vestibular nerve following a recent viral infection and presents with vertigo, but hearing is not affected.
Vestibular schwannomas, also known as acoustic neuromas, make up about 5% of intracranial tumors and 90% of cerebellopontine angle tumors. These tumors typically present with a combination of vertigo, hearing loss, tinnitus, and an absent corneal reflex. The specific symptoms can be predicted based on which cranial nerves are affected. For example, cranial nerve VIII involvement can cause vertigo, unilateral sensorineural hearing loss, and unilateral tinnitus. Bilateral vestibular schwannomas are associated with neurofibromatosis type 2.
If a vestibular schwannoma is suspected, it is important to refer the patient to an ear, nose, and throat specialist urgently. However, it is worth noting that these tumors are often benign and slow-growing, so observation may be appropriate initially. The diagnosis is typically confirmed with an MRI of the cerebellopontine angle, and audiometry is also important as most patients will have some degree of hearing loss. Treatment options include surgery, radiotherapy, or continued observation.
-
This question is part of the following fields:
- Neurological System
-
-
Question 36
Incorrect
-
A 23-year-old patient comes to your dermatology clinic with a patch of inflamed skin covered with white, scaly skin on their arm. The lesion is causing intense itching and is becoming embarrassing for the patient. They mention that their mother has also been suffering from the same condition since childhood. After examination, you diagnose the patient with psoriasis. The patient asks for more information about their condition, and you explain that it is believed to be associated with overexpression of interleukin-2 (IL-2). The patient then asks where these inflammatory mediators are secreted from.
Your Answer: Macrophages
Correct Answer: T-helper 1 (Th1) cells
Explanation:Overview of Cytokines and Their Functions
Cytokines are signaling molecules that play a crucial role in the immune system. Interleukins are a type of cytokine that are produced by various immune cells and have specific functions. IL-1, produced by macrophages, induces acute inflammation and fever. IL-2, produced by Th1 cells, stimulates the growth and differentiation of T cell responses. IL-3, produced by activated T helper cells, stimulates the differentiation and proliferation of myeloid progenitor cells. IL-4, produced by Th2 cells, stimulates the proliferation and differentiation of B cells. IL-5, also produced by Th2 cells, stimulates the production of eosinophils. IL-6, produced by macrophages and Th2 cells, stimulates the differentiation of B cells and induces fever. IL-8, produced by macrophages, promotes neutrophil chemotaxis. IL-10, produced by Th2 cells, inhibits Th1 cytokine production and is known as an anti-inflammatory cytokine. IL-12, produced by dendritic cells, macrophages, and B cells, activates NK cells and stimulates the differentiation of naive T cells into Th1 cells.
In addition to interleukins, there are other cytokines with specific functions. Tumor necrosis factor-alpha, produced by macrophages, induces fever and promotes neutrophil chemotaxis. Interferon-gamma, produced by Th1 cells, activates macrophages. Understanding the functions of cytokines is important in developing treatments for various immune-related diseases.
-
This question is part of the following fields:
- General Principles
-
-
Question 37
Correct
-
A 22-year-old woman presented to the hospital with a sudden onset headache. She reports no history of trauma prior to the headache. The pain began at the back of her head while she was watching TV and quickly reached its peak intensity within 2 seconds, rated at 10/10. She has never experienced a headache before.
The patient also reported photophobia and neck stiffness after the headache. Neurological examination did not reveal any focal deficits, and her Glasgow Coma Scale score was 15/15.
What is the most probable underlying diagnosis?Your Answer: Subarachnoid haemorrhage
Explanation:If you experience a sudden headache in the occipital region, it could be a sign of subarachnoid haemorrhage. This is especially true if you also develop sensitivity to light and stiffness in the neck. To investigate this possibility, a CT scan of the head may be ordered. If the results are inconclusive, a lumbar puncture with xanthochromia screen may be performed.
In contrast, intracerebral haemorrhage typically causes focal neurological deficits or a decrease in consciousness. It is often associated with risk factors such as hypertension and diabetes.
Extradural haemorrhage, on the other hand, usually occurs after head trauma, particularly to the temporal regions. It is caused by injury to the middle meningeal artery and can cause a lucid patient to lose consciousness gradually over several hours. As intracranial pressure increases, patients may also experience focal neurological deficits and cranial nerve palsies.
There are different types of traumatic brain injury, including focal (contusion/haematoma) or diffuse (diffuse axonal injury). Diffuse axonal injury occurs due to mechanical shearing following deceleration, causing disruption and tearing of axons. Intracranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact. Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury.
-
This question is part of the following fields:
- Neurological System
-
-
Question 38
Correct
-
An aging patient with Parkinson's disease is admitted to a neurology ward after experiencing a fall. While conducting a cranial nerves examination, the physician observes that the patient is unable to gaze upward when their head is fixed in place. The physician begins to consider other potential diagnoses. What would be the most appropriate diagnosis?
Your Answer: Progressive supranuclear palsy
Explanation:These are all syndromes that share the main symptoms of Parkinson’s disease, but also have additional specific symptoms:
– Progressive supranuclear palsy affects the muscles used for looking upwards.
– Vascular dementia is a type of dementia that usually occurs after several small strokes.
– Dementia with Lewy bodies is characterized by the buildup of Lewy bodies, which are clumps of a protein called alpha-synuclein, and often includes visual hallucinations.
– Multiple system atrophy often involves problems with the autonomic nervous system, such as low blood pressure when standing and difficulty emptying the bladder.Progressive supranuclear palsy, also known as Steele-Richardson-Olszewski syndrome, is a type of ‘Parkinson Plus’ syndrome. It is characterized by postural instability and falls, as well as a stiff, broad-based gait. Patients with this condition also experience impairment of vertical gaze, with down gaze being worse than up gaze. This can lead to difficulty reading or descending stairs. Parkinsonism is also present, with bradykinesia being a prominent feature. Cognitive impairment is also common, primarily due to frontal lobe dysfunction. Unfortunately, this condition has a poor response to L-dopa.
-
This question is part of the following fields:
- Neurological System
-
-
Question 39
Correct
-
You examine a patient who suffered a severe stroke two years prior.
What clinical examination features would you anticipate observing?Your Answer: Increased deep tendon reflexes
Explanation:If there is an increased reflex response, it may indicate an upper motor neuron lesion. This type of lesion can be caused by a stroke and can result in spastic weakness and heightened reflex responses. The reason for hyperreflexia is due to the loss of inhibitory signals that normally regulate spinal reflex circuits. On the other hand, a lower motor neuron lesion will cause flaccid weakness, reduced deep tendon reflexes, fasciculations, and muscle atrophy.
Reflexes are automatic responses that our body makes in response to certain stimuli. These responses are controlled by the nervous system and do not require conscious thought. There are several common reflexes that are associated with specific roots in the spinal cord. For example, the ankle reflex is associated with the S1-S2 root, while the knee reflex is associated with the L3-L4 root. Similarly, the biceps reflex is associated with the C5-C6 root, and the triceps reflex is associated with the C7-C8 root. Understanding these reflexes can help healthcare professionals diagnose and treat certain conditions.
-
This question is part of the following fields:
- Neurological System
-
-
Question 40
Correct
-
A 23-year-old man gets into a brawl outside a nightclub and is stabbed in the back, on the left side, about 3 cm below the 12th rib in the mid scapular line. Which structure is most likely to be injured first as a result of this incident?
Your Answer: Left kidney
Explanation:The most probable structure to be injured is the left kidney, which is situated in this area. The left adrenal and ureter are unlikely to be injured alone, while the spleen is located higher up.
Anatomical Planes and Levels in the Human Body
The human body can be divided into different planes and levels to aid in anatomical study and medical procedures. One such plane is the transpyloric plane, which runs horizontally through the body of L1 and intersects with various organs such as the pylorus of the stomach, left kidney hilum, and duodenojejunal flexure. Another way to identify planes is by using common level landmarks, such as the inferior mesenteric artery at L3 or the formation of the IVC at L5.
In addition to planes and levels, there are also diaphragm apertures located at specific levels in the body. These include the vena cava at T8, the esophagus at T10, and the aortic hiatus at T12. By understanding these planes, levels, and apertures, medical professionals can better navigate the human body during procedures and accurately diagnose and treat various conditions.
-
This question is part of the following fields:
- Neurological System
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Mins)