-
Question 1
Incorrect
-
A woman in her early fifties comes in with a painful shoulder and limited range of motion. The shoulder is sensitive to touch, and there is no record of injury. During the examination, both active and passive movement are restricted due to pain. Based on these symptoms, you suspect the patient has a frozen shoulder. What is the primary location of inflammation in this condition?
Your Answer: Articular cartilage of the humeral head
Correct Answer: Shoulder capsule
Explanation:Frozen shoulder is caused by inflammation of the shoulder capsule, leading to pain and reduced range of movement. Other conditions that can cause shoulder pain include biceps tendonitis, shoulder arthritis, and glenoid labrum tears.
Adhesive capsulitis, also known as frozen shoulder, is a common cause of shoulder pain that is more prevalent in middle-aged women. The exact cause of this condition is not fully understood. It is associated with diabetes mellitus, with up to 20% of diabetics experiencing an episode of frozen shoulder. Symptoms typically develop over a few days and affect external rotation more than internal rotation or abduction. Both active and passive movement are affected, and patients usually experience a painful freezing phase, an adhesive phase, and a recovery phase. Bilateral frozen shoulder occurs in up to 20% of patients, and the episode typically lasts between 6 months and 2 years.
The diagnosis of frozen shoulder is usually made based on clinical presentation, although imaging may be necessary for atypical or persistent symptoms. There is no single intervention that has been proven to improve long-term outcomes. Treatment options include nonsteroidal anti-inflammatory drugs (NSAIDs), physiotherapy, oral corticosteroids, and intra-articular corticosteroids. It is important to note that the management of frozen shoulder should be tailored to the individual patient, and a multidisciplinary approach may be necessary for optimal outcomes.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 2
Correct
-
A 14-year-old girl is referred to the endocrine clinic by her GP due to bed wetting episodes. She experiences constant thirst and frequent urination. A dipstick test reveals diluted urine with low osmolality, and her blood tests show hypernatremia with high serum osmolality. Her family has a history of diabetes insipidus. What is the most suitable follow-up examination?
Your Answer: Water deprivation test
Explanation:A water deprivation test is the most appropriate method for diagnosing diabetes insipidus. This test involves withholding water from the patient for a period of time to stimulate the release of antidiuretic hormone (ADH) and monitor changes in serum and urine osmolality. Other methods such as urinary sodium or bladder ultrasound scan are not as effective in diagnosing this condition.
The water deprivation test is a diagnostic tool used to assess patients with polydipsia, or excessive thirst. During the test, the patient is instructed to refrain from drinking water, and their bladder is emptied. Hourly measurements of urine and plasma osmolalities are taken to monitor changes in the body’s fluid balance. The results of the test can help identify the underlying cause of the patient’s polydipsia. Normal results show a high urine osmolality after the administration of DDAVP, while psychogenic polydipsia is characterized by a low urine osmolality. Cranial DI and nephrogenic DI are both associated with high plasma osmolalities and low urine osmolalities.
-
This question is part of the following fields:
- Endocrine System
-
-
Question 3
Incorrect
-
A 15-year-old male patient comes to the clinic with a skin rash and tremors. Upon conducting a urine chromatography test, it is found that he has elevated levels of neutral amino acids. The diagnosis is Hartnup disease. Can you identify which of the following options is an essential neutral amino acid?
Your Answer: Aspartate
Correct Answer: Tryptophan
Explanation:Essential Amino Acids
Essential amino acids are those that the body cannot produce in sufficient quantities to meet the needs of cells. Therefore, they must be obtained through the diet. The essential amino acids include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. During childhood, arginine and histidine are also considered essential amino acids. Mnemonics can be used to help remember these essential amino acids. Aspartate and serine are not essential amino acids, while arginine and histidine are positively charged and therefore not essential. The only essential amino acid that is both neutral and essential is tryptophan.
-
This question is part of the following fields:
- Clinical Sciences
-
-
Question 4
Incorrect
-
Which one of the following is not a branch of the posterior cord of the brachial plexus?
Your Answer: Thoracodorsal nerve
Correct Answer: Musculocutaneous nerve
Explanation:The posterior cord gives rise to mnemonic branches, including the subscapular (upper and lower), thoracodorsal, axillary, and radial nerves. On the other hand, the musculocutaneous nerve is a branch originating from the lateral cord.
Understanding the Brachial Plexus and Cutaneous Sensation of the Upper Limb
The brachial plexus is a network of nerves that originates from the anterior rami of C5 to T1. It is divided into five sections: roots, trunks, divisions, cords, and branches. To remember these sections, a common mnemonic used is Real Teenagers Drink Cold Beer.
The roots of the brachial plexus are located in the posterior triangle and pass between the scalenus anterior and medius muscles. The trunks are located posterior to the middle third of the clavicle, with the upper and middle trunks related superiorly to the subclavian artery. The lower trunk passes over the first rib posterior to the subclavian artery. The divisions of the brachial plexus are located at the apex of the axilla, while the cords are related to the axillary artery.
The branches of the brachial plexus provide cutaneous sensation to the upper limb. This includes the radial nerve, which provides sensation to the posterior arm, forearm, and hand; the median nerve, which provides sensation to the palmar aspect of the thumb, index, middle, and half of the ring finger; and the ulnar nerve, which provides sensation to the palmar and dorsal aspects of the fifth finger and half of the ring finger.
Understanding the brachial plexus and its branches is important in diagnosing and treating conditions that affect the upper limb, such as nerve injuries and neuropathies. It also helps in understanding the cutaneous sensation of the upper limb and how it relates to the different nerves of the brachial plexus.
-
This question is part of the following fields:
- Neurological System
-
-
Question 5
Correct
-
An 82-year-old man arrives at the emergency department with sepsis of unknown origin. During a thorough examination, it is discovered that his big toe is swollen, black, and tender. A fluid collection is also present at the nail bed. The patient has a history of uncontrolled type 1 diabetes mellitus. An MRI confirms the diagnosis of osteomyelitis. What is the probable causative organism?
Your Answer: Staphylococcus aureus
Explanation:The most common cause of osteomyelitis is Staphylococcus aureus, a bacteria that is normally found on the skin and mucus membranes but can become pathogenic in individuals who are immunocompromised or have risk factors for infections. Clostridium perfringens, Pseudomonas aeruginosa, and Staphylococcus epidermidis are not common causes of osteomyelitis, although they may cause other types of infections.
Understanding Osteomyelitis: Types, Causes, and Treatment
Osteomyelitis is a bone infection that can be classified into two types: haematogenous and non-haematogenous. Haematogenous osteomyelitis is caused by bacteria in the bloodstream and is usually monomicrobial. It is more common in children and can be caused by risk factors such as sickle cell anaemia, intravenous drug use, immunosuppression, and infective endocarditis. On the other hand, non-haematogenous osteomyelitis is caused by the spread of infection from adjacent soft tissues or direct injury to the bone. It is often polymicrobial and more common in adults, with risk factors such as diabetic foot ulcers, pressure sores, diabetes mellitus, and peripheral arterial disease.
Staphylococcus aureus is the most common cause of osteomyelitis, except in patients with sickle-cell anaemia where Salmonella species are more prevalent. To diagnose osteomyelitis, MRI is the imaging modality of choice, with a sensitivity of 90-100%.
The treatment for osteomyelitis involves a course of antibiotics for six weeks. Flucloxacillin is the preferred antibiotic, but clindamycin can be used for patients who are allergic to penicillin. Understanding the types, causes, and treatment of osteomyelitis is crucial in managing this bone infection.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 6
Correct
-
A 2-year-old toddler is brought to the cardiology clinic by her mother due to concerns of episodes of turning blue, especially when laughing or crying. During the examination, the toddler is observed to have clubbing of the fingernails and confirmed to be cyanotic. Further investigation with an echocardiogram reveals a large ventricular septal defect, leading to a diagnosis of Eisenmenger's syndrome. What is the ultimate treatment for this condition?
Your Answer: Heart- lung transplant
Explanation:The most effective way to manage Eisenmenger’s syndrome is through a heart-lung transplant. Calcium-channel blockers can be used to decrease the strain on the right side of the circulation by increasing the right to left shunt. Antibiotics are also useful in preventing endocarditis. However, the use of oxygen as a long-term treatment is still a topic of debate and is not considered a definitive solution. Patients with Eisenmenger’s syndrome may also experience significant polycythemia, which may require venesection as a treatment option.
Understanding Eisenmenger’s Syndrome
Eisenmenger’s syndrome is a medical condition that occurs when a congenital heart defect leads to pulmonary hypertension, causing a reversal of a left-to-right shunt. This happens when the left-to-right shunt is not corrected, leading to the remodeling of the pulmonary microvasculature, which eventually obstructs pulmonary blood and causes pulmonary hypertension. The condition is commonly associated with ventricular septal defect, atrial septal defect, and patent ductus arteriosus.
The original murmur may disappear, and patients may experience cyanosis, clubbing, right ventricular failure, haemoptysis, and embolism. Management of Eisenmenger’s syndrome requires heart-lung transplantation. It is essential to diagnose and treat the condition early to prevent complications and improve the patient’s quality of life. Understanding the causes, symptoms, and management of Eisenmenger’s syndrome is crucial for healthcare professionals to provide appropriate care and support to patients with this condition.
-
This question is part of the following fields:
- Cardiovascular System
-
-
Question 7
Incorrect
-
A high school football player comes to the emergency department after a hard tackle. He complains of pain in the front of his shoulder, limited movement in his affected arm, and notices that his collarbone is protruding outward. An X-ray shows that his clavicle is displaced, particularly at the lateral end, but still intact. The medial end of the clavicle is still in contact with the sternum, and there are no other bone abnormalities. Given the extent of the dislocation, you suspect that multiple ligaments have been torn. Which of the following ligaments is the least likely to be affected?
Your Answer: Trapezoid ligament
Correct Answer: Coracoacromial ligament
Explanation:The coracoacromial ligament is not likely to be damaged in a clavicle dislocation, as it does not connect to the clavicle. The ligaments that attach to the lateral end of the clavicle include the acromioclavicular ligament, trapezoid ligament, and conoid ligament (collectively known as the coracoclavicular ligament). In the case of an acromioclavicular joint dislocation, the severity of the injury depends on which ligaments are damaged. Mild cases may involve only a sprain or rupture of the acromioclavicular ligament, while more severe cases may involve rupture of all ligaments attaching to the lateral end of the clavicle.
Anatomy of the Clavicle
The clavicle is a bone that runs from the sternum to the acromion and plays a crucial role in preventing the shoulder from falling forwards and downwards. Its inferior surface is marked by ligaments at each end, including the trapezoid line and conoid tubercle, which provide attachment to the coracoclavicular ligament. The costoclavicular ligament attaches to the irregular surface on the medial part of the inferior surface, while the subclavius muscle attaches to the intermediate portion’s groove.
The superior part of the clavicle’s medial end has a raised surface that gives attachment to the clavicular head of sternocleidomastoid, while the posterior surface attaches to the sternohyoid. On the lateral end, there is an oval articular facet for the acromion, and a disk lies between the clavicle and acromion. The joint’s capsule attaches to the ridge on the margin of the facet.
In summary, the clavicle is a vital bone that helps stabilize the shoulder joint and provides attachment points for various ligaments and muscles. Its anatomy is marked by distinct features that allow for proper function and movement.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 8
Incorrect
-
A newborn with clubbed feet passes away shortly after birth due to severe respiratory distress. The mother did not receive any prenatal care. Autopsy reveals pulmonary hypoplasia.
What other clinical manifestations are likely to be present?Your Answer: Bilateral renal agenesis and polyhydramnios
Correct Answer: Bilateral renal agenesis and oligohydramnios
Explanation:Potter sequence is a condition characterized by oligohydramnios, which can be caused by renal diseases like bilateral renal agenesis, ARPKD, and ADPKD. This condition often leads to pulmonary hypoplasia, clubbed feet, and cranial anomalies in neonates. However, oesophageal atresia, which causes polyhydramnios, is not associated with Potter sequence.
Understanding Autosomal Recessive Polycystic Kidney Disease (ARPKD)
Autosomal recessive polycystic kidney disease (ARPKD) is a rare genetic disorder that affects the kidneys and liver. Unlike the more common autosomal dominant polycystic kidney disease (ADPKD), ARPKD is caused by a defect in a gene on chromosome 6 that encodes fibrocystin, a protein essential for normal renal tubule development.
ARPKD is typically diagnosed during prenatal ultrasound or in early infancy when abdominal masses and renal failure are observed. Newborns with ARPKD may also exhibit features consistent with Potter’s syndrome due to oligohydramnios. The disease progresses rapidly, and end-stage renal failure usually develops in childhood. In addition to kidney involvement, patients with ARPKD often have liver complications such as portal and interlobular fibrosis.
Renal biopsy is a common diagnostic tool for ARPKD, which typically shows multiple cylindrical lesions at right angles to the cortical surface. Early diagnosis and management are crucial in improving outcomes for patients with ARPKD.
-
This question is part of the following fields:
- Renal System
-
-
Question 9
Incorrect
-
Your next patient, Emily, is a 26-year-old female who is an avid athlete. She arrives at the emergency department with an arm injury. After a basic x-ray, it is revealed that she has a humerus shaft fracture.
Considering the probable nerve damage, which of the subsequent movements will Emily have difficulty with?Your Answer: Opposition of the thumb
Correct Answer: Wrist extension
Explanation:The radial nerve is susceptible to injury in the case of a humerus shaft fracture, which can result in impaired wrist extension.
The Radial Nerve: Anatomy, Innervation, and Patterns of Damage
The radial nerve is a continuation of the posterior cord of the brachial plexus, with root values ranging from C5 to T1. It travels through the axilla, posterior to the axillary artery, and enters the arm between the brachial artery and the long head of triceps. From there, it spirals around the posterior surface of the humerus in the groove for the radial nerve before piercing the intermuscular septum and descending in front of the lateral epicondyle. At the lateral epicondyle, it divides into a superficial and deep terminal branch, with the deep branch crossing the supinator to become the posterior interosseous nerve.
The radial nerve innervates several muscles, including triceps, anconeus, brachioradialis, and extensor carpi radialis. The posterior interosseous branch innervates supinator, extensor carpi ulnaris, extensor digitorum, and other muscles. Denervation of these muscles can lead to weakness or paralysis, with effects ranging from minor effects on shoulder stability to loss of elbow extension and weakening of supination of prone hand and elbow flexion in mid prone position.
Damage to the radial nerve can result in wrist drop and sensory loss to a small area between the dorsal aspect of the 1st and 2nd metacarpals. Axillary damage can also cause paralysis of triceps. Understanding the anatomy, innervation, and patterns of damage of the radial nerve is important for diagnosing and treating conditions that affect this nerve.
-
This question is part of the following fields:
- Neurological System
-
-
Question 10
Incorrect
-
A 45-year-old woman presents with unsteadiness on her feet. She reports leaning to her right and has sustained scrapes on her right arm from falling on this side. During her walk to the examination room, she displays a broad-based ataxic gait, with a tendency to lean to the right.
Upon neurological examination, she exhibits an intention tremor and dysdiadochokinesia of her right hand. Her right lower limb is positive for the heel-shin test. Additionally, there is a gaze-evoked nystagmus of the right eye.
What is the likely location of the brain lesion?Your Answer: Left temporal
Correct Answer: Right cerebellum
Explanation:Unilateral damage to the cerebellum results in symptoms that are on the same side as the lesion. In this case, if the right cerebellum is damaged, the individual may experience dysdiadochokinesia, ataxia, nystagmus, intention tremor, scanning dysarthria, and a positive heel-shin test. Damage to the left cerebellum would not cause symptoms on the right side. Damage to the left temporal lobe may result in changes in behavior and emotions, forgetfulness, disruptions in the sense of smell, taste, and hearing, and language and speech disorders. Damage to the right parietal lobe may cause alexia, agraphia, acalculia, left-sided hemi-spatial neglect, homonymous inferior quadrantanopia, loss of sensations like touch, apraxias, or astereognosis.
Cerebellar syndrome is a condition that affects the cerebellum, a part of the brain responsible for coordinating movement and balance. When there is damage or injury to one side of the cerebellum, it can cause symptoms on the same side of the body. These symptoms can be remembered using the mnemonic DANISH, which stands for Dysdiadochokinesia, Dysmetria, Ataxia, Nystagmus, Intention tremour, Slurred staccato speech, and Hypotonia.
There are several possible causes of cerebellar syndrome, including genetic conditions like Friedreich’s ataxia and ataxic telangiectasia, neoplastic growths like cerebellar haemangioma, strokes, alcohol use, multiple sclerosis, hypothyroidism, and certain medications or toxins like phenytoin or lead poisoning. In some cases, cerebellar syndrome may be a paraneoplastic condition, meaning it is a secondary effect of an underlying cancer like lung cancer. It is important to identify the underlying cause of cerebellar syndrome in order to provide appropriate treatment and management.
-
This question is part of the following fields:
- Neurological System
-
-
Question 11
Incorrect
-
A patient in his 50s becomes dehydrated, resulting in increased water absorption in the collecting duct. If the concentration of his urine is measured, it would be around 1200mOsm/L. At which point in the nephron would a comparable osmolarity be observed?
Your Answer: Thick ascending Loop of Henle
Correct Answer: The tip of the Loop of Henle
Explanation:The Loop of Henle creates the highest osmolarity in the nephron, while the proximal tubule absorbs most of the water. The tip of the papilla has the greatest osmolarity, which is also the maximum osmolarity that urine can attain after water absorption in the collecting ducts. The medulla of the kidney facilitates water reabsorption in the collecting ducts due to the osmotic gradient formed by the Loops of Henle.
The Loop of Henle and its Role in Renal Physiology
The Loop of Henle is a crucial component of the renal system, located in the juxtamedullary nephrons and running deep into the medulla. Approximately 60 litres of water containing 9000 mmol sodium enters the descending limb of the loop of Henle in 24 hours. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thin ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb, the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, which have similar solute compositions to the surrounding extracellular fluid, preventing the diffusion and subsequent removal of this hypertonic fluid. The energy-dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient. Overall, the Loop of Henle plays a crucial role in regulating the concentration of solutes in the renal system.
-
This question is part of the following fields:
- Renal System
-
-
Question 12
Incorrect
-
Which of the following organisms is not a common cause of respiratory tract infections in elderly patients, with cystic fibrosis?
Your Answer: Burkholderia cepacia
Correct Answer: Strongyloides stercoralis
Explanation:Understanding Cystic Fibrosis
Cystic fibrosis is a genetic disorder that causes thickened secretions in the lungs and pancreas. It is an autosomal recessive condition that occurs due to a defect in the cystic fibrosis transmembrane conductance regulator gene (CFTR), which regulates a chloride channel. In the UK, 80% of CF cases are caused by delta F508 on chromosome 7, and the carrier rate is approximately 1 in 25.
CF patients are at risk of colonization by certain organisms, including Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia (previously known as Pseudomonas cepacia), and Aspergillus. These organisms can cause infections and exacerbate symptoms in CF patients. It is important for healthcare providers to monitor and manage these infections to prevent further complications.
Overall, understanding cystic fibrosis and its associated risks can help healthcare providers provide better care for patients with this condition.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 13
Incorrect
-
A 10-year-old boy has been admitted to the hospital due to a swollen and painful right knee. His mother reports that he has always had large bruises after minor injuries. About six months ago, he had bleeding that lasted for ten days after biting his tongue, which required a blood transfusion. The patient has not taken any medication except for Paracetamol for knee pain two hours ago. In the family history, the patient's uncle required a blood transfusion after tonsillectomy and had bleeding after a dental extraction, while their grandfather had severe bleeding after a routine knee operation. Which of the following test results would be expected? The tests are BT (bleeding time), APTT (activated partial thromboplastin time), PT (prothrombin time), and TT (thrombin time).
Your Answer: BT - Abnormal; APTT - Normal; PT - Abnormal; TT - Normal
Correct Answer: BT - Normal; APTT - Abnormal; PT - Normal; TT - Normal
Explanation:Haemophilia and its Laboratory Findings
Haemophilia is a genetic disorder that affects males in the family. It can either be haemophilia A or B, which are both sex-linked recessive disorders. Haemophilia A is caused by a deficiency of factor VIII, while haemophilia B is caused by a deficiency of factor IX. Females are carriers of the gene, but only males express the disease. The hallmark symptoms of haemophilia include haemorrhage into the joints, bleeding with tooth extraction, and skin bruising.
Laboratory findings in haemophilia include normal prothrombin time and bleeding time, as well as normal fibrinogen levels. However, there is a prolongation of the partial thromboplastin time. It is important to differentiate haemophilia from other bleeding disorders, such as Von Willebrand’s disease. While the bleeding phenotype in Von Willebrand’s disease is generally less severe, the family history is more in keeping with haemophilia. Coagulation tests in Von Willebrand’s disease are often normal.
In summary, haemophilia is a genetic disorder that affects males in the family and can either be haemophilia A or B. The hallmark symptoms include haemorrhage into the joints, bleeding with tooth extraction, and skin bruising. Laboratory findings in haemophilia include normal prothrombin time and bleeding time, normal fibrinogen levels, and a prolongation of the partial thromboplastin time. It is important to differentiate haemophilia from other bleeding disorders, such as Von Willebrand’s disease, which has different coagulation test results.
-
This question is part of the following fields:
- Haematology And Oncology
-
-
Question 14
Correct
-
A 55-year-old woman complains of discomfort and pain in her hand. She is employed as a typist and experiences the most pain while working. She also experiences symptoms during the night. The pain is less severe in her little finger. Which nerve is most likely to be affected?
Your Answer: Median
Explanation:EIWRTREY
Anatomy and Function of the Median Nerve
The median nerve is a nerve that originates from the lateral and medial cords of the brachial plexus. It descends lateral to the brachial artery and passes deep to the bicipital aponeurosis and the median cubital vein at the elbow. The nerve then passes between the two heads of the pronator teres muscle and runs on the deep surface of flexor digitorum superficialis. Near the wrist, it becomes superficial between the tendons of flexor digitorum superficialis and flexor carpi radialis, passing deep to the flexor retinaculum to enter the palm.
The median nerve has several branches that supply the upper arm, forearm, and hand. These branches include the pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor pollicis longus, and palmar cutaneous branch. The nerve also provides motor supply to the lateral two lumbricals, opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis muscles, as well as sensory supply to the palmar aspect of the lateral 2 ½ fingers.
Damage to the median nerve can occur at the wrist or elbow, resulting in various symptoms such as paralysis and wasting of thenar eminence muscles, weakness of wrist flexion, and sensory loss to the palmar aspect of the fingers. Additionally, damage to the anterior interosseous nerve, a branch of the median nerve, can result in loss of pronation of the forearm and weakness of long flexors of the thumb and index finger. Understanding the anatomy and function of the median nerve is important in diagnosing and treating conditions that affect this nerve.
-
This question is part of the following fields:
- Neurological System
-
-
Question 15
Incorrect
-
You examine a patient who suffered a severe stroke two years prior.
What clinical examination features would you anticipate observing?Your Answer: Fasciculations
Correct 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 16
Incorrect
-
A 25-year-old man experiences a thermal injury to his right hand, resulting in redness and pain. Which of the following mediators is not implicated in this process?
Your Answer: Serotonin
Correct Answer: Free radicals
Explanation:Free radicals do not play a role in acute inflammation. Instead, chemical mediators are responsible for spreading inflammation to healthy tissue. These mediators include lysosomal compounds and chemokines like serotonin and histamine, which are released by mast cells and platelets. Enzyme cascades, such as the complement, kinin, coagulation, and fibrinolytic systems, also produce inflammatory mediators.
Acute inflammation is a response to cell injury in vascularized tissue. It is triggered by chemical factors produced in response to a stimulus, such as fibrin, antibodies, bradykinin, and the complement system. The goal of acute inflammation is to neutralize the offending agent and initiate the repair process. The main characteristics of inflammation are fluid exudation, exudation of plasma proteins, and migration of white blood cells.
The vascular changes that occur during acute inflammation include transient vasoconstriction, vasodilation, increased permeability of vessels, RBC concentration, and neutrophil margination. These changes are followed by leukocyte extravasation, margination, rolling, and adhesion of neutrophils, transmigration across the endothelium, and migration towards chemotactic stimulus.
Leukocyte activation is induced by microbes, products of necrotic cells, antigen-antibody complexes, production of prostaglandins, degranulation and secretion of lysosomal enzymes, cytokine secretion, and modulation of leukocyte adhesion molecules. This leads to phagocytosis and termination of the acute inflammatory response.
-
This question is part of the following fields:
- General Principles
-
-
Question 17
Incorrect
-
A 23-year-old man presents to an after-hours medical clinic following his return from a backpacking trip in Southeast Asia. He complains of abdominal pain, diarrhoea, and healing sores on the soles of his feet. Additionally, he has developed a new and extremely itchy rash that began in the perianal area and has spread to his buttocks over the last two hours. His vital signs include a respiratory rate of 18 breaths per minute, a heart rate of 92 beats per minute, and a blood pressure of 124/86 mmHg. He is not running a fever. What is the probable pathogen responsible for this presentation?
Your Answer: Pinworm
Correct Answer: Strongyloides stercoralis
Explanation:Helminths are a group of parasitic worms that can infect humans and cause various diseases. Nematodes, also known as roundworms, are one type of helminth. Strongyloides stercoralis is a type of roundworm that enters the body through the skin and can cause symptoms such as diarrhea, abdominal pain, and skin lesions. Treatment for this infection typically involves the use of ivermectin or benzimidazoles. Enterobius vermicularis, also known as pinworm, is another type of roundworm that can cause perianal itching and other symptoms. Diagnosis is made by examining sticky tape applied to the perianal area. Treatment typically involves benzimidazoles.
Hookworms, such as Ancylostoma duodenale and Necator americanus, are another type of roundworm that can cause gastrointestinal infections and anemia. Treatment typically involves benzimidazoles. Loa loa is a type of roundworm that is transmitted by deer fly and mango fly and can cause red, itchy swellings called Calabar swellings. Treatment involves the use of diethylcarbamazine. Trichinella spiralis is a type of roundworm that can develop after eating raw pork and can cause fever, periorbital edema, and myositis. Treatment typically involves benzimidazoles.
Onchocerca volvulus is a type of roundworm that causes river blindness and is spread by female blackflies. Treatment involves the use of ivermectin. Wuchereria bancrofti is another type of roundworm that is transmitted by female mosquitoes and can cause blockage of lymphatics and elephantiasis. Treatment involves the use of diethylcarbamazine. Toxocara canis, also known as dog roundworm, is transmitted through ingestion of infective eggs and can cause visceral larva migrans and retinal granulomas. Treatment involves the use of diethylcarbamazine. Ascaris lumbricoides, also known as giant roundworm, can cause intestinal obstruction and occasionally migrate to the lung. Treatment typically involves benzimidazoles.
Cestodes, also known as tapeworms, are another type of helminth. Echinococcus granulosus is a tapeworm that is transmitted through ingestion of eggs in dog feces and can cause liver cysts and anaphylaxis if the cyst ruptures
-
This question is part of the following fields:
- General Principles
-
-
Question 18
Incorrect
-
An 80-year-old man arrives at the emergency department accompanied by his wife. According to her, he has experienced sudden hearing loss and is currently unable to perceive any sounds. A stroke is suspected, and he is sent for an MRI scan which reveals a thalamic lesion.
Which specific nucleus of the thalamus is most likely affected by the lesion?Your Answer: Ventral anterior nucleus
Correct Answer: Medial geniculate nucleus
Explanation:Hearing impairment can result from damage to the medial geniculate nucleus of the thalamus, which is responsible for relaying auditory signals to the cerebral cortex. Similarly, damage to other regions of the thalamus can affect different types of sensory and motor functioning, such as visual loss from damage to the lateral geniculate nucleus, facial sensation from damage to the medial portion of the ventral posterior nucleus, and motor functioning from damage to the ventral anterior nucleus.
The Thalamus: Relay Station for Motor and Sensory Signals
The thalamus is a structure located between the midbrain and cerebral cortex that serves as a relay station for motor and sensory signals. Its main function is to transmit these signals to the cerebral cortex, which is responsible for processing and interpreting them. The thalamus is composed of different nuclei, each with a specific function. The lateral geniculate nucleus relays visual signals, while the medial geniculate nucleus transmits auditory signals. The medial portion of the ventral posterior nucleus (VML) is responsible for facial sensation, while the ventral anterior/lateral nuclei relay motor signals. Finally, the lateral portion of the ventral posterior nucleus is responsible for body sensation, including touch, pain, proprioception, pressure, and vibration. Overall, the thalamus plays a crucial role in the transmission of sensory and motor information to the brain, allowing us to perceive and interact with the world around us.
-
This question is part of the following fields:
- Neurological System
-
-
Question 19
Incorrect
-
A 35-year-old man comes to the doctor after returning from a cheese and wine tasting trip in Portugal. He mentions trying unpasteurized cheese and now feels very sick. He reports experiencing fluctuating temperatures, transient joint and muscle pain, and excessive sweating with a distinct wet hay odor. What organism is most likely responsible for his symptoms?
Your Answer: Wuchereria bancrofti
Correct Answer: Brucella melitensis
Explanation:The patient’s symptoms are consistent with Brucellosis, including fluctuating temperatures, temporary joint and muscle pain, excessive sweating with a distinct odor. The key factor in the patient’s history is their consumption of unpasteurized cheese, which can contain the Brucella melitensis bacteria responsible for the infection.
If the patient had been infected with Bartonella henselae, the cause of cat scratch disease, they would have a history of exposure to cat scratches.
In the case of Yersinia pestis, the bacteria responsible for bubonic plague, the patient would have a history of exposure to flea bites in an area where the disease is prevalent. Additionally, their temperature would remain constant rather than fluctuating.
Understanding Brucellosis
Brucellosis is a disease that can be transmitted from animals to humans, and is more commonly found in the Middle East and among individuals who work with animals such as farmers, vets, and abattoir workers. The disease is caused by four major species of bacteria: B. melitensis (sheep), B. abortus (cattle), B. canis and B. suis (pigs). The incubation period for brucellosis is typically 2-6 weeks.
Symptoms of brucellosis are non-specific and may include fever and malaise, as well as hepatosplenomegaly and spinal tenderness. Complications of the disease can include osteomyelitis, infective endocarditis, meningoencephalitis, and orchitis. Leukopenia is also commonly seen in patients with brucellosis.
Diagnosis of brucellosis can be done through the Rose Bengal plate test for screening, but other tests are required to confirm the diagnosis. Brucella serology is the best test for diagnosis, and blood and bone marrow cultures may be suitable in certain patients, although these tests are often negative.
Management of brucellosis typically involves the use of doxycycline and streptomycin. It is important for individuals who work with animals to take precautions to prevent the transmission of brucellosis, such as wearing protective clothing and practicing good hygiene.
-
This question is part of the following fields:
- General Principles
-
-
Question 20
Incorrect
-
A 25-year-old male presents with suspected ureteric colic. Where is the stone most likely to be visualized on a KUB style x-ray?
Your Answer: At the crest of the ilium
Correct Answer: The tips of the transverse processes between L2 and L5
Explanation:The stones in the ureter can be seen at the anterior of L2 to L5, as well as over the sacro-iliac joints.
Anatomy of the Ureter
The ureter is a muscular tube that measures 25-35 cm in length and is lined by transitional epithelium. It is surrounded by a thick muscular coat that becomes three muscular layers as it crosses the bony pelvis. This retroperitoneal structure overlies the transverse processes L2-L5 and lies anterior to the bifurcation of iliac vessels. The blood supply to the ureter is segmental and includes the renal artery, aortic branches, gonadal branches, common iliac, and internal iliac. It is important to note that the ureter lies beneath the uterine artery.
In summary, the ureter is a vital structure in the urinary system that plays a crucial role in transporting urine from the kidneys to the bladder. Its unique anatomy and blood supply make it a complex structure that requires careful consideration in any surgical or medical intervention.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 21
Incorrect
-
A 27-year-old female patient complains of lower abdominal pain and dysuria for the past 5 days. Upon examination, her GP orders cultures which reveal visible organism growth on Thayer-Martin agar plate. What is the probable pathogen responsible for her symptoms?
Your Answer: Escherichia coli
Correct Answer: Neisseria gonorrhoeae
Explanation:Neisseria gonorrhoeae is the correct answer. The growth of this organism on Thayer-Martin agar, a heated blood agar plate that inhibits the growth of contaminating bacteria and fungi, is indicative of a possible infection. Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa are all potential causes of urinary symptoms, but they are not cultured using Thayer-Martin agar. Escherichia coli is cultured using MacConkey’s agar, while Proteus mirabilis and Pseudomonas aeruginosa are cultured using other types of agar.
Culture Requirements for Common Organisms
Different microorganisms require specific culture conditions to grow and thrive. The table above lists some of the culture requirements for the more common organisms. For instance, Neisseria gonorrhoeae requires Thayer-Martin agar, which is a variant of chocolate agar, and the addition of Vancomycin, Polymyxin, and Nystatin to inhibit Gram-positive, Gram-negative, and fungal growth, respectively. Haemophilus influenzae, on the other hand, grows on chocolate agar with factors V (NAD+) and X (hematin).
To remember the culture requirements for some of these organisms, some mnemonics can be used. For example, Nice Homes have chocolate can help recall that Neisseria and Haemophilus grow on chocolate agar. If I Tell-U the Corny joke Right, you’ll Laugh can be used to remember that Corynebacterium diphtheriae grows on tellurite agar or Loeffler’s media. Lactating pink monkeys can help recall that lactose fermenting bacteria, such as Escherichia coli, grow on MacConkey agar resulting in pink colonies. Finally, BORDETella pertussis can be used to remember that Bordetella pertussis grows on Bordet-Gengou (potato) agar.
-
This question is part of the following fields:
- General Principles
-
-
Question 22
Incorrect
-
A group of teachers in the kindergarten team want to establish the levels of literacy skills among their students.
They collect data over the course of a month and compare their results against the National Association for the Education of Young Children (NAEYC) guidelines for kindergarten literacy skills and find that they recommend all students should have basic literacy skills.
After the first month, they find that only 25% of their students have basic literacy skills.
They go on to develop a literacy program and repeat the data collection one month later. They find the levels of basic literacy skills have now improved to 75%.
What type of project is this?Your Answer: Cohort study
Correct Answer: Clinical audit
Explanation:The purpose of a clinical audit is to identify areas where clinical practice falls short of the required standard and to implement interventions to improve these shortcomings. Developing interventions, such as electronic prompts, is a crucial aspect of clinical audits.
A case-control study is not applicable in this scenario. Case-control studies compare two groups based on different outcomes and retrospectively look for possible causal factors. However, in this case, there is only one group being evaluated, and the team is not looking for cause and effect.
Similarly, a cohort study is not appropriate. Cohort studies compare two groups with different characteristics over time to observe differing outcomes. This is a type of research study, which is not the aim of the clinical audit.
A risk assessment is also not relevant. Risk assessments evaluate the potential risks of an activity and are not appropriate for this scenario. A risk assessment may be conducted to assess the safety of oxygen delivery systems or the harms of not delivering oxygen to patients. However, the purpose of a clinical audit is to identify areas for improvement in clinical practice.
Likewise, a service evaluation is not the correct option. Service evaluations review clinical services for performance and outcomes, but not against any defined standards. Improving a service is an inherent part of a clinical audit and does not need to be explicitly mentioned.
Understanding Clinical Audit
Clinical audit is a process that aims to improve the quality of patient care and outcomes by systematically reviewing care against specific criteria and implementing changes. It is a quality improvement process that involves the collection and analysis of data to identify areas where improvements can be made. The process involves reviewing current practices, identifying areas for improvement, and implementing changes to improve patient care and outcomes.
Clinical audit is an essential tool for healthcare professionals to ensure that they are providing the best possible care to their patients. It helps to identify areas where improvements can be made and provides a framework for implementing changes. The process involves a team of healthcare professionals working together to review current practices and identify areas for improvement. Once areas for improvement have been identified, changes can be implemented to improve patient care and outcomes.
In summary, clinical audit is a quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and the implementation of change. It is an essential tool for healthcare professionals to ensure that they are providing the best possible care to their patients. By identifying areas for improvement and implementing changes, clinical audit helps to improve patient care and outcomes.
-
This question is part of the following fields:
- General Principles
-
-
Question 23
Correct
-
A 40-year-old female presents to the hepatology clinic with a 4-month history of abdominal pain, jaundice, and abdominal swelling. She has a medical history of systemic lupus erythematosus and is currently taking the combined oral contraceptive pill. During abdominal examination, a palpable mass is detected in the right upper quadrant and shifting dullness is observed. Further investigations reveal a high serum-ascites albumin gradient (> 11g/L) in a small amount of ascitic fluid that was collected for analysis. What is the most likely diagnosis?
Your Answer: Budd-Chiari syndrome
Explanation:A high SAAG gradient (> 11g/L) on ascitic tap indicates portal hypertension, but in this case, the correct diagnosis is Budd-Chiari syndrome. This condition occurs when the hepatic veins, which drain the liver, become blocked, leading to abdominal pain, ascites, and hepatomegaly. The patient’s medical history of systemic lupus erythematosus and combined oral contraceptive pill use put her at risk for blood clot formation, which likely caused the hepatic vein occlusion. The high SAAG gradient is due to increased hydrostatic pressure within the hepatic portal system. Other conditions that cause portal hypertension, such as right heart failure, liver metastasis, and alcoholic liver disease, also produce a high SAAG gradient. Acute pancreatitis, on the other hand, has a low SAAG gradient since it is not associated with increased portal pressure. Focal segmental glomerulosclerosis and Kwashiorkor also have low SAAG gradients.
Ascites is a medical condition characterized by the accumulation of abnormal amounts of fluid in the abdominal cavity. The causes of ascites can be classified into two groups based on the serum-ascites albumin gradient (SAAG) level. If the SAAG level is greater than 11g/L, it indicates portal hypertension, which is commonly caused by liver disorders such as cirrhosis, alcoholic liver disease, and liver metastases. Other causes of portal hypertension include cardiac conditions like right heart failure and constrictive pericarditis, as well as infections like tuberculous peritonitis. On the other hand, if the SAAG level is less than 11g/L, ascites may be caused by hypoalbuminaemia, malignancy, pancreatitis, bowel obstruction, and other conditions.
The management of ascites involves reducing dietary sodium and sometimes fluid restriction if the sodium level is less than 125 mmol/L. Aldosterone antagonists like spironolactone are often prescribed, and loop diuretics may be added if necessary. Therapeutic abdominal paracentesis may be performed for tense ascites, and large-volume paracentesis requires albumin cover to reduce the risk of complications. Prophylactic antibiotics may also be given to prevent spontaneous bacterial peritonitis. In some cases, a transjugular intrahepatic portosystemic shunt (TIPS) may be considered.
-
This question is part of the following fields:
- Gastrointestinal System
-
-
Question 24
Incorrect
-
A man in his early fifties presents to the GP with hearing loss in his right ear. After conducting a Webber's and Rinne's test, the following results were obtained:
- Webber's test: lateralizes to the left ear
- Rinne's test (left ear): Air > Bone
- Rinne's test (right ear): Air > Bone
What is the probable cause of his hearing loss?Your Answer: Otitis externa
Correct Answer: Acoustic neuroma
Explanation:Sensorineural hearing loss in the right ear is indicative of an acoustic neuroma, which is the only option listed as a cause for this type of hearing loss. Other options such as otitis media with effusion and otitis externa cause conductive hearing loss, while ossicular fracture is a rare cause of conductive hearing loss. Understanding the Weber and Rinne tests is important in interpreting these results accurately.
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 25
Correct
-
A young man in his early twenties collapses during a game of basketball and is declared dead upon arrival at the hospital. The autopsy shows irregularities in his heart. What is the probable cause of the irregularities?
Your Answer: Hypertrophic cardiomyopathy
Explanation:The condition that is most commonly associated with sudden death is hypertrophic cardiomyopathy, making the other options less likely.
Symptoms of acute myocarditis may include chest pain, fever, palpitations, tachycardia, and difficulty breathing.
Dilated cardiomyopathy may cause right ventricular failure, leading to symptoms such as difficulty breathing, pulmonary edema, and atrial fibrillation.
Restrictive cardiomyopathy and constrictive pericarditis have similar presentations, with right heart failure symptoms such as elevated JVP, hepatomegaly, edema, and ascites being predominant.
Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder that affects muscle tissue and is inherited in an autosomal dominant manner. It is caused by mutations in genes that encode contractile proteins, with the most common defects involving the β-myosin heavy chain protein or myosin-binding protein C. HOCM is characterized by left ventricle hypertrophy, which leads to decreased compliance and cardiac output, resulting in predominantly diastolic dysfunction. Biopsy findings show myofibrillar hypertrophy with disorganized myocytes and fibrosis. HOCM is often asymptomatic, but exertional dyspnea, angina, syncope, and sudden death can occur. Jerky pulse, systolic murmurs, and double apex beat are also common features. HOCM is associated with Friedreich’s ataxia and Wolff-Parkinson White. ECG findings include left ventricular hypertrophy, non-specific ST segment and T-wave abnormalities, and deep Q waves. Atrial fibrillation may occasionally be seen.
-
This question is part of the following fields:
- Cardiovascular System
-
-
Question 26
Incorrect
-
A 27-year-old male presents with lower back pain and painful feet that feel like walking on pebbles. He has been generally healthy, but he recently returned from a trip to Corfu where he had a diarrheal illness. He admits to infrequently taking ecstasy but takes no other medication. On examination, he has limited movement and pain in the sacroiliac joints and soreness in the soles of his feet upon deep palpation. What is the most probable diagnosis?
Your Answer: Inflammatory bowel disease (IBD) related arthropathy
Correct Answer: Reactive arthritis
Explanation:After a diarrhoeal illness, the patient may be at risk of developing reactive arthritis, which is a possible diagnosis for both sacroiliitis and plantar fasciitis. However, it is less likely to be related to inflammatory bowel disease (IBD) if there is only one acute episode of diarrhoea.
Sacroiliitis is a condition that affects the sacroiliac joint, which is located at the base of the spine where it connects to the pelvis. It causes inflammation and pain in the lower back, buttocks, and legs. Plantar fasciitis, on the other hand, is a condition that affects the plantar fascia, a thick band of tissue that runs along the bottom of the foot. It causes pain and stiffness in the heel and arch of the foot.
-
This question is part of the following fields:
- Rheumatology
-
-
Question 27
Incorrect
-
A 50-year-old man has been diagnosed with early onset Alzheimer's disease and has a significant family history of the condition. Which gene is the most probable to be mutated?
Your Answer: APOE e4
Correct Answer: Presenilin 1 gene (PSEN1)
Explanation:Mutations in the amyloid precursor protein gene (APP), presenilin 1 gene (PSEN1), or presenilin 2 gene (PSEN2) are responsible for early onset familial Alzheimer’s disease, which is inherited in an autosomal dominant manner. Sporadic Alzheimer’s disease is strongly linked to APOE e4 mutations. Familial Parkinson’s disease is associated with PARK7 mutations, while hereditary motor neuron disease is linked to SOD1 mutations. Trinucleotide repeat mutations are also implicated in certain genetic disorders.
Alzheimer’s disease is a type of dementia that gradually worsens over time and is caused by the degeneration of the brain. There are several risk factors associated with Alzheimer’s disease, including increasing age, family history, and certain genetic mutations. The disease is also more common in individuals of Caucasian ethnicity and those with Down’s syndrome.
The pathological changes associated with Alzheimer’s disease include widespread cerebral atrophy, particularly in the cortex and hippocampus. Microscopically, there are cortical plaques caused by the deposition of type A-Beta-amyloid protein and intraneuronal neurofibrillary tangles caused by abnormal aggregation of the tau protein. The hyperphosphorylation of the tau protein has been linked to Alzheimer’s disease. Additionally, there is a deficit of acetylcholine due to damage to an ascending forebrain projection.
Neurofibrillary tangles are a hallmark of Alzheimer’s disease and are partly made from a protein called tau. Tau is a protein that interacts with tubulin to stabilize microtubules and promote tubulin assembly into microtubules. In Alzheimer’s disease, tau proteins are excessively phosphorylated, impairing their function.
-
This question is part of the following fields:
- Neurological System
-
-
Question 28
Incorrect
-
A 35-year-old woman presents with a 4 week history of weakness that worsens towards the end of the day. She has difficulty getting out of her chair in the evening and complains of difficulty keeping her eyes open while driving at night, despite not feeling tired.
During examination, bilateral facial nerve weakness, complex ophthalmoplegia, and symmetrical proximal power loss (MRC power 4/5) are noted. Repetitive stimulation of movements reveals fatigability.
What Gell and Coombs hypersensitivity class is likely causing her symptoms?Your Answer: Type 2
Correct Answer: Type 5
Explanation:The individual is a young woman who is exhibiting symptoms of proximal myopathy and complex ophthalmoplegia, along with signs of fatigue. These symptoms are indicative of myasthenia gravis, an autoimmune disorder that occurs due to the presence of antibodies that target acetylcholine nicotinic postsynaptic receptors.
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
-
-
Question 29
Incorrect
-
A 14-year-old boy presents to the general practitioner with complaints of deteriorating balance and vision. His mother accompanies him to the appointment. Upon examination, the boy has a high arched palate and absent ankle tendon reflexes. The general practitioner refers the boy to a specialist who conducts genomic studies. The results reveal a trinucleotide repeat of GAA on chromosome 9.
What is the probable diagnosis?Your Answer: Marfan syndrome
Correct Answer: Friedreich's ataxia
Explanation:Friedreich’s ataxia is caused by a GAA trinucleotide repeat resulting from a mutation in the FXN gene located on chromosome 9.
Understanding Friedreich’s Ataxia
Friedreich’s ataxia is a common hereditary ataxia that usually affects individuals at an early age. It is caused by a trinucleotide repeat disorder that affects the X25 gene on chromosome 9. Unlike other trinucleotide repeat disorders, Friedreich’s ataxia does not show the phenomenon of anticipation. The condition is characterised by gait ataxia and kyphoscoliosis, which are the most common presenting features. Other neurological features include absent ankle jerks/extensor plantars, optic atrophy, and spinocerebellar tract degeneration. In addition, hypertrophic obstructive cardiomyopathy is the most common cause of death in individuals with Friedreich’s ataxia, while diabetes mellitus affects 10-20% of patients. A high-arched palate is also a common feature.
Overall, understanding Friedreich’s ataxia is important for early diagnosis and management of the condition. With proper care and support, individuals with Friedreich’s ataxia can lead fulfilling lives despite the challenges posed by the condition.
-
This question is part of the following fields:
- Neurological System
-
-
Question 30
Incorrect
-
A 49-year-old man with a history of chronic alcohol abuse presents with abdominal distension and is diagnosed with decompensated alcoholic liver disease with ascites. The consultant initiates treatment with spironolactone to aid in the management of his ascites.
What is the mode of action of spironolactone?Your Answer: Inhibition of the sodium/potassium/chloride transporter in the loop of Henle
Correct Answer: Inhibition of the mineralocorticoid receptor in the cortical collecting ducts
Explanation:Aldosterone antagonists function as diuretics by targeting the cortical collecting ducts.
By inhibiting the mineralocorticoid receptor in the cortical collecting ducts, spironolactone acts as an aldosterone antagonist.
Loop diuretics like furosemide work by blocking the sodium/potassium/chloride transporter in the loop of Henle.
Thiazide diuretics, such as bendroflumethiazide, block the sodium/chloride transporter in the distal convoluted tubules.
Carbonic anhydrase inhibitors, like dorzolamide, act on the proximal tubules.
Amiloride inhibits the epithelial sodium transporter in the distal convoluted tubules.
Spironolactone is a medication that works as an aldosterone antagonist in the cortical collecting duct. It is used to treat various conditions such as ascites, hypertension, heart failure, nephrotic syndrome, and Conn’s syndrome. In patients with cirrhosis, spironolactone is often prescribed in relatively large doses of 100 or 200 mg to counteract secondary hyperaldosteronism. It is also used as a NICE ‘step 4’ treatment for hypertension. In addition, spironolactone has been shown to reduce all-cause mortality in patients with NYHA III + IV heart failure who are already taking an ACE inhibitor, according to the RALES study.
However, spironolactone can cause adverse effects such as hyperkalaemia and gynaecomastia, although the latter is less common with eplerenone. It is important to monitor potassium levels in patients taking spironolactone to prevent hyperkalaemia, which can lead to serious complications such as cardiac arrhythmias. Overall, spironolactone is a useful medication for treating various conditions, but its potential adverse effects should be carefully considered and monitored.
-
This question is part of the following fields:
- Renal System
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Secs)