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Question 1
Incorrect
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A 79-year-old woman is admitted after a fall resulting in a wrist fracture. After diagnosis, she is prescribed a medication to increase bone density in accordance with NICE guidance. What is the mechanism of action of this drug?
Your Answer: Inhibits osteoblasts
Correct Answer: Inhibits osteoclasts
Explanation:Bisphosphonates work by inhibiting osteoclasts, the cells responsible for bone resorption. Therefore, NICE recommends discharging patients on bisphosphonates after fragility fractures without the need for a DEXA scan. While vitamin D and calcium supplementation increase calcium availability to bone, bisphosphonates are the first-line treatment for fragility fractures. Inhibiting osteoblasts would decrease bone density, so promoting osteoclasts would lead to increased bone resorption, which is incorrect.
Bisphosphonates: Uses, Adverse Effects, and Patient Counselling
Bisphosphonates are drugs that mimic the action of pyrophosphate, a molecule that helps prevent bone demineralization. They work by inhibiting osteoclasts, the cells responsible for breaking down bone tissue. Bisphosphonates are commonly used to prevent and treat osteoporosis, hypercalcemia, Paget’s disease, and pain from bone metastases.
However, bisphosphonates can cause adverse effects such as oesophageal reactions, osteonecrosis of the jaw, and an increased risk of atypical stress fractures of the proximal femoral shaft in patients taking alendronate. Patients may also experience an acute phase response, which includes fever, myalgia, and arthralgia following administration. Hypocalcemia may also occur due to reduced calcium efflux from bone, but this is usually clinically unimportant.
To minimize the risk of adverse effects, patients taking oral bisphosphonates should swallow the tablets whole with plenty of water while sitting or standing. They should take the medication on an empty stomach at least 30 minutes before breakfast or another oral medication and remain upright for at least 30 minutes after taking the tablet. Hypocalcemia and vitamin D deficiency should be corrected before starting bisphosphonate treatment. However, calcium supplements should only be prescribed if dietary intake is inadequate when starting bisphosphonate treatment for osteoporosis. Vitamin D supplements are usually given.
The duration of bisphosphonate treatment varies depending on the level of risk. Some experts recommend stopping bisphosphonates after five years if the patient is under 75 years old, has a femoral neck T-score of more than -2.5, and is at low risk according to FRAX/NOGG.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 2
Incorrect
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A 45-year-old carpenter comes to your medical practice complaining of weakness and numbness in his right hand. During the examination, you observe a decrease in sensation on the palmar side of his index finger, middle finger, and the radial half of his ring finger. Tinel's sign is positive, leading you to diagnose carpal tunnel syndrome. Which nerve is the most probable cause of this condition?
Your Answer:
Correct Answer: Median
Explanation:The carpal tunnel only allows the median nerve to pass through it, providing sensory innervation to the palmar aspect of the thumb, index, middle, and radial aspect of the ring finger. If the median nerve is damaged, it can also cause weakness in wrist flexion.
If any of the other nerves are affected, they would cause different patterns of sensory disturbance. For example, an ulnar nerve palsy would typically cause paresthesia on the ulnar half of the ring finger, the entire little finger, and the dorsal medial (ulnar) aspect of the hand. A radial nerve palsy would cause paresthesia on the dorsal lateral (radial) aspect of the hand, but not beyond the metacarpal-phalangeal joint. An axillary nerve palsy would only cause paresthesia in the deltoid area and not affect the sensation in the hands. Finally, a musculocutaneous nerve palsy would cause paresthesia along the lateral aspect of the forearm, but the sensation in the hand would remain intact.
Carpal tunnel syndrome is a condition that occurs when the median nerve in the carpal tunnel is compressed. This can cause pain and pins and needles sensations in the thumb, index, and middle fingers. In some cases, the symptoms may even travel up the arm. Patients may shake their hand to alleviate the discomfort, especially at night. During an examination, weakness in thumb abduction and wasting of the thenar eminence may be observed. Tapping on the affected area may also cause paraesthesia, and flexing the wrist can trigger symptoms.
There are several potential causes of carpal tunnel syndrome, including idiopathic factors, pregnancy, oedema, lunate fractures, and rheumatoid arthritis. Electrophysiology tests may reveal prolongation of the action potential in both motor and sensory nerves. Treatment options may include a six-week trial of conservative measures such as wrist splints at night or corticosteroid injections. If symptoms persist or are severe, surgical decompression may be necessary, which involves dividing the flexor retinaculum.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 3
Incorrect
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A woman is undergoing excision of a sub mandibular gland. During the procedure, a vessel is damaged that is located between the gland and the mandible. What is the most probable identity of this vessel?
Your Answer:
Correct Answer: Facial artery
Explanation:Stone formation is favored by the thick consistency of submandibular gland secretions. Additionally, the majority of stones are visible on radiographs. During gland removal surgery, the facial artery is typically tied off as it runs between the gland and mandible. The lingual artery may also be encountered later in the procedure when Wharton’s duct is being moved.
Anatomy of the Submandibular Gland
The submandibular gland is located beneath the mandible and is surrounded by the superficial platysma, deep fascia, and mandible. It is also in close proximity to various structures such as the submandibular lymph nodes, facial vein, marginal mandibular nerve, cervical branch of the facial nerve, deep facial artery, mylohyoid muscle, hyoglossus muscle, lingual nerve, submandibular ganglion, and hypoglossal nerve.
The submandibular duct, also known as Wharton’s duct, is responsible for draining saliva from the gland. It opens laterally to the lingual frenulum on the anterior floor of the mouth and is approximately 5 cm in length. The lingual nerve wraps around the duct, and as it passes forward, it crosses medial to the nerve to lie above it before crossing back, lateral to it, to reach a position below the nerve.
The submandibular gland receives sympathetic innervation from the superior cervical ganglion and parasympathetic innervation from the submandibular ganglion via the lingual nerve. Its arterial supply comes from a branch of the facial artery, which passes through the gland to groove its deep surface before emerging onto the face by passing between the gland and the mandible. The anterior facial vein provides venous drainage, and the gland’s lymphatic drainage goes to the deep cervical and jugular chains of nodes.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 4
Incorrect
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A 28-year-old woman presents with symptoms of carpal tunnel syndrome and requires surgical exploration of the carpal tunnel. What structure will be closest to the hamate bone within the carpal tunnel during the procedure?
Your Answer:
Correct Answer: The tendons of flexor digitorum profundus
Explanation:The nine flexor tendons found in the carpal tunnel include the flexor digitorum profundus, flexor digitorum superficialis, and flexor pollicis longus. Among these tendons, the flexor digitorum profundus is situated deepest in the tunnel and is therefore closest to the hamate bone.
Carpal Bones: The Wrist’s Building Blocks
The wrist is composed of eight carpal bones, which are arranged in two rows of four. These bones are convex from side to side posteriorly and concave anteriorly. The trapezium is located at the base of the first metacarpal bone, which is the base of the thumb. The scaphoid, lunate, and triquetrum bones do not have any tendons attached to them, but they are stabilized by ligaments.
In summary, the carpal bones are the building blocks of the wrist, and they play a crucial role in the wrist’s movement and stability. The trapezium bone is located at the base of the thumb, while the scaphoid, lunate, and triquetrum bones are stabilized by ligaments. Understanding the anatomy of the wrist is essential for diagnosing and treating wrist injuries and conditions.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 5
Incorrect
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A 9-year-old girl presents to the pediatrician with her mother. The mother reports that she has noticed the child's ankles have become swollen over the past few months. There is no history of any trauma and the girl has no other past medical history.
On examination the child is underweight and appears malnourished. She is alert and otherwise systemically well. Bony swellings are noted in both ankles.
Blood tests and an X-ray are ordered.
Bilirubin 8 µmol/L (3 - 17)
ALP 320 u/L (30 - 100)
ALT 29 u/L (3 - 40)
γGT 18 u/L (8 - 60)
Albumin 37 g/L (35 - 50)
X-ray both ankles cupping and fraying of the metaphyseal region
What is the pathophysiological process causing this child's symptoms?Your Answer:
Correct Answer: Excessive non-mineralised osteoid
Explanation:Rickets is a condition where the growth plate in the wrist joints widens due to an excess of non-mineralized osteoid. This is caused by a deficiency in vitamin D or calcium, which is usually due to poor dietary intake. Calcium is necessary for the mineralization of osteoid and the formation of mature bone tissue. When this process is disrupted, rickets can occur.
Monoclonal antibodies used to treat osteoporosis target RANKL, an enzyme that activates osteoclasts and promotes bone resorption. However, RANKL is not the cause of rickets.
Excessive mineralized osteoid is not the cause of rickets. Instead, rickets is caused by inadequate calcium for mineralization, leading to a buildup of non-mineralized osteoid.
While excessive osteoclast activity can cause diseases like osteoporosis and Paget’s disease, it is not the cause of rickets. Similarly, a deficiency of osteoclast activity can result in osteopetrosis, but not rickets.
Understanding Rickets
Rickets is a condition that occurs when bones in developing and growing bodies are inadequately mineralized, resulting in soft and easily deformed bones. This condition is usually caused by a deficiency in vitamin D. In adults, a similar condition is called osteomalacia.
There are several factors that can predispose individuals to rickets, including a dietary deficiency of calcium, prolonged breastfeeding, unsupplemented cow’s milk formula, and a lack of sunlight.
Symptoms of rickets include aching bones and joints, lower limb abnormalities such as bow legs or knock knees, swelling at the costochondral junction (known as a rickety rosary), kyphoscoliosis, craniotabes (soft skull bones in early life), and Harrison’s sulcus.
To diagnose rickets, doctors may check for low vitamin D levels, reduced serum calcium, and raised alkaline phosphatase. Treatment typically involves oral vitamin D supplementation.
Overall, understanding rickets and its causes can help individuals take steps to prevent this condition and ensure proper bone development and growth.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 6
Incorrect
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As a physician, assessing a 23-year-old male who arrived at the emergency department with a triceps muscle injury causing left elbow extension loss. Can you identify the origin of the long head of this muscle?
Your Answer:
Correct Answer: Infraglenoid tubercle of the scapula
Explanation:The triceps muscle, which gets its name from the Latin word for three-headed, is responsible for extending the elbow. It is made up of three heads: the long head, which originates from the infraglenoid tubercle of the scapula; the lateral head, which comes from the dorsal surface of the humerus; and the medial head, which originates from the posterior surface of the humerus. These three sets of fibers come together to form a single tendon that inserts onto the olecranon process of the ulna.
Anatomy of the Triceps Muscle
The triceps muscle is a large muscle located on the back of the upper arm. It is composed of three heads: the long head, lateral head, and medial head. The long head originates from the infraglenoid tubercle of the scapula, while the lateral head originates from the dorsal surface of the humerus, lateral and proximal to the groove of the radial nerve. The medial head originates from the posterior surface of the humerus on the inferomedial side of the radial groove and both of the intermuscular septae.
All three heads of the triceps muscle insert into the olecranon process of the ulna, with some fibers inserting into the deep fascia of the forearm and the posterior capsule of the elbow. The triceps muscle is innervated by the radial nerve and supplied with blood by the profunda brachii artery.
The primary action of the triceps muscle is elbow extension. The long head can also adduct the humerus and extend it from a flexed position. The radial nerve and profunda brachii vessels lie between the lateral and medial heads of the triceps muscle. Understanding the anatomy of the triceps muscle is important for proper diagnosis and treatment of injuries or conditions affecting this muscle.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 7
Incorrect
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A man in his early 50s complains of experiencing numbness and pain in his right hand's thumb, index finger, and middle finger. Which nerve roots are most likely to be impacted?
Your Answer:
Correct Answer: C5-T1
Explanation:Carpal tunnel syndrome is a condition that occurs when the median nerve in the carpal tunnel is compressed. This can cause pain and pins and needles sensations in the thumb, index, and middle fingers. In some cases, the symptoms may even travel up the arm. Patients may shake their hand to alleviate the discomfort, especially at night. During an examination, weakness in thumb abduction and wasting of the thenar eminence may be observed. Tapping on the affected area may also cause paraesthesia, and flexing the wrist can trigger symptoms.
There are several potential causes of carpal tunnel syndrome, including idiopathic factors, pregnancy, oedema, lunate fractures, and rheumatoid arthritis. Electrophysiology tests may reveal prolongation of the action potential in both motor and sensory nerves. Treatment options may include a six-week trial of conservative measures such as wrist splints at night or corticosteroid injections. If symptoms persist or are severe, surgical decompression may be necessary, which involves dividing the flexor retinaculum.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 8
Incorrect
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Which of the following poses the lowest risk of developing osteoporosis for individuals in their 20s?
Your Answer:
Correct Answer: Obesity
Explanation:Osteoporosis is more likely to occur in individuals with low body weight.
Osteoporosis is a condition that is more prevalent in women and increases with age. However, there are many other risk factors and secondary causes of osteoporosis. Some of the most significant risk factors include a history of glucocorticoid use, rheumatoid arthritis, alcohol excess, parental hip fracture history, low body mass index, and current smoking. Other risk factors include a sedentary lifestyle, premature menopause, certain ethnicities, endocrine disorders, gastrointestinal disorders, chronic kidney disease, and certain genetic disorders. Additionally, certain medications such as SSRIs, antiepileptics, and proton pump inhibitors may worsen osteoporosis.
If a patient is diagnosed with osteoporosis or has a fragility fracture, further investigations may be necessary to identify the cause of osteoporosis and assess the risk of subsequent fractures. Recommended investigations include a history and physical examination, blood tests such as a full blood count, urea and electrolytes, liver function tests, bone profile, CRP, and thyroid function tests. Other procedures may include bone densitometry, lateral radiographs, protein immunoelectrophoresis, and urinary Bence-Jones proteins. Additionally, markers of bone turnover and urinary calcium excretion may be assessed. By identifying the cause of osteoporosis and contributory factors, healthcare providers can select the most appropriate form of treatment.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 9
Incorrect
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A 28-year-old woman arrives at the emergency department complaining of intense epigastric pain, along with continuous nausea and vomiting. She had visited the emergency department a week ago due to severe bloody diarrhea and was hospitalized for a day before being released.
Her amylase levels are elevated.
Which medication is the most probable cause of her current symptoms?Your Answer:
Correct Answer: Azathioprine
Explanation:Azathioprine is known to cause pancreatitis, which is likely the adverse effect experienced by this patient. It is possible that the patient was prescribed azathioprine after presenting with severe bloody diarrhea, a symptom of an acute flare-up of ulcerative colitis. Other drugs listed are not commonly associated with pancreatitis, although erythromycin may have a weak association. For more information on serious adverse effects of the listed drugs, please refer to the table below.
Drug Serious adverse effects
Paracetamol Hepatotoxicity
Amitriptyline Anticholinergic side effects
Erythromycin GI disturbance and prolongs QT interval
Azathioprine Bone marrow depression and pancreatitisAzathioprine is a medication that is converted into mercaptopurine, which is an active compound that inhibits the production of purine. To determine if someone is at risk for azathioprine toxicity, a test for thiopurine methyltransferase (TPMT) may be necessary. Adverse effects of this medication include bone marrow depression, nausea and vomiting, pancreatitis, and an increased risk of non-melanoma skin cancer. If infection or bleeding occurs, a full blood count should be considered. It is important to note that there may be a significant interaction between azathioprine and allopurinol, so lower doses of azathioprine should be used. However, azathioprine is generally considered safe to use during pregnancy.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 10
Incorrect
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A 70-year-old woman visits the hand clinic for a check-up on her pre-existing osteoarthritis. During the consultation, the surgeon suggests the removal of a bone located at the base of her thumb to relieve some of her symptoms.
What bone would the surgeon consider removing?Your Answer:
Correct Answer: Trapezium
Explanation:The bone located at the base of the thumb is called the trapezium. In certain cases, it may be removed to relieve symptoms of osteoarthritis in the thumb. To remember the carpal bones in order from lateral to medial, you can use the mnemonic ‘Sam Left The Party To Take Curtis Home’, which stands for scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate.
Carpal Bones: The Wrist’s Building Blocks
The wrist is composed of eight carpal bones, which are arranged in two rows of four. These bones are convex from side to side posteriorly and concave anteriorly. The trapezium is located at the base of the first metacarpal bone, which is the base of the thumb. The scaphoid, lunate, and triquetrum bones do not have any tendons attached to them, but they are stabilized by ligaments.
In summary, the carpal bones are the building blocks of the wrist, and they play a crucial role in the wrist’s movement and stability. The trapezium bone is located at the base of the thumb, while the scaphoid, lunate, and triquetrum bones are stabilized by ligaments. Understanding the anatomy of the wrist is essential for diagnosing and treating wrist injuries and conditions.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 11
Incorrect
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A 50-year-old man presents to the emergency department with a 24-hour history of left knee pain and swelling. He has difficulty bearing weight on the left leg and reports no recent trauma, fevers, or chills. The patient has also been experiencing constipation, excessive urination, and fatigue for several months. He has a history of passing a kidney stone with hydration. He does not take prescription medications or use tobacco, alcohol, or illicit drugs.
During examination, the patient's temperature is 37.2 ºC (98.9ºF) and blood pressure is 130/76 mmHg. The right knee is tender, erythematous, and swollen. Arthrocentesis reveals a white blood cell count of 30,000/mm3, with a predominance of neutrophils and numerous rhomboid-shaped crystals.
What substance is most likely the composition of the crystals?Your Answer:
Correct Answer: Calcium pyrophosphate
Explanation:The patient is experiencing acute inflammatory arthritis, which is likely caused by pseudogout. This condition occurs when calcium pyrophosphate dihydrate crystals are deposited in the synovial fluid, and it is often associated with chronic hypercalcemia resulting from primary hyperparathyroidism. Pseudogout typically affects the knee joint, and the presence of rhomboid-shaped calcium pyrophosphate crystals in the synovial fluid is diagnostic. Calcium hydroxyapatite crystals are typically found in tendons, while calcium oxalate is the most common component of renal calculi. Xanthomas refer to the deposition of cholesterol and other lipids in soft tissues, while gout is characterized by the deposition of monosodium urate in joints and soft tissues.
Understanding Pseudogout
Pseudogout, also known as acute calcium pyrophosphate crystal deposition disease, is a type of microcrystal synovitis that occurs when calcium pyrophosphate dihydrate crystals are deposited in the synovium. This condition is commonly associated with increasing age, but younger patients who develop pseudogout usually have an underlying risk factor such as haemochromatosis, hyperparathyroidism, low magnesium or phosphate levels, acromegaly, or Wilson’s disease.
The knee, wrist, and shoulders are the most commonly affected joints in pseudogout. Diagnosis is made through joint aspiration, which reveals weakly-positively birefringent rhomboid-shaped crystals, and x-rays, which show chondrocalcinosis. In the knee, linear calcifications of the meniscus and articular cartilage can be seen.
Management of pseudogout involves joint fluid aspiration to rule out septic arthritis, followed by treatment with NSAIDs or intra-articular, intra-muscular, or oral steroids, similar to the treatment for gout. Understanding the risk factors and symptoms of pseudogout can help with early diagnosis and effective management of this condition.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 12
Incorrect
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Mary, an 82-year-old female, arrives at the emergency department after experiencing a minor fall. She reports discomfort in her left leg.
A radiograph is ordered and reveals a left intracapsular neck of femur fracture. As a result, Mary is scheduled for a hemiarthroplasty to avoid avascular necrosis of the femoral head.
In this particular fracture, which blood vessel is the primary source of blood supply to the femoral head and is most susceptible to damage?Your Answer:
Correct Answer: Medial femoral circumflex artery
Explanation:The medial femoral circumflex artery is a significant supplier of blood to the femoral head, while the perforating branches of the profunda femoris artery supply the medial and posterior thigh. The lateral femoral circumflex artery provides blood to some muscles of the lateral thigh and a portion of the femoral head. Additionally, the anterior branch of the obturator artery supplies blood to the obturator externus, pectineus, adductor muscles, and gracilis muscles.
Anatomy of the Femur: Structure and Blood Supply
The femur is the longest and strongest bone in the human body, extending from the hip joint to the knee joint. It consists of a rounded head that articulates with the acetabulum and two large condyles at its inferior aspect that articulate with the tibia. The superior aspect of the femur comprises a head and neck that pass inferolaterally to the body and the two trochanters. The neck meets the body of the femur at an angle of 125o and is demarcated from it by a wide rough intertrochanteric crest. The greater trochanter has discernible surfaces that form the site of attachment of the gluteal muscles, while the linea aspera forms part of the origin of the attachments of the thigh adductors.
The femur has a rich blood supply, with numerous vascular foramina existing throughout its length. The blood supply to the femoral head is clinically important and is provided by the medial circumflex femoral and lateral circumflex femoral arteries, which are branches of the profunda femoris. The inferior gluteal artery also contributes to the blood supply. These arteries form an anastomosis and travel up the femoral neck to supply the head. It is important to note that the neck is covered by synovial membrane up to the intertrochanteric line, and the posterior aspect of the neck is demarcated from the shaft by the intertrochanteric crest. Understanding the anatomy of the femur, including its structure and blood supply, is crucial for medical professionals in diagnosing and treating injuries and conditions related to this bone.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 13
Incorrect
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A 65-year-old woman has been referred to the osteoporosis clinic by her GP for alternate bone-sparing treatment. She recently had a bone density scan after experiencing a low impact distal radial fracture. Her T-score for her hip and spine were -2.6 and -2.2 respectively. Despite trying different bisphosphate preparations such as alendronate and risedronate, she experienced significant gastrointestinal side effects. The clinic has decided to start her on a RANKL inhibitor. What treatment is being referred to?
Your Answer:
Correct Answer: Denosumab
Explanation:Denosumab is the correct answer as it inhibits RANKL and prevents the development of osteoclasts, which are responsible for bone resorption. Strontium ranelate promotes bone formation and reduces bone resorption, while teriparatide promotes bone formation and zoledronic acid slows down the rate of bone change and is used in the treatment of osteoporosis and fracture prevention in cancer patients.
Denosumab for Osteoporosis: Uses, Side Effects, and Safety Concerns
Denosumab is a human monoclonal antibody that inhibits the development of osteoclasts, the cells that break down bone tissue. It is given as a subcutaneous injection every six months to treat osteoporosis. For patients with bone metastases from solid tumors, a larger dose of 120mg may be given every four weeks to prevent skeletal-related events. While oral bisphosphonates are still the first-line treatment for osteoporosis, denosumab may be used as a next-line drug if certain criteria are met.
The most common side effects of denosumab are dyspnea and diarrhea, occurring in about 1 in 10 patients. Other less common side effects include hypocalcemia and upper respiratory tract infections. However, doctors should be aware of the potential for atypical femoral fractures in patients taking denosumab and should monitor for unusual thigh, hip, or groin pain.
Overall, denosumab is generally well-tolerated and may have an increasing role in the management of osteoporosis, particularly in light of recent safety concerns regarding other next-line drugs. However, as with any medication, doctors should carefully consider the risks and benefits for each individual patient.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 14
Incorrect
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A 16-year-old adolescent is brought to the emergency department by his father after falling off his skateboard on an outstretched hand. The patient complains of pain at the base of the thumb which is worse with the use of the hand.
Upon examination, there is swelling and tenderness over the anatomical snuffbox.
The emergency physician is concerned about avascular necrosis of the scaphoid bone. The physician explains to the patient that the scaphoid bone receives its blood supply through a specific part of the bone and fracture to this area can result in bone death. Therefore, an urgent scaphoid x-ray is necessary.
Which part of the scaphoid bone, when fractured, increases the risk of avascular necrosis?Your Answer:
Correct Answer: Tubercle
Explanation:The scaphoid bone’s blood supply is only through the tubercle, and a fracture in this area can lead to avascular necrosis. It attaches to the trapezium and trapezoid bones at the greater and lesser multangular ends, respectively.
The scaphoid bone has various articular surfaces for different bones in the wrist. It has a concave surface for the head of the capitate and a crescentic surface for the lunate. The proximal end has a wide convex surface for the radius, while the distal end has a tubercle that can be felt. The remaining articular surface faces laterally and is associated with the trapezium and trapezoid bones. The narrow strip between the radial and trapezial surfaces and the tubercle gives rise to the radial collateral carpal ligament. The tubercle also receives part of the flexor retinaculum and is the only part of the scaphoid bone that allows for the entry of blood vessels. However, this area is commonly fractured and can lead to avascular necrosis.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 15
Incorrect
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A 60-year-old man comes to the dermatology clinic complaining of a rash. During the examination, the doctor observes a linear rash on the lateral thigh of the left leg. The patient reports having undergone a left hip replacement surgery recently, and the rash has developed over the surgical scar.
What skin condition is most likely responsible for this presentation?Your Answer:
Correct Answer: Psoriasis
Explanation:The Koebner Phenomenon: Skin Lesions at the Site of Injury
The Koebner phenomenon refers to the occurrence of skin lesions at the site of injury. This phenomenon is commonly observed in various skin conditions such as psoriasis, vitiligo, warts, lichen planus, lichen sclerosus, and molluscum contagiosum. In other words, if a person with any of these skin conditions experiences trauma or injury to their skin, they may develop new lesions in the affected area.
This phenomenon is named after Heinrich Koebner, a German dermatologist who first described it in 1876. The exact mechanism behind the Koebner phenomenon is not fully understood, but it is believed to be related to the immune system’s response to injury. In some cases, the injury may trigger an autoimmune response, leading to the development of new lesions.
The Koebner phenomenon can be a frustrating and challenging aspect of managing skin conditions. It is important for individuals with these conditions to take precautions to avoid injury to their skin, such as wearing protective clothing or avoiding activities that may cause trauma. Additionally, prompt treatment of any new lesions that develop can help prevent further spread of the condition.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 16
Incorrect
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Which one of the following structures does not pass behind the piriformis muscle in the greater sciatic foramen?
Your Answer:
Correct Answer: Obturator nerve
Explanation:The greater sciatic foramen does not serve as a pathway for the obturator nerve.
The Greater Sciatic Foramen and its Contents
The greater sciatic foramen is a space in the pelvis that is bounded by various ligaments and bones. It serves as a passageway for several important structures, including nerves and blood vessels. The piriformis muscle is a landmark for identifying these structures as they pass through the sciatic notch. Above the piriformis muscle, the superior gluteal vessels can be found, while below it are the inferior gluteal vessels, the sciatic nerve (which passes through it in only 10% of cases), and the posterior cutaneous nerve of the thigh.
The boundaries of the greater sciatic foramen include the greater sciatic notch of the ilium, the sacrotuberous ligament, the sacrospinous ligament, and the ischial spine. The anterior sacroiliac ligament forms the superior boundary. Structures passing through the greater sciatic foramen include the pudendal nerve, the internal pudendal artery, and the nerve to the obturator internus.
In contrast, the lesser sciatic foramen is a smaller space that contains the tendon of the obturator internus, the pudendal nerve, the internal pudendal artery and vein, and the nerve to the obturator internus. Understanding the contents and boundaries of these foramina is important for clinicians who may need to access or avoid these structures during surgical procedures or other interventions.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 17
Incorrect
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A 25-year-old male suffers a fracture in his left tibia during a sports activity. During which stage of the healing process is the fracture callus expected to be visible on radiographs?
Your Answer:
Correct Answer: 3 weeks
Explanation:The formation of fracture callus involves the production of fibroblasts and chondroblasts, which then synthesize fibrocartilage. This process can usually be observed on X-rays after a certain period of time.
Fracture Healing: Factors and Process
When a bone is fractured, bleeding vessels in the bone and periosteum cause clot and haematoma formation. Over a week, the clot organizes and improves in structure and collagen. Osteoblasts in the periosteum produce new bone, while mesenchymal cells produce cartilage in the soft tissue around the fracture. The connective tissue and hyaline cartilage form a callus, which is bridged by endochondral ossification as new bone approaches. Trabecular bone forms, which is then resorbed by osteoclasts and replaced with compact bone.
Several factors can affect fracture healing, including age, malnutrition, bone disorders like osteoporosis, systemic disorders like diabetes, and drugs like steroids and non-steroidal anti-inflammatory agents. The type of bone, degree of trauma, vascular injury, degree of immobilization, intra-articular fractures, separation of bone ends, and infection can also impact healing.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 18
Incorrect
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A 19-year-old male presents with a severe spreading sepsis in his hand. During surgical exploration of the palm, the flexor digiti minimi brevis muscle is mobilized to aid in drainage of the infection. Which of the following structures is not in close proximity to this muscle?
Your Answer:
Correct Answer: Median nerve
Explanation:The flexor digiti minimi brevis originates from the Hamate and is located beneath the ulnar contribution to the superficial palmar arterial arch and digital nerves. The median nerve is positioned over the flexor tendons.
Anatomy of the Hand: Fascia, Compartments, and Tendons
The hand is composed of bones, muscles, and tendons that work together to perform various functions. The bones of the hand include eight carpal bones, five metacarpals, and 14 phalanges. The intrinsic muscles of the hand include the interossei, which are supplied by the ulnar nerve, and the lumbricals, which flex the metacarpophalangeal joints and extend the interphalangeal joint. The thenar eminence contains the abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis, while the hypothenar eminence contains the opponens digiti minimi, flexor digiti minimi brevis, and abductor digiti minimi.
The fascia of the palm is thin over the thenar and hypothenar eminences but relatively thick elsewhere. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The palmar fascia is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The hand is divided into compartments by fibrous septa, with the thenar compartment lying lateral to the lateral septum, the hypothenar compartment lying medial to the medial septum, and the central compartment containing the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch, and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis.
The tendons of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths, extending from the heads of the metacarpals to the base of the distal phalanges.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 19
Incorrect
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Which of the following is not associated with an increase in ESR?
Your Answer:
Correct Answer: Polycythaemia
Explanation:Understanding Erythrocyte Sedimentation Rate (ESR)
The Erythrocyte Sedimentation Rate (ESR) is a test that measures the rate at which red blood cells settle in a tube over a period of time. It is a non-specific marker of inflammation and can be affected by various factors such as the size, shape, and number of red blood cells, as well as the concentration of plasma proteins like fibrinogen, alpha2-globulins, and gamma globulins.
A high ESR can be caused by various conditions such as temporal arteritis, myeloma, connective tissue disorders like systemic lupus erythematosus, malignancies, infections, and other factors like increasing age, female sex, and anaemia. On the other hand, a low ESR can be caused by conditions like polycythaemia, afibrinogenaemia, or hypofibrinogenaemia.
It is important to note that while a high ESR can indicate the presence of an underlying condition, it is not a definitive diagnosis and further testing may be required to determine the cause. Therefore, it is essential to consult a healthcare professional for proper evaluation and management.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 20
Incorrect
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A 25-year-old man comes to the doctor with a complaint of lower back pain that has been bothering him for the past 3 months. The pain spreads to his buttocks and is most severe in the morning, but gets better with physical activity. Sometimes, it even wakes him up at night.
What is the probable diagnosis for this patient?Your Answer:
Correct Answer: Ankylosing spondylitis
Explanation:Ankylosing spondylitis is a condition that typically affects young men and causes lower back pain and stiffness that is worse in the mornings. It is a type of seronegative spondyloarthropathy that leads to inflammation of the lower axial skeleton. Sacroiliitis, which is inflammation of the sacroiliac joints, is a common sign on x-ray. Unlike many other rheumatological conditions, ankylosing spondylitis is more prevalent in men than women.
Intervertebral disc herniation is not the correct answer. This condition typically causes back pain and dermatomal leg pain that does not improve throughout the day or with exercise. It is usually caused by an injury rather than developing gradually without a clear cause.
Reactive arthritis is also an incorrect answer. This is another type of seronegative spondyloarthropathy that occurs after exposure to certain gastrointestinal and genitourinary infections, such as Chlamydia, Salmonella, and Campylobacter jejuni.
Rheumatoid arthritis is also not the correct answer. This is a chronic inflammatory condition that causes inflammation of the synovial tissue and is more common in women. It typically presents with symmetrical, polyarticular arthritis of the small joints.
Ankylosing spondylitis is a type of spondyloarthropathy that is associated with HLA-B27. It is more commonly seen in young males, with a sex ratio of 3:1, and typically presents with lower back pain and stiffness that develops gradually. The stiffness is usually worse in the morning and improves with exercise, while the patient may experience night pain that improves upon getting up.
Clinical examination of patients with ankylosing spondylitis may reveal reduced lateral and forward flexion, as well as reduced chest expansion. The Schober’s test, which involves drawing a line 10 cm above and 5 cm below the back dimples and measuring the distance between them when the patient bends forward, may also be used to assess the condition. Other features associated with ankylosing spondylitis include apical fibrosis, anterior uveitis, aortic regurgitation, Achilles tendonitis, AV node block, amyloidosis, cauda equina syndrome, and peripheral arthritis (which is more common in females).
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 21
Incorrect
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A 58-year-old male presents to the urgent care centre with complaints of back pain after spending the day replanting hedges. During the examination, he exhibits weakness in hip abduction and great toe dorsiflexion, foot drop, and some sensory loss on the dorsum of his foot. There is no apparent change in his reflexes.
What could be the probable reason behind these symptoms?Your Answer:
Correct Answer: L5 radiculopathy
Explanation:Understanding Prolapsed Disc and its Features
A prolapsed disc in the lumbar region can cause leg pain and neurological deficits. The pain is usually more severe in the leg than in the back and worsens when sitting. The features of the prolapsed disc depend on the site of compression. For instance, compression of the L3 nerve root can cause sensory loss over the anterior thigh, weak quadriceps, reduced knee reflex, and a positive femoral stretch test. On the other hand, compression of the L4 nerve root can cause sensory loss in the anterior aspect of the knee, weak quadriceps, reduced knee reflex, and a positive femoral stretch test.
Similarly, compression of the L5 nerve root can cause sensory loss in the dorsum of the foot, weakness in foot and big toe dorsiflexion, intact reflexes, and a positive sciatic nerve stretch test. Lastly, compression of the S1 nerve root can cause sensory loss in the posterolateral aspect of the leg and lateral aspect of the foot, weakness in plantar flexion of the foot, reduced ankle reflex, and a positive sciatic nerve stretch test.
The management of prolapsed disc is similar to that of other musculoskeletal lower back pain, which includes analgesia, physiotherapy, and exercises. However, if the symptoms persist even after 4-6 weeks, referral for an MRI is appropriate. Understanding the features of prolapsed disc can help in early diagnosis and prompt management.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 22
Incorrect
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At what level does the inferior thyroid artery penetrate the thyroid gland?
Your Answer:
Correct Answer: C6
Explanation:Surface Anatomy of the Neck: Identifying Structures and Corresponding Levels
The neck is a complex region of the body that contains numerous structures and landmarks. By understanding the surface anatomy of the neck, healthcare professionals can accurately identify and locate important structures during physical examinations and medical procedures.
In the midline of the neck, several structures can be felt from top to bottom. These include the hyoid at the level of C3, the notch of the thyroid cartilage at C4, and the cricoid cartilage at C6. The lower border of the cricoid cartilage is particularly significant as it corresponds to several important structures, including the junction of the larynx and trachea, the junction of the pharynx and esophagus, and the level at which the inferior thyroid artery enters the thyroid gland. Additionally, the vertebral artery enters the transverse foramen in the 6th cervical vertebrae at this level, and the superior belly of the omohyoid muscle crosses the carotid sheath. The middle cervical sympathetic ganglion is also located at this level, as well as the carotid tubercle, which can be used to compress the carotid artery.
Overall, understanding the surface anatomy of the neck is crucial for healthcare professionals to accurately identify and locate important structures during physical examinations and medical procedures.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 23
Incorrect
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A 55-year-old man presents with a complaint of stiffness in his right shoulder for the past 8 months. Initially, he experienced severe pain, but now only stiffness persists. Upon examination, you observe that the right shoulder is stiff during both active and passive movements.
What is the probable underlying cause of this stiffness?Your Answer:
Correct Answer: Adhesive capsulitis
Explanation:Adhesive capsulitis is identified by a decrease in shoulder mobility, both when moving the shoulder voluntarily and when it is moved by someone else. The ability to rotate the shoulder outward is more affected than the ability to rotate it inward or lift it away from the body.
On the other hand, a tear in the rotator cuff muscles will result in a reduction in active movement due to muscle weakness. Passive movement may also be restricted due to pain. However, we would not anticipate a rigid joint that opposes passive movement.
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.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 24
Incorrect
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A 32-year-old female patient visits the GP with a concern about her middle finger's inability to flex at the end. During the examination, it is observed that she cannot bend the distal interphalangeal joint of her middle finger.
Which muscle is accountable for this movement?Your Answer:
Correct Answer: Flexor digitorum profundus
Explanation:The correct answer is that the flexor digitorum profundus muscle is responsible for flexing the distal interphalangeal joint. The other options, such as the flexor digitorum superficialis and flexor pollicis longus, are responsible for different movements and are therefore incorrect. The palmar interossei are also not responsible for flexion at the distal interphalangeal joint. Lastly, there is no such muscle as the flexor digiti medius.
The forearm flexor muscles include the flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, and flexor digitorum profundus. These muscles originate from the common flexor origin and surrounding fascia, and are innervated by the median and ulnar nerves. Their actions include flexion and abduction of the carpus, wrist flexion, adduction of the carpus, and flexion of the metacarpophalangeal and interphalangeal joints.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 25
Incorrect
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A 70-year-old man is recuperating from a fall that resulted in a fracture of his left fibular neck. He has observed that his left foot drags on the ground when he attempts to walk. Which nerve is the most probable to have been affected?
Your Answer:
Correct Answer: Common peroneal nerve
Explanation:The patient is likely to have suffered damage to their common peroneal nerve, resulting in foot drop, following a fibular neck fracture. This is a common occurrence in such cases.
It is important to note that damage to the lateral cutaneous nerve of the thigh, obturator nerve, or pudendal nerve is unlikely to cause foot drop. These nerves are associated with different symptoms and conditions.
Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteral lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 26
Incorrect
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A 24-year-old boxer presents to a physiotherapist with a wrist drop in his right arm, 8 weeks after sustaining a midshaft humeral fracture resulting in radial nerve palsy. An MRI scan reveals marked atrophy in the muscle inserting at the lateral supracondylar ridge of the humerus. To address this, the physiotherapist prescribes reverse dumbbell wrist curls to strengthen the affected muscle. Which muscle has undergone significant atrophy in this patient, based on the MRI findings and treatment plan?
Your Answer:
Correct Answer: Extensor carpi radialis longus
Explanation:The extensor carpi radialis longus muscle is innervated by the radial nerve. However, in a patient with a radial nerve palsy due to a midshaft humeral fracture, this muscle may be the only forearm extensor directly supplied by the radial nerve. Therefore, it is the most likely correct answer when considering exercises to strengthen the affected muscle.
The extensor carpi radialis brevis muscle, which originates from the lateral epicondyle of the humerus, is also innervated by a branch of the radial nerve. However, its insertion point is different from that described in the MRI, making it an unlikely answer.
The extensor digitorum brevis muscle, which assists in extending the toes, is not relevant to the patient’s wrist condition.
The extensor digitorum longus muscle, which is involved in foot dorsiflexion and toe extension, is also not relevant to the patient’s wrist condition.
Upper limb anatomy is a common topic in examinations, and it is important to know certain facts about the nerves and muscles involved. The musculocutaneous nerve is responsible for elbow flexion and supination, and typically only injured as part of a brachial plexus injury. The axillary nerve controls shoulder abduction and can be damaged in cases of humeral neck fracture or dislocation, resulting in a flattened deltoid. The radial nerve is responsible for extension in the forearm, wrist, fingers, and thumb, and can be damaged in cases of humeral midshaft fracture, resulting in wrist drop. The median nerve controls the LOAF muscles and can be damaged in cases of carpal tunnel syndrome or elbow injury. The ulnar nerve controls wrist flexion and can be damaged in cases of medial epicondyle fracture, resulting in a claw hand. The long thoracic nerve controls the serratus anterior and can be damaged during sports or as a complication of mastectomy, resulting in a winged scapula. The brachial plexus can also be damaged, resulting in Erb-Duchenne palsy or Klumpke injury, which can cause the arm to hang by the side and be internally rotated or associated with Horner’s syndrome, respectively.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 27
Incorrect
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A 40-year-old male presents to the GP with fatigue and shortness of breath. He states that he is taking methotrexate for psoriasis. The GP takes some bloods, and finds the following results in his full blood count (FBC):
Hb 90 g/L
MCV 90 fL
Platelets 70 * 109/L
WBC 2.5 * 109/L
Neuts 1.5 * 109/L)
Lymphs 0.7 * 109/L
Mono 0.2 * 109/L
Eosin 0.1 * 109/L
The GP suspects this to be an adverse effect of methotrexate.
What adverse effect is indicated by these results?Your Answer:
Correct Answer: Pancytopaenia
Explanation:The patient’s blood test indicates a decrease in red blood cells, white blood cells, and platelets, which is known as pancytopenia. This condition is caused by severe bone marrow suppression, which is a common side effect of methotrexate. Anemia, on the other hand, would only result in a low hemoglobin level and cannot account for the low platelet and white blood cell counts.
Methotrexate is an antimetabolite that hinders the activity of dihydrofolate reductase, an enzyme that is crucial for the synthesis of purines and pyrimidines. It is a significant drug that can effectively control diseases, but its side-effects can be life-threatening. Therefore, careful prescribing and close monitoring are essential. Methotrexate is commonly used to treat inflammatory arthritis, especially rheumatoid arthritis, psoriasis, and acute lymphoblastic leukaemia. However, it can cause adverse effects such as mucositis, myelosuppression, pneumonitis, pulmonary fibrosis, and liver fibrosis.
Women should avoid pregnancy for at least six months after stopping methotrexate treatment, and men using methotrexate should use effective contraception for at least six months after treatment. Prescribing methotrexate requires familiarity with guidelines relating to its use. It is taken weekly, and FBC, U&E, and LFTs need to be regularly monitored. Folic acid 5 mg once weekly should be co-prescribed, taken more than 24 hours after methotrexate dose. The starting dose of methotrexate is 7.5 mg weekly, and only one strength of methotrexate tablet should be prescribed.
It is important to avoid prescribing trimethoprim or co-trimoxazole concurrently as it increases the risk of marrow aplasia. High-dose aspirin also increases the risk of methotrexate toxicity due to reduced excretion. In case of methotrexate toxicity, the treatment of choice is folinic acid. Overall, methotrexate is a potent drug that requires careful prescribing and monitoring to ensure its effectiveness and safety.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 28
Incorrect
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A teenage boy presents with a left-sided winged scapula after getting into a scuffle at a party. During the examination, he struggles to perform a specific movement with his left arm. Which movement is most likely causing him difficulty?
Your Answer:
Correct Answer: Abduction
Explanation:Winged scapula is caused by paralysis of serratus anterior, which affects arm abduction. Triceps brachii is responsible for extension, biceps brachii for flexion, and latissimus dorsi for adduction.
Upper limb anatomy is a common topic in examinations, and it is important to know certain facts about the nerves and muscles involved. The musculocutaneous nerve is responsible for elbow flexion and supination, and typically only injured as part of a brachial plexus injury. The axillary nerve controls shoulder abduction and can be damaged in cases of humeral neck fracture or dislocation, resulting in a flattened deltoid. The radial nerve is responsible for extension in the forearm, wrist, fingers, and thumb, and can be damaged in cases of humeral midshaft fracture, resulting in wrist drop. The median nerve controls the LOAF muscles and can be damaged in cases of carpal tunnel syndrome or elbow injury. The ulnar nerve controls wrist flexion and can be damaged in cases of medial epicondyle fracture, resulting in a claw hand. The long thoracic nerve controls the serratus anterior and can be damaged during sports or as a complication of mastectomy, resulting in a winged scapula. The brachial plexus can also be damaged, resulting in Erb-Duchenne palsy or Klumpke injury, which can cause the arm to hang by the side and be internally rotated or associated with Horner’s syndrome, respectively.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 29
Incorrect
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Which of the following statements regarding psoriasis is inaccurate?
Your Answer:
Correct Answer: Mediated by type 2 helper T cells
Explanation:Psoriasis is caused by type 1 helper T cells that participate in the cellular immune response, as opposed to type 2 helper T cells.
Psoriasis: A Chronic Skin Disorder with Various Subtypes and Complications
Psoriasis is a prevalent chronic skin disorder that affects around 2% of the population. It is characterized by red, scaly patches on the skin, but it is now known that patients with psoriasis are at an increased risk of arthritis and cardiovascular disease. The pathophysiology of psoriasis is multifactorial and not yet fully understood. It is associated with genetic factors such as HLA-B13, -B17, and -Cw6, and abnormal T cell activity that stimulates keratinocyte proliferation. Environmental factors such as skin trauma, stress, streptococcal infection, and sunlight exposure can worsen, trigger, or improve psoriasis.
There are several recognized subtypes of psoriasis, including plaque psoriasis, flexural psoriasis, guttate psoriasis, and pustular psoriasis. Each subtype has its own unique characteristics and affects different areas of the body. Psoriasis can also cause nail signs such as pitting and onycholysis, as well as arthritis.
Complications of psoriasis include psoriatic arthropathy, metabolic syndrome, cardiovascular disease, venous thromboembolism, and psychological distress. It is important for patients with psoriasis to receive proper management and treatment to prevent these complications and improve their quality of life.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 30
Incorrect
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A basketball enthusiast in his early twenties visits his GP complaining of discomfort in his right shoulder and neck, and also reports an unusual appearance on the right side of his upper back.
To assess the condition, the GP asks the patient to stand facing a wall and extend his arms straight in front of him, with his palms flat against the wall. The GP then instructs the patient to bend his arms and push away from the wall. During the movement, the patient's right shoulder blade protrudes from his back.
Based on the symptoms, which nerve is most likely to be affected?Your Answer:
Correct Answer: Long thoracic nerve
Explanation:The correct nerve that supplies the serratus anterior muscle is the long thoracic nerve. This muscle is responsible for pulling the scapula around the thorax, and damage to this nerve can cause medial winging of the scapula.
The axillary nerve is not the correct answer as it supplies the deltoid muscle, which is responsible for shoulder abduction. Damage to this nerve results in a flattened deltoid muscle, not winging of the scapula.
The musculocutaneous nerve supplies the biceps brachii muscle, which is responsible for elbow flexion. Damage to this nerve does not affect the scapulae.
The spinal accessory nerve supplies the sternocleidomastoid and trapezius muscles, and injury to this nerve may result in difficulty turning the head from side to side or shrugging the shoulders. It does not affect the scapulae.
Trauma to the thoracodorsal nerve may cause atrophy of the latissimus dorsi muscle and difficulty moving the affected shoulder, but it does not cause winging of the scapula.
Upper limb anatomy is a common topic in examinations, and it is important to know certain facts about the nerves and muscles involved. The musculocutaneous nerve is responsible for elbow flexion and supination, and typically only injured as part of a brachial plexus injury. The axillary nerve controls shoulder abduction and can be damaged in cases of humeral neck fracture or dislocation, resulting in a flattened deltoid. The radial nerve is responsible for extension in the forearm, wrist, fingers, and thumb, and can be damaged in cases of humeral midshaft fracture, resulting in wrist drop. The median nerve controls the LOAF muscles and can be damaged in cases of carpal tunnel syndrome or elbow injury. The ulnar nerve controls wrist flexion and can be damaged in cases of medial epicondyle fracture, resulting in a claw hand. The long thoracic nerve controls the serratus anterior and can be damaged during sports or as a complication of mastectomy, resulting in a winged scapula. The brachial plexus can also be damaged, resulting in Erb-Duchenne palsy or Klumpke injury, which can cause the arm to hang by the side and be internally rotated or associated with Horner’s syndrome, respectively.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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