-
Question 1
Correct
-
Emma, a 26-year-old with ulcerative colitis attends for a routine clinic appointment. Her symptoms are now well-controlled on her current treatment. Her medication includes: azathioprine, citalopram, loperamide hydrochloride, paracetamol, salbutamol and a beclometasone dipropionate inhaler.
You check her most recent blood tests and find the following results:
Hb 98 g/l
MCV 90 fl
Platelets 124 x 109/l
WBC 2.8 x 109/l
CRP <5 mg/l
Which medication is most likely to have contributed to these blood results?Your Answer: Azathioprine
Explanation:Regular monitoring of a patient’s full blood count is important when taking Azathioprine, as it is an immunosuppressant drug that may cause myelosuppression. Patients should also be educated on signs of infection to watch out for. However, Citalopram, paracetamol, and salbutamol are not known to cause myelosuppression. Although beclometasone dipropionate is a steroid, the small and localized dose in an inhaler makes it highly unlikely to have contributed to the patient’s myelosuppression.
Azathioprine 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.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 2
Incorrect
-
Mrs. Smith presents to the clinic with a newly noticed lesion on her leg. Upon examination, concerning characteristics of malignancy are observed.
What signs would be most indicative of an in situ malignant melanoma in Mrs. Smith, who is in her early 50s?Your Answer:
Correct Answer: Having multiple colours
Explanation:When assessing a pigmented lesion, it is important to consider the ‘ABCDE’ criteria: Asymmetry, Border, Colour, Diameter, and Evolution. The British Association of Dermatologists (BAD) provides guidance on this assessment. According to BAD, a diameter of over 6mm is more indicative of a melanoma than a diameter of 4mm. A lesion’s color alone does not determine malignancy, as highly pigmented lesions can be benign. Rolled edges are more commonly associated with basal cell carcinoma than melanoma. However, the presence of multiple colors within a lesion, including different shades of black, brown, and pink, is a significant indicator of melanoma.
Skin cancer is a type of cancer that affects the skin. There are three main types of skin cancer: basal cell cancer, squamous cell cancer, and malignant melanoma. The risk factors for skin cancer include sun exposure, iatrogenic factors such as PUVA and UVB phototherapy, exposure to arsenic, and immunosuppression following renal transplant. People who have undergone renal transplant are at a higher risk of developing squamous cell cancer and basal cell cancer, and this may be linked to human papillomavirus.
Skin cancer is a type of cancer that affects the skin. It can be classified into three main types: basal cell cancer, squamous cell cancer, and malignant melanoma. The risk factors for skin cancer include exposure to the sun, iatrogenic factors such as PUVA and UVB phototherapy, exposure to arsenic, and immunosuppression following renal transplant. People who have undergone renal transplant are at a higher risk of developing squamous cell cancer and basal cell cancer, and this may be linked to human papillomavirus.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 3
Incorrect
-
An 80-year-old female presents to the emergency department with a tender, hot, and painful knee. Upon aspiration and light microscopy, rhomboid crystals with weakly positive birefringence are detected.
What is the composition of these crystals?Your Answer:
Correct Answer: Calcium pyrophosphate
Explanation:Pseudogout is a condition where calcium pyrophosphate dihydrate crystals are deposited in the joints, causing inflammation. This is different from gout, which is caused by the deposition of monosodium urate crystals due to factors such as inadequate urea excretion or high purine intake from foods like seafood.
Treatment for pseudogout involves the use of anti-inflammatory medications and joint replacement surgery may be necessary if the condition causes significant joint damage.
In gout, urea levels may be increased, but during an acute attack, they may actually be decreased. Struvite stones are formed from bacterial products, while staghorn stones are large stones that are often caused by Proteus mirabilis and can obstruct the renal pelvis.
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.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 4
Incorrect
-
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.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 5
Incorrect
-
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.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 6
Incorrect
-
A 65-year-old male with a history of hypertension, obesity, and chronic kidney disease complains of acute pain and redness in his right ankle, making it difficult for him to bear weight. He denies any recent injury and reports feeling generally well. Laboratory results reveal:
- Hemoglobin: 134 g/L
- Platelets: 312 * 10^9/L
- White blood cells: 9.1 * 10^9/L
- C-reactive protein: 49 mg/L
- Serum urate: 0.3 mmol/L
What is the most probable diagnosis?Your Answer:
Correct Answer: Gout
Explanation:Once the inflammation has subsided, it is recommended to test the serum urate in suspected cases of gout, as its levels may vary from high to low or normal during an acute attack. Additionally, the patient’s overall good health and moderately elevated CRP levels suggest that septic arthritis is less probable.
Understanding Gout: Symptoms and Diagnosis
Gout is a type of arthritis that causes inflammation and pain in the joints. Patients experience episodes of intense pain that can last for several days, followed by periods of no symptoms. The acute episodes usually reach their peak within 12 hours and can affect various joints, with the first metatarsophalangeal joint being the most commonly affected. Swelling and redness are also common symptoms of gout.
If left untreated, repeated acute episodes of gout can lead to joint damage and chronic joint problems. To diagnose gout, doctors may perform synovial fluid analysis to look for needle-shaped, negatively birefringent monosodium urate crystals under polarised light. Uric acid levels may also be checked once the acute episode has subsided, as they can be high, normal, or low during the attack.
Radiological features of gout include joint effusion, well-defined punched-out erosions with sclerotic margins, and eccentric erosions. Unlike rheumatoid arthritis, gout does not cause periarticular osteopenia. Soft tissue tophi may also be visible.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 7
Incorrect
-
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.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 8
Incorrect
-
A 50-year-old woman visits the rheumatology clinic due to worsening joint pain caused by her longstanding rheumatoid arthritis. Her symptoms have progressed to the point where she can no longer perform her daily activities. She is interested in trying infliximab after hearing about it from a friend and reading about it online. She wants to know how the drug works and how it can potentially alleviate her symptoms.
What is the mechanism of action of infliximab?Your Answer:
Correct Answer: Anti-TNF
Explanation:Infliximab targets TNF through its monoclonal antibody action, while rituximab targets CD20, cetuximab acts as an antagonist to epidermal growth factor receptor, alemtuzumab targets CD52, and OKT3 targets CD3.
Understanding Tumour Necrosis Factor and its Inhibitors
Tumour necrosis factor (TNF) is a cytokine that plays a crucial role in the immune system. It is mainly secreted by macrophages and has various effects on the immune system, such as activating macrophages and neutrophils, acting as a costimulator for T cell activation, and mediating the body’s response to Gram-negative septicaemia. TNF also has anti-tumour effects and binds to both the p55 and p75 receptor, inducing apoptosis and activating NFkB.
TNF has endothelial effects, including increased expression of selectins and production of platelet activating factor, IL-1, and prostaglandins. It also promotes the proliferation of fibroblasts and their production of protease and collagenase. TNF inhibitors are used to treat inflammatory conditions such as rheumatoid arthritis and Crohn’s disease. Examples of TNF inhibitors include infliximab, etanercept, adalimumab, and golimumab.
Infliximab is also used to treat active Crohn’s disease unresponsive to steroids. However, TNF blockers can have adverse effects such as reactivation of latent tuberculosis and demyelination. Understanding TNF and its inhibitors is crucial in the treatment of various inflammatory conditions.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 9
Incorrect
-
Which of the following nerves is responsible for the motor innervation of the sternocleidomastoid muscle?
Your Answer:
Correct Answer: Accessory nerve
Explanation:The accessory nerve provides the motor supply to the sternocleidomastoid, while the ansa cervicalis is responsible for supplying sensory information from the muscle.
The Sternocleidomastoid Muscle: Anatomy and Function
The sternocleidomastoid muscle is a large muscle located in the neck that plays an important role in head and neck movement. It is named after its origin and insertion points, which are the sternum, clavicle, mastoid process, and occipital bone. The muscle is innervated by the spinal part of the accessory nerve and the anterior rami of C2 and C3, which provide proprioceptive feedback.
The sternocleidomastoid muscle has several actions, including extending the head at the atlanto-occipital joint and flexing the cervical vertebral column. It also serves as an accessory muscle of inspiration. When only one side of the muscle contracts, it can laterally flex the neck and rotate the head so that the face looks upward to the opposite side.
The sternocleidomastoid muscle divides the neck into anterior and posterior triangles, which are important landmarks for medical professionals. The anterior triangle contains several important structures, including the carotid artery, jugular vein, and thyroid gland. The posterior triangle contains the brachial plexus, accessory nerve, and several lymph nodes.
Overall, the sternocleidomastoid muscle is a crucial muscle for head and neck movement and plays an important role in the anatomy of the neck.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
-
Question 10
Incorrect
-
A 55-year-old male with a history of gout presents with a suspected septic ankle joint. A diagnostic aspiration is performed and sent to microbiology. Which of the organisms below is most likely to be responsible?
Your Answer:
Correct Answer: Staphylococcus aureus
Explanation:The most frequently encountered organism in cases of septic arthritis is Staphylococcus aureus.
Septic Arthritis in Adults: Causes, Symptoms, and Treatment
Septic arthritis is a condition that occurs when bacteria infect a joint, leading to inflammation and swelling. The most common organism that causes septic arthritis in adults is Staphylococcus aureus, while Neisseria gonorrhoeae is the most common organism in sexually active young adults. The infection is usually spread through the bloodstream, often from distant bacterial infections such as abscesses. The knee is the most commonly affected joint in adults.
Symptoms of septic arthritis include acute joint swelling, restricted movement, warmth to the touch, and fever. To diagnose the condition, synovial fluid sampling is necessary and should be done before administering antibiotics if needed. Blood cultures and joint imaging may also be necessary.
Treatment for septic arthritis involves intravenous antibiotics that cover Gram-positive cocci, such as flucloxacillin or clindamycin if the patient is allergic to penicillin. Antibiotics are typically given for several weeks, and patients may be switched to oral antibiotics after two weeks. Needle aspiration is used to decompress the joint, and arthroscopic lavage may be required. Overall, prompt diagnosis and treatment are essential to prevent joint damage and other complications.
-
This question is part of the following fields:
- Musculoskeletal System And Skin
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Secs)