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Question 1
Correct
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A 46-year-old woman arrives at the emergency department after falling while walking her dog. She explains that she stumbled on the pavement and landed on her left hand, with her hands taking the brunt of the fall.
During the examination, the doctor notices tenderness over the anatomical snuffbox and telescoping of the left thumb. What other structure is in danger of being harmed, considering the probable diagnosis?Your Answer: Radial artery
Explanation:The anatomical snuffbox contains the radial artery and is a common site for scaphoid fractures. The scaphoid bone forms the floor of the snuffbox and the radial artery provides its blood supply. Missing a scaphoid fracture can lead to avascular necrosis. Other structures such as the flexor pollicis longus tendon, median nerve, pisiform bone, and ulnar artery do not lie within the snuffbox.
The Anatomical Snuffbox: A Triangle on the Wrist
The anatomical snuffbox is a triangular depression located on the lateral aspect of the wrist. It is bordered by tendons of the extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus muscles, as well as the styloid process of the radius. The floor of the snuffbox is formed by the trapezium and scaphoid bones. The apex of the triangle is located distally, while the posterior border is formed by the tendon of the extensor pollicis longus. The radial artery runs through the snuffbox, making it an important landmark for medical professionals.
In summary, the anatomical snuffbox is a small triangular area on the wrist that is bordered by tendons and bones. It is an important landmark for medical professionals due to the presence of the radial artery.
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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 35-year-old woman arrives at the emergency department complaining of worsening bone pain in her left hip over the past few days. She mentions feeling ill and feverish, but attributes it to a recent cold. The patient is a known IV drug user and has not traveled recently.
During the examination, the left hip appears red and tender, and multiple track marks are visible.
Which organism is most likely responsible for her symptoms?Your Answer: Mycobacterium tuberculosis
Correct Answer: Staphylococcus aureus
Explanation:Osteomyelitis is most commonly caused by Staphylococcus aureus in both adults and children. IV drug use is a known risk factor for this condition as it can introduce microorganisms directly into the bloodstream. While Escherichia coli can also cause osteomyelitis, it is more prevalent in children than adults. Mycobacterium tuberculosis can also lead to osteomyelitis, but it is less common than Staphylococcus aureus. Bone introduction typically occurs via the circulatory system from pulmonary tuberculosis. However, antitubercular therapy has reduced the incidence of tuberculosis, making bone introduction less likely than with Staphylococcus aureus, which is part of the normal skin flora. Salmonella enterica is the most common cause of osteomyelitis in individuals with sickle cell disease. As the patient is not known to have sickle cell, Staphylococcus aureus remains the most probable cause.
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.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 3
Correct
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A 26-year-old gardener presents to her GP with a two week history of elbow swelling. She reports a gradual onset of the swelling, with no apparent triggers, and experiences pain and warmth upon touch. She denies any swelling in other areas and is generally in good health.
The patient has a medical history of well-managed rheumatoid arthritis and is currently taking methotrexate. There are no other known medical conditions.
During the physical examination, a tender, soft, fluctuant mass is palpated on the posterior aspect of the patient's elbow.
Based on the above information, what is the most probable diagnosis?Your Answer: Olecranon bursitis
Explanation:Understanding Olecranon Bursitis
Olecranon bursitis is a condition that occurs when the olecranon bursa, a fluid-filled sac located over the olecranon process at the proximal end of the ulna, becomes inflamed. This bursa serves to reduce friction between the elbow joint and the surrounding soft tissues. The inflammation can be caused by trauma, infection, or systemic conditions such as rheumatoid arthritis or gout. It is also commonly known as student’s elbow due to the repetitive mild trauma of leaning on a desk using the elbows.
The condition is more common in men and typically presents between the ages of 30 and 60. Causes of olecranon bursitis include repetitive trauma, direct trauma, infection, gout, rheumatoid arthritis, and idiopathic reasons. Patients with non-septic olecranon bursitis typically present with swelling over the olecranon process, which is often the only symptom. Some patients may also experience tenderness and erythema over the bursa. On the other hand, patients with septic bursitis are more likely to have pain and fever.
Signs of olecranon bursitis include swelling over the posterior aspect of the elbow, tenderness on palpation of the swollen area, redness and warmth of the overlying skin, fever, skin abrasion overlying the bursa, effusions in other joints if associated with rheumatoid arthritis, and tophi if associated with gout. Movement at the elbow joint should be painless until the swollen bursa is compressed in full flexion.
Investigations are not always needed if a clinical diagnosis can be made and there is no concern about septic arthritis. However, if septic bursitis is suspected, aspiration of bursal fluid for microscopy and culture is essential. Purulent fluid suggests infection, while straw-coloured bursal fluid favours a non-infective cause. Understanding the causes, symptoms, and signs of olecranon bursitis can help in its diagnosis and management.
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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 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: Adduction
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 5
Incorrect
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A 65-year-old avid hiker complains of discomfort in her leg while ascending hills and using stairs. Which muscle is accountable for extending the hip?
Your Answer: Rectus femoris
Correct Answer: Gluteus maximus
Explanation:The gluteus medius and minimus muscles are responsible for hip abduction, while the gluteus maximus muscle externally rotates and extends the hip. The gluteus maximus muscle originates from the sacrum, coccyx, and posterior surface of the ilium, and inserts onto the gluteal tuberosity. The other gluteal muscles attach to the greater trochanter to facilitate abduction.
Anatomy of the Hip Joint
The hip joint is formed by the articulation of the head of the femur with the acetabulum of the pelvis. Both of these structures are covered by articular hyaline cartilage. The acetabulum is formed at the junction of the ilium, pubis, and ischium, and is separated by the triradiate cartilage, which is a Y-shaped growth plate. The femoral head is held in place by the acetabular labrum. The normal angle between the femoral head and shaft is 130 degrees.
There are several ligaments that support the hip joint. The transverse ligament connects the anterior and posterior ends of the articular cartilage, while the head of femur ligament (ligamentum teres) connects the acetabular notch to the fovea. In children, this ligament contains the arterial supply to the head of the femur. There are also extracapsular ligaments, including the iliofemoral ligament, which runs from the anterior iliac spine to the trochanteric line, the pubofemoral ligament, which connects the acetabulum to the lesser trochanter, and the ischiofemoral ligament, which provides posterior support from the ischium to the greater trochanter.
The blood supply to the hip joint comes from 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 of the femur.
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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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A 25-year-old male patient is diagnosed with appendicitis and requires an appendicectomy. The surgical procedure begins with a 5cm incision at McBurney's point. What is the first structure that will be encountered during the dissection?
Your Answer: Peritoneum
Correct Answer: External oblique aponeurosis
Explanation:The rectus sheath is located more medially than the external oblique, which is encountered first. The external oblique muscle is the most superficial muscle of the abdominal wall and originates from the 5th to 12th ribs. It inserts into the linea alba, pubic tubercle, and anterior half of the iliac crest by passing inferomedially. The muscle is innervated by the thoracoabdominal nerves (T7-T11) and subcostal nerves.
Muscles and Layers of the Abdominal Wall
The abdominal wall is composed of various muscles and layers that provide support and protection to the organs within the abdominal cavity. The two main muscles of the abdominal wall are the rectus abdominis and the quadratus lumborum. The rectus abdominis is located anteriorly, while the quadratus lumborum is located posteriorly.
The remaining abdominal wall is made up of three muscular layers, each passing from the lateral aspect of the quadratus lumborum to the lateral margin of the rectus sheath. These layers are muscular posterolaterally and aponeurotic anteriorly. The external oblique muscle lies most superficially and originates from the 5th to 12th ribs, inserting into the anterior half of the outer aspect of the iliac crest, linea alba, and pubic tubercle. The internal oblique arises from the thoracolumbar fascia, the anterior 2/3 of the iliac crest, and the lateral 2/3 of the inguinal ligament, while the transversus abdominis is the innermost muscle, arising from the inner aspect of the costal cartilages of the lower 6 ribs, the anterior 2/3 of the iliac crest, and the lateral 1/3 of the inguinal ligament.
During abdominal surgery, it is often necessary to divide either the muscles or their aponeuroses. It is desirable to divide the aponeurosis during a midline laparotomy, leaving the rectus sheath intact above the arcuate line and the muscles intact below it. Straying off the midline can lead to damage to the rectus muscles, particularly below the arcuate line where they may be in close proximity to each other. The nerve supply for these muscles is the anterior primary rami of T7-12.
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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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As a medical student on placement, while practising orthopaedic examinations, you come across a patient whose knee observation reveals that the centre of gravity is medial to the knee joint, causing the knees to bow outwards. What is the appropriate term for this condition?
Your Answer: Coxa varum
Correct Answer: Genu varum
Explanation:The knee joint is the largest and most complex synovial joint in the body, consisting of two condylar joints between the femur and tibia and a sellar joint between the patella and femur. The degree of congruence between the tibiofemoral articular surfaces is improved by the presence of the menisci, which compensate for the incongruence of the femoral and tibial condyles. The knee joint is divided into two compartments: the tibiofemoral and patellofemoral compartments. The fibrous capsule of the knee joint is a composite structure with contributions from adjacent tendons, and it contains several bursae and ligaments that provide stability to the joint. The knee joint is supplied by the femoral, tibial, and common peroneal divisions of the sciatic nerve and by a branch from the obturator nerve, while its blood supply comes from the genicular branches of the femoral artery, popliteal, and anterior tibial arteries.
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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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During a hip examination, Sarah, a 65-year-old female, is found to have a positive trendelenburg's sign. When she stands on only her left leg, her right pelvis drops.
If the cause of her positive trendelenburg's sign is neurological, which nerve is affected in Sarah?Your Answer: Left sciatic nerve
Correct Answer: Right superior gluteal
Explanation:If the superior gluteal nerve is damaged, it can result in a positive Trendelenburg sign. This nerve is responsible for providing innervation to the gluteus minimus and gluteus medius muscles, which are important for abducting and medially rotating the lower limb, as well as preventing pelvic drop of the opposing limb. For example, when standing on only the right leg, the right gluteus minimus and gluteus medius muscles stabilize the pelvis. However, if the right superior gluteal nerve is damaged, the right gluteus minimus and gluteus medius muscles will not receive proper innervation, leading to instability and a drop in the left pelvis when standing on the right leg. On the other hand, the inferior gluteal nerve innervates the gluteus maximus muscles, which are responsible for extending the thigh and performing lateral rotation.
The Trendelenburg Test: Assessing Gluteal Nerve Function
The Trendelenburg test is a diagnostic tool used to assess the function of the superior gluteal nerve. This nerve is responsible for the contraction of the gluteus medius muscle, which is essential for maintaining balance and stability while standing on one leg.
When the superior gluteal nerve is injured or damaged, the gluteus medius muscle is weakened, resulting in a compensatory shift of the body towards the unaffected side. This shift is characterized by a gravitational shift, which causes the body to be supported on the unaffected limb.
To perform the Trendelenburg test, the patient is asked to stand on one leg while the physician observes the position of the pelvis. In a healthy individual, the gluteus medius muscle contracts as soon as the contralateral leg leaves the floor, preventing the pelvis from dipping towards the unsupported side. However, in a person with paralysis of the superior gluteal nerve, the pelvis on the unsupported side descends, indicating that the gluteus medius on the affected side is weak or non-functional. This is known as a positive Trendelenburg test.
It is important to note that the Trendelenburg test is also used in vascular investigations to determine the presence of saphenofemoral incompetence. In this case, tourniquets are placed around the upper thigh to assess blood flow. However, in the context of assessing gluteal nerve function, the Trendelenburg test is a valuable tool for diagnosing and treating motor deficits and gait abnormalities.
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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 nine-year-old tumbles from the climbing equipment at the park and is taken to the emergency department. X-rays reveal a supracondylar fracture of the left distal humerus. During the examination, the child exhibits weakened finger flexion in the left hand, inability to perform opposition of the left thumb and little finger, and altered sensation over the lateral aspect of the palm and first three digits. Can you identify the location of the damaged structure in the antecubital fossa?
Your Answer: Lateral to the brachial artery
Correct Answer: Medial to the brachial artery
Explanation:The cubital fossa contains the following structures in order from lateral to medial: radial nerve, brachial tendon, brachial artery, and median nerve. In this case, the damaged nerve is the median nerve, which is located most medially in the cubital fossa, next to the brachial artery.
In the antecubital fossa, the radial nerve is located deep and laterally, next to the biceps tendon. The biceps tendon serves as a marker for finding the brachial artery, which is located medially to it.
It is incorrect to say that there is a nerve located between the biceps tendon and the brachial artery in the antecubital fossa.
The Antecubital Fossa: Anatomy and Clinical Significance
The antecubital fossa is a depression located on the anterior aspect of the arm, between the arm and forearm. It is an important area for medical professionals as it is where venous blood samples are typically taken from. The borders of the antecubital fossa are the brachioradialis muscle laterally, the pronator teres medially, and a line between the medial and lateral epicondyles superiorly.
There are both deep and superficial structures found in the antecubital fossa. Deep structures include the radial nerve, tendon of the biceps muscle, brachial artery, and medial nerve. Superficial structures consist of a network of veins, including the cephalic vein and basilic vein, which come together as the median cubital vein.
The main clinical relevance of the antecubital fossa is its use for blood sampling and cannulation. However, it is also important to have a working knowledge of the anatomy as structures can become damaged. Excessive straining of the biceps tendon can cause it to rupture, leading to a ‘Popeye sign’. Damage to the medial nerve can also occur, resulting in muscle paralysis in the forearm and hand. Overall, understanding the anatomy and clinical significance of the antecubital fossa is crucial for medical professionals.
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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 28-year-old presents to the hospital with severe wrist pain. He was playing basketball with his friends when he fell with his hand outstretched. On examination, there is significant tenderness at the anatomical snuffbox. Pain is elicited as the thumb is longitudinally compressed. His grip strength is also diminished.
A posteroanterior and lateral x-ray of the wrist joint is performed which gives inconclusive results. The patient's wrist is immobilized with a splint and he is advised an MRI in a week’s time for further evaluation.
The patient inquires about possible complications and the doctor expresses concern that if the blood supply is interrupted, the bone tissue may be compromised.
Which of the following structures is most likely to be responsible for this complication?Your Answer: Proper digital arteries
Correct Answer: Dorsal carpal branch of radial artery
Explanation:The primary neurovascular structure that can be affected by a scaphoid fracture is the dorsal carpal branch of the radial artery. This artery is responsible for supplying blood to the scaphoid bone, and a fracture can lead to a high risk of avascular necrosis in the proximal pole of the bone. Symptoms of a scaphoid fracture include tenderness in the anatomical snuffbox, pain when compressing the thumb longitudinally, and a loss of grip strength. While an X-ray may not provide a conclusive diagnosis, further imaging studies can confirm the presence of an occult fracture.
The other answer choices are incorrect. The common digital arteries originate from the superficial palmar arch and supply the fingers. The deep palmar arch primarily supplies the thumb and index finger. The proper digital arteries arise from the common digital arteries and supply the fingers.
A scaphoid fracture is a type of wrist fracture that usually occurs when a person falls onto an outstretched hand or during contact sports. It is important to identify scaphoid fractures as they can lead to avascular necrosis due to the unusual blood supply of the scaphoid bone. Patients with scaphoid fractures typically experience pain along the radial aspect of the wrist and loss of grip or pinch strength. Clinical examination involves checking for tenderness over the anatomical snuffbox, wrist joint effusion, pain on telescoping of the thumb, tenderness of the scaphoid tubercle, and pain on ulnar deviation of the wrist. Plain film radiographs and scaphoid views are used to diagnose scaphoid fractures, but MRI is considered the definitive investigation. Initial management involves immobilization with a splint or backslab and referral to orthopaedics. Orthopaedic management depends on the type of fracture, with undisplaced fractures typically treated with a cast and displaced fractures requiring surgical fixation. Complications of scaphoid fractures include non-union and avascular necrosis.
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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 35-year-old female presents to a clinic with worsening joint pains, low-grade fever and tiredness for the past 6 months. She also has chest pain that increases when breathing in. On examination, there are painless ulcers in her oral cavity. There is a reddish butterfly-patterned rash on her cheeks. She mentions that the rash worsens when she goes out into the sun. Her blood tests show:
Hb 98 g/L Male: (135-180)
Female: (115 - 160)
Platelets 95 * 109/L (150 - 400)
WBC 3.2 * 109/L (4.0 - 11.0)
ESR 90 mm/hr (0 - 20)
Urinalysis reveals proteinuria and red cell casts. Investigations for autoantibodies are sent for the patient.
What is the most sensitive test for the condition that this 35-year-old female patient is likely to have?Your Answer: Anti-Ro antibodies
Correct Answer: Antinuclear antibodies (ANA)
Explanation:Systemic lupus erythematosus (SLE) can be investigated through various tests, including antibody tests. ANA testing is highly sensitive and useful for ruling out SLE, but it has low specificity. About 99% of SLE patients are ANA positive. Rheumatoid factor testing is positive in 20% of SLE patients. Anti-dsDNA testing is highly specific (>99%) but less sensitive (70%). Anti-Smith testing is also highly specific (>99%) but has a lower sensitivity (30%). Other antibody tests that can be used include anti-U1 RNP, SS-A (anti-Ro), and SS-B (anti-La).
Monitoring of SLE can be done through various markers, including inflammatory markers such as ESR. During active disease, CRP levels may be normal, and a raised CRP may indicate an underlying infection. Complement levels (C3, C4) are low during active disease due to the formation of complexes that lead to the consumption of complement. Anti-dsDNA titres can also be used for disease monitoring, but it is important to note that they are not present in all SLE patients. Overall, these investigations can help diagnose and monitor SLE, allowing for appropriate management and treatment.
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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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A 25-year-old man is stabbed in the neck, in the area between the omohyoid and digastric muscles. During surgery to explore the injury, a nerve injury is discovered just above the lingual artery where it branches off from the external carotid artery. What is the most probable outcome of this injury?
Your Answer: Inability to abduct the shoulder
Correct Answer: Paralysis of the ipsilateral side of the tongue
Explanation:The external carotid artery is located posterior to the hypoglossal nerve, while the lingual arterial branch is situated below it. In case of damage to the nerve, the genioglossus, hyoglossus, and styloglossus muscles on the same side will become paralyzed. When the patient is instructed to stick out their tongue, it will deviate towards the affected side.
The Anterior Triangle of the Neck: Boundaries and Contents
The anterior triangle of the neck is a region that is bounded by the anterior border of the sternocleidomastoid muscle, the lower border of the mandible, and the anterior midline. It is further divided into three sub-triangles by the digastric muscle and the omohyoid muscle. The muscular triangle contains the neck strap muscles, while the carotid triangle contains the carotid sheath, which houses the common carotid artery, the vagus nerve, and the internal jugular vein. The submandibular triangle, located below the digastric muscle, contains the submandibular gland, submandibular nodes, facial vessels, hypoglossal nerve, and other structures.
The digastric muscle, which separates the submandibular triangle from the muscular triangle, is innervated by two different nerves. The anterior belly of the digastric muscle is supplied by the mylohyoid nerve, while the posterior belly is supplied by the facial nerve.
Overall, the anterior triangle of the neck is an important anatomical region that contains many vital structures, including blood vessels, nerves, and glands. Understanding the boundaries and contents of this region is essential for medical professionals who work in this area.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 13
Correct
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During a placement at a GP practice, a 16-year-old girl complains of knee pain. As part of the examination, the GP palpates her patella. What category of bone does the patella belong to?
Your Answer: Sesamoid bone
Explanation:The patella, which is the largest sesamoid bone in the body, shares an articular space with the femur and tibia. Sesamoid bones are embedded in tendons and often pass over joints to protect the tendon from damage.
Long bones, such as the femur, humerus, tibia, and fibula, have a body that is longer than it is wide.
Short bones, like the carpals, are as wide as they are long.
Flat bones are plate-like structures that serve to protect vital organs.
Irregular bones, such as the vertebrae and mandible, do not fit into any of the other categories.
Knee Problems in Children and Young Adults
Knee problems are common in children and young adults, and can be caused by a variety of conditions. Chondromalacia patellae is a condition that affects teenage girls and is characterized by softening of the cartilage of the patella. This can cause anterior knee pain when walking up and down stairs or rising from prolonged sitting. However, it usually responds well to physiotherapy.
Osgood-Schlatter disease, also known as tibial apophysitis, is often seen in sporty teenagers. It causes pain, tenderness, and swelling over the tibial tubercle. Osteochondritis dissecans can cause pain after exercise, as well as intermittent swelling and locking. Patellar subluxation can cause medial knee pain due to lateral subluxation of the patella, and the knee may give way. Patellar tendonitis is more common in athletic teenage boys and causes chronic anterior knee pain that worsens after running. It is tender below the patella on examination.
It is important to note that referred pain may come from hip problems such as slipped upper femoral epiphysis. Understanding the key features of these common knee problems can help with early diagnosis and appropriate treatment.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 14
Correct
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A 25-year-old male patient visits his physician complaining of a rash that has been present for two weeks. Upon examination, the doctor observes multiple oval-shaped lesions with a fine-scale on the outer aspects of the lesions. The rash has spread across the patient's trunk and back, resembling a fir tree. The patient reports feeling generally well. The doctor suspects pityriasis rosea and wonders which organism has been linked to its development.
Your Answer: Herpes hominis virus 7 (HHV-7)
Explanation:Herpes hominis virus 7 (HHV-7) is believed to be involved in the development of pityriasis rosea, while the other choices are not linked to this condition. Slapped cheek syndrome is associated with Parvovirus B-19, while Coxsackie B virus is an enterovirus that is associated with aseptic meningitis, Bornholm disease, pericarditis, and myocarditis.
Understanding Pityriasis Rosea
Pityriasis rosea is a rash that typically affects young adults and is characterized by an acute, self-limiting nature. While the exact cause is not fully understood, it is believed that herpes hominis virus 7 (HHV-7) may play a role. Most patients do not experience any warning signs, but some may report a recent viral infection. The rash begins with a herald patch on the trunk, followed by oval, scaly patches that follow a distinct pattern with the longitudinal diameters running parallel to the line of Langer, creating a fir-tree appearance.
The condition is self-limiting and usually disappears within 6-12 weeks. There is no specific treatment for pityriasis rosea, but topical agents used for psoriasis may be helpful. UVB phototherapy may also be an option. It is important to differentiate pityriasis rosea from guttate psoriasis, which is characterized by tear-drop shaped, scaly papules on the trunk and limbs. Guttate psoriasis is often preceded by a streptococcal sore throat, while pityriasis rosea may be associated with recent respiratory tract infections. Both conditions typically resolve spontaneously within a few months.
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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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Which one of the following muscles is not located in the posterior compartment of the lower leg?
Your Answer: Flexor hallucis longus
Correct Answer: Peroneus brevis
Explanation:The lateral compartment contains the peroneus brevis.
Fascial Compartments of the Leg
The leg is divided into compartments by fascial septae, which are thin layers of connective tissue. In the thigh, there are three compartments: the anterior, medial, and posterior compartments. The anterior compartment contains the femoral nerve and artery, as well as the quadriceps femoris muscle group. The medial compartment contains the obturator nerve and artery, as well as the adductor muscles and gracilis muscle. The posterior compartment contains the sciatic nerve and branches of the profunda femoris artery, as well as the hamstrings muscle group.
In the lower leg, there are four compartments: the anterior, posterior (divided into deep and superficial compartments), lateral, and deep posterior compartments. The anterior compartment contains the deep peroneal nerve and anterior tibial artery, as well as the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and peroneus tertius muscles. The posterior compartment contains the tibial nerve and posterior tibial artery, as well as the deep and superficial muscles. The lateral compartment contains the superficial peroneal nerve and peroneal artery, as well as the peroneus longus and brevis muscles. The deep posterior compartment contains the tibial nerve and posterior tibial artery, as well as the flexor hallucis longus, flexor digitorum longus, tibialis posterior, and popliteus muscles.
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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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A 25-year-old man gets into a brawl and receives a cut on the back of his right arm, about 2 cm above the olecranon process. Upon examination at the ER, he is unable to straighten his elbow. Which tendon is the most probable one to have been severed?
Your Answer: Pronator teres
Correct Answer: Triceps
Explanation:The elbow joint is extended by the triceps muscle, while the remaining muscles listed are responsible for flexion of the elbow joint.
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 17
Correct
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Sarah, a 30-year-old woman presents to the emergency department with severe pain in her left big toe. Her first MTP joint is swollen, hot, and red. She is seen biting her nails and hitting her head against the wall. Her caregiver informs you that this is her usual behavior.
Upon joint aspiration, negative birefringent needle-shaped crystals are found. Sarah's medical history includes a learning disability, depression, and asthma. She takes sertraline for depression and frequently uses hydrocortisone cream for eczema. Sarah does not consume red meat and prefers a vegetable-based diet.
What factors predispose Sarah to this type of crystalline arthritis?Your Answer: Lesch-Nyhan syndrome
Explanation:If an individual with learning difficulties and a history of gout exhibits self-mutilating behaviors such as head-banging or nail-biting, it may indicate the presence of Lesch-Nyhan syndrome. However, risk factors for gout do not include sertraline, hydrocortisone, or asthma, but rather red meat consumption. Lesch-Nyhan syndrome is an X-linked recessive condition caused by a deficiency in hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) and is characterized by hyperuricemia, learning disability, self-mutilating behavior, gout, and renal failure.
Predisposing Factors for Gout
Gout is a type of synovitis caused by the accumulation of monosodium urate monohydrate in the synovium. This condition is triggered by chronic hyperuricaemia, which is characterized by uric acid levels exceeding 0.45 mmol/l. There are two main factors that contribute to the development of hyperuricaemia: decreased excretion of uric acid and increased production of uric acid.
Decreased excretion of uric acid can be caused by various factors, including the use of diuretics, chronic kidney disease, and lead toxicity. On the other hand, increased production of uric acid can be triggered by myeloproliferative/lymphoproliferative disorders, cytotoxic drugs, and severe psoriasis.
In rare cases, gout can also be caused by genetic disorders such as Lesch-Nyhan syndrome, which is characterized by hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency. This condition is x-linked recessive, which means it is only seen in boys. Lesch-Nyhan syndrome is associated with gout, renal failure, neurological deficits, learning difficulties, and self-mutilation.
It is worth noting that aspirin in low doses (75-150mg) is not believed to have a significant impact on plasma urate levels. Therefore, the British Society for Rheumatology recommends that it should be continued if necessary for cardiovascular prophylaxis.
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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 47-year-old woman visits her primary care physician complaining of vaginal itching and dryness. During the consultation, she mentions that she also experiences dry skin and has noticed an increase in dryness in her mouth. She regularly uses over-the-counter eye drops.
Upon examination, her Schirmer's strip indicates insufficient tear production. Additionally, her maternal aunt has pernicious anemia, and her grandmother had rheumatoid arthritis.
What condition is associated with this patient's symptoms?Your Answer: Hyperparathyroidism
Correct Answer: Hashimoto's thyroiditis
Explanation:Based on her symptoms, positive Schirmer’s test, and family history of autoimmune conditions, it can be concluded that she is suffering from Sjogren’s syndrome. This condition is linked to various other medical conditions, most of which are autoimmune or rheumatic disorders, including coeliac disease, fibromyalgia, lupus, multiple sclerosis, spondyloarthropathy, and certain types of cancer like non-Hodgkin lymphoma. However, there is no known association between Sjogren’s syndrome and atrial fibrillation, hyperparathyroidism, Conn’s syndrome, or osteoarthritis.
Understanding Sjogren’s Syndrome
Sjogren’s syndrome is a medical condition that affects the exocrine glands, leading to dry mucosal surfaces. It can either be primary or secondary to other connective tissue disorders, such as rheumatoid arthritis. The condition is more common in females, with a ratio of 9:1. Patients with Sjogren’s syndrome have a higher risk of developing lymphoid malignancy, which is 40-60 times more likely than the general population.
The symptoms of Sjogren’s syndrome include dry eyes, dry mouth, vaginal dryness, arthralgia, Raynaud’s, myalgia, sensory polyneuropathy, recurrent episodes of parotitis, and subclinical renal tubular acidosis. To diagnose the condition, doctors may perform a Schirmer’s test to measure tear formation, as well as check for the presence of rheumatoid factor, ANA, anti-Ro (SSA) antibodies, and anti-La (SSB) antibodies.
Management of Sjogren’s syndrome involves the use of artificial saliva and tears, as well as medications like pilocarpine to stimulate saliva production. It is important for patients with Sjogren’s syndrome to receive regular medical care and monitoring to manage their symptoms and reduce the risk of complications.
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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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A 42-year-old woman is experiencing cubital tunnel syndrome in her left arm. Can you identify which muscle in her forearm may be impacted by this condition?
Your Answer: Pronator teres
Correct Answer: Flexor carpi ulnaris
Explanation:The ulnar nerve supplies the flexor carpi ulnaris muscle, while all other flexor muscles in the anterior compartment of the forearm are innervated by the median nerve. Therefore, the correct answer is flexor carpi ulnaris.
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 20
Incorrect
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A 25-year-old male arrives at the emergency department with a deep cut on his left forearm following a knife assault. Upon examination, a deep laceration is observed on his anterior forearm, exposing muscle and subcutaneous tissue. He is unable to flex his left metacarpophalangeal and proximal interphalangeal joints, but his distal interphalangeal joint flexion remains intact. Which structure is the most likely to have been affected?
Your Answer:
Correct Answer: Flexor digitorum superficialis
Explanation: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 21
Incorrect
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Which one of the following muscles does not attach to the radius?
Your Answer:
Correct Answer: Brachialis
Explanation:The ulna serves as the insertion point for the brachialis muscle, while the remaining muscles are inserted onto the radius.
Anatomy of the Radius Bone
The radius bone is one of the two long bones in the forearm that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, with the distal end being the larger one. The upper end of the radius bone has articular cartilage that covers the medial to lateral side and articulates with the radial notch of the ulna by the annular ligament. The biceps brachii muscle attaches to the tuberosity of the upper end.
The shaft of the radius bone has several muscle attachments. The upper third of the body has the supinator, flexor digitorum superficialis, and flexor pollicis longus muscles. The middle third of the body has the pronator teres muscle, while the lower quarter of the body has the pronator quadratus muscle and the tendon of supinator longus.
The lower end of the radius bone is quadrilateral in shape. The anterior surface is covered by the capsule of the wrist joint, while the medial surface has the head of the ulna. The lateral surface ends in the styloid process, and the posterior surface has three grooves that contain the tendons of extensor carpi radialis longus and brevis, extensor pollicis longus, and extensor indicis. Understanding the anatomy of the radius bone is crucial in diagnosing and treating injuries and conditions that affect this bone.
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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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A 4-year-old boy is presented to the GP by his father. He has developed a rash around his mouth and nose over the past few days. It started as a flat red patch at the corner of his mouth but quickly progressed to a blistering rash that oozes fluid. During today's examination, the rash appears to have a crusty, golden appearance on the surface. The child is healthy otherwise and has no prior history of skin problems. Based on this history and examination, what is the most probable diagnosis?
Your Answer:
Correct Answer: Impetigo
Explanation:The most likely diagnosis based on the history and examination is impetigo or eczema herpeticum, which can have similar presentations and are difficult to differentiate clinically. However, since the child has no prior history of skin conditions, eczema herpeticum is less probable. Therefore, option 2 is the correct answer.
Option 1: Atopic eczema would not manifest with a yellowish crust.
Option 3: Chickenpox would not exhibit this particular progression.
Understanding Impetigo: Causes, Symptoms, and Management
Impetigo is a common bacterial skin infection that is caused by either Staphylococcus aureus or Streptococcus pyogenes. It can occur as a primary infection or as a complication of an existing skin condition such as eczema. Impetigo is most common in children, especially during warm weather. The infection can develop anywhere on the body, but it tends to occur on the face, flexures, and limbs not covered by clothing.
The infection spreads through direct contact with discharges from the scabs of an infected person. The bacteria invade the skin through minor abrasions and then spread to other sites by scratching. Infection is spread mainly by the hands, but indirect spread via toys, clothing, equipment, and the environment may occur. The incubation period is between 4 to 10 days.
Symptoms of impetigo include ‘golden’, crusted skin lesions typically found around the mouth. It is highly contagious, and children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment.
Management of impetigo depends on the extent of the disease. Limited, localized disease can be treated with hydrogen peroxide 1% cream or topical antibiotic creams such as fusidic acid or mupirocin. MRSA is not susceptible to either fusidic acid or retapamulin, so topical mupirocin should be used in this situation. Extensive disease may require oral flucloxacillin or oral erythromycin if penicillin-allergic. The use of hydrogen peroxide 1% cream was recommended by NICE and Public Health England in 2020 to cut antibiotic resistance. The evidence base shows it is just as effective at treating non-bullous impetigo as a topical antibiotic.
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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 25-year-old man comes to the doctor complaining of difficulty with bowel movements. He reports having a good appetite and drinking enough fluids. He denies experiencing weight loss, night sweats, or fevers. The patient has a history of rhinitis and indigestion. He takes two medications regularly, but he cannot recall their names. Additionally, he has a learning disability.
Which of the following medications could be responsible for his constipation?Your Answer:
Correct Answer: Chlorphenamine
Explanation:Antihistamines for Allergic Rhinitis and Urticaria
Antihistamines, specifically H1 inhibitors, are effective in treating allergic rhinitis and urticaria. Sedating antihistamines like chlorpheniramine have antimuscarinic properties that can cause dry mouth and urinary retention. On the other hand, non-sedating antihistamines like loratadine and cetirizine are less likely to cause drowsiness. However, there is some evidence that cetirizine may still cause some level of drowsiness compared to other non-sedating antihistamines. Overall, antihistamines are a valuable treatment option for those suffering from allergic rhinitis and urticaria.
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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 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 25
Incorrect
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An 81-year-old female is admitted to the hospital with a Colles fracture in her left wrist. Upon conducting a bone scan, it is revealed that she has osteoporosis. The medical team decides to initiate treatment. What category of medications is recommended?
Your Answer:
Correct Answer: Bisphosphonates
Explanation:Bisphosphonates, particularly alendronate, are the recommended treatment for fragility fractures in postmenopausal women. Additionally, calcium and vitamin D supplementation should be considered, along with lifestyle advice on nutrition, exercise, and fall prevention.
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 26
Incorrect
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A 28-year-old woman comes in with a pigmented lesion measuring 1.5cm on her back. The surgeon suspects it may be a melanoma. What would be the best course of action?
Your Answer:
Correct Answer: Excisional biopsy of the lesion
Explanation:It is not recommended to partially sample suspicious naevi as this can greatly compromise the accuracy of histological interpretation. Complete excision is necessary for lesions that meet diagnostic criteria. However, it may be acceptable to delay wide excision for margins until definitive histology results are available.
When dealing with suspicious melanomas, it is important to excise them with complete margins. Radical excision is not typically performed for diagnostic purposes, so if subsequent histopathological analysis confirms the presence of melanoma, further excision of margins may be necessary. Incisional punch biopsies of potential melanomas can make histological interpretation challenging and should be avoided whenever possible.
Malignant melanoma is a type of skin cancer that has four main subtypes: superficial spreading, nodular, lentigo maligna, and acral lentiginous. Nodular melanoma is the most aggressive, while the other forms spread more slowly. Superficial spreading melanoma typically affects young people on sun-exposed areas such as the arms, legs, back, and chest. Nodular melanoma appears as a red or black lump that bleeds or oozes and affects middle-aged people. Lentigo maligna affects chronically sun-exposed skin in older people, while acral lentiginous melanoma appears on nails, palms, or soles in people with darker skin pigmentation. Other rare forms of melanoma include desmoplastic melanoma, amelanotic melanoma, and melanoma arising in other parts of the body such as ocular melanoma.
The main diagnostic features of melanoma are changes in size, shape, and color. Secondary features include a diameter of 7mm or more, inflammation, oozing or bleeding, and altered sensation. Suspicious lesions should undergo excision biopsy, and the lesion should be completely removed to facilitate subsequent histopathological assessment. Once the diagnosis is confirmed, the pathology report should be reviewed to determine whether further re-excision of margins is required. The margins of excision are related to Breslow thickness, with lesions 0-1mm thick requiring a margin of 1 cm, lesions 1-2mm thick requiring a margin of 1-2 cm (depending on site and pathological features), lesions 2-4mm thick requiring a margin of 2-3 cm (depending on site and pathological features), and lesions over 4mm thick requiring a margin of 3 cm. Further treatments such as sentinel lymph node mapping, isolated limb perfusion, and block dissection of regional lymph node groups should be selectively applied.
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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 67-year-old man is being evaluated by a vascular specialist for poor diabetes control. His HbA1c is 7.8% and he has a medical history of type II diabetes, hypertension, hyperlipidaemia, and hypothyroidism. During the examination, the specialist observes diminished posterior tibial pulses. Which area is likely to experience compromised blood supply due to reduced blood flow through the posterior tibial artery?
Your Answer:
Correct Answer: Posterior compartment of the leg and plantar surface of the foot
Explanation:The posterior tibial artery is responsible for supplying oxygenated blood to the posterior compartment of the leg as well as the plantar surface of the foot.
Anatomy of the Posterior Tibial Artery
The posterior tibial artery is a major branch of the popliteal artery that terminates by dividing into the medial and lateral plantar arteries. It is accompanied by two veins throughout its length and its position corresponds to a line drawn from the lower angle of the popliteal fossa to a point midway between the medial malleolus and the most prominent part of the heel.
The artery is located anteriorly to the tibialis posterior and flexor digitorum longus muscles, and posteriorly to the surface of the tibia and ankle joint. The posterior tibial nerve is located 2.5 cm distal to its origin. The proximal part of the artery is covered by the gastrocnemius and soleus muscles, while the distal part is covered by skin and fascia. The artery is also covered by the fascia overlying the deep muscular layer.
Understanding the anatomy of the posterior tibial artery is important for medical professionals, as it plays a crucial role in the blood supply to the foot and ankle. Any damage or blockage to this artery can lead to serious complications, such as peripheral artery disease or even amputation.
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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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Which one of the following is not a pathological response to extensive burns in elderly patients?
Your Answer:
Correct Answer: Absolute polycythaemia
Explanation:The primary pathological response is haemolysis.
Pathology of Burns
Extensive burns can cause various pathological changes in the body. The heat and microangiopathy can damage erythrocytes, leading to haemolysis. The loss of capillary membrane integrity can cause plasma leakage into the interstitial space, resulting in hypovolaemic shock. This shock can occur up to 48 hours after the injury and can cause a decrease in blood volume and an increase in haematocrit. Additionally, protein loss and secondary infections, such as Staphylococcus aureus, can occur. There is also a risk of acute peptic stress ulcers, known as Curling’s ulcers. Furthermore, full-thickness circumferential burns in an extremity can lead to compartment syndrome.
The healing process of burns depends on the severity of the burn. Superficial burns can heal through the migration of keratinocytes to form a new layer over the burn site. However, full-thickness burns can result in dermal scarring, which may require skin grafts to provide optimal coverage. It is important to understand the pathology of burns to provide appropriate treatment and prevent further complications.
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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 structures listed below articulates with the head of the radius superiorly?
Your Answer:
Correct Answer: Capitulum
Explanation:The capitulum of the humerus forms a joint with the head of the radius.
Anatomy of the Radius Bone
The radius bone is one of the two long bones in the forearm that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, with the distal end being the larger one. The upper end of the radius bone has articular cartilage that covers the medial to lateral side and articulates with the radial notch of the ulna by the annular ligament. The biceps brachii muscle attaches to the tuberosity of the upper end.
The shaft of the radius bone has several muscle attachments. The upper third of the body has the supinator, flexor digitorum superficialis, and flexor pollicis longus muscles. The middle third of the body has the pronator teres muscle, while the lower quarter of the body has the pronator quadratus muscle and the tendon of supinator longus.
The lower end of the radius bone is quadrilateral in shape. The anterior surface is covered by the capsule of the wrist joint, while the medial surface has the head of the ulna. The lateral surface ends in the styloid process, and the posterior surface has three grooves that contain the tendons of extensor carpi radialis longus and brevis, extensor pollicis longus, and extensor indicis. Understanding the anatomy of the radius bone is crucial in diagnosing and treating injuries and conditions that affect this bone.
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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 65-year-old woman is recuperating from a tibia fracture and has been wearing a snug cast over the proximal knee for three weeks. She reports numbness over the lateral two-thirds of the outer leg. During a lower limb neurological examination, the junior doctor suspects injury to the common fibular nerve. Which muscle is expected to be unaffected in this patient?
Your Answer:
Correct Answer: Biceps femoris
Explanation:The short head of the biceps femoris muscle is supplied by the common peroneal division of the sciatic nerve, while the long head is innervated by the tibial branch of the sciatic nerve. Despite this, the biceps femoris can still perform knee flexion. The extensor digitorum longus, extensor hallucis longus, and fibularis tertius muscles are all innervated by the deep fibular nerve, which is a branch of the common fibular nerve. Weakness in toe extension and big-toe extension may occur due to damage to these muscles, while the fibularis tertius muscle is important for eversion of the foot during walking.
The Biceps Femoris Muscle
The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.
On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.
Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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