MSK open review answers (1)

OVERACHIEVERS1 10/14/2018 MSK OPEN REVIEW 1 Total Questions: 21 Most Correct Answers: #12 Least Correct Answers: #8 1. A 42 y.o male presented to the clinic after falling while ice skating onto his shoulder. He complains of severe pain with palpation and limited mobility at the shoulder joint. Xray indicates a fracture. Strength examination shows weakness likely due to the nerve most at risk with this fracture. Which of the following deficits would most likely be seen on exam? 3/86 A elbow flexion 1/86 B shoulder retraction 9/86 C medial rotation 22/86 D lateral rotation 2/86 E elbow extension 18/86 F shoulder abduction (0-15 degrees) 16/86 G shoulder abduction above 90 degrees 2. A 8 y.o boy scraped his right forearm while learning how to roller blade last weekend. His injury was superficial as he only developed a small scab on the ulnar aspect of his ventral forearm. Which of the following lymph nodes would lymph from this injury drain to first? 11/86 A apical 9/86 B central 8/86 C humeral 35/86 D lateral 4/86 E pectoral 1/86 F suprascapular 2/86 G subclavian 0/86 H deltopectoral Page 1 of 8

3. A 22 y.o male presented to the ED after receiving a stab wound in his scapular region. The knife penetrated just inferior to his teres minor but medial to the lateral head of his triceps brachii and superior to the teres major. Which of the following arteries was most likely damaged given the location of his injury? 4/86 A suprascapular atery 9/86 B subscapular atery 11/86 C dorsal scapular atery 6/86 D thoracodorsal artery 36/86 E circumflex scapular atery 5/86 F descending branch of transverse cervical artery 4. A 21 y.o female presents to the clinic with acute shoulder pain after falling while playing rugby. Physical examination is notable for a step off deformity of the shoulder and decreased range of motion. Xray is shown. Which of the following ligaments are most likely torn? 6/86 A acromioclavicular and coracohumeral ligaments 4/86 B glenohumeral and coracoclavicular ligaments 49/86 C acromioclavicular and coracoclavicular ligaments 10/86 D glenohumeral and acromioclavicular ligaments 2/86 E coracohumeral and coracoclavicular ligaments 5. A 16 y.o male presents to the ED with severe shoulder pain. He said that he and his buddy were arm wrestling when he felt a pop in his shoulder followed by a sudden onset of sharp pain. Physical exam showed decreased deltoid contour and significantly reduced range of motion at the shoulder joint both passively and actively. He reports loss of sensation on the lateral upper arm. Xray is shown. Which of the following arteries is most at risk with this injury? 8/86 A subscapular artery 35/86 B posterior circumflex humeral artery 15/86 C anterior circumflex humeral artery 2/86 D thoracodorsal artery 6/86 E circumflex scapuar artery 3/86 F thoracoacromial artery 1/86 G superior thoracic artery Page 2 of 8

9. A 6 y.o girl falls off the swing at school. She has difficulty moving her shoulder and has numbness over the lateral aspect of her upper arm. Plain radiographs reveal a fracture of the proximal humerus. Where would the cell bodies of the injured nerve fibers involved in the sensory loss most likely be found? 7/86 A anterior horn 48/86 B dorsal root ganglia 4/86 C sympathetic chain ganglia 3/86 D posterior horn 5/86 E lateral horn 0/86 F subarachnoid space 10. A 15 y.o boy presents to the clinic with inability to flex the distal interphalangeal joint of his right index finger. Plain radiographs reveals a supracondylar fracture which is likely contributing to his condition. Which of the following would also likely be seen with this nerve damage? 11/86 A weakness with supination 16/86 B inability to flex the DIP joint of the little finger 12/86 C inability to adduct the thumb 5/86 D atrophy of the hypothenar eminence 24/86 E loss of sensation over the distal middle finger 11. A 50 y.o man presents to the ED unconscious after falling down the stairs. The doctors are concerned for a subarachnoid hematoma. They decide to do a lumbar puncture at the L4/5 level to check for blood in the cerebral spinal fluid. Which of the following ligamentums/dural layers does the aspiration needle pass through just prior to entering the epidural space? 3/86 A supraspinous ligament 0/86 B anterior longitudinal ligament 1/86 C dura mater 5/86 D arachnoid mater 2/86 E pia mater 1/86 F interspinous ligament 54/86 G ligamentum flavum Page 4 of 8

12. A 55 y.o male complains of sudden onset neck pain. MRI reveals herniation of the intervertebral disc between C3 and C4. Which of the following spinal nerve roots would most likely be compressed? 0/86 A C2 5/86 B C3 60/86 C C4 1/86 D C5 0/86 E C6 0/86 F S1 13. A 65 y.o woman with a history of degenerative disc disease of the lumbar spine returns to the clinic with acute on chronic low back pain. She states that she "threw out" her back when shoveling the sidewalk this morning. Plain radiographs shows the L4 vertebra slipping anteriorly relative to L5. Which of the following terms would best describe this condition? 52/86 A spondylolisthesis 4/86 B spondylolysis 0/86 C kyphosis 4/86 D disc herniation 0/86 E spondyloarthropathy 3/86 F lordosis 0/86 G spondylostenosis 14. A 18 y.o female injured her spinal cord in a car accident. Examination showed weakness of her right upper limb. The doctor believes that the cell bodies of the somatic efferent nerve fibers at the C6 level are damaged. The general location of these cell bodies developed from which of the following embryological structures? 2/86 A marginal zone 7/86 B alar plate 0/86 C sulcus limitans 8/86 D basal plate 41/86 E neural crest cells 5/86 F ventricular zone Page 5 of 8

18. An 18 y.o complains of a rash that is consistent with herpes zoster infection. The affected area wraps around from the back to the right nipple. Which of the following is most likely contains the active virus? 2/86 A Dorsal root of T3 45/86 B Dorsal root of T4 2/86 C ventral root of T3 1/86 D dorsal root of T3 8/86 E dorsal root of T5 2/86 F ventral root of T5 19. The diagrams show the records taken from isolated skeletal contracting with various loads. Both the length and force were measured. The x axis represents time. An upward deflection of the length graph represents shortening. Which of the following best shows isometric contraction? 47/86 A 1 3/86 B 2 7/86 C 3 4/86 D 4 20. The following diagram shows the length tension curve of in vitro skeletal muscle. The blue line represents active tension and the green line represents passive tension. Which circle represents the length where the greatest tension is produced during contraction? 1/86 A 1 1/86 B 2 37/86 C 3 14/86 D 4 8/86 E 5 Page 7 of 8

21. Which of the following terminates smooth muscle contraction? 38/86 A Dephosphorylation of myosin light chain 11/86 B Dephosphorylation of myosin kinase 1/86 C Inhibition of myosin phosphatase 9/86 D uptake of Ca2+ ions into the sarcoplasmic reticulum 2/86 E efflux of Ca2+ ions across the plasma membrane Page 8 of 8