MSK Review Answers

STRINGFELLOW1655 03/24/2018 MSK review Total Questions: 38 Most Correct Answers: #9 Least Correct Answers: #11 1. A 38-year-old woman with a history of carcinoma of the left breast and who had a lumpectomy 2 years previously, presents to her surgeon with complaints of a hard mass in the left breast. On ultrasound examination, a 3 cm x 4 cm hard mass is discovered in the upper outer quadrant extending in the axillary tail (of Spence). A radical mastectomy is performed successfully and the tumor is removed. Three weeks postoperatively the patient complains of difficulty raising her left arm above her head. Which of the following is most likely to be expected to be found during physical examination? 4/66 A Protraction of both scapulae 41/66 B Protrusion of the medial border of the left scapula with hands are pushed against the wall 2/66 C Weak abduction of the left upper limb in the 15 to 90 degree range 1/66 D Weak retraction of the scapula 0/66 E Weak adduction of the humerus 2. A 53 year old female reports difficulty walking. Physical exam showed a positive Trendelenburg sign when asked to stand on the right leg. Which nerve has been compromised to produce the positive sign? 6/66 A Right inferior gluteal 0/66 B Sciatic 6/66 C Left inferior gluteal 30/66 D Right superior gluteal 12/66 E Left superior gluteal 3. A lateral blow to the knee during a football game injures a 24-year-old man. Field exam reveals a positive anterior drawer test. MRI was later done which also revealed a medial meniscus tear. Which structure listed below is most likely to accompany the presenting injuries? 2/66 A Posterior cruciate ligament 1/66 B Lateral meniscus 50/66 C Medial collateral ligament 2/66 D Lateral collateral ligament 0/66 E Tendon of semitendinous muscle Page 1 of 13

4. A mother brings her 2 year old child to the ER after the child fell onto an outstretched hand, which resulted in a fracture to the humerus. The child has difficulty making a fist and cannot extend at the wrist. Which of the following would be most likely identified as the location of the fracture upon radiographic examination? 0/66 A Anatomical neck 38/66 B Midshaft 7/66 C Supracondylar fracture 6/66 D Medial epicondyle 2/66 E Surgical neck 5. A 52 year old female band director suffered problems in her right arm several days after strenuous field exercises for a major athletic tournament. Examination in the orthopedic clinic reveals wrist drop and weakness of grasp but normal extension at the elbow joint. There is no loss of sensation over the affected limb. Which nerve was most likely affected? 2/66 A Ulnar 6/66 B Anterior interosseous 42/66 C Posterior interosseous 1/66 D Median 3/66 E Superficial radial 6. A 26 year old gymnast falls from a balance beam and suffers a fracture. Radiology indicates that the fracture is located at the area indicated by the "X" and has lesioned a nerve. Which of the following is most likely to be evident on physical exam? 9/66 A Altered sensation in skin of the lateral palm 5/66 B Altered sensation in skin overlying the anatomical snuffbox 4/66 C Weakness in ability to extend the forearm at the elbow 3/66 D Weakness in ability to do the pushup 34/66 E Weakness in ability to spread the fingers Page 2 of 13

10. A 45-year-old man was admitted to the hospital with groin pain and a palpable mass just superior to the inguinal ligament. The patient was diagnosed with an inguinal hernia and a surgical repair was performed. During the operation the surgeon found a loop of intestine passing through the deep inguinal ring. Which of the following is also true about the type of hernia this man is suffering from? 12/66 A Medial to inferior epigastric vessels 0/66 B Lateral to rectus abdominis 45/66 C Lateral to inferior epigastric vessels 0/66 D Lateral to the pubic tubercle 0/66 E More common in females 11. A 30 year old man was brought to the trauma center by ambulance after being involved in a motorcycle accident. The physician approaches the stretcher and notices the patient's trachea was not centered. Upon further examination patient was found to have a tension pneumothorax. The doctor quickly performed a needle decompression. The physician plans to do place a chest tube. Which of the following locations is the correct placement for insertion of the chest tube? 0/66 A 7th intercostal space MCL 6/66 B 5th intercostal space mid-axillary line 2/66 C 10th intercostal space MCL 41/66 D 8th intercostal space mid-axillary line 7/66 E 9th intercostal space paravertebral. 12. A 90 year old male with osteoarthritis presents to the ER with a fracture at the neck of the femur. Branches of which artery are at most risk following this injury and can lead to avascular necrosis of the femoral head? 2/66 A Superior gluteal 44/66 B Medial circumflex femoral 4/66 C 1st perforating branch 1/66 D Inferior gluteal 3/66 E Obturator Page 4 of 13

13. A 36-year-old woman complains of impaired speech and frequent aspiration of food. Physical examination reveals double vision (diplopia) and drooping eyelids (ptosis). The patient is subsequently diagnosed with myasthenia gravis. The symptoms of muscle weakness in this patient are caused by autoantibodies directed against which of the following cellular components? 3/66 A Acetylcholine 51/66 B Acetylcholine receptor 0/66 C Calcium channel 0/66 D Epinephrine receptor 0/66 E Dopamine 14. Light micrograph prepared from a biopsy specimen taken from the nervous system of a 45-year-old man is shown below. This patient had a crush injury to this region a week ago, leading to death of the cells shown below. Which of the following will this result in? 6/66 A Loss of sensory perception 5/66 B Loss of CSF production 3/66 C Loss of phagocytic activity in tissues 42/66 D Loss of motor activity 0/66 E Loss of peristalsis of gut 15. A 63-year-old man presents to his physician with a swelling to his left thigh. On examination this swelling is smooth, mobile and well circumscribed. A biopsy is done and the tissue is studied under electron microscope. (image shown below). Which of the following lines/ bands can be identified at the pointers? 1/66 A A bands 0/66 B H zones 2/66 C I bands 2/66 D M lines 49/66 E Z lines Page 5 of 13

19. Which of the following labeled dots on the right graph corresponds to the dot plotted on the left graph? 45/66 A A 3/66 B B 3/66 C C 2/66 D D 0/66 E E 3/66 F F 20. Match the numbers on the Force length curve to the numbers on the force velocity curve. 7/66 A A 4/66 B B 1/66 C C 45/66 D D 21. Rigor mortis occurs approximately 3-4 hours after death. The muscles of the body become very stiff and it is therefore difficult to move and manipulate a corpse's limbs. The inability of the muscle fibers to relax is due to the lack of a certain chemical substance. The lack of this molecule impairs which of the following below resulting in rigor mortis? 0/66 A Binding of actin to myosin 0/66 B Binding of troponin to tropomyosin 1/66 C Power stroke of the myosin head 53/66 D Release of actin from myosin 0/66 E Release of Ca2+ from the Sarcoplasmic reticulum Page 7 of 13

22. A 9-month-old child of strict vegan parents is brought to the pediatrician due to perceived muscle weakness. Due to their strict dietary beliefs, the child has not been given vitamin supplements. An image of the anterior of the knee reveals cupped and widened metaphyses. As the child is very fair skinned, the parents always cover up the child when they go outside such that minimal skin is exposed to the sun. In order to correct these problems the physician prescribes treatment with which of the following? 0/66 A Folic acid 0/66 B Vitamin K 51/66 C Vitamin D 1/66 D Vitamin B12 0/66 E Vitamin E 23. A mother brings her 5-year-old boy, who has a 2-year history of progressive muscle weakness, to the pediatrician. She notices that the boy has trouble moving himself from a sitting position to a standing position, and that he has to push off the floor or pull himself up in order to stand. Physical examination reveals a happy boy with normal height and weight, normal reflexes, and large calves. A biopsy of his gastrocnemius would most likely show which of the following? 0/66 A Increased proportion of slow-twitch red muscle fibers 2/66 B Massive necrosis of all muscle fibers 0/66 C Unusually high capillary density 46/66 D Fibrofatty replacement of muscle fibers 5/66 E Hypertrophy of fast twitch white muscle fibers 24. A 74-year-old man with chronic renal failure has had repeated pathological fractures. Laboratory analysis reveals a serum Ca2+ of 6.3 mg/dL (Norm = 8.4-10), phosphate of 4.7 mg/dL (N = 3-4.5), PTH hormone of 750 pg/mL (N = 230-630). Which of the following most likely contributes to the pathogenesis of this man's bone disease? 3/66 A Decreased Ca2+ intake 4/66 B Decreased 25-hydroxyvitamin D production 49/66 C Decreased 1,25-dihydroxycholecalciferol production 0/66 D Decreased vitamin D2 intake 0/66 E Decreased vitamin D3 intake Page 8 of 13

28. A 24 year old man complains of inability to button his shirt 2 days after cutting himself while cooking dinner. Examination reveals that he can still hold a sheet of paper between his 2nd and 3rd fingers and there is no sensory loss to the hand. Which nerve has most likely been affected? 11/66 A Deep branch of the ulnar 0/66 B Deep branch of the radial 39/66 C Recurrent branch of median 4/66 D Anterior interosseous 1/66 E Median nerve 29. A 30 year old man presents to his physician with complaints of heart burn. The doctor performs an endoscopy, which reveals the presence of a sliding hiatal hernia that resulted in the onset of GERD. Which of the following vertebral levels does this structure transverse through the diaphragm? 5/66 A T7 6/66 B T8 0/66 C T9 37/66 D T10 0/66 E T11 7/66 F T12 30. A 45-year-old man goes to his family physician complaining of lower back pain after spending a weekend clearing trees off his property. During examination, the doctor notes a tuft of hair and a dimple on the skin of the patient’s lower back. A plain film reveals a congenital defect in his L5 vertebra, indicated by the black arrow in the given X-ray. No other structural abnor- malities are noted. Based on these findings, what is the most likely diagnosis for this patient? 0/66 A Meningocele 0/66 B Anencephaly 52/66 C Spina bifida occulta 1/66 D Spina bifida cystica 0/66 E Spina bifida with myeloschisis Page 10 of 13

31. During a physical examination of a 35-year-old man with a spinal cord injury, the neurologist lightly strokes the right upper medial side of the thigh to test the integrity of the L1-2 spinal cord segments. He notes the patient's cojones don't move. Which of the following nerves carries the efferent limb of this reflex arc? 1/66 A Iliohypogastric 44/66 B Genital branch of the genitofemoral 3/66 C Femoral branch of the genitofemoral 3/66 D Femoral 4/66 E Ilioinguinal 32. Idling at a stoplight in his vintage car without headrests, a 71-year-old-man’s car is struck from behind by a truck going approximately 30 mph (48 kph). The man is brought to the ER suffering from a severe hyperextension neck injury due to the crash. The given T2-weighted MRI shows a rupture of the anterior anulus of the C4-5 intervertebral disc, inflamma- tion of that disc (the white appearance), and a prevertebral hematoma, which compromised his airway and required intu- bation. Which of the following ligaments is disrupted in this injury? 51/66 A Anterior longitudinal ligament 1/66 B Posterior longitudinal ligament 0/66 C Ligamentum flavum 0/66 D Interspinous ligament 0/66 E Inter-transverse ligament 33. A 21-year-old female basketball player lands on her opponent’s foot after jumping to rebound the basketball. Her foot is forcefully inverted, and when leaving the court, she tells her trainer that she twisted or sprained her ankle. After getting her ankle taped for support, she reenters the game. What ligament was most likely damaged? 20/66 A Calcaneofibular ligament 21/66 B Anterior talofibular ligament 5/66 C Posterior talofibular ligament 5/66 D Plantar calcaneonavicular ligament 2/66 E Medial (deltoid) ligament Page 11 of 13

37. A 42-year-old woman gave birth to an 8 lb baby girl with two additional toes to the right of her big toe. Which of the following best describes this anomaly 0/66 A Amelia 0/66 B Clef foot 0/66 C Club foot 49/66 D polydactyly 0/66 E syndactyly 38. A 69 year old female comes to the emergency room complaining of severe shortness of breath. Physical exam reveals patient is hypertensive and has fluid in the lungs. Patient was later diagnosed with congestive heart failure. The doctor administered digoxin in order to increase which of the following? 7/66 A Afterload 8/66 B Preload 1/66 C Passive tension 18/66 D Number of cross-bridges formed 16/66 E Activity of the SERCA pump Page 13 of 13