Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
A 27-year-old man was admitted to the emergencydepartment after an automobile collision in which hesuffered a fracture of the lateral border of the scapula. Six weeks after the accident, physical examination reveals weakness in medial rotation and adduction of thehumerus. Which nerve was most likely injured?
A) Lower subscapular B) Axillary C) Radial D) Spinal accessory E) Ulnar |
Answer: A Lower subscapular nerves arise from the cervical spinal nerves 5 and 6. It innervates the subscapularis and teres major muscles. The subscapularis and teres major are both responsible for adducting and medially rotating the arm. A lesion of this nerve would result in weakness in these motions.
▪︎The axillary nerve also arises from cervical spinal nerves 5 and 6 and innervates the deltoid and teres minor muscles. The deltoid muscle is large and covers the entire surface of the shoulder, and contributes to arm movement in any plane. The teres minor is a lateral rotator and a member of the rotator cuff group of muscles.
▪︎The radial nerve arises from the posterior cord of the brachial plexus. It is the largest branch, and it innervates the triceps brachii and anconeus in the arm.
▪︎The spinal accessory nerve is cranial nerve XI, and it innervates the trapezius muscle, which elevates and depresses the scapula.
▪︎The ulnar nerve arises from the medial cord of the brachial plexus and runs down the medial aspect of the arm. It innervates muscles of the forearm and hand. |
What muscles are responsible for both adducting and medial rotating of the arm? |
|
|
A 48-year-old female court stenographer is admitted to the orthopedic clinic with symptoms of carpal tunnel syndrome, with which she has suffered for almost a year. Which muscles most typically become weakened in this condition?
A) DI B) Lumbricals III & IV C) Thenar D) PI E) Hypothenar |
Answer: C. ▪︎The thenar muscles (and lumbricals I and II) are innervated by the median nerve, which runs through the carpal tunnel. The carpal tunnel is formed anteriorly by the flexor retinaculum and posteriorly by the carpal bones. Carpal tunnel syndrome is caused by compression of the median nerve, due to reduced space in the carpal tunnel. The carpal tunnel contains the tendons of flexor pollicis longus, flexor digitorum profundus, and flexor digitorum superficialis muscles.
▪︎The dorsal interossei, lumbricals III and IV, palmar interossei, and hypothenar muscles are all innervated by the ulnar nerve.
|
Which nerve is run through carpal tunnel? |
|
|
A 45-year-old male arrived at the emergency department with injuries to his left elbow after he fell in a bicycle race. Radiographic and MRI examinations show a fracture of the medial epicondyle and a torn ulnar nerve. Which of the following muscles would be most likely to be paralyzed? A. Flexor digitorum superficialis B. Biceps brachii C. Brachioradialis D. Flexor carpi ulnaris E. Supinator |
Answer: D. ▪︎Fracture of the medial epicondyle often causes damage to the ulnar nerve due to its position in the groove behind the epicondyle. The ulnar nerve innervates one and a half muscles in the forearm the flexor carpi ulnaris and the medial half of the flexor digitorum profundus. The nerve continues on to innervate muscles in the hypothenar
▪︎The flexor digitorum superficialis is innervated by the median nerve.
▪︎The biceps brachii by the musculocutaneous.
▪︎The radial nerve innervates both the brachioradialis and supinator muscles. |
|
|
|
While walking to his classroom building, a first year medical student slipped on the wet pavement and fell against the curb, injuring his right arm. Radiographic images showed a midshaft fracture of the humerus. Which pair of structures was most likely injured at the fracture site?
A) Median nerve & Brachial artery B) Axillary nerve and posterior circumflex humeral artery C) Radial nerve & deep brachial artery D) Suprascapular nerve & artery E) Long thoracic nerve & lateral thoracic artery |
Answer: C. ▪︎A midshaft humeral fracture can result in injury to the radial nerve and deep brachial artery because they lie in the spiral groove located in the midshaft.
▪︎Injury to the median nerve and brachial artery can be caused by a supracondylar fracture that occurs by falling on an outstretched hand and partially flexed elbow.
▪︎A fracture of the surgical neck of the humerus can injure the axillary nerve and posterior humeral circumflex artery.
▪︎The suprascapular artery and nerve can be injured in a shoulder dislocation.
▪︎The long thoracic nerve and lateral thoracic artery may be damaged during a mastectomy procedure. |
What nerve that runs through midshaft of humerus? |
|
|
An 18-year-old male is brought to the emergency department after an injury while playing rugby. Imaging reveals a transverse fracture of the humerus about 1 inch proximal to the epicondyles. Which nerve is most frequently injured by the jagged edges of the broken bone at this location? A. Axillary B. Median C. Musculocutaneous D. Ulnar |
Answer: B. ▪︎A supracondylar fracture often results in injury to the median nerve. The course of the median nerve is anterolateral, and at the elbow it lies medial to the brachial artery on the brachialis muscle.
▪︎The axillary nerve passes posteriorly through the quadrangular space, accompanied by the posterior circumflex humeral artery, and winds around the surgical neck of the humerus. Injury to the surgical neck may damage the axillary nerve.
▪︎The musculocutaneous nerve pierces the coracobrachialis muscle and descends between the biceps and brachialis muscle. It continues into the forearm as the lateral antebrachial cutaneous nerve.
▪︎The ulnar nerve descends behind the medial epicondyle in its groove and is easily injured and produces “funny bone” symptoms.
|
|
|
|
A 52-year-old band director suffered problems in her right arm several days after strenuous fi eld exercises for a major athletic tournament. Examination in the orthopedic clinic reveals wrist drop and weakness of grasp but normal extension of the elbow joint. There is no loss of sensation in the affected limb. Which nerve was most likely affected?
A. Ulnar B. Anterior interosseous C. Posterior interosseous D. Median E. Superficial radial |
Answer: C. The radial nerve descends posteriorly between the long and lateral heads of the triceps and passes inferolaterally on the back of the humerus betweenthe medial and lateral heads of the triceps. It eventually enters the anterior compartment and descends toenter the cubital fossa, where it divides into superficial and deep branches. The deep branch of the radial nerve winds laterally around the radius and runs between the two heads of the supinator and continues as the posterior interosseous nerve, innervating extensor muscles of the forearm. Because this injury does not result in loss of sensation over the skin of the upper limb, it is likely that the superfi cial branch of the radial nerve is not injured. If the radial nerve were injured very proximally, the woman would not have extension of her elbow. The branches of the radial nerve to the triceps arise proximal to where the nerve runs in the spiral groove.
▪︎The anterior interosseous nerve arises from the median nerve and supplies the flexor digitorum profundus, flexor pollicis longus, and pronator quadratus, none of which seemto be injured in this example.
▪︎Injury to the median nerve causes a characteristic flattening (atrophy) of the thenar eminence. |
|
|
|
A 32-year-old woman is admitted to the emergency department after an automobile collision. Radiographic examination reveals multiple fractures of the humerus. Flexion and supination of the forearm are severely weakened. She also has loss of sensation on the lateral surface of the forearm. Which of the following nerves has most likely been injured?
A. Radial B. Musculocutaneous C. Median D. Lateral cord of brachial plexus E. Lateral cutaneous nerve of the forearm |
Answer: B. The musculocutaneous nerve supplies the biceps brachii and brachialis, which are the flexors of the forearm at the elbow. ︎The musculocutaneous nerve continues as the lateral antebrachial cutaneous nerve, which supplies sensation to the lateral side of the forearm (with the forearm in the anatomic position). The biceps brachii is the most powerful supinator muscle.Injury to this nerve would result in weakness of supination and forearm flexion and lateral forearm sensory loss.
▪︎Injury to the radial nerve would result in weakened extension and a characteristic wrist drop.
▪︎Injury to the median nerve causes paralysis of flexor digitorumsuperfi cialis and other flexors in the forearm and results in a characteristic flattening of the thenar eminence. ▪︎The lateral cord of the brachial plexus gives origin both to the musculocutaneous and lateral pectoral nerves. There is no indication of pectoral paralysis or weakness. Injury to the lateral cord can result in weakened flexion and supination in the forearm, and weakened adduction and medial rotation of the arm.
▪︎The lateral cutaneous nerve of the forearm is a branch of the musculocutaneous nerve and does not supply any motorinnervation. Injury to the musculocutaneous nerve alone is unusual but can follow penetrating injuries. |
|
|
|
A 24-year-old medical student was bitten at the base of her thumb by her dog. The wound became infected and the infection spread into the radial bursa. The tendon(s) of which muscle will most likely be affected?
A. Flexor digitorum profundus B. Flexor digitorum superficialis C. Flexor pollicis longus D. Flexor carpi radialis E. Flexor pollicis brevis |
Answer: C. Tenosynovitis can be due to an infection of the synovial sheaths of the digits. Tenosynovitis in the thumb may spread through the synovial sheath of the flexor pollicis longus tendon, also known as theradial bursa.
▪︎The tendons of the flexor digitorum superficialis and profundus muscles are enveloped inthe common synovial flexor sheath, or ulnar bursa.
▪︎Neither the flexor carpi radialis nor flexor pollicis brevis tendons are contained in synovial flexor sheaths. |
|
|
|
Laboratory studies in the outpatient clinic on a 24-year-old female included assessment of circulating blood chemistry. Which of the following arteries is most likely at risk during venipuncture at the cubital fossa?
A. Brachial B. Common interosseous C. Ulnar D. Anterior interosseous E. Radial |
Answer: A. The three chief contents of the cubital fossa are the biceps brachii tendon, brachial artery, and median nerve (lateral to medial).
▪︎The common and anterior interosseous arteries arise distal to the cubital fossa
▪︎The ulnar and radial arteries are the result of the bifurcationof the brachial artery distal to the cubital fossa. |
|
|
|
A 22-year-old male is diagnosed with metastatic malignant melanoma of the skin over the xiphoid process. Which nodes receive most of the lymph from this area and are therefore most likely to be involved inmetastasis of the tumor?
A. Deep inguinal B. Vertical group of superficial inguinal C. Horizontal group of superficial inguinal D. Axillary E. Deep and superficial inguinal |
Answer: D. Lymph from the skin of the anterior chestwall primarily drains to the axillary lymph nodes. |
|
|
|
A 22-year-old woman is admitted to the emergency department in an unconscious state. The nurse takes a radial pulse to determine the heart rate of the patient. This pulse is felt lateral to which tendon?
A. Palmaris longus B. Flexor pollicis longus C. Flexor digitorum profundus D. Flexor carpi radialis E. Flexor digitorum superficialis |
Answer: D. The location for palpation of the radial pulse is lateral to the tendon of the flexor carpiradialis, where the radial artery can be compressed against the distal radius. The radial pulse can also be felt in the anatomic snuffbox between the tendons of the extensor pollicis brevis and extensor pollicis longus muscles, where theradial artery can be compressed against the scaphoid. |
|
|
|
A 49-year-old female who had suffered a myocardialinfarction must undergo a bypass graft procedure using the internal thoracic artery. Which vessels willmost likely continue to supply blood to the anterior part of the upper intercostal spaces? A. Musculophrenic B. Superior epigastric C. Posterior intercostal D. Lateral thoracic E. Thoracodorsal |
Answer: C. The anterior intercostal arteries are 12 small arteries, two in each of the upper six intercostal spaces at the upper and lower borders. The upper artery lying in each space anastomoses with the posterior intercostal arteries, whereas the lower one usually joins the collateral branch of the posterior intercostal artery.
▪︎The musculophrenic artery supplies the pericardium, diaphragm, and muscles of the abdominal wall. It anastomoses with the deep circumflex iliac artery.
▪︎The superior epigastric artery supplies the diaphragm, peritoneum, and the anterior abdominal wall and anastomoses with the inferior epigastric artery. ▪︎The lateral thoracic artery runs along the lateral border of the pectoralis minor muscle and supplies the pectoralis major, pectoralis minor, and serratus anterior. ▪︎The thoracodorsal artery accompanies the thoracodorsal nerve in supplying the latissimus dorsi muscle and lateral thoracic wall. |
|
|
|
A 24-year-old man is admitted with a wound to the palm of his hand. He cannot touch the pads of his fingers with his thumb but can grip a sheet of paper between all fingers and has no loss of sensation on the skin of his hand. Which of the following nerves hasmost likely been injured? A 24-year-old man is admitted with a wound to the palm of his hand. He cannot touch the pads of his fingers with his thumb but can grip a sheet of paper between all fingers and has no loss of sensation on the skin of his hand. Which of the following nerves hasmost likely been injured? A. Deep branch of ulnar B. Anterior interosseous C. Median D. Recurrent branch of median E. Deep branch of radial |
Answer: D. The recurrent branch of the median nerve is motor to the muscles of the thenar eminence, which is an elevation caused by the abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis. If the opponens pollicis is paralyzed, one cannot oppose the pad of the thumb to the pads of the other digits. The recurrent branch does not have a cutaneous distribution.
▪︎Holding a piece of paper between the fingers is a simple test of adduction of the fingers. These movements are controlled by the deep branch of the ulnar nerve, which is not injured in this patient. |
|
|
|
A 55-year-old male is examined in a neighborhood clinic after receiving blunt trauma to his right axilla in a fall. He has diffi culty elevating the right arm above the level of his shoulder. Physical examination shows the inferior angle of his right scapula protrudesmore than the lower part of the left scapula. The right scapula protrudes far more when the patient pushes against resistance. Which of the following neural structureshas most likely been injured? A. The posterior cord of the brachial plexus B. The long thoracic nerve C. The upper trunk of the brachial plexus D. The site of origin of the middle and lowersubscapular nerves E. Spinal nerve roots C7, C8, and T1
|
Answer: B. “Winging” of the scapula occurs when the medial border of the scapula lifts off the chest wall when the patient pushes against resistance, such as a wall. The serratus anterior muscle holds the medial border of the scapula against the chest wall and is innervated by the long thoracic nerve. The serratus anterior assists in abduction of the arm above the horizontal plane.
|
|
|
|
A mother tugs violently on her male child’s handto pull him out of the way of an oncoming car and thechild screams in pain. Thereafter, it becomes obviousthat the child cannot straighten his forearm at the elbow.When the child is seen in the emergency department,radiographic examination reveals a dislocation of thehead of the radius. Which of the following ligaments ismost likely directly associated with this injury? A. Anular B. Joint capsular C. Interosseous D. Radial collateral E. Ulnar collateral |
Answer: A. The anular ligament is a fibrous band that encircles the head of the radius, forming a collar that fuses with the radial collateral ligament and articular capsule of the elbow. The anular ligament functions to prevent displacement of the head of the radius from its socket.
▪︎The joint capsule functions to allow free rotation of the joint and does not function in its stabilization.
▪︎The interosseous membrane is a fibrous layer between the radius and ulna helping to hold these two bones together.
▪︎The radial collateral ligament extends from the lateral epicondyle to the margins of the radial notch of the ulnar and the anular ligament of the radius.
▪︎The ulnar collateral ligament is triangular ligament and extends from the medialepicondyle to the olecranon of the ulna. |
|
|
|
After a forceps delivery of a male infant, the babypresents with his left upper limb adducted, internally rotated, and flexed at the wrist. The startle reflex is absent on the ipsilateral side. Which part of the brachial plexus was most likely injured during this delivery? A. Lateral cord B. Medial cord C. Roots of the lower trunk D. Root of the middle trunk E. Roots of the upper trunk |
Answer: E. The injury being described is also known as Erb-Duchenne paralysis or “waiter’s tip-hand.” This usually results from an injury to the upper trunk of the brachial plexus, presenting with loss of abduction, flexion, and lateral rotation of the arm. The superiortrunk of the brachial plexus consists of spinal nerve roots C5-6. |
|
|
|
A 47-year-old female tennis professional is informed by her physician that she has a rotator cuff injury that will require surgery. Her physician explains that over the years of play a shoulder ligament has gradually caused severe damage to the underlying muscle. To which of the following ligaments is the physicianmost likely referring? A. Acromioclavicular ligament B. Coracohumeral ligament C. Transverse scapular ligament D. Glenohumeral ligament E. Coracoacromial ligament |
Answer: E. The coracoacromial ligament contributes to the coracoacromial arch, preventing superior displacement of the head of the humerus. Because this ligamentis very strong, it will rarely be damaged; instead, the ligament can cause inflammation or erosion of thetendon of the supraspinatus muscle as the tendon passes back and forth under the ligament.
▪︎The acromioclavicular ligament, connecting the acromion withthe lateral end of the clavicle, is not in contact with the supraspinatus tendon.
▪︎The coracohumeral ligament is located too far anteriorly to impinge upon the supraspinatus tendon.
▪︎The glenohumeral ligament is located deep to the rotator cuff muscles and would not contribute to injury of the supraspinatus muscle.
▪︎The transverse scapular ligament crosses the scapular notch andis not in contact with the supraspinatus tendon. |
|
|
|
A 54-year-old female marathon runner presents with pain in her right wrist that resulted when she fell with force on her outstretched hand (Smith's fracture). Radiographic studies indicate an anterior dislocation of a carpal bone. Which of the following bones is most likely dislocated? A. Capitate B. Lunate C. Scaphoid D. Trapezoid E. Triquetrum |
Answer: B. The lunate is the most commonly dislocated carpal bone because of its shape and relatively weak ligaments anteriorly.
▪︎Dislocations of the scaphoid and triquetrum are relatively rare.
▪︎The trapezoid and capitate bones are located in the distal row of the carpalbones. |
|
|
|
47-year-old female patient’s right breast exhibitedcharacteristics of peau d’orange; that is, the skinresembled orange peel. This condition is primarily aresult of which of the following? A. Shortening of the suspensory ligaments bycancer in the axillary tail B. Blockage of cutaneous lymphatic vessels C. Contraction of the retinacula cutis of the areolaand nipple D. Invasion of the pectoralis major by the cancer E. Ipsilateral (same side) inversion of the periareolarskin from ductular cancer
|
Answer: B. When cutaneous lymphatics of the breast areblocked by cancer, the skin becomes edematous, except where hair follicles cause small indentations of the skin, giving an overall resemblance to orange peel.
▪︎Shortening of the suspensory ligaments or retinacula cutis leads to pitting of the overlying skin, pitting that is intensified if the patient raises her arm above her head.
▪︎Invasion of the pectoralis major by cancer can result in fixation of the breast, seen upon elevation of the ipsilateral limb.
▪︎Inversion of areolar skin with involvement of the ducts would also be dueto involvement of the retinacula cutis. |
|
|
|
A 68-year-old female is examined by the senior resident in emergency medicine after her fall on a wet bathroom floor in the shopping center. Physical examination reveals a posterior displacement of the left distal wrist and hand. Radiographic examination reveals an oblique fracture of the radius. Which of the following is the most likely fracture involved in this case? A. Colles’ fracture B. Scaphoid fracture C. Bennett’s fracture D. Volkmann’s ischemic contracture E. Boxer’s fracture |
Answer: A. Colles’ fracture is a fracture of the distal end of the radius. The proximal portion of the radius is displaced anteriorly, with the distal bone fragment projectingposteriorly. The displacement of the radius from the wrist often gives the appearance of a dinner fork, thus a Colles’ fracture is often referred to as a “dinner fork”deformity.
▪︎A scaphoid fracture results from a fracture of the scaphoid bone and would thus not cause displace- ment of the radius. This fracture usually occurs at the narrow aspect (“waist”) of the scaphoid bone.
▪︎Bennett’s and boxer’s fractures both result from fractures of the metacarpals (fi rst and fi fth, respectively).
▪︎Volkmann’s ischemic contracture is a muscular deformity that can follow a supracondylar fracture of the humerus, with arterial laceration into the flexor compartment of the forearm. Ischemia and muscle contracture, with extreme pain, accompany this fracture. |
|
|
|
A 45-year-old woman is being examined as a candidate for cosmetic breast surgery. The surgeon notes that both of her breasts sag considerably. Which structure has most likely become stretched to result in this condition? A. Scarpa’s fascia B. Pectoralis major muscle C. Pectoralis minor muscle D. Suspensory (Cooper’s) ligaments E. Serratus anterior muscle |
Answer: D. The suspensory ligaments of the breast, also known as Cooper’s ligaments, are fibrous bands that run from the dermis of the skin to the deep layer of superficial fascia and are primary supports for the breasts against gravity. Ptosis of the breast is usually due to the stretching of these ligaments and can be repaired with plastic surgery.
▪︎Scarpa’s fascia is the deep membranous layer of superficial fascia of the anterior abdominal wall.
▪︎The pectoralis major and pectoralis minor are muscles that move the upperlimb and lie deep to the breast but do not provide any direct support structure to the breast.
▪︎The serratus anterior muscle is involved in the movements of the scapula. |
|
