Upper Limb B

Question 1

Question 182 of 328 The cephalic vein pierces the clavipectoral fascia to terminate in which of the veins listed below? A. External jugular B. Axillary C. Internal jugular D. Azygos E. Brachial

Answer 1

Axillary

Question 2

Question 187 of 328 Damage to the posterior cord of the brachial plexus will not result in any of the following except: A. Klumpkes palsy B. Anaesthesia overlying the lateral aspect of the forearm C. A warm sweaty hand on the affected side

Answer 2

Anaesthesia overlying the posterior surface of the armThe radial nerve gives cutaneous branches which supply the forearm posteriorly and the arm laterally. Division of the posterior cord will impair the upper level of cutaneous sensation. However, the lateral cutaneous nerve of the forearm arises from the musculocutaneous nerve and would be unaffected. Loss of sympathetic function, from the posterior cord alone, would not result in a sweaty hand. Klumpkes palsy occurs when the lower roots are C8-T1 are damaged.

Question 3

Question 189 of 328 A woman develops winging of the scapula following a Patey mastectomy. What is the most likely cause? A. Division of pectoralis minor to access level 3 axillary nodes B. Damage to the brachial plexus during axillary di

Answer 3

Damage to the long thoracic nerve during axillary dissection

Question 4

Question 192 of 328 Which of the following is not closely related to the capitate bone? A. Lunate bone B. Scaphoid bone C. Ulnar nerve D. Hamate bone E. Trapezoid bone

Answer 4

The ulnar nerve and artery lie adjacent to the pisiform bone. The capitate bone articulates with the lunate, scaphoid, hamate and trapezoid bones, which are therefore closely related to it.

Question 5

Question 202 of 328 A 23 year old man falls over whilst intoxicated and a shard of glass transects his median nerve at the proximal border of the flexor retinaculum. His tendons escape injury. Which of the following features is least likely to be pre

Answer 5

Loss of sensation on the dorsal aspect of the thenar eminenceThe median nerve may be injured proximal to the flexor retinaculum. This will result in loss of flexor pollicis brevis, opponens pollicis and the first and second lumbricals. When the patient is asked to close the hand slowly there is a lag of the index and middle fingers reflecting the impaired lumbrical muscle function. The sensory changes are minor and do not extend to the dorsal aspect of the thenar eminence.Abductor pollicis longus will contribute to thumb abduction (and is innervated by the posterior interosseous nerve) and therefore abduction will be weaker than prior to the injury.

Question 6

Question 206 of 328 Which of the following relationship descriptions regarding the scalene muscles is incorrect? A. The brachial plexus passes anterior to the middle scalene muscle B. The phrenic nerve lies anterior to the anterior scalene mu

Answer 6

The subclavian artery passes anterior to the middle scalene.

Question 7

Question 208 of 328 A 23 year old man falls and injures his hand. There are concerns that he may have a scaphoid fracture as there is tenderness in his anatomical snuffbox on clinical examination. Which of the following forms the posterior border of

Answer 7

Extensor pollicis longusTheme from 2009 ExamTheme from September 2012 ExamIts boundaries are extensor pollicis longus, medially (posterior border) and laterally (anterior border) by the tendons of abductor pollicis longus and extensor pollicis brevis.

Question 8

Question 218 of 328 A 28 year old man is stabbed outside a nightclub in the upper arm. The median nerve is transected. Which of the following muscles will demonstrate impaired function as a result? A. Palmaris brevis B. Second and third inter

Answer 8

Abductor pollicis brevisPalmaris brevis - Ulnar nervePalmar interossei- Ulnar nerveAdductor pollicis - Ulnar nerveAbductor pollicis longus - Posterior interosseous nerveAbductor pollicis brevis - Median nerveThe median nerve innervates all the short muscles of the thumb except the adductor and the deep head of the short flexor. Palmaris and the interossei are innervated by the ulnar nerve.

Question 9

Question 228 of 328 Which of the following is not a branch of the posterior cord of the brachial plexus? A. Thoracodorsal nerve B. Axillary nerve C. Radial nerve D. Lower subscapular nerve E. Musculocutaneous nerve

Answer 9

Musculocutaneous nerveMnemonic branches off the posterior cordS ubscapular (upper and lower)T horacodorsalA xillaryR adialThe musculocutaneous nerve is a branch off the lateral cord.

Question 10

Question 233 of 328 A 56 year old machinist has his arm entrapped in a steel grinder and is brought to the emergency department. On examination, he is unable to extend his metacarpophalangeal joints and abduct his shoulder. He has weakness of his

Answer 10

Posterior cord of brachial plexusThe posterior cord gives rise to: Radial nerve ((innervates the triceps, brachioradialis, wrist extensors, and finger extensors) Axillary nerve (innervates deltoid and teres minor) Upper subscapular nerve (innervates subscapularis) Lower subscapular nerve (innervates teres major and subscapularis) Thoracodorsal nerve (innervates latissimus dorsi) Theme from September 2012 examThis is a description of a posterior cord lesion. Remember that the posterior cord gives rise to the axillary and radial nerve.

Question 11

Question 241 of 328 A motor cyclist is involved in a road traffic accident causing severe right shoulder injuries. He is found to have an adducted, medially rotated shoulder. The elbow is fully extended and the forearm pronated. Which is the most lik

Answer 11

. C5, C6 root lesionErbs Palsy C5, C6 lesionThe features include: Waiter’s tip position Loss of shoulder abduction (deltoid and supraspinatus paralysis) Loss of external rotation of the shoulder (paralysis of infraspinatus and teres major) Loss of elbow flexion (paralysis of biceps, brachialis and brachioradialis) Loss of forearm supination (paralysis of Biceps)The motorcyclist has had an Erb’s palsy (C5, C6 root lesion). This is commonly known to be associated with birth injury when a baby has a shoulder dystocia.

Question 12

Question 248 of 328 A 23 year old man has a cannula inserted into his cephalic vein. Through which structure does the cephalic vein pass? A. Interosseous membrane B. Triceps C. Pectoralis major D. Clavipectoral fascia E. Tendon o

Answer 12

Clavipectoral fasciaThe cephalic vein is a favored vessel for arteriovenous fistula formation and should be preserved in patients with end stage renal failureThe cephalic vein penetrates the calvipectoral fascia (but not the pectoralis major) prior to terminating in the axillary vein.

Question 13

Question 250 of 328 Which of the following is not a carpal bone? A. Trapezium B. Triquetrum C. Trapezoid D. Trapezius E. Lunate

Answer 13

TrapeziusMnemonic for the Carpal BonesSally Likes To Play The Tiny Chrome HarmonicaShe Looks Too Pretty Try To Catch HerScared Lovers Try Positions That They Can’t Handle

Question 14

Question 268 of 328 A 32 year old man is stabbed in the neck and the inferior trunk of his brachial plexus is injured. Which of the modalities listed below is least likely to be affected? A. Initiating abduction of the shoulder B. Abduction o

Answer 14

Initiating abduction of the shoulderInferior trunk of brachial plexus. C8 and T1 roots Contributes to ulnar nerve and part of median nerveTheme from September 2012 ExamThe inferior trunk of the brachial plexus is rarely injured. Nerve roots C8 and T1 are the main contributors to this trunk. Therefore an injury to this site will most consistently affect the ulnar nerve. The inferior trunk also contributes to the median nerve by way of the posterior division and therefore some impairment of grip is almost inevitable.

Question 15

Question 278 of 328 A 62 year old man presents with arm weakness. On examination he has a weakness of elbow extension and loss of sensation on the dorsal aspect of the first digit. What is the site of the most likely underlying defect? A. A

Answer 15

Radial nerveTheme from April 2012 ExamThe long head of the triceps muscle may be innervated by the axillary nerve and therefore complete loss of triceps muscles function may not be present even with proximally sited nerve lesions.

Question 16

Question 279 of 328 From which of the following structures does the long head of the triceps muscle arise? A. Coracoid process B. Acromion C. Infraglenoid tubercle D. Coraco-acromial ligament E. Coraco-humeral ligament

Answer 16

Infraglenoid tubercleThe long head arises from the infraglenoid tubercle. The fleshy lateral and medial heads are attached to the posterior aspect of the humerus between the insertion of the teres minor and the olecranon fossa.

Question 17

Question 289-291 of 328 Theme: Nerve injuryA. Median nerveB. Ulnar nerveC. Radial nerveD. Anterior interosseous nerveE. Posterior interosseous nerveF. Axillary nerveG. Musculocutaneous nervePlease select the nerve at risk of injur

Answer 17

Question 289-291 of 328 Theme: Nerve injuryA. Median nerveB. Ulnar nerveC. Radial nerveD. Anterior interosseous nerveE. Posterior interosseous nerveF. Axillary nerveG. Musculocutaneous nervePlease select the nerve at risk of injury in each scenario. Each option may be used once, more than once or not at all.289. A 43 year old typist presents with pain at the dorsal aspect of the upper part of her forearm. She also complains of weakness when extending her fingers. On examination triceps and supinator are both functioning normally. There is weakness of most of the extensor muscles. However, there is no sensory deficit.You answered Ulnar nerveThe correct answer is Posterior interosseous nerveThe radial nerve may become entrapped in the “arcade of Frohse” which is a superficial part of the supinator muscle which overlies the posterior interosseous nerve. This nerve is entirely muscular and articular in its distribution. It passes postero-inferiorly and gives branches to extensor carpi radialis brevis and supinator. It enters supinator and curves around the lateral and posterior surfaces of the radius. On emerging from the supinator the posterior interosseous nerve lies between the superficial extensor muscles and the lowermost fibres of supinator. It then gives branches to the extensors.290. A 28 year teacher reports difficulty with writing. There is no sensory loss. She is known to have an aberrant Gantzer muscle.You answered Posterior interosseous nerveThe correct answer is Anterior interosseous nerveAnterior interosseous lesions occur due to fracture, or rarely due to compression. The Gantzer muscle is an aberrant accessory of the flexor pollicis longus and is a risk factor for anterior interosseous nerve compression. Remember loss of pincer grip and normal sensation indicates an interosseous nerve lesion.291. A 35 year tennis player attends reporting tingling down his arm. He says that his ‘funny bone’ was hit very hard by a tennis ball. There is weakness of abduction and adduction of his extended fingers.You answered Radial nerveThe correct answer is Ulnar nerveTheme from September 2012 examThe ulnar nerve arises from the medial cord of the brachial plexus (C8, T1 and contribution from C7). The nerve descends between the axillary artery and vein, posterior to the cutaneous nerve of the forearm and then lies anterior to triceps on the medial side of the brachial artery. In the distal half of the arm it passes through the medial intermuscular septum, and continues between this structure and the medial head of triceps to enter the forearm between the medial epicondyle of the humerus and the olecranon. It may be injured at this site in this scenario.

Question 18

Question 297 of 328 A 53 year old lady presents with pain and discomfort in her hand. She works as a typist and notices that the pain is worst when she is working. She also suffers symptoms at night. Her little finger is less affected by the pain

Answer 18

MedianMotor supply: LOAFL ateral 2 lumbricalsO pponens pollicisA bductor pollicisbrevisF lexor pollicis brevisTheme from April 2012 ExamThe most likely diagnosis here is carpal tunnel syndrome, the median nerve is compressed in the wrist and symptoms usually affect the fingers and wrist either at night or when the hand is being used (e.g. as a typist).

Question 19

Question 298 of 328 Which of the following muscles lies medial to the long thoracic nerve? A. Serratus anterior B. Latissimus dorsi C. Pectoralis major D. Pectoralis minor E. None of the above

Answer 19

Serratus anterior

Question 20

Question 304 of 328 A 24 year female is admitted to A&E with tingling of her hand after a fall. She is found to have a fracture of the medial epicondyle. What is the most likely nerve lesion? A. Ulnar nerve B. Radial nerve C. Median ne

Answer 20

ulnar nerveThe radial nerve is located near the lateral epicondyle.

Question 21

Question 317 of 328 A 73 year old lady with long standing atrial fibrillation develops a cold and pulseless white arm. A brachial embolus is suspected and a brachial embolectomy is performed. Which of the following structures is at greatest risk of i

Answer 21

Median nerveThe median nerve lies close to the brachial artery in the antecubital fossa. This is the usual site of surgical access to the brachial artery for an embolectomy procedure. The median nerve may be damaged during clumsy application of vascular clamps to the artery.

Question 22

Question 319 of 328 Which of the following fingers is not a point of attachment for the palmar interossei? A. Middle finger B. Little finger C. Ring finger D. Index finger E. None of the above

Answer 22

The middle finger has no attachment of the palmar interosseous.

Question 23

Question 320 of 328 A 6 year old sustains a supracondylar fracture of the distal humerus. There are concerns that the radial nerve may have been injured. What is the relationship of the radial nerve to the humerus at this point? A. Anterolateral

Answer 23

. AnterolateralThe radial nerve lies anterolateral to the humerus in the supracondylar area.

Question 24

Question 322 of 328 The following are true of the ulnar nerve except: A. It innervates the palmar interossei B. Derived from the medial cord of the brachial plexus C. Supplies the muscles of the thenar eminence D. Supplies the medial ha

Answer 24

Supplies the muscles of the thenar eminenceThese are supplied by the median nerve and atrophy of these is a feature of carpal tunnel syndrome