Nerves
A 23-year-old football player sustains a midshaft humeral fracture. On exam, he cannot extend his wrist and fingers. Which nerve is most likely injured?
Radial Nerve
A patient is asked to supinate the forearm against resistance while the elbow is flexed. Which muscle is being primarily tested?
Biceps Brachii
Which carpal bone is most often fractured and causes pain in the anatomical snuffbox?
Scaphoid
Which artery is the direct continuation of the subclavian artery?
Axillary artery
Which nerve innervates most of the anterior forearm?
Median nerve
Which nerve injury at the medial epicondyle causes ‘claw hand’?
Ulnar nerve
Which muscle is the main flexor of the forearm in all positions?
Brachialis
Which nerve innervates the thenar muscles?
Recurrent branch of the median nerve
How many branches arise from they 2nd part of the axillary artery
Two
Which two muscles are exceptions to median nerve innervation in the forearm?
Flexor carpi ulnaris & medial half of FDP (ulnar nerve)
Carpal tunnel syndrome involves compression of which nerve?
Median nerve
Which muscle is unique among extensors for flexing the forearm?
Brachioradialis
Which condition involves thickening of the palmar fascia, causing flexion deformities of the 4th and 5th fingers?
Dupuytren’s contracture
Which cord of the brachial plexus gives rise to the Musculocutaneous nerve?
Lateral cord
Which muscle extends the distal phalanx of the thumb?
Extensor pollicis longus
Which nerve is commonly injured in a superior brachial plexus lesion (Erb-Duchenne palsy)?
Axillary nerve
A patient is unable to flex the distal interphalangeal joints of the index and middle fingers but can still flex those of the ring and little fingers. Which muscle is paralyzed?
Lateral half of Flexor digitorum profundus (median nerve – anterior interosseous branch)
Opposition of the thumb
Which nerve arises from the posterior cord and innervated the latissimus dorsi?
Thoracodorsal nerve
Which artery gives rise to the anterior and posterior interosseous arteries?
Ulnar artery
Which nerve injury causes loss of interossei function (loss of finger ab/adduction)?
Ulnar nerve
During a physical exam, a physician asks a patient to abduct their arm against resistance. The patient can initiate abduction but cannot maintain it beyond 15°. Which muscle and nerve are affected?
Deltoid muscle, Axillary nerve
Which carpal bone is most likely dislocated anteriorly into the carpal tunnel, compressing the median nerve?
Lunate
Injury to the inferior brachial plexus (C8–T1) impairs which movement most severely?
Intrinsic hand muscle function (finger ab/adduction, grip strength)
Injury to this nerve superior to its branches causes wrist drop, loss of elbow extension, and inability to extend fingers. Which nerve?
Radial nerve