Forearm Anatomy Review

Which artery is NOT a direct branch of the brachial artery in the forearm?

What region of the forearm is supplied by the posterior interosseous artery?

Which nerve innervates the coracobrachialis muscle?

If a patient has lost sensation on the lateral half of the palm, which nerve is most likely injured?

Which muscle is innervated by the axillary nerve?

Which nerve provides sensory innervation to the posterior forearm?

Which of the following muscles is innervated by the ulnar nerve?

Which nerve innervates most of the anterior forearm muscles?

What sensory region is associated with the musculocutaneous nerve?

A patient presents with an inability to extend their wrist and fingers. Which nerve is MOST likely affected?

Which muscle is innervated by the ulnar nerve in the superficial anterior compartment of the forearm?

What action would be MOST affected by damage to the median nerve in the deep anterior compartment of the forearm?

Which of the following muscles is NOT located in the posterior compartment of the forearm?

A patient has difficulty tightening their palmar aponeurosis. Which muscle might be affected?

Which of the following muscles in the posterior compartment of the forearm assists in flexing the forearm at the elbow?

Damage to the radial nerve at the elbow would MOST directly affect the function of which of the following muscles?

If a patient is unable to pronate their forearm regardless of elbow angle, which muscle is MOST likely damaged?

Which of the following muscles inserts onto the styloid process of the radius?

Which of the following muscles is responsible for flexing the hand at the wrist and adducting the hand?

Concerning arterial supply to the deep flexor muscles of the forearm, a compromise to the patency of the anterior interosseous artery at its origin would MOST significantly jeopardize perfusion to which structure?

Following a penetrating injury to the posterior forearm resulting in verifiable damage to the posterior interosseous nerve distal to the supinator muscle, which precise motor deficit is MOST likely observed?

In a complex reconstruction of the proximal forearm, a surgeon inadvertently severs a nerve subsequently confirmed to exclusively carry motor efferents to the brachialis muscle. Which functional deficit would be MOST anticipated postoperatively?

A patient presents with isolated sensory loss confined to the thenar eminence (excluding the fingertips) and sparing the central palm. Compression of which specific neural structure is MOST suspected?

During a surgical exploration of the axilla, a lesion is identified affecting the nerve supply to teres minor, but surprisingly sparing the deltoid. Topographically, where is the MOST probable location of this isolated neural compromise?

A patient reports paresthesia along the dorsal radial aspect of the hand AND weakness in thumb abduction in the plane of the palm. This constellation of findings MOST strongly implicates injury to which structure?

Surgical transection of the ulnar nerve at the wrist level would spare the motor function of which of the following muscles?

A patient exhibits selective paralysis of forearm pronation, coupled with impaired flexion of digits II and III at the distal interphalangeal joints and sensory loss at the median-innervated palm. Which anatomical structure is MOST likely compromised?

Following a high radial nerve injury proximal to the spiral groove, which compensatory mechanism would MOST likely contribute to a degree of wrist extension, albeit significantly weakened?

A patient presents with an inability to abduct the small finger against resistance, accompanied by sensory loss over the medial aspect of the hand. Which surgical intervention would MOST directly address the underlying pathology?

A surgeon is performing a delicate exploration of the cubital fossa and encounters a bifurcating nerve, one branch coursing deep to the pronator teres muscle's two heads, the other remaining superficial. Which nerve and its respective branches are most likely being observed?

Following a penetrating injury to the distal forearm, a patient exhibits a selective loss of motor function: specifically impaired flexion of the distal interphalangeal joints of the 2nd and 3rd digits, but intact flexion of the 4th and 5th digits. Sensation is unaffected. Which specific neural structure is MOST likely compromised?

A high-performance cellist reports experiencing progressive weakness and diminished fine motor control in their left hand. Clinical examination reveals atrophy of the thenar eminence and impaired pronation, but normal wrist flexion and adduction. Nerve conduction studies indicate a lesion affecting a specific branch as it passes between the two heads of pronator teres. Which neural element is MOST implicated?

During a complex surgical reconstruction involving the distal radius and ulna, meticulous dissection is required to identify and protect key neurovascular structures. Which of the following neurovascular bundles, defined by their anatomical relationship to forearm muscles, is MOST vulnerable during volar plate fixation of a distal radius fracture?

A patient presents with paralysis of the extensor carpi ulnaris, extensor digiti minimi, and the ulnar portion of the extensor digitorum. Sensation is intact. Electrophysiological studies reveal a lesion affecting a nerve as it courses around the radial head. Which of the following is the MOST likely diagnosis?

A highly skilled pianist develops an insidious onset of pain and weakness in their forearm, specifically noting difficulty with rapid, alternating pronation and supination movements. On examination, resisted pronation is weak with the elbow flexed at 90 degrees. There is no sensory loss. Imaging reveals no structural abnormalities. Where is the MOST likely site of pathology?

A researcher is investigating the biomechanics of wrist stabilization during forceful gripping. They selectively paralyze specific forearm muscles to assess their individual contributions. If the flexor carpi ulnaris is completely inhibited, what specific compensatory adaptation would MOST likely be observed to maintain grip strength and wrist stability?

A patient presents with impaired thumb abduction in the plane of the palm alongside weakened wrist extension, but normal thumb extension. Which of the following represents the MOST likely lesion involving the deep posterior compartment muscles of the forearm?

In a study investigating the comparative effectiveness of surgical approaches for decompressing the radial nerve in patients with recalcitrant radial tunnel syndrome, one approach involves releasing the arcade of Frohse. What anatomical structure is directly released by this procedure?

A research team is developing a novel prosthetic hand controlled by electromyographic (EMG) signals from spared forearm muscles following a high median nerve injury at the elbow. Which combination of muscles would be the MOST effective for generating proportional control of both wrist flexion/extension and pronation/supination?

Musculocutaneous nerve

Radial nerve

Median nerve

Ulnar nerve

Pronator teres

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

Extensor digitorum

Supinator

Common interosseous artery

Anterior interosseous artery

Posterior interosseous artery

Axillary nerve

Deltoid innervation

Radial artery

Posterior arm nerve

Styloid process of radius

Olecranon

Anterior forearm compartment

Pronator quadratus

Posterior forearm compartment

Abductor pollicis longus

Extensor carpi radialis longus & brevis

Extensor digiti minimi

Brachioradialis

Brachial artery

Musculocutaneous Nerve: Function

Axillary Nerve: Function

Radial Nerve: Function

Median Nerve: Function

Ulnar Nerve: Function

Anterior interosseous artery function

Posterior interosseous artery function

Flexor Carpi Ulnaris: Action