upper limb anatomy Flashcards
What muscles are supplied by anterior interosseous nerve?
Deep flexors of forearm:
-FDP radial half
-FPL
-pronator quadratus
What muscles are supplied by anterior interosseous nerve?
Deep flexors of forearm:
-FDP radial half
-FPL
-pronator quadratus
What are the branches of the median nerve? Where are they given off? What do they supply?
2 branches in forearm:
–> AIN: supplies deep muscles in anterior forearm
–>Palmar cutaneous: supplies skin of lateral palm
2 branches in hand:
–> recurrent motor branch (supplies thenar muscles)
–> Palmar digital branch: palmar aspect lateral 3.5 fingers
What muscles are supplied directly by the median nerve?
Superficial flexors in forearm:
-Flexor carpi radialis longus
-Flexor digitorum superficialis
-palmaris longus
-Pronator teres
Course of median nerve
-Formed in axilla by union lateral root from lateral cord and medial root from medial cord (C5-T1)
-Crosses from lateral to medial brachial artery middle of arm
-enters cubital fossa, lies deep to bicipital aponeurosis and median cubital vein and medial to brachial artery
-Supplies articular branches to elbow joint
-Enters forearm between 2 heads pronator teres: gives off ain
-Runs in forearm deep to FDS until just before wrist when it becomes superficial
-Palmar cutaneous branch arises 5cm proximal to wrist crease–> supplies sensation to thenar eminence
-Passes through wrist in carpal tunnel, gives off recurrent motor branch just distal to flexor retinaculum.
Which structures of flexor compartment forearm are not supplied by median nerve?
Flexor carpi ulnaris
ulnar half flexor digitorum profundus
How would you test anterior interosseous nerve?
OK sign: flexion IP joint of thumb, DIPJ index finger are impaired
Pinch test: weakness flexion distal phalanx thumb and index
Where does anterior interosseous nerve originate?
Arises between two heads pronator teres
What is origin of recurrent motor branch median nerve? What is its function? why is it clinically significant?
-In or just distal to carpal tunnel
-Hooks back to supply thenar muscles
-Can exit through or superficial to flexor retinaculum, can be injured in carpal tunnel
What is sensation of hand?
Volar:
-Radial 3.5 digits median
-Ulnar 1.5 digits ulnar
Dorsal
-Radial 3.5 supplied by radial nerve to PIPJ
-Distal two phalanx median
-Ulnar 1.5 digits ulnar nerve
Describe term ‘ulnar clawing’
-Lumbricals flex mcpj and extend IPJ
-Intrinsic muscles of hand denervated in distal ulnar nerve injuries
-Loss of ulnar two lumbricals results in hyperextension at MCPJ and flexion at ipj
Describe term ulnar paradox
-Clawing is more marked in distal injuries as the fdp tendons are still functional so the fingers can be flexed
-In more proximal injuries the FDP is denervated so the clawing is less marked
What muscles does ulnar innervate in forearm
Ulnar half FDP
Flexor carpi ulnaris
What does superficial branch ulnar nerve innervate in hand?
Palmaris brevis
Sensation to ulnar 1.5 digits
What is innervation to muscles in hand?
All ulnar except: one half LOAF
-Lateral two lumbricals
-Opponens pollicis
-Abductor pollicis brevis
-flexor pollicis brevis (superficial head)
Abductor pollicis longus innervation
Radial nerve
Flexor pollicis brevis deep head innervation:
Ulnar nerve
What muscles do the deep branch of the ulnar nerve innervate in the hand?
-Hypothenar muscles: Abductor digiti minimi, opponens digiti minimi, flexor digiti minimi brevis
-4x dorsal interossei, 4x palmar interossei
-Ulnar two lumbricals
-Adductor pollicis
-Deep head FPB
What muscles are supplied by Deep branch radial nerve
-Supinator
-Extensor carpi radialis brevis
What muscles are supplied by muscular branches radial nerve
Triceps
Anconeus
Brachioradialis
Extensor carpi radialis longus
What muscles are supplied by posterior interosseous nerve?
-Extensor digiti minimi
-Extensor carpi ulnaris
-Extensor digitorum communis
-Extensor indicis
-Extensor pollicis longus + brevis
-Abductor pollicis longus
What are the branches of the radial nerve?
Muscular branches to triceps
Cutaneous branch
Posterior interosseous branch
What is sensory supply of radial nerve?
-most of the skin of the posterior forearm
-lateral aspect of the dorsum of the hand
-dorsal surface of the lateral three and a half digits
How would you test ulnar function in hand
-Abduct and adduct fingers
-Froment’s test: adduct thumb against index finger (positive if flexion of ipj instead of normal adduction-i.e. compensating for denervated adductor pollicis with FPL)
Nerves that supply thumb muscles
Ulnar:
-Adductor pollicis
-Flexor pollicis brevis (deep head)
Median
-Abductor pollicis brevis
-Opponens pollicis
-Flexor pollicis brevis (superficial head)
Radial nerve
-APL
-EPL
-EPB
What are the muscles supplied by the radial nerve and its branches?
Muscular branches from radial nerve:
Triceps
Anconeus
Brachioradialis
Extensor carpi radialis longus
Sensation over posterior arm and dorsum of forearm via posterior cutaneous branch
Deep branch
-Supinator
-Extensor carpi radialis brevis
Posterior interosseous
-Extensor digiti minimi
-Extensor carpi ulnaris
-Extensor digitorum communis
-Extensor indicis
-Extensor pollicis longus + brevis
-Abductor pollicis longus
Describe course of radial nerve
-Continuation posterior cord brachial plexus, nerve roots C5-T1
-Enters posterior compartement of arm via triangular interval with profunda brachii
-Gives off branches to long and lateral heads of triceps then lies in spiral groove
-Wraps around humerus laterally and gives off branch to medial head triceps
-Travels anterior to lateral epicondyle of humerus to enter cubital fossa
-Passes between two heads supinator
-Gives of PIN and continues as sensory nerve
Name muscles originating from common extensor origin
Tendon that attaches to lateral epicondyle of humerus
–> extensor carpi radialis brevis
–> extensor digitorum communis
–> extensor carpi ulnaris
–> extensor digiti minimi
Extensors originating from lateral epicondyle of humerus
Anconeus
Supinator
Name muscles attaching to lateral supracondylar ridge of humerus
Brachioradialis
Extensor carpi radialis longus
What attaches to Radius, ulna and interosseus membrane
Extensor indicis
EPL
EPB
APL
Describe origins of extensors
Lateral supracondylar ridge humerus (Brachioradialis, ECRL)
Lateral epicondyle of humerus: anconeus, supinator
Common extensor origin:
–> extensor carpi radialis brevis
–> extensor digitorum communis
–> extensor carpi ulnaris
–> extensor digiti minimi
Radius, ulna, interosseous membrane: EI, EPL, EPB, APL