nerves Flashcards
Nerves of the arm and forearm
Musculocutaneous nerve, radial nerve, median nerve and ulnar nerve
Musculocutaneous nerve
Innervates muscles of the anterior arm. Lateral cutaneous nerve of the forearm - lateral aspect of forearm
Nerve roots C5-7
Radial nerve
Innervates muscles of the posterior arm and posterior compartment of the forearm
Nerve roots C5-T1
Lower lateral cutaneous nerve of arm
Innervates the lateral aspect of the upper arm, below the delts
C5-C6
Posterior cutaneous nerve of arm
Innervates the posterior surface of the upper arm
C6-C8
Posterior cutaneous nerve of forearm
Innervates a strip of skin down the middle of the posterior forearm
C6-C8
Superficial branch of radial nerve
Innervates the dorsal surface of the hand and lateral 3 and half digits and dorsum of thumb
C7-C8
Median nerve
Innervates muscles of the anterior (flexor) compartment of the forearm. Thenar muscles of the hand and first two lumbricals
Nerve roots C6-T1
Palmar cutaneous branch of radial
Innervates lateral aspect of palm
Palmar digital cutaneous branch of radial
Innervates the palmar surface and fingertips of the lateral three and half digits
Ulnar nerve
Innervates two muscles of the anterior compartment of the forearm: flexor digitorum profundus and flexor carpi ulnaris
Nerve roots: C8-T1
Palmar cutaneous branch of ulnar
Innervates the skin of the medial half of the palm
Dorsal cutaneous branch of ulnar
Innervates skin of dorsal surface of medial aspect of the hand and medial one and half fingers
Superficial branch of ulnar
Innervates the palmar surface of the medial one and a half fingers
Axillary Nerve
Gives of superior lateral cutaneous nerve of the arm, which innervates the inferior region of the deltoid. C5-C6
Deltoids, teres major
Medial brachial cutaneous nerve from medial cord
Innervates medial surface of upper arm
Medial antebrachial cutaneous nerve of medial cord
Innervates anterior surface of the arm and medial surface of the lower arm
Musculocutaneous nerve injury
Flexion of the shoulder and elbow and supination of forearm are weakened
Pec and brachioradialis unaffected
Loss of sensation (lateral aspect)
Radial nerve injury - In Axilla
Loss of function of all muscles innervated by radial nerve. Wrist drop
Loss of sensation
Radial nerve injury - in radial groove
Weakening of triceps, loss of function of muscles in posterior forearm.
Some innervation of triceps above radial groove
Radial nerve injury in forearm - Deep branch (posterior interosseous nerve)
Majority of muscles in posterior forearm are affected. Wrist drop doesn’t occur. Some innervation occurs at top of forearm.
Radial nerve injury in forearm - Superficial branch
Loss of sensation of dorsal three and half of digits
Median nerve injury
Damage at elbow, pronation of forearm affected, weak flexion of the wrist, opposition of thumb and flexion of first two fingers affected.
Damage at wrist - Thenar muscles and lateral two lumbricals. Opposition of thumb and flexion of first two fingers affected
Median nerve injury - carpal tunnel syndrome
Caused by nerve being trapped in carpal tunnel
Leads to numbness of areas of hand innervated by median nerve
Get thenar wasting
Ulnar nerve injury
Damage to medial epicondyle, flexion of wrist can still occur but is accompanied by abduction
Get impairment of muscles of the hand innervated by ulnar nerve. Finger ab/adduction affection with flex/extension of index and ring finger
Loss of sensation from medial aspect of hand and fingers.
