Lecture 17 Flashcards
What nerve roots is a post fixed brachial plexus composed of ?
C6, 7, 8, T1, 2
What nerve roots is the brachial plexus composed of?
C5, 6, 7, 8, T1
Which nerve innervates the serratus anterior and contributes to winging of the scapula?
Long thoracic nerve (C5, 6, 7)
Which nerves are of the anterior division of the brachial plexus?
Musculocutaneous
Median
Ulnar
What are the three anterior divisions of the brachial plexus?
Superior
Middle
Inferior
What muscles does the musculocutaneous nerve innervate?
Brachialis
Biceps brachii
Brachioradialis
What are the nerve roots of the musculocutaneous nerve?
C5, 6
What is the cutaneous innervation of the musculocutaneous nerve?
Lateral aspect of the the forearm
What nerve roots is a pre fixed brachial plexus composed of?
C4, 5, 6, 7, 8
What nerve does the musculocutaneous nerve give rise to?
The lateral cutaneous nerve of the forearm.
Motor supply ends at the elbow.
What muscle does the musculocutaneous nerve pierce?
The coracobrachialis
What happens if the musculocutaneous nerve is injured?
Can’t flex elbow
Lose sensation on lateral side of forearm
What muscles does the median nerve innervate?
All of the flexor muscles of the anterior compartment of the forearm (except what the ulnar nerve supplies), the thenar muscles and the lateral two lumbricals.
What are the nerve roots of the median nerve?
C5, 6, 7, 8, T1
What is the cutaneous innervation of the median nerve?
Lateral 3 1/2 digits on the palmar side.
Lateral 3 1/2 nail beds on the dorsal side (variable).
What are the nerve roots of the ulnar nerve?
C8, T1 however can also get C7
What muscles does the ulnar nerve innervate?
FCU
Medial side of FDP and two medial lumbricals
Palmar/dorsal interossei
Adductor pollicis
What is the cutaneous innervation of the ulnar nerve?
The medial 1 1/2 digits on the dorsal and palmar sides.
What are the regional features of the ulnar nerve?
Passes down the medial side behind the medial epicondyle.
Slips between the two heads of FCU and tucks under FCU lying on FDP.
Passes over flexor retinaculum into hand and tucked next to pisiform.
Where is the ulnar nerve vulnerable to injury?
Behind the medial epicondyle and the flexor retinaculum.
Is an injury to the musculocutaneous nerve common?
No, as it is well protected in the axilla.
Stab wound.
How is the median nerve commonly injured at the elbow?
Supracondylar fracture of the humerus.
What is ulnar claw?
Hyperextension of the MCP joints of the little and ring fingers as a result of paralysis of the medial two lumbricals and the now unopposed action if the extensor muscles.
Flexion at the IP joints.
Wasting of interossei.
What are the nerve roots of the axillary nerve?
C5, 6
What is the cutaneous innervation of the axillary nerve?
Skin over the lower deltoid (regimental badge area)
What muscles do the axillary nerve innervate?
Teres minor
Deltoid
Abductors of the arm and shoulder
What are the regional features of the axillary nerve?
Through posterior wall of axilla.
Through quadrangular space.
Between teres minor and major.
What are the nerve roots of the radial nerve?
C5, 6, 7, 8, T1
What type of injury endangers the axillary nerve?
Inferior dislocation of the shoulder joint.
What is the cutaneous innervation of the radial nerve?
Most of the skin on the posterior side of the forearm.
Dorsal surface on the lateral side of the palm.
Lateral 3 1/2 digits.
What are the regional features of the radial nerve?
Exits below teres major.
Travels in the radial groove of the humerus.
Runs over the lateral epicondyle and through the cubital fossa.
