Brachial Plexus Part 2 Flashcards
What nerves branch off of the lateral cord of the brachial plexus?
lateral pectoral nerve and musculocutaneous nerve
Where does the lateral pectoral nerve receive fibers from?
C5-C7
What supplies the pectoralis major?
lateral pectoral nerve (and medial pectoral nerve of the medial cord)
What structures combine to form the “M” of the brachial plexus?
lateral cord, medial cord, and musculocutaneous nerve
T/F: the musculocutaneous nerve is one of 2 terminal branches of the medial cord.
False; it is one of 2 terminal branches of the LATERAL cord
What cord levels contribute fibers to the musculocutaneous nerve?
C5-C7
What muscles are supplied by the musculocutaneous nerve?
Corocobrachialis, Biceps brachii (both heads), and the brachialis
As the musculocutaneous nerve continues between the biceps brachii and the brachialis into the forearm, what nerve does it become?
the lateral cutaneous nerve of the forearm
What nerve supplies skin over the lateral aspect of the forearm, but not the hand?
lateral cutaneous nerve of the forearm
What two (major) nerves are supplied by the terminal branches of the lateral cord?
musculocutaneous and median nerves
T/F: all of the branches off of the medial cord have “medial” in their name.
False; ulnar nerve, median nerve, and radial nerve are also supplied by the medial cord
What are the branches off the medial cord of the brachial plexus?
medial pectoral nerve, medial cutaneous (brachial) nerve of the arm, medial cutaneous (antebrachial) nerve of the forearm, the ulnar nerve, and the median nerve.
Where does the medial pectoral nerve receive fibers?
C8 and T1
What muscles are supplied by the medial pectoral nerve?
pectoralis major and minor
Where does the medial cutaneous nerve of the arm receive fibers?
C8 and T1 (and some from T2 through a communication)
What nerve supplies the skin of the medial arm between the axilla and the elbow?
medial cutaneous nerve of the arm
What nerve does the medial cutaneous nerve of the arm communicate with to receive some fibers from T2?
intercostobrachial nerve
What cord leves contribute fibers to the medial cutaneous nerve of the forearm?
C8 and T1
Which nerve supplies the skin over the biceps brachii and the skin over the anterior and medial aspects of the forearm distal to the wrist?
medial cutaneous nerve of the forearm
T/F: the ulnar nerve is one of two terminal branches of the medial cord.
True
What cord levels contribute to the ulnar nerve?
C8, T1, and sometimes C7
T/F: the ulnar nerve travels lateral to the brachial artery in the medial bicipital sulcus.
False; travels medial to the brachial artery
How many branches does the ulnar nerve give off in the arm?
zero
Where does the ulnar nerve cross the elbow?
on the posterior side of the medial epicondyle in the sulcus for the ulnar nerve
Where does the ulnar nerve continue into the forearm?
between the two heads of the flexor carpi ulnaris
What muscles of the forearm are supplied by the ulnar nerve?
flexor carpi ulnaris and the medial half of the flexor digitorum profundus
What sensory branches are given off in the forearm by the ulnar nerve?
dorsal branch of the ulnar nerve and the palmer branch of the unlnar nerve
What nerve supplies the skin on the ulnar side of the posterior hand?
dorsal branch of the ulnar nerve
What nerve supplies the skin over the hypothenar eminence?
palmar branch of the ulnar nerve
T/F: the ulnar nerve travels deep to the flexor carpi ulnaris and passes deep to the flexor retinaculum before dividing into two branches.
False; travels superficial to the flexor retinaculum
What does the ulnar nerve divide into after passing the flexor retinaculum?
superficial and deep branches
T/F: the superficial branch of the ulnar nerve divides into 2 terminal branches (proper palmer branches) that supply the palmer aspect of the little finger and medial half of the ring finger.
False; divides into 3 terminal branches to do this
The deep branch of the ulnar nerve curves towards the thenar eminence and gives off branches. What muscles does it supply?
abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, adductor pollicis, deep head of the flexor pollicis brevis, all interossei (dorsal and palmar), and lumbricals 3 and 4
What clinical consideration is associated with the ulnar nerve?
claw hand
