Exam 3 Brachioplexus Flashcards
What does the brachial plexus supply
Upper extremities
What forms the brachial plexus
Formed by anterior primary rami of C5 through T1 (maybe also from C4 and/or T2)
Where does the brachial plexus travel
Laterally over rib 1 into the axilla
Traveling medial to lateral what are the categories of the brachial plexus
Roots combine into trunks, trunks divide into divisions, divisions combine to form cords, cords divide into terminal nerves
Each root receives what from the sympathetic trunk
Gray ramus communicans
Where do roots pass
Between anterior and middle scalene muscles into posterior triangle
What are the brachial plexus roots relation to the subclavian artery
Posterior and superior to it
What do trunks of the brachial plexus spit into
Anterior and posterior division
What forms the superior trunk of brachial plexus
Roots of C5 and C6
What forms the middle trunk of the brachial plexus
Root of C7
What forms the inferior trunk of the brachial plexus
Roots of C8 and T1
Where do trunk pass through
Over rib 1 into the axilla
What do divisions of the brachial plexus split into
Anterior and posterior divisions
What do the anterior/poster divisions of the divisions of the brachial plexus supply
Anterior division supply anterior compartments of arm/forearm, posterior supplies posterior compartments of arm/forearm
How are cords named
In relation to the axillary artery
What forms the lateral cord
Anterior divisions of the superior and middle trunks
What fibers does the lateral cord contain
Fibers from C5, C6, C7
Where does the lateral cord lie
Lateral to second part of axillary artery
What forms the medial cord and where does it lie
Anterior division of inferior trunk lying medial to second part of axillary artery
What fibers are contained in the medial cord
Fibers from C8 and T1
What forms the posterior cord and where does it lie
Formed by the union of the posterior division of all three trunks lying posterior to second part of axillary artery
What fibers are contained in the posterior cord
C5-T1
What nerve branches off of the C5 root and contains fibers from C5 only
Dorsal scapular nerve
What muscles does the dorsal scapular nerve supply
Levator scapula, rhomboid major/minor
What also supplies levator scapula besides the dorsal scapular nerve
Fibers from C3 and C4
What is the long thoracic nerve formed by
Roos of C5, C6, and C7
What does the long thoracic nerve supply
Serratus anterior muscle
What nerves branch off the superior trunk of the brachial plexus
Supra-scapular nerve and nerve to the subclavius
What fibers does the suprascapular nerve contain
Fibers fro C5 and C6
What muscles are supplied by the suprascapular nerve
Supraspinatus, infraspinatus
What fibers does the nerve to the subclavius contain
C5 and C6
What does the nerve to the subclavius supply
The subclavius
What nerves branch off the lateral cord of brachial plexus
Lateral pectoral nerve, musculocutaneous nerve
What fibers are contained in the lateral pectoral nerve
C5, C6, and C7
What does the lateral pectoral nerve supply
Pectoralis major (also from medial pectoral nerve)
What is significant about the musculocutaneous nerve
One of two terminal branches of the lateral cord
What fibers are contained in the musculocutaneous nerve
C5, C6, C7
What muscles does the musculocutaneous nerve supply
3/4 muscles of anterior arm: coracobrachialis belly, both long and short heads of biceps brachii, brachialis
What happens to the musculocutaneous nerve after continuing between biceps brachii and brachialis into forearm
Becomes lateral cutaneous nerve of forearm
What does the lateral cutaneous nerve of the forearm supply
Supplies skin over the lateral aspect of forearm, NOT hand
What is the other terminal branch of the lateral cord besides the musculocutaneous nerve
The median nerve
What are the branches off the medial cord of the brachial plexus
Medial pectoral, medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm, ulnar nerve, median nerve,
What fibers does the medial pectoral nerve contain and what muscles does it supply
C8 and T1; supplies pectoralis major and minor
What fibers does the medial cutaneous nerve of the arm contain
Fibers from C8 and T1
The medial cutaneous nerve of the arm receive some fibers from T2 through a communication with what
The intercostobrachial nerve
What does the medial cutaneous nerve of the arm supply
Ramifies in the axilla and supplies the skin of the medial arm between the axilla and the elbow
What fibers does the medial cutaneous nerve of the forearm contain
C8 and T1
What does the medial cutaneous nerve of the forearm supply
Supplies skin over biceps brachii and over anterior and medial aspects of forearm proximal to the wrist
Where does the medial cutaneous nerve of the forearm leave
Leaves the medial cord just distal to medial cutaneous nerve of the arm
What is significant about the ulnar nerve
It is one of two terminal branches of the medial cord
What fibers does the ulnar nerve contain
C8 and T1 sometimes C7
How does the ulnar nerve travel
Medial to brachial artery in the medial bicipital sulcus
Does the ulnar nerve give branches off in the arm
NO
Where is the ulnar nerve palpable
Where it crosses the elbow on the posterior side of the medial epicondyle in the sulcus for the ulnar nerve this is the “funny bone”
After crossing the elbow at the medial epicondyle where does the ulnar nerve go?
Continues into the forearm between the two heads of the flexor carpi ulnaris
What muscles does the ulnar nerve innervate
Flexor carpi ulnaris and the medial half of the flexor digitorum profundus
What sensory branches does the ulnar give off
Sensory of the forearm are the dorsal branch of ulnar nerve and the palmar branch of the ulnar nerve
What does the dorsal branch of the ulnar nerve supply
Skin on the ulnar side of posterior hand
What does the palmar branch of the ulnar nerve supply
Skin over the hypothenar eminence
Where does the ulnar nerve travel deep
To flexor carpi ulnaris to the wrist passing superficially to the flexor retinaculum dividing into two branches
What does the superficial branch of the ulnar nerve do
Divides into 3 terminal branches that supply palmar aspect of the little finger and medial half of the ring finger
What does the deep branch of the ulnar nerve do
In the hand it curves toward the thenar eminence
What does the deep branch of the ulnar nerve supply
Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, adductor pollicis, deep head of the flexor pollicis brevis, all interossei (dorsal and plamar) lumbricals 3 and 4
What clinical considerations are associated with the ulnar nerve
Claw hand
What fibers does the median nerve contain
Contributions from lateral and medial cords, containing fibers from C6-T1
How does the median nerve travel
Through the arm in the bicipital sulcus crossing the elbow on the anterior side and enters the forearm after passing between the two heads of pronator teres
Does the median nerve give any branches off in the arm
NO
What 7 muscles are innervated by the median nerve
Pronator teres, flexor carpi radalis, palmaris longus, flexor digitorum superficialis, pronator quadratus,flexor pollicis longus and lateral bellies of flexor digitorum profundus
How is the pronator quadratus,flexor pollicis longus and lateral bellies of flexor digitorum profundus innervated
By way of anterior interosseous nerve of the forearm given off median nerve in elbow
Where is the palmar branch of the median nerve given off and what does it supply
Given off at the distal third of the forearm supplying skin of thenar eminence, lateral wrist, and palm
Where does the median nerve divide
Through the carpal tunnel dividing into three common palmar digital nerves
What do the three common palmar digital nerves do?
Supply first two lumbrical muscles
Branches off the first common palmar digital nerve supply what
Abductor pollicis brevis, flexor pollicis brevis (superficial head), opponens pollicis
Each common palmar digital nerve splits into what
Two proper palmar digital nerves
What do proper palmar digital nerves do
Sensory function only supplying sking over lateral three and a half digits anteriorly and lateral two and half digits posteriorly
What does the median nerve supply also, not muscular
Periosteum, elbow, radiocarpal, midcarpal joints, usually comminicating with ulnar nerve at the wrist
What are clinical considerations of median nerve
Hand of oath/benediction, carpal tunnel syndrome, unable to pronate
What branches come off the posterior cord of the brachial plexus
Superior scapular nerve, thoracodorsal nerve, inferior subscapular nerve, axillary nerve, radial nerve,
What fibers are contained in superior scapular nerve and what does it supply
C5 and C6, supplies the subscapularis
What fibers are a part of the thoracodorsal nerve
C6, C7, C8
How does the thoracodorsl nerve travel
Travels along the posterior axillary wall to supply the latissimus dorsi
What fibers are contained in the inferior subscapular nerve and what does it supply
Fibers from C5 and C6 supplying the subscapularis and teres major
What fibers does the axillary nerve contain and what does it supply
C5 and C6 fibers supplying deltoid and teres minor
How does the axillary nerve travel
Posteriorly around surgical neck of the humerus then anteriorward to anterior deltoid
What sensory branch comes off the axillary nerve
Superior lateral cutaneous nerve of the arm
What does the superior lateral cutaneous nerve of the arm supply
The skin over the lateral shoulder and upper arm
What fibers are contained in the radial nerve
C5-C8 sometimes T1
What does the radial nerve supply
All of the muscles in the posterior compartment of the arm and forearm
How does the radial nerve travel
- from medial bicipital sulcus of humerus
- enters forearm anterior to elbow traveling between brachialis and brachioradialis
- splits into superficial and deep branches
What branches off the radial nerve in the upper arm and what does it supply
The posterior cutaneous nerve of the arm supplying skin on the posterior side of upper arm
What branches off the radial nerve in the middle arm
The inferior lateral cutaneous nerve of the arm
Muscular branches given off the radial nerve in the arm supply what
All three heads of triceps brachii, anconeous (by branch to medial head of triceps brachii), brachialis (in combo with musculocutaneous)
Where is the posterior cutaneous nerve of the forearm given off of and what does it supply
In the upper arm supplying narrow area of skin on the lateral side of the posterior forearm
Branches of the radial nerve given off at the lateral epicondyle supply what
Brachioradialisand extensor carpi radialis
Where does the radial nerve pass into the forearm on the anterior side
Anterior side of elbow after traveling between brachialis and brachioradialis
What does the radial nerve divide into at the level of the radial head
Superficial and deep branch
How does the superficial branch of the radial nerve travel
Follows the brachioradialis to the distal third of forearm, from where it travels between the brachioradialis and the radius to the posterior surface of the hand and gives rise to dorsal digital nerves
What does the superficial branch of the radial nerve supply sensory info to
Radial side of posterior hand, extensor side of the thumb, extensor side of the proximal phalanges of digits 2 and 3, lateral half of the extensor side of ring finger
What does the superficial branch of the radial nerve give off
Communicating branch with the ulnar nerve
What branch penetrates the supinator muscle and what does it give off
The deep branch of the radial nerve giving off a series of branches to supply posterior forearm muscles before terminating as the posterior interosseous nerve
What does the posterior interosseous nerve supply (9 muscles)
Extensor carpi radialis brevis, supinator, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, abductor policis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
The radial nerve sends articular branches to where
The shoulder and wrist
What are some clinical considerations of the radial nerve
Wrist drop (muscles affected, no nerve innervations), triceps and brachioradialis reflexes
What is Erb-Duchenne’s
Brachial plexus injury of the supraclavicular nerve due to damage of roots of C5 and C6
What nerves are impacted in erb duchenne’s
Supraclavicular n, musculocutaneous n, axillary n. (And others, but these are most significant
What happens when someone has Erb-Duchenne’s and how does it happen
“Waiters tip” deformity, MC etiology = birth trauma
What brachial plexus injury affects the infraclavicular nerve
Klumke’s Palsy
What roots of brachial plexus is affected in klumpke’s
C8 and T1 (T1 is important due to pregang sympathetic fibers)
What is Klumpke’s palsy also known as
Dejerine klumpke’s
What happens in klumpke’s palsy
Atrophy in muscles innervated by ulnar nerve, especially hypothenar, thenar, flexor carpi ulnaris and medial 1/2 of flexor digi profundus
What is horner’s syndrome
Involves ptosis and miosis due to involvment of T1
