Brachial Plexus Flashcards
What forms the brachial plexus?
Anterior primary rami of C5-T1
Where does the brachial plexus travel?
Laterally over rib 1 into the axils
Roots combine into____
Trunks
Trunks divide into ______
Division
Divisions combine ______ to form
Cords
Cords divide into ______ _______
Terminal nerves
Each root receives a ____ ______ ______ from sympathetic trunk
Gray ramus communicans
Roots of the brachial plexus pass between the _____ and ______ _____ in the posterior triangle
Anterior and middle scalene
What is the relation of the brachial plexus’s roots to the subclavian artery
Posterior and superior
What roots combine to form the superior trunk?
C5 and C6
What root(s) form the middle trunk?
C7
what root (s) combine to form the inferior trunk?
C8 and T1
Each trunk of the brachial plexus splits into an _____ and _____ ______.
Anterior and posterior division
Cords of the brachial plexus are named for their relation to?
The axillary artery
The lateral cord of the brachial plexus is formed by what?
Anterior divisions of the superior and middle trunks
The lateral cord of the brachial plexus is made by what fibers?
C5, C6, C7
The medial cord of the brachial plexus is formed by what?
Anterior division of the inferior trunk
The medial cord of the brachial plexus is formed by what fibers?
C8 and T1
The posterior cord of the brachial plexus is formed by what?
The posterior division of all 3 trunks
The posterior cord of the brachial plexus is formed by what fibers?
C5-T1
The dorsal scapular nerved is from branches off what root?
C5
What is formed from a branch of the C5 root?
Dorsal scapular nerve
What muscles does the dorsal scapular nerve supply?
Levator scapula
Rhomboid major/minor
What nerve supplies the levator scapula and rhomboids?
Dorsal scapular nerve, C5
What roots forms the long thoracic nerve?
C5, C6, C7
What muscle does the long thoracic nerve supply?
Serrated anterior
What supplies the serratus anterior?
The long thoracic nerve
what nerves branch off the superior trunk of the brachial plexus?
Suprascapular nerve
Nerve to subclavius
What forms the suprascapular nerve and what does the nerve supply?
C5 and C6
Supraspinatus and infraspinatus
What forms the nerve to the subclavius and what does it supply?
C5 and C6
Subclavius
What branches off the lateral cord of the brachial plexus?
Lateral pectoral nerve
Musculocutaneous
Median nerve (terminal branch)
What forms the lateral pectoral nerve and what does it supply?
C5-C7 Pectoralis major (also gets fibers from medial pectoral nerve)
What are the two terminal branches of the lateral cord?
Musculocutaneous nerve and median nerve
What forms the musculocutaneous nerve and what does it supply?
C5-C7
Coracobrachialis, biceps brachii, brachialis
What supplies the coracobrachialis, biceps brachii, and the brachialis?
Musculocutaneous nerve (C5-C7)
What does the musculocutaneous nerve pierce?
Coracobrachialis
What two muscles does the musculocutaneous nerve travel through within the forearm where it becomes the lateral cutaneous nerve of the forearm?
Biceps brachii and brachialis
What does the musculocutaneous nerve turn into in the forearm after it passes through the biceps brachii and brachialis in the arm?
Lateral cutaneous nerve of the forearm
What does the lateral cutaneous nerve of the forearm supply?
Skin over lateral forearm (NOT HAND)
What are the branches off of the medial cord of the brachial plexus?
Medial pectoral nerve
Medial cutaneous nerve of the arm
Medial cutaneous nerve of the forearm
Ulnar nerve
What makes up the medial pectoral nerve and what does it supply?
C8 and T1
Pectoralis major and minor
What supplies the pectoralis major and minor?
Medial pectoral nerve
What makes up the medial cutaneous nerve of the arm and what does it supply?
C8 and T1
Skin of the medial arm between the axilla and the elbow
What supplies the medial arm between the axilla and the elbow?
Medial cutaneous nerve of the arm
What nerve receives come fibers from T2 through a communication with the intercostobrachial nerve?
Medial cutaneous nerve of the arm
What forms the medial cutaneous nerve of the forearm and what does it supply?
C8 and T1
Skin over biceps brachii and over anterior and medial aspects of the forearm proximal to the wrist
What nerve supplies the skin over the biceps brachii and the skin of the anterior/medial forearm?
Medial cutaneous nerve of the forearm
What forms the ulnar nerve?
C8-T1 and sometimes C7
Where does the ulnar nerve travel?
Within the bicipital sulcus, medial to the brachial artery
Does the ulnar nerve give off branches in the arm?
No
The ulnar nerve crosses the elbow on the posterior side of the ____ ____ in the ______ for the _____ ______
Medial epicondyle in the sulcus for the ulnar nerve
What two muscles of the forearm does the ulnar nerve innervate?
- Flexor carpi ulnaris
2. Medial half of flexor digitorum profundus
What two sensory branches does the ulnar nerve give off in the forearm?
Dorsal and palmar branch
What does the dorsal branch of the ulnar nerve supply?
Skin on the ulnar side of the posterior hand
What does the palmar branch of the ulnar nerve supply?
Skin over the hypothenar eminence
The ulnar nerve travels ____ to the ____ ____ _____ to the wrist, and passes superficial to the _____ _____ and divides into _____ and_____ branches
Deep to the flexor carpi ulnaris
Flexor retinaculum
Superficial and deep
The superficial branch of the ulnar nerve (within the wrist) further divides into three _____ ______ that supply what?
Terminal branches
Palmer aspect of the little finger and the medial half of the ring finger
The deep branch of the ulnar nerve (within the wrist) gives off branches that supply what 7 muscles?
Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi Adductor pollicis Deep head of flexor pollicis brevis All interossei Lumbricals 3 and 4
What (specific) supplies the follow muscles?
Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, adductor pollicis, deep head of the flexor pollicis brevis, all interossei, and lumbricals 3 and 4?
Deep branch of the ulnar nerve (within the wrist)
What are the clinical considerations regarding the ulnar nerve?
Claw and ape hand
What cords contribute to the formation of the median nerve?
Lateral and medial
What fibers form the median nerve?
C6-T1
The median nerve travels through what structure within the arm?
Medial bicipital sulcus
Does the median nerve branch in the arm?
No
The median nerve crosses on the _____ side and enters the forearm after passing between what?
Anterior
Between the two heads of the pronator there’s
The median nerve innervates what 7 muscles of the forearm
- Pronator teres
- Flexor carpi radialis
- Palmeris longus
- Flexor digitorum superficialis
- Pronator quadratus
- Flexor pollicis longus
- Lateral bellies of flexor digitorum profundus
* **5-7 through anterior interosseous nerve of the forearm—given off at the median nerve in the elbow
The anterior interosseous nerve of the forearm is a branch of what nerve given off at the elbow
Median
What 3 muscles does the anterior interossesous nerve of the forearm supply?
Pronator quadratus
Flexor pollicis longus
Lateral bellies of flexor digitorum profundus
Where is the palmar branch of of the median nerve given off?
Distal 1/3 forearm
What does the palmar branch of the median nerve supply?
Skin of the thenar eminence, lateral wrist and palm
The median nerve passes through the _____ _____ and divides into 3 common _____ _____ _____
Carpal tunnel
Palmar digital nerves
The common palmar digital nerves of the median nerve supply what?
- 1st 2 lumbricals
- FIRST COMMON PALMAR DIGITAL NERVE: - Abductor pollicis brevis
- Flexor pollicis brevis
- Opponens brevis
Each common palmar digital nerve splits into what?
Proper palmar digital nerves
What do the the proper palmar digital nerves do?
- Sensory function
- Skin over the lateral three and a half digits anteriorly
- Skin lateral two and a half posteriorly
What supplies the periosteum, elbow, radiocarpall and midcarpal joints?
Median nerve
What nerve usually communicates with the ulnar nerve at the wrist?
Median
What are some clinical considerations with regards to the median nerve?
- Hand of oath/benediction (atrophy to thenar eminence)
- Carpal tunnel syndrome
- Unable to probate
What are the branches off the posterior cord of the brachial plexus?
- /2.Superior/inferior subscapular
- Thoracodorsal
- Axillary
- Radial
What fibers make up the superior subscapular nerve and what does it supply?
C5 and C6
Subscapular is
What supplies the subscapularis?
Superior subscapular nerve (c5/C6)
What fibers make up the thoracodorsal nerve and what does it supply?
C6-C8
Latissimus Doris
What nerve supplies the latissimus dorsi?
Thoracodorsal nerve (C6-C8)
What fibers make up the inferior subscapular nerve and what does it supply?
C5-C6
Subscapularis and teres major?
What nerve supplies the subscapularis and the teres major
Inferior subscapular nerve
What fibers make up the axillary nerve and what does it supply?
C5 and C6
Deltoid and teres minor
What nerve supplies the deltoid and teres minor?
Axillary nerve (c5-C6)
The axillary nerve travels _______ around the _____ neck of the humerus
Posteriorly
Surgical
Where is the superior lateral cutaneous nerve of the arm given off and from what nerve?
At the same level that the branch to the teres minor is given off of the AXILLARY nerve
What does the superior lateral cutaneous nerve of the arm supply?
Skin over lateral shoulder and upper arm
What nerve supplies the skin of the lateral shoulder and upper arm?
Lateral superior cutaneous nerve of the arm (branch of the axillary nerve)
What fibers form the radial nerve and what does it supply?
C5-T1 (sometimes
All of the muscles of the posterior compartment of arm AND forearm
The radial nerve spirals around the ______ humerus from the ____ _____ ______
Posterior
Medial bicipital sulcus
What branches off the radial nerve in the upper arm to supply the skin on the posterior side of the upper arm?
Posterior cutaneous nerve of the arm
What branches off the radial nerve in the middle arm?
Interior lateral cutaneous nerve of the arm
What do the muscular branches of the radial nerve supply?
- Triceps brachii
- Anconeus (by way of a branch off the medial head)
- Brachialis (also musculocutaneous)
What is the branch of the radial nerve that is given off in the upper arm that supplies a narrow area of skin on the lateral side of the posterior forearm?
Posterior cutaneous nerve of the forearm
Branches given off the radial nerve at the level of the epicondyle supply what?
Brachioradialis
Extensor carpi radialis longus
The radial nerve passes into the forearm on the ________ side of the elbow after traveling between what two muscles?
Anterior
Brachialis and brachioradialis
At the level of the radial head what happens to the radial nerve?
Splits into a superficial and deep branch
The superficial branch of the radial nerve follows the _________ muscle to the posterior surface of the hand and gives rise to what?
Brachioradialis
Dorsal digital nerves
What to the dorsal digital nerves, a branch of the radial nerve supply?
- radial side of posterior hand
- extensor side of thumb
- extensor side of proximal phalanges of digits 2/3
- lateral half of extensor side of ring finger
The superficial branch of the radial nerve gives off what?
Communicating branch with the ulnar nerve
The deep branch of the radial nerve penetrates the _______ muscle and gives off branches that supply _____ _______ muscles
Supinator
Posterior forearm
The deep branch of the radial nerve terminates as what nerve?
Posterior interosseous nerve
What does the posterior interosseous nerve supply?
- Extensor carpi radialis brevis
- Supinator
- Extensor digitorum
- Extensor digit minimi
- Extensor carpi ulnaris
- Abductor pollicis longus/brevis
- Extensor indicis
To where does the radial nerve send articular branches?
Shoulder and wrist
What are clinical considerations regarding the radial nerve?
- wrist drop (damage doesn’t inhibit supination bc biceps brachii is primary supinator)
- triceps and brachioradialis reflexes
brachial plexus injuries:
Supraclavicular
Erb-duchenne
What does erb-duchenne affect what nerves?
- suprascapular
- musculocutaneous
- axillary
C5-C6 nerve roots affected
Erb-duchenne causes atrophy of what muscles?
Brachialis, biceps brachii, deltoid
What clinical appearance might you see wit erb-duchenne?
Waits “tip”
Brachial plexus injuries
Infraclavicular
Klumpke
What nerves are affected with Klumpke syndrome?
C8-T1
Ulnar nerve affected
**T1 root damage would damage sympathetic trunk
=horner’s syndrome
What muscles are affected with klumpke?
Hand muscles-hypothenar, interossei, thenar
Forearm- flexor carpi ulnaris, medial 1/2 of flexor digitorum profundus
What is horner’s syndrome
In infraclavicular-klumpke’s if T1 nerve root affected= horner’s
= pots is, miosis