Download the brachial plexus

THE
BRACHIAL PLEXUS
DORSAL SCAPULAR NERVE (C5)
•  supraclavicular branch
•  innervates rhomboids (major and minor) and levator scapulae
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
PHRENIC NERVE
•  supraclavicular branch
•  supplies the diaphragm
C 3, 4, 5
KEEPS
THE DIAPHRAGM
ALIVE
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
LONG THORACIC NERVE (C5, C6, C7)
•  supraclavicular branch
•  innervates serratus anterior
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
SUPRASCAPULAR NERVE (C5, C6)
•  supraclavicular branch
•  innervates supraspinatus and infraspinatus muscles (Rotator
Cuff Muscles) and shoulder joint
SUBCLAVIAN NERVE (C5, C6) – nerve to subclavius
•  supraclavicular branch
•  innervates subclavius and sternoclavicular joint
THE SUPERIOR TRUNK
is the ONLY trunk
to give off branches
THE DIVISIONS
don’t have
any BRANCHES
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
THE LATERAL CORD:
•  Lateral pectoral n.
•  Musculocutaneous n.
•  Median n.
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
LATERAL PECTORAL NERVE (C5-C7)
•  infraclavicular branch
•  innervates pectoralis major, pectoralis minor
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
THE POSTERIOR CORD:
STARS
•  Subscapular upper n.
•  Thoracodorsal n.
•  Axillary n.
•  Radial n.
•  Subscapular lower n.
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
UPPER SUBSCAPULAR NERVE (C5)
•  infraclavicular branch
•  innervates superior part of subscapularis (Rotator Cuff Muscles)
LOWER SUBSCAPULAR NERVE (C6)
•  infraclavicular branch
•  innervates inferior part of subscapularis and teres minor (Rotator
Cuff Muscles)
THORACODORSAL NERVE (C6-C8)
•  infraclavicular branch
•  innervates la[ssimus dorsi
BRACHIAL PLEXUS
SCHEMA OF THE BRACHIAL PLEXUS
THE MEDIAL CORD:
•  Ulnar n.
•  Median n.
•  Medial pectoral n.
•  Medial cutaneous n. of arm
•  Medial cutaneous n. of forearm
Think MEDIAL – think ULNAR
the rest begin with M…
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
MEDIAL PECTORAL NERVE (C8-T1)
•  infraclavicular branch
•  innervates pectoralis minor and sternocostal part of pectoris major
MEDIAL CUTANEOUS NERVE OF ARM (C8-T1)
•  infraclavicular branch
•  innervates skin of the medial side of the arm, as far distal as medial
epicondyle of humerus and olecranon of ulna
MEDIAL CUTANEOUS NERVE OF FOREAM (C8-T1)
•  infraclavicular branch
•  innervates skin of the medial side of the forearm, as far distal as
wrist
BRACHIAL PLEXUS
THE BRACHIAL PLEXUS
LESIONS OF THE PLEXUS
BRACHIAL PLEXUS
BRACHIAL PLEXUS
LESIONS OF THE PLEXUS
Mechanisms of Injury:
A. Percussion
B. Traction
C. Cervical nerve compression
BRACHIAL PLEXUS
ERB-DUCHENNE PALSY (SUPERIOR TRUNK lesion (C5-C6)
BRACHIAL PLEXUS
ERB-DUCHENNE PALSY
•  is a SUPERIOR TRUNK lesion (C5-C6)
•  caused by trauma (violent stretch between the head and shoulder) or
trauma[c birth – excessive increase in the angle between the head and the
shoulder
MUSCULOCUTANEOUS + SUPRASCAPULAR + SUBCLAVIAN+ PHRENIC
NERVES LESION
FINDINGS:
•  upper limb with an adducted shoulder
•  medially rotated arm
•  extended elbow
•  deformity of the affected wrist (waiter’s [p hand)
•  lateral aspect of the forearm also experiences some loss of sensa[on.
A superior brachial plexus injury may produce muscle spasms and severe
disability in hikers (backpacker’s palsy) who carry heavy backpacks for long
periods.
BRACHIAL PLEXUS
KLUMPKE’S PALSY (INFERIOR TRUNK lesion (C8-T1)
BRACHIAL PLEXUS
KLUMPKE’S PALSY (INFERIOR TRUNK lesion (C8-T1)
KLUMPKE’S PALSY
is the most infrequent pahern and manifests as isolated hand paralysis.
Inferior brachial plexus injuries may occur when the upper limb is suddenly pulled
superiorly (for example, when a person grasps something to break a fall or a baby’s
upper limb is pulled excessively during delivery).
MEDIAN + RADIAL + ULNAR NERVES LESION
FINDINGS:
•  loss of all lumbricals
•  all fingers are clawed
CAUSE:
•  Pancoast tumor
•  trauma[c birth
•  loss of flexors and extensors
ARTERIAL SUPPLY
ARTERIAL SUPPLY
SUBCLAVIAN ARTERY extends from the arch of the aorta to
the lateral border of the first rib.
The subclavian artery gives off the following branches:
1. Internal thoracic artery is con[nuous with the superior epigastric
artery, which anastomoses with the inferior epigastric artery (a
branch of the external iliac artery).
This may provide a route of collateral circula[on if the abdominal
aorta is blocked.
2. Vertebral artery
3. Thyrocervical trunk has three branches:
•  suprascapular artery, which par[cipates in collateral circula[on
around the shoulder
•  transverse cervical artery, which par[cipates in collateral
circula[on around the shoulder
•  inferior thyroid artery
ARTERIAL SUPPLY
AXILLARY ARTERY is a con[nua[on of the subclavian artery and extends from the
lateral border of the first rib to the inferior border of the teres major muscle. The
tendon of the pectoralis minor muscle crosses the axillary artery anteriorly and
divides the axillary artery into three dis[nct parts (i.e., the first part is medial, the
second part is posterior, and the third part lateral to the muscle). The axillary
artery gives off the following branches:
1. First Part
•  superior thoracic artery
2. Second Part
•  thoracoacromial artery is a short, wide trunk that divides into four branches:
acromial, deltoid, pectoral, and clavicular.
•  lateral thoracic artery
3. Third Part
•  anterior humeral circumflex artery
•  posterior humeral circumflex artery
•  subscapular artery, which gives off the circumflex scapular artery and the
thoracodorsal artery
ARTERIAL SUPPLY
AXILLARY ARTERY
A. Superior or Supreme Thoracic Artery
Supplies the intercostal muscles in the first and second anterior intercostal
spaces and adjacent muscles.
B. Thoracoacromial Artery
Is a short trunk from the first or second part of the axillary artery and has
pectoral, clavicular, acromial, and deltoid branches.
Pierces the costocoracoid membrane (or clavipectoral fascia).
C. Lateral Thoracic Artery
Runs along the lateral border of the pectoralis minor muscle.
Supplies the pectoralis major, pectoralis minor, and serratus anterior muscles
and the axillary lymph nodes and gives rise to lateral mammary branches.
ARTERIAL SUPPLY
AXILLARY ARTERY
D. Subscapular Artery
Is the largest branch of the axillary artery, arises at the lower border of the
subscapularis muscle, and descends along the axillary border of the
scapula. Divides into the thoracodorsal and circumflex scapular arteries:
•  Thoracodorsal Artery accompanies the thoracodorsal nerve and supplies the
la[ssimus dorsi muscle and the lateral thoracic wall.
•  Circumflex Scapular Artery passes posteriorly into the triangular space
bounded by the subscapularis muscle and the teres minor muscle above, the
teres major muscle below, and the long head of the triceps brachii laterally.
Ramifies in the infraspinous fossa and anastomoses with branches of the
dorsal scapular and suprascapular arteries.
ARTERIAL SUPPLY
AXILLARY ARTERY
E. Anterior Humeral Circumflex Artery
Passes anteriorly around the surgical neck of the humerus.
Anastomoses with the posterior humeral circumflex artery.
F. Posterior Humeral Circumflex Artery
Runs posteriorly with the axillary nerve through the quadrangular space
bounded by the teres minor and teres major muscles, the long head of the
triceps brachii, and the humerus.
Anastomoses with the anterior humeral circumflex artery and an ascending
branch of the profunda brachii artery and also sends a branch to the acromial rete.
ARTERIAL SUPPLY
BRACHIAL ARTERY is a con[nua[on of the axillary artery and extends from the
inferior border of the teres major muscle to the cubital fossa, where it ends in
the cubital fossa opposite the neck of the radius. The brachial artery gives off the
following branches:
1. Profunda brachii (deep brachial) artery
•  a fracture of the humerus at midshao may damage the deep brachial artery and
radial nerve as they travel together on the posterior aspect of the humerus in
the radial groove.
•  the deep brachial artery ends by dividing into the middle collateral artery and
radial collateral artery.
2. Superior ulnar collateral artery runs with the ulnar nerve posterior to the
medial epicondyle and anastomoses with the posterior ulnar recurrent artery
to par[cipate in collateral circula[on around the elbow.
3. Inferior ulnar collateral artery anastomoses with the anterior ulnar
recurrent artery to par[cipate in collateral circula[on around the elbow.
ARTERIAL SUPPLY
BRACHIAL ARTERY
4. Radial artery arises as the smaller lateral branch of the brachial artery in the
cubital fossa and descends laterally under cover of the brachioradialis muscle,
with the superficial radial nerve on its lateral side, on the supinator and flexor
pollicis longus muscles.
Curves over the radial side of the carpal bones beneath the tendons of the
abductor pollicis longus muscle, the extensor pollicis longus and brevis
muscles, and over the surface of the scaphoid and trapezium bones.
Runs through the anatomic snupox.
Divides into the princeps pollicis artery and the deep palmar arch.
Accounts for the radial pulse, which can be felt proximal to the wrist between
the tendons of the brachioradialis and flexor carpi radialis muscles.
ARTERIAL SUPPLY
BRACHIAL ARTERY
Radial artery gives off the following branches:
•  recurrent radial artery anastomoses with the radial collateral artery.
•  palmar carpal branch
•  dorsal carpal branch
•  superficial palmar branch completes the superficial palmar arch.
•  princeps pollicis artery divides into two proper digital arteries for each side of
the thumb.
•  radialis indicis artery
•  deep palmar arch is the main termina[on of the radial artery and anastomoses
with the deep palmar branch of the ulnar artery. It gives rise to three palmar
metacarpal arteries, which join the common palmar digital arteries from the
superficial arch.
ARTERIAL SUPPLY
BRACHIAL ARTERY
5. Ulnar artery is the larger medial branch of the brachial artery in the
cubital fossa.
Descends behind the ulnar head of the pronator teres muscle and lies between the
flexor digitorum superficialis and profundus muscles.
Enters the hand anterior to the flexor re[naculum, lateral to the pisiform bone,
and medial to the hook of the hamate bone.
Divides into the superficial palmar arch and the deep palmar branch.
Accounts for the ulnar pulse, which is palpable just to the radial side of
the inser[on of the flexor carpi ulnaris into the pisiform bone.
ARTERIAL SUPPLY
BRACHIAL ARTERY
5. Ulnar artery gives off the following branches:
•  anterior ulnar recurrent artery
•  posterior ulnar recurrent artery
•  common interosseous artery, which divides into the anterior interosseous
artery and posterior interosseous artery. The posterior interosseous artery
gives rise to the recurrent interosseous artery.
•  palmar carpal branch
•  dorsal carpal branch
•  deep palmar branch completes the deep palmar arch.
•  superficial palmar arch is the main termina[on of the ulnar artery and
anastomoses with the superficial palmar branch of the radial artery. It gives
rise to three common palmar digital arteries, each of which divides into proper
palmar