Download Axilla and Brachial Plexus - University of Kansas Medical

Axilla and Brachial Plexus
Boundaries of Base of Axilla

Anterior:
Pectoralis major muscle

Posterior:
Latissimus dorsi muscle

Medial:
Thoracic wall

Lateral:
Humerus
Boundaries of Apex of Axilla

Anterior:
Clavicle

Posterior:
Superior border of the scapula

Medial:
First rib
Contents of Axilla

Great vessels:
Axillary vein and artery
Cephalic vein and basilic vein
Axillary lymph nodes

Nerves:
Long thoracic nerve
Cords of brachial plexus
Proximal ends of terminal nerves of brachial
plexus
Origin of Brachial Plexus

Ventral rami of C5 – T1:
Exit neck between scalenus anterior and
scalenus medius muscles.
Direct branches from rami:
Dorsal scapular nerve
C5
To rhomboid muscles
Long thoracic nerve
C5-7
To serratus anterior muscle
Trunks of Brachial Plexus
Formed by ventral rami.
 Located superior to clavicle above and
behind subclavian artery.
 Superior (upper)

From C5 and C6 ventral rami
Trunks of Brachial Plexus

Middle:
From C7 ventral ramus

Inferior (lower):
From C8 and T1 ventral rami
Trunks of Brachial Plexus

Direct branches from trunks:
From Superior Trunk:
Suprascapular nerve
C5,C6
To supraspinatus and infraspinatus
muscles
Nerve to subclavius
Divisions of Brachial Plexus

Anterior divisions:
Carry fibers from trunks to anterior
compartments of upper extremity.
Form lateral and medial cords

Posterior Divisions:
Carry fibers from trunks to posterior
compartments of upper extremity.
Form posterior cord.
Cords of Brachial Plexus
Formed from divisions.
 Accompany axillary artery.

Cords of Brachial Plexus

Named for relationship to artery.
Lateral:
From anterior divisions of upper and middle
trunks.
Posterior:
From posterior divisions of all trunks.
Medial:
From anterior divisions of lower trunk.
Lateral Cord

Direct branches:
Lateral pectoral nerve:
C5-7
To clavicular head of pectoralis major muscle

Terminal nerves:
Musculocutaneous:
C5-7
Lateral root of median nerve:
C5-7
Medial Cord: Direct Branches

Medial pectoral nerve:
C8-T1
To sternal head of pectoralis major muscle
and pectoralis minor muscle.
Medial cutaneous nerve to arm (brachium)
 Medial cutaneous nerve to forearm
(antebrachium)

Medial Cord: Terminal Nerves

Ulnar
C8-T1

Medial root of median nerve
C8-T1
Posterior Cord Direct Branches

Upper subscapular nerve:
C5-6
To subscapularis muscle

Thoracodorsal nerve:
C6-7
To latissimus dorsi muscle

Lower subscapular nerve:
C5-6
To subscapularis and teres major muscles
Posterior Cord Terminal Nerves

Axillary nerve:
C5-6
Motor:
To deltoid and teres minor muscles.
Sensory:
Skin on arm over deltoid muscle:
Upper lateral cutaneous nerve
Posterior Cord Terminal Nerves

Radial nerve:
C5-T1
Motor:
Posterior compartments of arm and forearm.
Brachioradialis muscle
Sensory:
Back of arm, forearm, hand