Shoulder Anatomy and Brachial Plexus Flashcards
Subscapularis
Origin: Subscapular fossa
Insertion: Lesser tuberosity
N: upper and lower subscapular N (C5/C6)
A: IR of humerus, ext, adduct, depress
Supraspinatus
O: Suprascapular Fossa
I: Superior facet of greater tuberosity
N: Suprascapular N (C5, C6)
A: Abd of humerus, ER
Infraspinatus
O: Infraspinatus fossa
I: Middle facet of greater tuberosity
N: Suprascapular N (C5, C6)
A: ER of humerus, ext
Teres Minor
O: superior lateral border of scapula
I: Inferior facet of greater tuberosity
N: Axillary Nerve (C5, C6)
A: ext and ER
Teres Major
O: Inferior lateral border, inferior angle of scapula
I: Medial intertubercular groove
N: Lower subscapular nerve (C5, C6)
A: IR, adducts arm
Serratus Anterior
O: Ext ribs 1-8
I: Medial border of anterior scapula
N: Long Thoracic Nerve (C5, 6, 7)
A: maintains scapula on thoracic wall, protracts and rotates scapula superiorly
Latissimus Dorsi
O: Spinous process of T7-T12, lumbar sp, thoracolumbar fascia, iliac crest, lower 3 ribs
I: floor of intertubercular groove
N: thoracodorsal nerve (C6,7,8)
A: IR of humerus, adduction, ext of humerus
Deltoid
O: lateral one third of clavicle, acromion, spine os scapula
I: Deltoid tuberosity of humerus (just lateral of greater tubercle)
N: Axillary Nerve (C5, C6)
A: Flexes, abducts, extends arm
Trapezius
O: spinous process of cervical and thoracic vertebrae
I: spine of scapula and acromion
N: CN XI (spinal accessory nerve), branches of ansa cervicalis
A: elevates, retracts, rotates scapula
Levator Scapula
O: Posterior tubercle of transverse processes of C1-C4
I: Sperior medial border of scapula to spine of scapulae
N: Dorsal Scapular Nerve (C5)
A: Elevates scapulae, inferior rotation of scapulae
Rhomboid major and minor
O: ligamentum nuchae, spinous process of C7-T5
I: medial border of scapulae from spine to inferior angle
A: retracts scapulae, rotates to depress scapulae
N: dorsal scapular nerve (C5)
Triceps
O: Superior one third of post and lateral humerus, inferior glenoid tubercle
I: Olecranon process
N: Radial Nerve (C5-T1)
A: elbow extension, ext arm at shoulder
Pectoralis Minor
O: Anterior surfaces of ribs 3-5 near costal cartilage
I: medial and superior coracoid process
N: Medial Pectoral Nerve (C8, T1)
A: stabilizes scapula by drawing it inferiorly and anteriorly against thoraic wall
Coracobrachialis
O: Tip of coracoid process
I: Middle medial border of humerus
N: Musculocutaneous (C5,6,7)
A: Horizontal flexion and adduction of humerus
Biceps Brachii
O: tip of coracoid and supraglenoid tubercle
I: radial tuberosity and lacertus fibrosis
N: musculocutaneous (C5, 6, 7)
A: flexes elbow and supinates forearm
Omohyoid
O: Superior border of scapula and suprascapular ligament
I: inferior hyoid bone
N; Ansa cervicalis (C1-C3)
A: functions in swallowing and phonation
Dorsal Scapular nerve
Branch of C5 nerve root.
M: levator scap, rhomboid major and minor
Long Thoracic Nerve
Branch of C5-7 nerve roots.
M: Serratus anterior
“C5,6,7, raise your arms to heaven”
Suprascapular nerve
Branch of the upper trunk, C5, 6
M: supraspinatus, infraspinatus
Nerve to Subclavius
Branch of upper trunk, C5
M: Subclavian muscle
Lateral Pectoral Nerve
Branch of the lateral cord (C5,C6,C7)
M: Pec major, possibly pec minor through a communicating branch
Upper Subscapular Nerve
Branch of the posterior cord (C5, C6)
M: subscapularis (upper portion)
Lower Subscapular Nerve
Branch of the posterior cord (C5,C6)
M: subscapularis (lower portion)
Thoracodorsal Nerve
Branch of the posterior cord (C6,7,8)
M: Latissimus Dorsi
AKA Middle subscapular nerve
Medial Pectoral Nerve
Branch of the medial cord (C8, T1)
M: Pec Major, Pec minor
Pierces pec minor usually
Medial Brachial Cutaneous Nerve
Branch of the medial cord (T1)
Sensory to medial and anterior humerus
Medial Antebrachial Cutaneous Nerve
Branch of the medial cord (C8, T1)
Sensory to medial forearm
Musculocutaneous nerve
Terminal Branch of lateral cord (C5, C6, C7)
M: coracobrachialis, brachialis, biceps brachii
Terminates as lateral antebrachial cutaneous nerve
Axillary nerve
Terminal Branch of posterior cord (C5, C6)
M: Deltoid, Teres Minor
Becomes lateral brachial cutaneous nerve
Radial nerve
Terminal branch of the posterior cord (C5-T1)
M: Triceps, Anconeus, supinator, brachioradialis, forearm extensors
Becomes posterior brachial cutaneous nerve
Median Nerve
Terminal branches of lateral and medial cords (C5-T1)
M: Pronator Teres, Flexor Carpi Radialis, Palmaris Longus, Flexor digitorm superficialis
Anterior interosseus nerve branches off to innervate lateral half of FDP, Flexor pollicis longus, pronator quadratus, lateral 2 lumbricals
Passes through carpal tunnel
Ulnar Nerve
Terminal branch of the medial cord (C7,C8,T1)
M: Flexor carpi ulnaris, medial two FDP, intrinsic hand muscles except thenar group, medial 2 lumbricals
Upper Trunk
Sends posterior division to middle trunk, anterior division continues as lateral cord. Gives off suprascapular nerve and nerve to subclavius.
middle Tunk
Gives anterior branch to join upper trunk and contribute to lateral cord
lower trunk
Gives posterior branch to join middle trunk, continues to medial cord
Lateral cord
Gives off lateral pectoral nerve, terminates as musculocutaneous nerve and branches to median nerve
posterior cord
Gives off 3 nerves in this order: upper subscapular nerve, thoracodorsal nerve, lower subscapular nerve. terminates as axillary nerve and Radial nerve
Medial cord
Gives off 3 branches in this order; Medial pectoral nerve, medial brachial cutaneous nerve, medial antebrachial cutaneous nerve. Terminates as ulnar nerve and branches to median nerve
