Shoulder Anatomy and Brachial Plexus

Question 1

Subscapularis

Answer 1

Origin: Subscapular fossa
Insertion: Lesser tuberosity
N: upper and lower subscapular N (C5/C6)
A: IR of humerus, ext, adduct, depress

Question 2

Supraspinatus

Answer 2

O: Suprascapular Fossa
I: Superior facet of greater tuberosity
N: Suprascapular N (C5, C6)
A: Abd of humerus, ER

Question 3

Infraspinatus

Answer 3

O: Infraspinatus fossa
I: Middle facet of greater tuberosity
N: Suprascapular N (C5, C6)
A: ER of humerus, ext

Question 4

Teres Minor

Answer 4

O: superior lateral border of scapula
I: Inferior facet of greater tuberosity
N: Axillary Nerve (C5, C6)
A: ext and ER

Question 5

Teres Major

Answer 5

O: Inferior lateral border, inferior angle of scapula
I: Medial intertubercular groove
N: Lower subscapular nerve (C5, C6)
A: IR, adducts arm

Question 6

Serratus Anterior

Answer 6

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

Question 7

Latissimus Dorsi

Answer 7

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

Question 8

Deltoid

Answer 8

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

Question 9

Trapezius

Answer 9

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

Question 10

Levator Scapula

Answer 10

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

Question 11

Rhomboid major and minor

Answer 11

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)

Question 12

Triceps

Answer 12

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

Question 13

Pectoralis Minor

Answer 13

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

Question 14

Coracobrachialis

Answer 14

O: Tip of coracoid process
I: Middle medial border of humerus
N: Musculocutaneous (C5,6,7)
A: Horizontal flexion and adduction of humerus

Question 15

Biceps Brachii

Answer 15

O: tip of coracoid and supraglenoid tubercle
I: radial tuberosity and lacertus fibrosis
N: musculocutaneous (C5, 6, 7)
A: flexes elbow and supinates forearm

Question 16

Omohyoid

Answer 16

O: Superior border of scapula and suprascapular ligament
I: inferior hyoid bone
N; Ansa cervicalis (C1-C3)
A: functions in swallowing and phonation

Question 17

Dorsal Scapular nerve

Answer 17

Branch of C5 nerve root.

M: levator scap, rhomboid major and minor

Question 18

Long Thoracic Nerve

Answer 18

Branch of C5-7 nerve roots.
M: Serratus anterior
“C5,6,7, raise your arms to heaven”

Question 19

Suprascapular nerve

Answer 19

Branch of the upper trunk, C5, 6

M: supraspinatus, infraspinatus

Question 20

Nerve to Subclavius

Answer 20

Branch of upper trunk, C5

M: Subclavian muscle

Question 21

Lateral Pectoral Nerve

Answer 21

Branch of the lateral cord (C5,C6,C7)

M: Pec major, possibly pec minor through a communicating branch

Question 22

Upper Subscapular Nerve

Answer 22

Branch of the posterior cord (C5, C6)

M: subscapularis (upper portion)

Question 23

Lower Subscapular Nerve

Answer 23

Branch of the posterior cord (C5,C6)

M: subscapularis (lower portion)

Question 24

Thoracodorsal Nerve

Answer 24

Branch of the posterior cord (C6,7,8)
M: Latissimus Dorsi
AKA Middle subscapular nerve

Question 25

Medial Pectoral Nerve

Answer 25

Branch of the medial cord (C8, T1) M: Pec Major, Pec minor Pierces pec minor usually

Question 26

Medial Brachial Cutaneous Nerve

Answer 26

Branch of the medial cord (T1) | Sensory to medial and anterior humerus

Question 27

Medial Antebrachial Cutaneous Nerve

Answer 27

Branch of the medial cord (C8, T1) | Sensory to medial forearm

Question 28

Musculocutaneous nerve

Answer 28

Terminal Branch of lateral cord (C5, C6, C7) M: coracobrachialis, brachialis, biceps brachii Terminates as lateral antebrachial cutaneous nerve

Question 29

Axillary nerve

Answer 29

Terminal Branch of posterior cord (C5, C6) M: Deltoid, Teres Minor Becomes lateral brachial cutaneous nerve

Question 30

Radial nerve

Answer 30

Terminal branch of the posterior cord (C5-T1) M: Triceps, Anconeus, supinator, brachioradialis, forearm extensors Becomes posterior brachial cutaneous nerve

Question 31

Median Nerve

Answer 31

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

Question 32

Ulnar Nerve

Answer 32

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

Question 33

Upper Trunk

Answer 33

Sends posterior division to middle trunk, anterior division continues as lateral cord. Gives off suprascapular nerve and nerve to subclavius.

Question 34

middle Tunk

Answer 34

Gives anterior branch to join upper trunk and contribute to lateral cord

Question 35

lower trunk

Answer 35

Gives posterior branch to join middle trunk, continues to medial cord

Question 36

Lateral cord

Answer 36

Gives off lateral pectoral nerve, terminates as musculocutaneous nerve and branches to median nerve

Question 37

posterior cord

Answer 37

Gives off 3 nerves in this order: upper subscapular nerve, thoracodorsal nerve, lower subscapular nerve. terminates as axillary nerve and Radial nerve

Question 38

Medial cord

Answer 38

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