Chest, shoulders, and back

Question 1

Pectoralis major m

Answer 1

Origin: Sternum, ribs, and clavicle

Insertion: Greater tubercle

Innervation: Lateral pectoral n and medial pectoral n

Arterial: Pectoral a (from thoracoacromial trunk)

Action: ADduction, medial rotation

Question 2

Pectoralis minor m

Answer 2

Origin: Rib 3-5

Insertion: coracoid process

Innervation: Medial pectoral n

Arterial: Pectoral a from thoracoacromial trunk

Action: Depress and protract scapula

Question 3

Serratus anterior m

Answer 3

Origin: Ribs 1-8/9, Lateral wall of thorax

Insertion: Medial border of scapula

Innervation: Long thoracic n

Arterial: Lateral thoracic a

Action: Protract scapula

Question 4

Subclavius m

Answer 4

Origin: Rib 1 and sternal end

Insertion: Clavicle

Innervation: Subclavian n

Arterial: Clavicular a (thoracoacromial trunk)

Action: Depress clavicle and stabilize sternoclavicular joint

Question 5

Trapezius m

Answer 5

Origin: Superior nuchal line, external occipital protruberance, C7-C12, Spinous processes

Insertion: Clavicle, acromion, scapular, and spine

Innervation: CN XI

Arterial: Transverse cervical a

Action: Elevate, retract, and depress scapula

Question 6

Levator scapulae m

Answer 6

Origin: C1 - C4 transverse process

Insertion: Superior medial border of scapula

Innervation: Dorsal scapular n and C3,4 (like phrenic)

Arterial: Dorsal scapular a

Action: Elevation of scapula

Question 7

Rhomboids m

Minor superior, major inferior

Answer 7

Origin: Nuchal ligament, C7-T5 transverse process

Insertion: Medial border of scapula

Innervation: Dorsal scapula n

Arterial: Dorsal scapular a

Action: Retract scapula

Question 8

Latissimus Dorsi m

Answer 8

Origin: T7-T12 spinous processes, inferior 3-4 ribs, thoracolumbar fascia, and iliac crest

Insertion: Floor of intertubercular groove (below lesser tubercle)

Innervation: Thoracodorsal n (aka middle subscapular n)

Arterial: Thoracodorsal a (from subscapular trunk)

Action: ADduction, medial rotation and extension of humerus

Question 9

Deltoid m

Answer 9

Origin: Lateral 1/3 of clavicle, acromion, and scapular spine

Insertion: Detoid tuberosity

Innervation: Axillary n

Arterial: Deltoid a (thoracoacromial trunk)

Action: ABduct arm, flex, extend humerus

Question 10

Supraspinatus m

Answer 10

Origin: Supraspinus fossa

Insertion: Greater tubercle (superior)

Innervation: Suprascapular n

Arterial: Suprascapular a

Action: ABduction first 30 degrees (initiation)

Question 11

Infraspinatus m

Answer 11

Origin: infrapinous fossa

Insertion: Greater tubercle (middle)

Innervation: Suprascapular n

Arterial: Suprascapular a and circumflex scapular a (from subscapular trunk)

Action: Lateral rotation of humerus

Question 12

Teres Minor m

Answer 12

Origin: superior lateral border of scapula

Insertion: Greater tubercle (inferior)

Innervation: Axillary n

Arterial: Posterior circumflex humeral a and circumflex scapular a

Action: Lateral rotation of humerus

Question 13

Subscapularis m

Answer 13

Origin: subscapular fossa

Insertion: Lesser tubercle

Innervation: Upper and lower Subscapular n (branch from posterior cord C5,6)

Arterial: Subscapular a

Action: Medial rotation

Question 14

Teres Major m

Answer 14

Origin: Inferior angle of scapula

Insertion: Medial aspect of intertubercular groove

Innervation: Lower subscapular n

Arterial: circumflex scapular a and subscapular trunk

Action: ADduction and medial rotation