Exam 1 muscle cards

Pectoralis major - clavicular portion

O: anterior surface of sternal ½ of clavicle

I: greater tubercle of humerus

A: shoulder medial rotation, horizontal adduction

N: lateral pectoral (C5-C7)

Pectoralis major - sternocostal portion

O: anterior surface of sternum, ribs 1-6/7

I: greater tubercle of humerus

A: shoulder depression, oblique adduction

N: medial & lateral pectoral (C6-T1)

Pectoralis minor

O: ribs 2-5 near cartilage

I: coracoid process of scapula

A: origin fixed - downward rotation, depression, adduction of scapula; insertion fixed - assists in forced inspiration

N: medial & communicating branch of lateral pectoral (C8, T1)

Serratus anterior

O: outer surface & superior borders of ribs 1-8/9

I: costal surface of medial border of scapula

A: origin fixed - abduction & upward rotation of scapula, holds medial border of scapula to rib cage; upper fibers elevate & lower fibers depress scapula; posteriorly displaces thorax; insertion fixed - expands ribcage for inspiration

N: long thoracic (C5-7)

Coracobrachialis

O: coracoid process of scapula

I: shaft of humerus opposite deltoid tuberosity

A: shoulder flexion & adduction

N: musculocutaneous (C6, C7)

Subscapularis

O: subscapular fossa of scapula

I: lesser tubercle of humerus, shoulder joint capsule

A: shoulder medial rotation, stabilizes shoulder joint

N: upper & lower subscapular (C5, C6)

Supraspinatus

O: supraspinous fossa of scapula

I: greater tubercle of humerus

A: shoulder lateral rotation & abduction, stabilizes shoulder joint

N: suprascapular (C5)

Teres minor

O: upper 2/3 dorsal surface of lateral border of scapula

I: greater tubercle of humerus, shoulder joint capsule

A: lateral rotation; stabilizes shoulder joint

N: axillary (C5, C6)

Infraspinatus

O: infraspinous fossa of scapula

I: greater tubercle of humerus

A: lateral rotation, stabilizes shoulder joint

N: suprascapular (C5, C6)

Teres major

O: inferior angle & lower 1/3 of lateral border of scapula

I: lesser tubercle of humerus

A: medial rotation, extension, & adduction

N: lower subscapular (C6)

Rhomboid major

O: spinous processes of T2-T5

I: medial border of scapula between spine & inferior angle

A: adduction, elevation, downward rotation of scapula

N: dorsal scapular (C5)

Rhomboid minor

O: spinous processes of C7-T1

I: medial border of scapula at root of spine

A: adduction, elevation, downward rotation of scapula

N: dorsal scapular (C5)

Latissimus dorsi

O: spinous processes of T6-T12, lower 3-4 ribs, iliac crest, inferior angle of scapula

I: intertubercular groove of humerus

A: origin fixed - medial rotation, adduction, extension, depression of shoulder, lateral flexion of trunk; insertion fixed - anterior & lateral pelvic tilt, spine hyperextension & flexion; accessory muscle of respiration

N: thoracodorsal (C6-C8)

Deltoid

O: anterior - anterior border, superior surface, lateral 1/3 of clavicle; middle - acromion of scapula; posterior - spine of scapula

I: deltoid tuberosity of humerus

A: abduction of shoulder; anterior fibers - shoulder flexion, medial rotation; posterior fibers - shoulder extension, lateral rotation

N: axillary (C5, C6)

Levator scapulae

O: transverse processes of C1-C4

I: medial border of scapula between superior angle & root of spine

A: origin fixed - elevates scapula, assists in downward rotation; insertion fixed - Ipsilateral flexion of cervical vertebrae, lateral rotation towards same side; assists in extension of cervical spine

N: cervical ventral rami of C3 & C4; dorsal scapular (C5)

Upper trapezius

O: external occipital protuberance, superior nuchal line, spinous process of C7

I: lateral 1/3 clavicle, acromion of scapula

A: origin fixed - upward rotation & elevation of scapula; insertion fixed - extension, lateral flexion, cervical rotation, extends cubical intervertebral joints

N: CN XI (accessory); ventral rami of C3 & C4