Gross Anatomy I Lecture - Shoulder Muscles

what are the origins of the trapezius?

1. external occipital protuberance (EOP)

2. superior nuchal line

3. ligamentous nuchae

4. spines of C7-T12

what are the insertions of the trapezius?

1. clavicle

2. acromion process/scapula

3. spine/scapula

what action does the trapezius as a whole carry out?

stabilizes the scapula

what action does the upper portion of the trapezius carry out?

elevates the scapula

what actions do the middle and lower portions of the trapezius carry out?

1. adducts scapula

2. depresses scapula

what is the motor innervation of the trapezius?

spinal accessory nerve (XI)

what is the sensory innervation of the trapezius?

C3, C4

what are the origins of the rhomboid major?

spines/upper thoracic vertebrae

what is the insertion of the rhomboid major?

vertebral boarder/scapula

what actions does the rhomboid major carry out?

1. elevates scapula

2. adducts scapula

3. stabilizes scapula

what is the innervation of the rhomboid major?

dorsal scapular nerve

what are the origins of the rhomboid minor?

spines/C7 and T1

what is the insertion of the rhomboid minor?

vertebral boarder/scapula

what actions does the rhomboid minor carry out?

1. elevates scapula

2. adducts scapula

3. stabilizes scapula

what is the innervation of the rhomboid minor?

dorsal scapular nerve

what are the origins of the levator scapula?

transverse processes/upper cervical vertebrae

what are the insertions of the levator scapula?

1. upper medial boarder/scapula

2. superior angle/scapula

what actions does the levator scapula carry out?

1. elevates scapula

2. adducts scapula

3. stabilizes scapula

what is the innervation of the levator scapula?

dorsal scapular nerve

what are the origins of the latissimus dorsi?

1. spines/lower thoracic vertebrae

2. thoracodorsal fascia

3. crest/ilium

4. lower ribs

what is the insertion of the latissiumus dorsi?

intertubercular groove (lesser tubercle)/humerus

what actions does the latissimus dorsi carry out?

1. extends humerus

2. adducts humerus

3. medially rotates humerus

4. involved in forced expiration

what is the innervation of the latissimus dorsi?

thoracodorsal nerve

what are the origins of the serratus anterior?

upper 8 or 9 ribs

what is the insertion of the serratus anterior?

vertebral boarder/scapula

what actions does the serratus anterior carry out?

1. abduction/protraction of scapula

2. stabilizes scapula

3. invovled in forced expiration when humerus is abducted

what is the innervation of the serratus anterior?

long throacic nerve