muscles of the posterior thorax: scapula

Question 1

Trapezius

Answer 1

O: occipital bone, ligamentum nuchae and spinous process of c7-t12
I: acromion and spine of scapula and lateral third of clavicle
N: accessory nerve (cranial nerve XI). root: c3, c4
K: adduct, elevate or depress scapula or extend head with scapula fixed

Question 2

Levator scapulae

Answer 2

O: traverse processes of c1-c4
I: medial border of scapula
N: cervical spinal nerve and dorsal scapular nerve. roots c3-c5
K: elevates, adducts scapula, tilts glenoid cavity down when scapula fixed, flexes neck at same side

Question 3

Rhomboids: major and minor

Answer 3

O: spinous processes of c7-t1 (minor), spinous processes of t2-t5 (major)
I: medial border of scapula
N: dorsal scapular nerve. root c4, c5
K: adduct scapula, rotate scapula so glenoid cavity downward