Muscles of ant/post Thorax

Question 1

Subclavius

Answer 1

O: first rib
I: clavicle
A: depress and move clavicle anteriorly, stabilize pectoral girdle
N: subclavian nerve

Question 2

pectorlais major

Answer 2

O: 2-5, 3-5 or 2-4th ribs
I: coracoid process of scapula
A: abduct scapula & rotates it downward RMA: elevates 3-5th ribs during forced inhalation when scapula stabilized
N: medial pectoral nerve

Question 3

serratus anterior

Answer 3

O: superior 8 or 9 ribs
I: vertebral border and inferior angle of scapula
A: abducts scapula, rotates it upward. RMA: elevates ribs when scapula stabilized
AKA; boxer’s muscle (punching and pushing)
N: long thoracic nerve

Question 4

trapezius

Answer 4

O: superior nuchal line of occipital bone, ligamentum nuchae, spines of C7-T12
I: clavicle and acromion and spine of scapula
A: superior fibers upward rotation scapula, middle fibers adduct, inferior fibers depress and upward rotate, stabilize scapula, RMA: superior fibers extend head
N: CNXI - accessory and cervical spinal nerves C3-C5

Question 5

levator scapulae

Answer 5

O: transverse processes of C1-C4
I: superior vertebral border of scapula
A: elevate and downward rotation of scapula
N: dorsal scapular nerve and cervical spinal nerves C3-C5

Question 6

rhomboid major

Answer 6

O: spines of T2-T5
I: vertebral border of scapula inferior to spine
A: elevate and adduct scapula, downward rotation, stabilize
N: dorsal scapular nerve

Question 7

rhomboid minor

Answer 7

O: spines of C7-T1
I: vertebral border of scapula superior to spine
A: elevate and adduct, downward rotation, stabilize
N: dorsal scapular nerve