muscles

Question 1

serrtus anterior

Answer 1

origin: external surfaces of the lateral parts of ribs 1-8
insertion: anterior surfaces of the medial border of the scapula
action: protracts the scapula and hold it against the thoracic wall; rotates the scapula in an upward rotation
intervention: long thoracic nerve (C5, C6, C7)

Question 2

pectorals major

Answer 2

origin: clavicular head: anterior surface of the medial half of the clavicle
sternocostal head: anterior surface of the sternum, superior six costal cartridges, aponeurosis of the external oblique muscle
insertion: lateral lip of the anterior groove of the humerus
action: adducts and medially rotates the humerus; draws the scapula anteriorly and inferiorly. acting alone the clavicular head flexes the humerus and the sternocostal head will extend the humerus from a flexed position
intervention: lateral and medial pectoral nerves. clavicular head (C5, C6), sternocostal head (C7, C8, T1)

Question 3

pectoralis minor

Answer 3

origin: ant. surface of ribs 3, 4, 5
insertion: coracoid process of the scapula
action: anchors and depresses the scapula
intervention: medial pectoral (C8, T1)

Question 5

middle fibers of the trapezius

Answer 5

origin: spinous process of the first-with thoracic vertebrae
insertion: medial margin of the acromion and superior lip of the spine of the scapula
action: retracts the scapula
innervation: spinal accessory nerves (CN XI)

Question 6

lower fibers of the trapezius

Answer 6

origin: spinous process of the 6th-12th thoracic vertebrae
insertion: tubercule at the apex of the spine of the scapula
action: depresses the scapula and retracts scapula
innervation: spinal accessory nerves (CN XI)

Question 7

rhomboids minor/ major

Answer 7

origin: minor-ligamentous nuchal, spinous process of the 7th cervical and 1st thoracic vertebrae
major- spinous process of the thoracic vertebrae 2-5
insertion: minor- medial border of the scapula, at the root of the spine of the scapula
major- by fibrous attachment to the medial border of the scapula between the spine and inferior angle
action: adducts and elevates the scapula, downwardly rotates the scapula
innervation: dorsal scapular nerve (C4, C5)

Question 8

levator scapula

Answer 8

origin: transverse process of the first 4 cervial vertebrae (C1-C4)
insertion: medial border of the scapula, between the superior angle and the root of the spine
action: elevates the scapula and assists with downward rotation of the scapula. (ipsilateral) lateral flexion of the c-spine, extension of the c-spine
innervation: cervical 3 &4 and dorsal scapula nerve (C4, C5)

Question 9

subclavius

Answer 9

origin: junction of the first rib and its costal cartridge
insertion: inferior surface of the middle third of the clavicle
action: anchors and depresses the scapula
innervation: nerve to subclavius (C5, C6)