Muscles of the Trunk

Question 1

Trapezius

Answer 1

O: Occipital Bone
I: Along acromion, spine of scapula and lateral clavicle
A: Stabilizes, raises, retracts and rotates scapula
N: Accessory Nerve (CN XI)

Question 2

Latissimus Dorsi

Answer 2

O: Spines of lower 6 thoracic vertebrae, lumbar vertebrae, ribs 3-4, iliac crest, scapula
I: Intertubercular sulcus of Humerus
A: Prime mover of arm extension, powerful arm adductor and medially rotates arm at shoulder
N: Thoracodorsal Nerve

Question 3

Levator Scapulae

Answer 3

O: Transverse processes of cervical vertebrae 1-4
I: Medial border of scapula, superior to spine
A: Elevates/Adducts scapula
N: Cervical spinal nerves and dorsal scapular nerve

Question 4

Pectoralis Major

Answer 4

O: Sternal end of clavicle, sternum cartilage of ribs 1-6
I: intertubercular sulcus and greater tubercle of humerus
A: Prime mover of arm flexion, rotates arm medially, adducts arm
N: Lateral Pectoral Nerve

Question 5

Rhomboid major

Answer 5

O: Spinous process of thoracic vertebrae 2-5
I: Medial border of scapula
A: adduct and rotate scapula
N: Dorsal Scapular Nerve

Question 6

Rhomboid Minor

Answer 6

O: Spinous process of cervical vertebrae 7 to thoracic vertebrae 1
I: Medial border of scapula
A: adduct and rotate scapula
N: dorsal scapular nerve

Question 7

External Oblique

Answer 7

O: ribs 5-12 (lower 8 ribs)
I: linea alba, iliac crest, pubic crest and tubercle
A: Flexes vertebral column, compresses abdominal wall, rotates and laterally flexes trunk
N: Intercostal Nerve