Pectoral Girdle

Question 1

Trapezius

Answer 1

Origin: occipital bone, ligamentum nuchae, and spinous process of seventh cervical and all thoracic vertebrae

Insertion: clavicle, spine, and a domino process of scapula

Action: rotate and retract scapula . Superior portion elevates scapula. Inferior portion depresses scapula

Nerve supply: accessory nerve

Question 2

Rhomboid major

Answer 2

Origin: spinous process of upper thoracic vertebrae

Insertion: medial border of scapula

Action: retracts, elevates and rotates scapula

Nerve supply: dorsal scapular nerve

Question 3

Serratus anterior

Answer 3

Origin: anterior surfaces of upper ribs

Insertion: medial border of scapula

Action: protracts and rotates scapula

Nerve supply: long thoracic nerve

Question 4

Pectoral is minor

Answer 4

Origin: anterior surface of ribs 3-5

Insertion: coracoid process of scapula

Action: depresses and protracts scapula, elevates ribs during forceful inhalation