Thoracoappendicular muscles

Question 1

What is the origin, insertion, action and innervation of Pectoralis Major

Answer 1

Origin: clavicle, sternum, ribs 2-7

Insertion: intertubercular sulcus

Action: adducts and medially rotates humerous

Innervation: lateral and medical pectoral nerve

Question 2

What is the origin, insertion action and innervation of Pectoralis Minor

Answer 2

Origin: Ribs 3-5

Insertion: coracoid process

Action: scapula forward (abduct) and downward and when scapula is fixed elevates ribs for forced inhalation

Innervation: medial pec nerve

Question 3

What is the origin, insertion action and innervation of Serratus Anterior

Answer 3

Origin: Ribs 1-8

Insertion: vertebral (medial) border and inferior angle of the scapula

Action: Boxing muscle= scapula is pulled forward (abduct) and around the rib cage

Innervation: long thoracic nerve

Question 4

What can injury of the long thoracic nerve result in

Answer 4

winged scapula= paralysis of the serratus anterior causes the medial border to pull away from the rib cage and protrude.

Question 5

What is the origin, insertion action and innervation of Subclavius muscle

Answer 5

Origin: 1st rib

Insertion: clavicle

Action: depresses clavicle and stabilize

Innervation: subclavian nerve

Question 6

What is the origin, insertion action and innervation of Latissimus Dorsi

Answer 6

Origin: spinous process of lower thoracic vertebrae, lumber vertebrae, sacrum and ileum

Insertion: intertubercular groove of the humerus

Action: raises body towards arms in climbing

Innervation: thoracodorsal nerve