Muscles lll Flashcards

Pectoralis Major
O: clavicle, sternum
I: Humerus below glenoid tubercle
A: Medially rotate humerus (hug)

Pectoralis Minor
O: ribs 3-5
I: coracoid process
A: depresses scapula, “pick up pectoralis”

Serratus Anterior
O: ribs 1-9
I: scapula (medial and inferior border)
A: abducts scapula (boxer’s muscle)

Diaphragm
O: Xiphoid, ribs 5-12, L1-L5
I: central tendon (inserts into itself)
A: pulls central tendon down during inspiration

External Intercostals
O: Lower margin of ribs
I: rib below
A: draws ribs up during inspiration

Internal Intercostals
O: upper margin of ribs
I: rib above
A: draws ribs down during expiration

Splenius Capitis
O: C7-T3 or T4
I: occipital and temporal bones
A: extend and rotate head at neck

Sternocleidomastoid
O: sternum, clavicle
I: mastoid process
A: Flex neck

Middle Scalene
O: C2-C7, posterior transverse process
I: 1st rib
A: elevates ribs 1-2 in inspiration, flex head laterally