5.2 Anatomy of Muscular System Flashcards
What does the trapezius act on?
shoulder
neck
upper spine
What are the muscles of the shoulder and upper extremity?
trapezius
levator scapulae
rhomboids
pectoralis minor
serratus anterior
What is the origin and insertion of the trapezius?
origin = occipital bone and spinous process of T1-12
insertion = lateral clavicle, acromion, and scapular spine of scapula
What is the action of the trapezius?
rotation, retraction, elevation, depression of scapula
extends neck
stabilizes shoulder
What is the innervation of the trapezius?
CN11 (accessory nerve)
What is the origin and insertion of the levator scapulae?
origin = transverse process of C1-4
insertion = medial border of scapula
What is the action of the levator scapulae?
elevates the scapula
What is the innervation of the levator scapulae?
dorsal scapular nerve
What is the origin and insertion of the rhomboids?
origin = spinous process (minor is C7-T1 and major is T2-5)
insertion = medial border of scapula
What is the action of the rhomboids?
retraction of scapula
What is the innervation of the rhomboids?
dorsal scapular nerve
What is the origin and insertion of the pectoralis minor?
origin = ribs 3-5
insertion = coracoid process of scapular
What is the action of the pectoralis minor?
elevates ribs
draws scapula down and medially
What is the innervation of the pectoralis minor?
medial pectoral nerve
What is the origin and insertion of the serratus anterior?
origin = upper 8-9 ribs
insertion - medial border of scapula
