back muscles cont

Question 1

muscles of the back are separated

Answer 1

superficial (extrinsic) muscle group: 2 layers, move the upper limbs
deep (intrinsic) muscle group: move vert. column

Question 2

superficial extrinsic muscle group
function
main innervation

Answer 2

movements of the upper limb (scapula)
ventral rami

Question 3

superficial extrinsic muscles

Answer 3

trapezius
levator scapulae
rhomboids
latissimus dorsi

Question 4

superficial extrinsic muscles
trapezius

Answer 4

function: elevates, retracts, and depresses the scapula
-3 divisions
-innervation: spinal accessory nerve CN 11; cranial nerve
origin: spinous process and inserts on the scapula

Question 5

superficial extrinsic muscles
levator scapulae

Answer 5

function: elevates the scapula, rotates the scapula. minimal action
-structure: small tube-shaped muscle, thin
-innervation: dorsal scapular nerve, C3,C4, spinal nerve
origin: inserts on medial superior border of the scapula to transverse process of cervical vertebra

Question 6

superficial extrinsic muscles
rhomboids

Answer 6

function: retract the scapula
has a major and minor muscle; both work in unison
-innervation: dorsal scapular nerve (C4,C5)
-origin: medial border of scapula to spinous process

Question 7

superficial extrinsic muscles
latissimus dorsi

Answer 7

function: adduct humerus; extends and internally (medially) rotates the arm. raises body towards the arms during climbing
innervated: thoracodorsal nerve (C6,C7,C8)
-structure: broad, thin muscle with a wide origin and narrow insertion
origin: lower back and thoracolumbar fascia to humeros

Question 8

deep intrinsic muscle group
function
main innervation

Answer 8

function: trunk extension and posture maintenance
innervation: dorsal rami of spinal nerves

Question 9

deep (intrinsic) muscle group
-superficial-splenius

Answer 9

extends from the head
lateral flexion and head extension

Question 10

deep (intrinsic) muscle group
intermediate-erector spinae group

Answer 10

extensors when acting bilaterally, the largest group of deep. unilaterally flexes the vert column
-extends: back bend
adjacent to spinous process

Question 11

deep (intrinsic) muscle group
deep-transversospinales group

Answer 11

assists in spine extension, rotation, and stabilization.
between adjacent vertebra