Superficial and Deep Muscles of the Back Flashcards
What defines extrinsic back muscles? (and where do they attach usually?)
assist in the movement of upper limbs and ribs, attach from vertebral column to ribs or upper limbs
Which nerve innervates extrinsic back muscles?
anterior rami
what information does the anterior rami carry?
both sensory and motor
What defines the intrinsic back muscles?
they support and move the vertebral column, maintain posture, and are DEEP
Which nerve innervates the intrinsic back muscles?
posterior rami
what info does the posterior rami carry?
both sensory and motor
Which are the superficial extrinsic back muscles?
trapezius, latissimus dorsi, major and minor rhomboids, levator scapulae
Which are the intermediate layer extrinsic back muscles?
serratus posterior superior, serratus posterior inferior
What is the depth of the deep intrinsic back muscles from superficial to deep?
spinotransversalis, erector spinae, transversospinales, intrinsics
Where does the descending portion of the trapezius originate?
superior nuchal line on the occipital bone, spinous process of C7, external occipital protuberance, and ligamentum nuchae
where does the middle/transverse portion of the trapezius originate?
spinous processes C7 - T12
Where does the descending portion of the trapezius attach?
lateral 1/3 of clavicle and acromion
Where does the middle/transverse trapezius attach?
acromion, superior lip of the posterior border of the scapular spine
Where does the ascending trapezius originate?
spinous processes of T4 - T12
where does the ascending trapezius attach?
medial end of scapular spine
what is the function of the descending trapezius?
elevate scapular (shrug)
what is the function of the middle trapezius
adduction/retraction of the scapula
what is the function of the ascending trapezius?
depress scapula
what is the synergistic function of the descending and ascending trapezius?
upward rotation of the scapula
innervation of trapezius?
CN11 or the spinal accessory nerve
trapezius blood supply? and where does it run
superficial branch of the transverse cervical artery, runs medial to scapula
examples of causes of spinal accessory nerve injury (7)
lymph node bx, neck dissection, carotid endarterectomy, parotid surgery, facelift, tumor, trauma (such as whiplash, blunt trauma, neck manipulation, penetration, love bites)
where is the triangle of ascultation located?
border of latissimus dorsi, medial scapula and trapezius around the 6th intercostal space (T6/T7)
origin of latissimus dorsi?
T7 spinous process to the thoracolumbar fascia to the sacrum to the iliac crest
insertion latissimus dorsi
intertubercular sulcus on humerus, and the lateral lower 3-4 ribs
innervation latissimus dorsi?
thoracodorsal nerve (C6,C7,C8)
what is the blood supply to the latissimus dorsi?
thoracodorsal artery
actions of latissimus dorsi
adduction and extension of humerus, internally rotates humerus (d/t intertubercular groove)
Where is the thoracolumbar fascia?
it covers the deep back muscles, and is continuous with the nuchal fascia
What portion of the latissimus dorsi arises from the thoracolumbar fascia?
aponeurosis of latissimus dorsi
origin levator scapulae
transverse processes of C1-C4
insertion levator scapulae
medial border of scapula at superior angle
function of the levator scapulae?
elevates scapula (shrug)
Where does the rhomboid minor originate?
spinous processes of C7 to T1
Where does the rhomboid minor attach?
medial margin of scapula at the level of the spine
Where does the rhomboid major originate?
spinous proesses of T2 to T5/T6
Where does the rhomboid major attach?
medial margin of scapula below the spine
What is the function of the rhomboid major and minor?
adduct and retract the scapula (party in the back)
what innvervates the rhomboids and levator scapulae?
dorsal scapular nerve (C4/5 from the anterior rami)
If the dorsal scapular nerve is damaged, what could happen?
the scapula could be further from midline ipsilaterally
what is the blood supply to the levator scapulae and rhomboids?
dorsal scapular artery (which is the deep branch of the transverse cervical artery)
What innervates the serratus posterior superior and inferior?
intercostal nerves
what is the function of serratus posterior muscles?
proprioception of the back, elevation/depression of ribs during forced respiration
Where do the serratus posterior inferior muscles originate?
spinous processes T11-L2
Where do the serratus posterior inferior muscles attach?
ribs 9-12, superior borders lateral to their angles
Where do the serratus posterior superior muscles originate:
spinous processes of C7-T3
where do the serratus posterior superior muscles attach?
superior border of ribs 2-5, lateral to their angles
what innervates the deep layer of intrinsic muscles?
the dorsal/posterior rami
What muscles make up the spinotransversalis group?
splenius capitus and splenius cervicis
what muscles make up the erector spinae group?
iliocostalis, longissimus, spinalis
what muscles make up the transverseospinales group?
semispinalis, multifidus, rotatores
origin of splenius capitus?
nuchal ligament, spinous processes of C7-T4
where does the splenius capitus attach?
mastoid process of temporal bone, superior nuchal line of occipital bone (lateral 1/3)
where does the splenius cervicis originate?
spinous process of T3-T6
where does the splenius cervicis attach?
posterior tubercles of transverse process of C1-C3
What is the function of splenius capitus and cervicis?
bilaterally extend head and neck, unilaterally rotate head and neck to SAME SIDE
What are the 3 branches of the iliocostalis?
illiocostalis cervicis, thoracis and lumborum
what are the 3 branches of the longissimus?
capitis, cervicis, thoracis
what are the 2 branches of the spinalis?
cervicis and thoracis
what is the function of the erector spinae?
posture, bilaterally extend vertebral column and head, unilaterally flex laterally to SAME side
where do the rotatores brevis stretch to and from?
from the transverse process to the spinous process of the same vertebra
where do the rotatores longus stretch to and from?
from the transverse process to the spinous bprocess of the previous vertebra
origin of multifidus?
sacrum, ilium, transverse processes T1-L5, articular processes C4-C7
where do the interspinales stretch to and from?
between spinous processes of adjacent vertebra
origin of semispinalis capitus?
transverse process C7-T6/7, articular process of C4-C6
function of the transversospinalis?
proprioception, rotates head and spine to contralateral side, bilaterally extend spine and head, maintain posture
origin of erector spinae?
median sacral crest, posterior surface of the sacrum, spinal processes of lumbar and lower thoracic vertebra, medial part of iliac cresh
insertion of erector spinae?
iliocostalis: angles of lower ribs and transverse processes of cervical spine
longissimus: between tubercles and angles of ribs and transverse processes of thoracic and cervical vertebrae
spinalis: spinous processes of thoracic and lumbar vertebrae
innvervation of spinotransversalis muscle group?
posterior rami of middle cervical nerves
insertion of semispinalis capitis?
between inferior and superior nuchal lines
action of semispinalis capitis?
unilaterally rotates/extends head to opposite side
bilaterally extends head
origin of semispinalis cervicis?
transverse process of T1-T5/6
insertion of semispinalis cervicis?
spinous process of C2-C5
action of semispinalis cervicis?
unilaterally rotates/extends neck to opposite side
bilaterally extends neck
insertion of multifidus?
spinous processes L5-C2
action of multifidus?
extends and rotates vertebral column to opposite side
