Back Muscles Flashcards
Extrinsic back muscles
innervated by the anterior rami
superficial group moves the upper limb
intermediate (respiratory) group moves ribs
Intrinsic (true) back muscles
innervated by posterior rami
move vertebral column and head
superficial back muscles
immediately deep to superficial fascia
attach to upper appendicular skeleton
traps, lats, levator scap, rhomboid major, rhomboid minor
Intermediate (respiratory) back muscles
2 thin muscular serrated sheets in superior and inferior back
pass obliquely form vertebral column to attach to ribs
serratus posterior superior
serratus posterior inferior
spinotransversalis back muscles
spinous process to ligamentum nuchae upward and laterally
insert onto transverse processes of C1-3 and mastoid process of occipital bone
bilateral contraction=extend neck
unilateral contraction=rotate head to ipsilateral side
splenius capitus and splenius cervicis
erector spinae back muscles
3 vertical columns
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-illiocostalis
-longissimus
-spinalis
primary extensors of the vertebral column and head
bilateral contraction=straighten back and pull back head from flexed position
unilateral=bend vertebral column or head laterally (laterally flex)
transversospinales back muscles
run obliquely upward and medially from transverse process to spinous process
fills the grooves between transverse and spinous processes
semispinalis-superficial
multifidus-intermediate
rotatores-deepest
segmental back muscles
deep postural muscles
stabilize vertebrae during movement of vertebral column
levatores costarum-transverse process to rib below
interspinales-between spinous processes
intertransversarii-between transverse processes
suboccipital back muscles
base of occipital bone
move head
connect C1, C2, and occipital bone
innervated by posterior ramus of C1
primary curvatures
thoracic and sacral
anteriorly concave
like embryo
kyphosis
secondary curvature
cervical and lumbar
concave posteriorly
lordosis
curvatures of the spinal column
Thoracic kyphosis
Lumbar lordosis
Center of gravity is a vertical line allowing body’s weight to be balanced on vertebral column in a way that expends minimal muscle energy for bipedalism
ligamentum nuchae
ligamen anchored between the bifid spinous process
where do the vertebral arteries run through?
transverse foramen
uncovertebral joint
uncinate process articulating with the bodies of the cervical vertebra above
uncinate process
crests on superolateral part of the body
facilitates flexion and extension
limits lateral flexion
atlanto-occipital joint
nods head up and down
atlanto-axial joint
rotates the head
transverse ligament of the atlas
holds dens in position
alar ligaments
connect dens to occipital condyle
dens
superior projection of the axis (C2)
demifacets
on each side of the body
articulate with head of its own rib and head of rib below
superior-articulates with own rib
inferior-articulates with rib below
Zygapophysial joint
between superior and inferior articular processes
what does the slope of the cervical vertebrae help with?
flexion and extension
what does the vertical angle of the thoracic vertebrae help with? what does it limit?
facilitates rotation; limits flexion and extension
what does the curved and interlocked lumbar vertebrae do?
limits ROM
anterior longitudinal ligament
base of skull to sacrum
attached to anterior part of bodies and intervertebral discs
posterior longitudinal ligament
attached to posterior part of bodies and intervertebral discs
lines anterior surface of vertebral canal
tectorial membrane-connects C2 to base of the skull
ligamenta flava
between laminae of adjacent vertebrae
elastic tissue
posterior surface of vertebral canal
runs between posterior surface of lamina below to anterior surface of lamina above
resists separation of laminae during flexion
assists extension back to anatomical position
supraspinous ligament
connects tips of spinous processes from C7-sacrum
ligamentum nuchae
continuation of supraspinous ligement
suports head
resists flexion
facilitates extension back to anatomical position
attachment of traps and splenius capitis
interspinous ligaments
pass between adjacent spinous processes
blend with supraspinous posteriorly and ligamentum flavum anteriorly
conus medullaris
distal end of the spinal cord
filum terminale
continues inferiorly from conus medullaris
longitudinal support to spinal cord
attached to coccyx
segmental arteries
enter through intervertebral foramina
arise from vertebral and deep cervical arteries in neck, post. Intercostal arteries in thorax, lumbar arteries in abdomen
give rise to anterior and posterior radicular arteries
largest is arteria radicularis magna (artery of Adamkiewicz)
longitudinal arteries
anterior spinal artery: originates from vertebral artery in cranial cavity
posterior spinal artery: originates from vertebral arteries or posterior inferior cerebellar artery in cranial cavity.
spinal cord veins
form longitudinal channels
2 pairs on each side
drain into internal vertebral plexus
trapezius
origin: occiput
insertion: lateral 3rd of clavicle, acromion, spine of the scapula
innervation: motor-accessory
function: upper fibers elevate, middle fibers adduct, and lower fibers depress scapula
latissimus dorsi
origin: spinous processes of T7 to L5 and sacrum, iliac crest, ribs 10 to 12 via thoracolumbar fascia
insertion: floor of intertubercular sulcus of humerus
innervation: thoracodorsal nerve (C6 to C8)
function: extends, adducts, and medially rotates humerus
levator scapulae
origin: transverse processes of C1 to C4
insertion: upper portion medial border of scapula
innervation: C3 to C4 and dorsal scapular nerve (C4, C5)
function: elevates scapula
rhomboid major
origin: spinous processes of T2 to T5
insertion: medial border of scapula between spine and inferior angle
innervation: dorsal scapular nerve (C4, C5)
function: retracts (adducts) and elevates scapula
rhomboid minor
origin: lower portion of ligamentum nuchae, spinous processes of C7 and T1
insertion: medial border of scapula at spine of scapula
innervation: dorsal scapular nerve (C4, C5)
function: retracts (adducts) and elevates scapula
serratus posterior superior
origin: lower portion of ligamentum nuchae, spinous processes of C7 to T3, and supraspinous ligaments
insertion: upper border of ribs II to V just lateral to their angles
innervation: anterior rami of upper thoracic nerves (T2 to T5)
function: elevates ribs 2 to 5
serratus posterior inferior
origin: spinous processes of T11 to L3 and supraspinous ligaments
insertion: lower border of ribs IX to XII just lateral to their angles
innervation: anterior rami of lower thoracic nerves (T9 to T12)
function:depresses ribs IX to XII and may prevent lower ribs from being elevated when the diaphragm contracts
splenius capitis
origin: lower half of ligamentum nuchae, spinous processes of C7 to T4
insertion: mastoid process, skull below lateral one third of superior nuchal line
innervation: posterior rami
function: together—draw head backward, extending neck; individually—draw and rotate head to one side (turn face to same side)
splenius cervicis
origin: spinous processes of T3 to T6
insertion: transverse processes of C1 to C3
innervation: posterior rami
function: together—extend neck; individually—draw and rotate head to one side (turn face to same side)
illiocostalis lumborum
origin: sacrum, spinous processes of lumbar and lower two thoracic vertebrae and their supraspinous ligaments, and the iliac crest
insertion: angles of the lower six or seven ribs
innervation: posterior rami
function: extend and laterally flex trunk
illiocostalis thoracis
origin: angles of the lower six ribs
insertion: angles of the upper six ribs and the transverse process of C7
innervation: posterior rami
function: extend and laterally flex trunk
illiocostalis cervicis
origin: angles of ribs III to VI
insertion: transverse processes of C4 to C6
innervation: posterior rami
function: extend and laterally flex neck
longissimus thoracis
origin: blends with iliocostalis in lumbar region and is attached to transverse processes of lumbar vertebrae
insertion: transverse processes of all thoracic vertebrae and just lateral to the tubercles of the lower nine or ten ribs
innervation: posterior rami
function: extend and laterally flex trunk
longissimus cervicis
origin: transverse processes of upper four or five thoracic vertebrae
insertion: transverse processes of C2 to C6
innervation: posterior rami
function: extend and laterally flex neck
longissimus capitis
origin: transverse processes of upper four or five thoracic vertebrae and articular processes of lower three or four cervical vertebrae
insertion: posterior margin of the mastoid process
innervation: posterior rami
function: extend, rotate, and laterally flex head
spinalis thoracis
origin: spinous processes of T10 or T11 to L2
insertion: spinous processes of TI to TVIII (varies)
innervation: posterior rami
function: extend and laterally flex trunk
spinalis cervicis
origin: lower part of ligamentum nuchae and spinous process of CVII (sometimes T1 to T2)
insertion: spinous process of C2 (axis)
innervation: posterior rami
function: extend and laterally flex neck
semispinalis thoracis
origin: transverse processes of T6 to T10
insertion: spinous processes of upper four thoracic and lower two cervical vertebrae
innervation: posterior rami
function: extend and rotate trunk
semispinalis cervicis
origin: transverse processes of upper five or six thoracic vertebrae
insertion: spinous processes of C2 (axis) to C5
innervation: posterior rami
function: extend and rotate neck
semispinalis capitis
origin: transverse processes of T1 to T6 (or T7) and C7 and articular processes of C4 to C6
insertion: medial area between the superior and inferior nuchal lines of occipital bone
innervation: posterior rami
function: extend and rotate head
multifidus
origin: sacrum
insertion: base of spinous processes of all vertebrae from L5 to C2 (axis)
innervation: posterior rami
function: extend neck and trunk; stabilize vertebral column
rotatores lumborum
origin: transverse processes of lumbar vertebrae
insertion: spinous processes of lumbar vertebrae
innervation: posterior rami
function: extend and rotate trunk; stabilize vertebral column
rotatores thoracis
origin: transverse processes of thoracic vertebrae
insertion: spinous processes of thoracic vertebrae
innervation: posterior rami
function: extend and rotate trunk; stabilize vertebral column
rotatores cervicis
origin: articular processes of cervical vertebrae
insertion: spinous processes of cervical vertebrae
innervation: posterior rami
function: extend and rotate trunk; stabilize vertebral column
levatores costarum
origin: short paired muscles arising from transverse processes of C7 to T11
insertion: the rib below vertebra of origin near tubercle
innervation: posterior rami
function: contraction elevates rib
interspinales
origin: short paired muscles attached to the spinous processes of contiguous vertebrae, one on each side of the interspinous ligament
insertion: spinous process
innervation: posterior rami
function: postural muscles that stabilize adjoining vertebrae during movements of vertebral column
intertransversarii
origin: small muscles between the transverse processes of contiguous vertebrae
insertion: transverse process
innervation: posterior rmai
function: postural muscles that stabilize adjoining vertebrae during movements of vertebral column
rectus capitis posterior major
origin: spinous process of axis (C2)
insertion: lateral portion of occipital bone below inferior nuchal line
innervation: posterior ramus of C1
function: extension of head; rotation of face to same side as muscle
rectus capitis posterior minor
origin: posterior tubercle of atlas (C1)
insertion: medial portion of occipital bone below inferior nuchal line
innervation: posterior ramus of C1
function: extension of head
obliquus capitis superior
origin: transverse process of atlas (C1)
insertion: occipital bone between superior and inferior nuchal lines
innervation: posterior ramus of C1
function: extension of head and bends it to same side
obliquus capitis inferior
origin: spinous process of axis (C2)
insertion: transverse process of atlas (C1)
innervation: posterior ramus of C1
function: rotation of face to same side
