Muscles of Back Region Flashcards
erector spinae origin
iliac crest, sacrum, transverse and spinous processes of vertebrae and supraspinal ligament
erector spinae insertion
angles of the ribs (illiocostalis), transverse and spinous processes of vertebrae (longissiums), posterior aspect of the skull (spinalis)
erector spinae action
extends and laterally bends the trunk, neck and head
erector spinae innervention
segmentally innervated by dorsal primary rami of spinal nerves C1-S5
erector spinae artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
erector spinae notes
the erector spinae m. is separated into 3 columns of muscle: iliocostalis laterally, longissimus in an intermediate position and spinalis medially; each of these columns has multiple named parts
iliocostalis origin
iliac crest and sacrum
iliocostalis insertion
angles of the ribs
iliocostalis action
extends and laterally bends the trunk and neck
iliocostalis innervation
dorsal primary rami of spinal nerves C4-S5
iliocostalis artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
iliocostalis notes
the most lateral part of the erector spinae; it may be subdivided into lumborum, thoracis and cervicis portions
interspinales origin
upper border of spinous process
interspinales insertion
lower border of spinous process above
interspinales action
extend trunk and neck
interspinales innervation
dorsal primary rami of spinal nerves C1-L5
interspinales artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
interspinales notes
these are small and fairly insignificant muscles
intertransversarii origin
upper border of transverse process
intertransversarii insertion
lower border of transverse process above
intertransversarii action
laterally bend trunk and neck
intertransversarii innervation
dorsal primary rami of spinal nerves C1-L5
intertransversarii artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
intertransversarii notes
these are small and fairly insignificant muscles
longissimus origin
transverse process at inferior vertebral levels
longissimus insertion
transverse process at superior vertebral levels and mastoid process
longissimus action
extends and laterally bends the trunk, neck and head
longissimus innervation
dorsal primary rami of spinal nerves C1-S1
longissimus artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
longissimus notes
the intermediate part of the erector spinae;it may be subdivided into thoracis, cervicis and capitis portions
multifidus origin
sacrum, transverse processes of C3-L5
multifidus insertion
spinous processes 2-4 vertebral levels superior to their origin
multifidus action
extend and laterally bend trunk and neck, rotate to opposite side
multifidus innervation
dorsal primary rami of spinal nerves C1-L5
multifidus artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
multifidus notes
semispinalis, multifidus and rotatores make up the transversospinal muscle group
rotatores origin
transverse processes
rotatores insertion
long rotatores: spines 2 vertebrae above origin; short rotatores: spines 1 vertebrae above origin
rotatores action
rotates the vertebral column to the opposite side
rotatores innervation
dorsal primary rami of spinal nerves C1-L5
rotatores artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
rotatores notes
semispinalis, multifidus and rotatores make up the transversospinal muscle group
semispinalis origin
transverse processes of C7-T12
semispinalis insertion
capitis: back of skull between nuchal lines; cervicis & thoracis: spines 4-6 vertebrae above origin
semispinalis action
extends the trunk and laterally bends the trunk, rotates the trunk to the opposite side
semispinalis innervation
dorsal primary rami of spinal nerves C1-T12
semispinalis artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
semispinalis notes
three parts are named based on their insertions: capitis, cervicis and thoracis; semispinalis, multifidus and rotatores make up the transversospinal muscle group
serratus posterior inferior origin
thoracolumbar fascia, spines of vertebrae T11-T12 and L1-L2
serratus posterior inferior innervation
ribs 9-12, lateral to the angles
serratus posterior inferior action
pulls down lower ribs
serratus posterior inferior innervation
branches of the ventral primary rami of spinal nerves T9-T12
serratus posterior inferior artery
lowest posterior intercostal a., subcostal a., first two lumbar aa.
serratus posterior inferior notes
a respiratory muscle, it receives ventral ramus innervation; embryonically related to the intercostal muscles, not the deep back mm.
serratus posterior superior origin
ligamentum nuchae, spines of vertebrae C7 and T1-T3
serratus posterior superior insertion
ribs 1-4, lateral to the angles
serratus posterior superior action
elevates the upper ribs
serratus posterior superior innervation
branches of the ventral primary rami of spinal nerves T1-T4
serratus posterior superior artery
posterior intercostal aa. 1-4
serratus posterior superior notes
a respiratory muscle, it receives ventral ramus innervation; embryonically related to the intercostal muscles, not the deep back mm.
spinalis origin
spinous processes at inferior vertebral levels
spinalis insertion
spinous processes at superior vertebral levels and base of the skull
spinalis action
extends and laterally bends trunk and neck
spinalis innervation
dorsal primary rami of spinal nerves C2-L3
spinalis artery
supplied segmentally by: deep cervical a., posterior intercostal aa., subcostal aa., lumbar aa.
spinalis notes
most medial part of the erector spinae; may be subdivided into thoracis, cervicis and capitis portions
splenius capitis origin
ligamentum nuchae and spines of C7-T6 vertebrae
splenius capitis insertion
mastoid process and lateral end of the superior nuchal line
splenius capitis action
extends and laterally bends the neck and head, rotates head to the same side
splenius capitis innervation
dorsal primary rami of spinal nerves C2-C6
splenius capitis artery
supplied segmentally by: deep cervical a., posterior intercostal aa.
splenius capitis notes
named for its shape: splenius means bandage and capitis refers to the insertion of this portion of the muscle
splenius capitis origin
ligamentum nuchae and spines of C7-T6 vertebrae
splenius capitis insertion
mastoid process and lateral end of the superior nuchal line
splenius capitis action
extends and laterally bends the neck and head, rotates head to the same side
splenius capitis innervation
dorsal primary rami of spinal nerves C2-C6
splenius capitis artery
supplied segmentally by: deep cervical a., posterior intercostal aa.
splenius capitis notes
named for its shape: splenius means bandage and capitis refers to the insertion of this portion of the muscle
splenius cervicis origin
ligamentum nuchae and spines of C7-T6 vertebrae
splenius cervicis insertion
posterior tubercles of the transverse processes of C1-C3 vertebrae
splenius cervicis action
extends and laterally bends neck and head, rotates head to the same side
splenius cervicis innervation
dorsal primary rami of spinal nerves C2-C6
splenius cervicis artery
supplied segmentally by: deep cervical a., posterior intercostal aa.
splenius cervicis notes
named for its shape: splenius means bandage and cervicis refers to the insertion of this portion of the muscle