Intrinsic Back & Suboccipitals Lec Flashcards
Intermediate Layer of Back
serratus posterior superior & serratus posterior inferior
Bony Landmarks on Skull
mastoid process, external occipital protuberance, superior nuchal line, inferior nuchal line
Deep Back - Superficial Layer
splenius capitis and cervicis
Which direction do the fibers of the splenius run?
oblique, superiolaterally
Ventral Nerve Roots
motor
Dorsal Nerve Roots
sensory
Ventral Rami
innervate ventral body wall, superficial back, and all limb parts
Dorsal Rami
innervate skin and deep muscles of back
Deep Back - Intermediate Layer
erector spinae group (“paraspinals”)
- iliocostalis, longissimus, spinalis
- chief extensors of the vertebral column
- broken into regions
Erector Spinae Group Directionality
order from most lateral to most medial is iliocostalis, longissimus, and spinalis
Unique Feature of Iliocostalis
only muscle of the erector spinae group to have a lumbar region
Deep Back - Deep Layer
transversospinalis group
- rotatores, multifidus, semispinalis
Back Muscles from Deep to Superficial (Thoracic Region)
rotatores > multifidus > semispinalis > spinalis, longissimus, iliocostalis > serratus posterior inferior > latissimus dorsi, trapezius
Back Muscles from Deep to Superficial (Cervical Region)
suboccipitals > semispinalis > splenius > upper trapezius
4 Suboccipital Muscles
rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, obliquus capitis inferior
Obliquus Capitis Superior
fibers run vertically, so it laterally flexes the neck but does not rotate it
Obliquus Capitis Inferior
does not attach to the skull unlike the other suboccipitals, so it rotates the neck but does not extend it
Rectus Capitis Posterior Major
cervical extension and ipsilateral rotation, spans 2 vertebrae (major)
Rectus Capitis Posterior Minor
cervical extension and ipsilateral rotation, not involved in the suboccipital triangle, spans 1 vertebrae (minor)
Boundaries of Suboccipital Triangle
superomedial: rectus capitis posterior major
superolateral: obliquus capitis superior
inferolateral: obliquus capitis inferior
Aspects of Suboccipital Triangle
floor (deep): posterior atlanto-occipital membrane and posterior arch of C1
roof (superficial): semispinalis capitis
contents: vertebral artery and suboccipital nerve (C1)
Vertebral Artery
runs through the suboccipital triangle and through the transverse foramen of cervical vertebrae
