Deep Back Muscles and Spinal Cord Flashcards
What are the superficial/ extrensic back muscles and what are they innervated by?
Trapezius, Latissimus Dorsi, Rhomboids, Levator Scapulae
Innervated by ventral rami
What are the intermediate extrensic back muscles?
They play a role in what?
They are innervated by what?
- Serratus posterior superior/ inferior
- They play a role in proprioception
- Innervated by intercostal nerves (ventral rami)
The intrinsic back muscles are innervated by what?
They also act to _______________ and have what actions?
- Innervated by dorsal rami
- maintain posture and extend, ab/adduct, and rotate the vertebral column
The intrinsic back muscles unilaterally do what and bilaterally do what?
- Ab/adduct, rotate
- Extend
The intrinsic back muscles cumulatively attach from the ______ to the ______.
Pelvis to the skull
What are the muscles of the superficial intrinsic back muscles and what are their attachments?
Splenius Capitis:
-Attachment: Nuchal ligament→ mastoid process of temporal bone
Splenius Cervicis:
-Attachment: Upper thoracic→ transverse process of C1 and C2
What are the actions of splenius capitis and cervicis and what are they innervated by?
Extend, rotate, and abducts neck
Innervated by dorsal rami
What are the muscles of the intermediate intrinsic back muscles?
- Iliocostalis (lumborum, thoracic, cervicis)
- Longissimus (thoracic, cervicis, capitis)
- Spinalis (thoracic, cervicis, capitis)
Attachent, Action, and Innervation of Iliocostalis?
- Attachment- Pelvis, lumbar spinous process→ribs and lower cervical transverse (post tubercles)
- Actions- extend lumbar and inferior cervical, ab/adduct, and rotate
- Innervation- dorsal rami
Attachment, Action, and Innervation of Longissimus?
- Attachment- Spinous processes of lumbar, transverse processes of thoracic→ costotransverse joint, cervical transverse process, mastoid process
- Action- extend head/cervical, ab/adduct, and rotate
- Innervation- dorsal rami
Attachment, Action, and Innervation of Spinalis?
-Attachment- vertebral column spinous process→ spinous process or cranium
(S or 8 shaped muscle)
-Action- extend head/cervical, ab/adduct and rotate thoracic,cervical,head
-Innervation- dorsal rami
What are the deep intrinsic back muscles?
- Semispinalis (thoracic, cervicis, capitis)
- Multifidus (lumborum, thoracic, cervicis)
- Rotatores (mostly thoracic)
Attachment, Action, and Innervation of the Semispinalis?
- Attachment- lower cervical an thoracic transverse processes→ thoracic, cervical spinous processes and occipital/nuchal lines
- Action- extend cervical/head, ab/adduct and rotate thoracic/cervical/head
- Innervation- dorsal rami
Attachment, Action, and Innervation of the Multifidus?
- Attachment- pelvis, lumbar, thoracic, lower cervical transverse processes→ spinous processes 2-4 segments above
- Action- extend lumbar/cervical, ab/adduct and rotate lumbar/thoracic/cervical
- Innervation- dorsal rami
What is different about the multifidus?
It is the most massive in lumborum lordotic curve.
It also is a series of parallel straps with different proximal and distal attachments that run from sacrum to cervical vertebrae
Attachment, Action, and Innervation of the Rotatores muscle?
- Attachment- transverse process thoracic vertebrae→ spinous process or lamina 1 or 2 segments above
- Action- extend, ab/adduct and rotate thoracic
- Innervation- dorsal rami
What are the minor deep layer muscles of the back and their attachments?
Interspinales: (cervicis, thoracic,lumborum)
-Attachment- spinous p. to spinous p.
Intertransversari: (cervicis, lumborum)
-Attachment- transverse p. to transverse p.
Levatores costarum: (thoracic)
-Attachment- thoracic transverse p. → adjacent rib
What is important about the levatores costarum muscles?
Functions in respiration to assist in lifting the rib cage for inspiration
What is the purpose of the suboccipital muscles?
Postural muscles that work directly or indirectly on the head.
What are the suboccipital muscles innervated by?
Suboccipital nerve dorsal rami C1
What are the suboccipital muscles and their attachments?
Rectus capitis posterior major:
-Attachment- C2 spinous p.→ occipital bone/lateral nuchal line
Rectus capitis posterior minor:
-Attachment- C1 posterior tubercle→ occipital bone/ medial nuchal line
Obliquus capitis inferior:
-Attachment- C2 spinous process→ C1 transverse process
Obliquus capitis superior:
-Attachment- C1 transverse process→ occipital bone/ lateral nuchal line
What muscles make up the suboccipital triangle?
- Rectus Capitis posterior major (superior/medial)
- Obliquus capitis inferior (inferolateral)
- Obliquus capitis superior (superolateral)
What is the floor and the roof of the suboccipital triangle?
Floor-posterior atlanto-occipital membrane
Roof-semispinalis capitis
What are the contents of the suboccipital triangle?
Vertebral artery/vein and suboccipital nerve
