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
What are the cutaneous nerves that go under the suboccipital triangle?
Greater occipital, lesser occipital, and the great auricular
Spinal cord protective layers order.
- ) Soft tissue around vertebral column (skin, muscles/tendons, ligaments)
- )Vertebral canal (aligned vertebral foramen of cervical, thoracic, lumbar, and sacral vertebra
- )Meninges and spaces between meninges
What is the order of all the mininges and spaces between meninges?
- Epidural space- lipid filled space between wall of vertebral canal and dura mater
- Dural mater- connectice tissue membrane covering of spinal cord from foramen magnus to sacral hiatus
- Subdural space- dura-arachnoid interface: potential space filled with interstitial fluid
- Arachnoid mater- connective tissue membrane (thinner than dura mater) covering the spinal cord, roots, and dorsal root ganglion
- Subarachnoid space- between arachnoid and pia mater; filled with CSF; also contains connective tissue trabeculae connecting arachnoid and pia maters
- Pia Mater- thin translucent covering adhering to spinal cord
2 parts of pia mater:
- denticulate ligaments- lateral sheets of pia running from sacrum to foramen magnus attaching laterally to arachnoid to hold spinal cord in place
- filum terminale- inferior continuation of pia connectiong the conus medullaris to the coccyx
The spinal cord runs from the _______ and ends in the ________. It occupies ___ of the vertebral column.
Foramen magnum, conus medullaris
2/3
Where is the cord enlarged and why?
Enlarges in the cervical and lumbosacral region becuase this is where it carries more neurons to form the brachial and lumbosacral plexi.
On both the right and left side of the spinal cord, a ______ and ________ exit the spinal cord and fuse to form the proximal ____________.
dorsal root, ventral root
spinal nerve
Spinal nerves exit the vertebral column through what?
Intervertebral foramen
Spinal nerves divide distally into what?
Ventral and dorsal rami
How many spinal cord segments are there?
31 pairs (62 total spinal nerves)
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
What is the cuada equina?
Structure in lumbosacral vertebral canal consisting of roots from lumbosacral spinal cord segments
What is the filum terminal?
continuation of pia mater attaching conus medullaris to coccyx
What are the main arteries supplying the cord?
a. )vertebral, subclavian arteries- supply the cervical spinal cord
b. ) intercostals arteries- supply thoracic spinal cord
c. ) lumbar arteries- supply lumbar spinal cord
d. ) lateral sacral arteries- supply the sacral spinal cord
What are the segmental branches from the main arteries?
a. )anterior spinal artery
b. )2 posterior spinal arteries
What are the veins?
They follow the distribution and nomenclature of arteries
