Flashcards in Spine & Spinal Cord Deck (23):
At what vertebral level does the hyoid bone lie? Which bones does it articulate with?
- the hyoid bone sits at the C3 level
- it does NOT directly articulate with any other bones
What passes through the transverse foramina of cervical vertebrae?
- the vertebral arteries
What part of axis (C2) allows for axial rotation between C1 and C2?
- the odontoid peg (the dens)
What are the four natural curves in the vertebral column? Which are primary curves and which are secondary?
- cervical lordosis (a secondary curve)
- thoracic kyphosis (a primary curve)
- lumbar lordosis (a secondary curve)
- sacral kyphosis (a primary curve)
What is the normal number of vertebrae?
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 fused sacral
- 4 fused coccygeal
What are the major general features of a vertebrae?
- vertebral arch w/ 1 spinous and 2 transverse processes; superior and inferior articular processes
- vertebral foramen (forms the vertebral canal)
- vertebral body
- inferior and superior vertebral notches (these form the intervertebral foramina from which the spinal nerves exit)
What are the parts of an intervertebral disc?
- a gel-like nucleus pulposus surrounded by a tough capsule (the anulus fibrosus)
- (note that only the outer 1/3 of the anulus fibrosus is innervated)
What are joints involving adjacent vertebrae (via their articular processes) called?
- zygapophysial joints
What are the major defining characteristics of the cervical vertebrae?
- small body
- vertebral foramen is large and triangular
- *C1-C6 have bifid spinous processes*
- *presence of transverse foramina* (for the vertebral arteries to ascend through)
What are the major defining characteristics of the thoracic vertebrae?
- large heart shaped body
- vertebral foramen is more round
- spinous processes are long and slender
- *costal/rib facets on the body and transverse processes*
What are the major defining characteristics of the lumbar vertebrae?
- very large kidney shaped body
- vertebral foramen is triangular
- large spinous processes
- long, slender transverse processes
- *lack of unique features of the other vertebrae*
What are the major features of C1 and C2?
- C1 (atlas): lack of a body; fovea for articulation of C2's dens; articular surfaces for the occipital bone (for nodding)
- C2 (axis): dens (odontoid peg) for articulation with C1 (for rotating head)
What are the major features of the sacrum?
- S1's ala (superior surface) with the auricular surfaces
- fusion of the spinous processes into the median sacral crest
- sacral foramina (no longer called vertebral foramina)
- sacral canal and sacral hiatus (found on posterior side)
Which major ligaments are involved in the atlantoaxial joint?
- apical ligament (between C2 and occipital)
- alar ligaments (between C2 and foramen magnum)
- *transverse ligament* (forms part of the cruciate ligament)
Which major ligaments are involved in forming the vertebral column?
- anterior longitudinal ligament
- posterior longitudinal ligament
- ligamentum flavum
- interspinous ligament
- supraspinous ligament
- ligamentum nuchae (posterior aspect of cervical vertebrae only)
Back muscles are also known as what? How many layers of these muscles are there?
- post-vertebral muscles; 3 layers
- deep layer containing the true intrinsic back muscles
- intermediate layer (serratus posterior, rhomboids)
- superficial layer (trapezius, latissimus dorsi)
What is the superficial layer of the deep intrinsic back muscles made up of? Which muscle lies at the upper end of this layer?
- superficial (of deep): erector spinae muscles (most superior is the splenius capitis)
- (these muscles run straight and longitudinally)
- these are the extensors of the spine
What is the largest group of muscles making up the deep layer of the deep intrinsic back muscles?
- deep layer (of deep): multifidus
- (these muscles run obliquely)
- these are the rotators of the spine
At what vertebral level does the spinal cord end? What structures arise at its termination?
- ends at L1/L2 (tapered end part is the conus medullaris)
- from here meninges and spinal nerves continue to form the cauda equina
- additionally, the thin filum terminale (made up of pia mater) extends to the coccyx
What is the blood supply to the spinal cord?
- the single median anterior spinal cord and the bilateral posterior spinal arteries
What is a denticulate ligament?
- a ligamentous structure connecting the pia mater and arachnoid mater
- a denticulate ligament is found between the dorsal and ventral spinal roots at each level
What muscles are involved in the sub-occipital triangle?
- (these muscles are just deep to the splenius capitus)
- lateral border: obliquus capitis superior
- inferior border: obliquus capitis inferior
- medial border: rectus capitilis posterior major and minor (major is INFERIOR to minor)