Vertebral Column and Spinal Cord Flashcards
Number of vertebrae in each area of the vertebral column?
7 Cervical (C1-C7) 12 Thoracic (T1-T12) 5 Lumbar (L1-L5) 5 Sacral (S1-S5) - fused into sacrum 4 Coccygeal (Co) fused into one coccyx
roles of the subdivisions of the vertebral arch?
Pedicle - attaches transverse process to body of vertebra
Lamina - attaches transverse process to spinous process
Paired sup. and inf. articular processes and notches
Spinous and transverse processes - for attachment of muscles and ligaments
Distinctive feature(s) of the cervical vertebrae?
Transverse foramen
bifid spinous process on C2
smalles of the movable vertebrae
What passes through the transverse foramen?
The vertebral vessels (artery + vein)
Sympathetic nerve plexuses
Describe what makes C1 and C2 atypical vertebrae?
C1 (atlas) - facets for articulation with occipital condyle
- facet for dens of C2
- NO vertebral body
- NO intervertebral disc between C1 and C2
C2 (Axis) - 2 large flat surfaces, upon which atlas rotates
- superiorly protruding Dens (odontoid process), held in place by transverse ligament of atlas
Distinguishing features of thoracic vertebrae?
2 demi-facets on each side of vertebral body for articulation with head of their own rib and the rib below
transverse process also has facet for articulation with tubercle of the rib
vertebral canal/body more heart shaped
spinous process is long and extends postero-inferiorly
Distinguishing features of lumbar vertebrae?
Much larger in size
no facets for articulation with ribs
vertebral canal triangular
L5 has large thick stocky spinous process for attachment of iliolumbar ligaments
What holds vertebrae together?
Facet joints
Intervertebral discs
Ligaments
What are facet joints?
aka ZYgapophyseal joints
connect superior and inferior articular processes of adjacent vertebrae
Role and components of intervertebral discs?
provide flexibility to the spine
act as shock absorbers
Peripherally - Annulus Fibrosus (outer ring of collagen and fibrocartilage)
Centrally - Nucleus Pulposus (gelatinous to absorb compression forces between vertebrae)
How many joints does a typical vertebrae have?
6 Joints
- 4 articular - 2 above, 2 below
- 2 symphyses - one above, one below between discs
Ligaments binding together the vertebral column?
Anterior Longitudinal Ligament Posterior Longitudinal Ligament Ligamentum Flavum Ligamentum Nuchae Interspinous ligaments
Description of Anterior Longitudinal Ligament?
runs down anterior surface of vertebral column
from inferior occipital to sacrum
holds together verteral bodies and intervertebral discs
broadens as it descends
Description of Posterior Longitudinal Ligament?
runs down posterior surface of vertebral column, along bodies
from back of axis (c2) to back of sacrum
narrows as it descends
holds together vertebral bodies and intervertebral discs
Description of Ligamentum Flavum?
Extends from lamina to lamina of same vertebrae from C2 to first segment of sacrum aids in preservation of upright posture very elastic so aids in bending back up prevents spinal cord from buckling
Description of Ligamentum Nuchae?
from external occipital protruberance to spinous process of C7
aids in sustaining the weight of the head
helps in running
Description of interspinous ligaments?
Connect adjacent spinous processes
extend from root to apex of each spinous process
limit flexion of the spine
At what vertebral level does the spinal cord end in:
- the newborn?
- the adult?
Newborn - L3/L4
Adult - L1/L2
Contents of the subdural space?
It is a potential space and so doesn’t contain anything
Contents of the subarachnoid space?
CSF
Trabeculae - interconnect arachnoid mater and pia mater
- thin delicate strips of tissue
- blood vessels suspended from these (spinal arteries)
Contents of the epidural space?
Lymphatics loose connective tissue fat venous plexuses spinal nerve roots
Blood supply of the spinal cord?
1 anterior and 2 posterior spinal arteries
origin of the spinal arteries?
Anterior spinal artery (ASA) - arises from branches of vertebral arteries and travels along anterior aspect of the spinal cord
Posterior Spinal Ateries (PSA) - also vertebral arteries, adjacent to medulla oblongata
Both are reinforced by radicular branches of intercostal and lumbar arteries
Describe the venous drainage of the spinal cord?
Two channels run longitudinally in anterior and posterior sulci
via medullary and radicular veins these drain into internal venous plexus in epidural space
this drains into SVC
Describe how the spinal nerves exit the spinal cord
Spinal nerves from C1-7 leave the vertebral column above their corresponding vertebrae
- 7 vertebrae but 8 nerves, as C8 leaves below C7, but above T1
From T1 and below the rest leave below their corresponding vertebrae
What is the cauda equina?
Formed from dorsal and ventral spinal nerve roots caudal to the spinal cord termination at T1
consists of L2-L5, S1-S5 and coccygeal nerve
all emerge from lumbar enlargement
