Vertbral Column & Spinal Cord Flashcards
What are the 3 Atlanto-axial joints?
Movement at all three Atlanta-axial joints. Permits the head to be turned from the side to side to indicate disapproval (the ‘no’ movement). Here, the cranium and C1 rotate as a unit over C2. When the head rotates to the side, the dens of C2 is the axis point or pivot that is held in a socket formed anteriorly by the anterior arch of the atlas and posteriorly by the TRANSVERSE LIGAMENT OF THE. ATLAS
What is the transverse ligament of atlas?
This ligament is a thick, strong band, which arches across the ring of the atlas, and surrounding the odontoid process at this bone articulates with the atlas
Where are the superior and inferior ligaments bands of the Cruciate ligament?
These pass from the transverse ligament to the occipital bone superiorly and inferiorly to the bidy of C2
Describe ligament support for atlas and axis
Cruciate ligament- hold dens in place during rotation of the head. Has 3 bands
Alar ligaments- laterally from dens to skull
Apical ligaments- is deep to the Cruciate ligament, attaching the dens to the skull
Contrast primary and secondary curvature development on the spinal cord
Primary curvature- they develop during the fetal period in relaxation to the (flexed) fetal position
Secondary curvature- they result from extension from the flexed fetal position and are maintained by the differences in thickness between anterior and posterior parts of IV discs. Control of head (1-2 months), sitting at about 6 months and walking about 1 year old
What is kyphosis?
Hunchback
Is an abnormal increase in thoracic curvature, leading to a posterior protrusion of the vertebral column
What is lordosis?
Is characterized by an anterior tilting of the pelvis (the upper sacrum is flexed or rotate antero-inferiorly) with increased inward curve of the spine
What is scoliosis?
Common in young adults - is characterized by an abnormal lateral curvature that is accompanied by rotation of the vertebrae
What is the spinal cord?
- Part of the CNS
- zconduction pathway between body and brain
- protected by vertebral column, meninges and CSF
What are the enlargements of the spinal column?
Cervical and lumbosacral
What is the cauda equina?
Segment of the spinal cord that continues into lumbar cistern
What are the spinal nerves?
31 of them
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
What are the main sources of arterial blood to the spinal cord?
Longitudinal artery- originate from vertebral artery
Location:one anterior, two posterior
Describe the segmental blood supply to the spinal cord
Feeder arteries enter through the IV Foramina
Originate from body wall arteries at each segment of the spinal cord
Two types:
-Segmental medullary arteries which anastomose with the longitudinal spinal arteries
-Segmental Radicular branches that supply the dorsal and ventral roots
Explain the significance of the Artery of Adamkiewicz for blood supply to the spinal cord
- Great anterior segmental medullary artery (Artery of Adamkiewicz)
- Largest segmental medullary artery
- Arises from the lower thoracic or upper lumbar region
- Important source of blood supply to lower lumbar and sacral roots (conus medullaris) of the spinal cord8
The spinal cord may suffer circulatory impairment if there is damage to segmental medullary arteries
Artery of Adamkiewicz is important for…
Circulation to lumbar & sacral parts of the spinal co4d
What veins drain the spinal cord?
Anterior and posterior spinal cord veins
What is the significance of Baston’s plexus?
Spinal veins drain into internal vertebral (Batson’s). plexus
-located in the epidural space
- communicates with pelvic veins dural venous sinuses of the cranial vault and external vertebral venous plexus
- can serve as collateral pathway For venous flow to systemic vein (caval & azygos veins)
- vessels are valveless so blood, and thus infection or metastases of tumors may travel from the pelvic region to vertebrae and to the cranial vault . The reverse is also possible
What is the spinal meninges function?
Protective membranes covering the spinal cord
Continuous with cranial meninges covering the brain
What are the layers of the spinal cord?
- Dura mater(tough mater)- subdural space(potential space)
- Arachnoid mater (spider web )- subarachnoid space (actual space containing CSF )
- Pia mater- (gentle mater)
Where is the epidural space?
Surrounds the dura mater and contains spinal nerve roots, loose fatty tissue, small arteries , and the internal vertebral venous plexus of batson
What is the dural sac?
Dural sac/lumbar cistern- contains cauda equina (dorsal & ventral roots of spinal nerves), filum terminale and CSF
What are denticulate ligaments?
21 pairs of fibrous strips of pia mater that extends from the craniovertebral junction to T12 (superior fibers), and inferior fibers run from conus medullaris to T12 and L1
Each ligament features 18- 20 triangular extensions of pia mater that attach to the dura at their apices
What is the function of denticulate ligaments?
Separates the ventral and dorsal rootlets from each other and helps to hold the spinal cord
What is a lumbar puncture?
Procedure to draw out CSF from the lumbar cistern for diagnostic and/or therapeutic reasons
Site for an adult- between L3/L4 or L4/L5
approaches -median and paramedian
What is the site for lumbar puncture in children?
L4/L5 for LP in children
How to prepare for a lumbar puncture ?
The skin covering the lower lumbar vertebrae is anesthetizes and a lumbar puncture needle is inserted in the midline between the spinous processes of L4 and L5 at the supracristal line
After 4-6 cm the needle pops through the Ligamentum flavum and then “pops” again when penetrates the dura to enter the lumbar cistern
Lumbar puncture is not performed in the presence of increased intracranial pressure
What are the layers through which a needle must pass through for a lumbar puncture?
Midline approach
- skin
- subcutaneous tissue
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space
Dura mater
Arachnoid mater
Subarachnoid mater
