Spinal Cord and Meninges Flashcards
What do spinal roots form?1
Spinal nerves.
What are the lateral structures of the vertebrae?
The intervertebral foramen and pedicle.
What are the anterior structures in the vertebrae?
Vertebral body, the intervertebral disc and the posterior longitudinal ligament.
What are the posterior structures in the vertebrae?
Spinous process, the lamina and the ligamentum flavum.
What connects the inferior articular and superior articular facets?
The zygapophysial joint.
What is the ligament that runs down the posterior of the vertebral column?
The supraspinous ligament.
What ligament lies between the spinous processes of the vertebra?
The interspinous ligament.
What is in the middle of the intervertebral disc?
The nucleus pulposus.
What is on the edge of the intervertebral disc?
The anulus fibrosus.
Where does the spinal cord begin?
Begins at the foramen magnum of skull as a continuation of the medulla.
Where does the spinal cord end?
At L1/2 vertebrae in adults.
What is the inferior end of the spinal cord known as?
The conus medullaris that narrows as the filum terminale.
.Where is the cervical enlargement?
Between C4-T1.
What does the cervical enlargement contribute to?
The brachial plexus.
What is the brachial plexus?
The network of nerves that sends signals from the spinal cord to the shoulder, arm and hand.
Where is the lumbosacral enlargement?
Between T11-S1.
What does the lumbosacral enlargement contribute to?
The lumbosacral plexus.
Where does the spinal cord end in neonates?
At L3 vertebra.
Why is the vertebral column longer than the spinal cord?
The vertebral column grows faster than the spinal cord.
Where do the spinal nerves emerge from?
The intervertebral foramina.
What is the order of the spinal vertebrae?
CTLSC.
From top to bottom how many of each spinal nerves are there?
8, 12, 5, 5 and 1.
What forms roots?
Rootlets converge to become roots.
What do the ventral and dorsal roots become?
The spinal nerve.
What does the spinal nerve divide into?
The ventral and dorsal rami (mixes motor and sensory fibres).
Which nerves are found in the ventral roots?
Motor (efferent) neurons.
Which nerves are found in the dorsal roots?
Sensory (afferent) neurons
What do dorsal and ventral mean?
Posterior and anterior.
Where does C1 emerge from?
Between the occipital bone of the skull and C1 (atlas)
Where does the C3 nerve pass out?
Between C2 and C3.
Where do the lumbar, sacral and coccygeal spinal nerve roots pass?
Down the vertebral canal to their own intervertebral foramen before exiting the canal.
What does the lower 1/3rd of the vertebral canal contain?
The roots of the above spinal nerves as well as the filum terminale.
Where do the lower spinal segments of the spinal cord lie?
Adjacent to a vertebrae that is above their own level.
Adjacent to a vertebrae that is above their own level.
1.
What are the layers of the cranial dura?
Outer periosteal layer and inner meningeal layer.
What is the dura mater called as it descends through the vertebral canal?
The dural sac and does not attach to bone.
What happens to the dural sac at the lower border of S2?
It narrows and fuses with the filum terminale and eventually with the coccyx.
What does the dura mater cover in the nervous system?
The roots of spinal nerves as they pass through the intervertebral foramina.
Where is the arachnoid mater in the spinal canal?
Lies deep to the dura and also ends at lower border of S2
How does the arachnoid mater connect to the pia mater?
Via arachnoid trabeculae.
What does the subarachnoid space in the spinal canal contain?
CSF and blood vessels supported by spider-like fibres.
What does the arachnoid mater enclose in the lumbar cistern?
The caudal equina
What does the pia mater become in the spinal canal?
The filum terminale at the inferior end of the spinal cord which attaches to the coccyx.
What are the triangular extensions of pia mater called?
Denticulate ligaments.
What are denticulate ligaments called?
Are laterally attached to the arachnoid mater in the dural sac and suspend the spinal cord.
What does the pia mater cover in the spinal canal?
spinal canal?
Surface of the spinal cord and spinal roots.
Where does the extradural (epidural) space lie?
extradural (epidural) space lie?
From foramen magnum to the sacral hiatus.
Where is the extradural space positioned?
Internal to the periosteum.
What does the extradural space contain?
Internal vertebral venous plexus.
What are the 2 sets of arteries that supply the spinal cord?
The 3 longitudinal arteries and the numerous segmental spinal arteries.
What do the longitudinal arteries branch from?
The subclavian artery.
What do the segmental spinal arteries branch from?
The aorta.
Where do the longitudinal arteries lie?
On the surface of the spinal cord.
Where are the segmental spinal arteries?
Enter vertebral canal via the intervertebral foramina at every level.
What do the longitudinal arteries divide into?
2 paired posterior spinal arteries and 1 anterior spinal artery.
Where do the paired posterior spinal arteries arise from?
Vertebral arteries and posterior inferior cerebellar arteries.
Where does the anterior spinal artery arise from?
Vertebral arteries.
Where does the anterior spinal artery sit?
In anterior median fissure and gives of sulcal arteries.
Where are the vertebral arteries positioned?
Ascend in the neck via the foramina transversaria of the cervical vertebrae.
Where do the vertebral arteries branch?
At approximately the level of the foramen magnum.
What do segmental spinal arteries give off?
Segmental medullary arteries.
What does the cervical region arise from?
Predominantly the vertebral arteries.
Where does the thoracic region arise from?
Predominantly the posterior intercostal arteries.
Predominantly the posterior intercostal arteries.
Predominantly the lumbar arteries.
What is the danger with venous connections in the spinal canal?
They allow the metastatic spread of tumours to vertebral bodies
What is the function of the longitudinal channels on the surface of the spinal cord?
No valves and blood flows in either direction.
Where does the internal vertebral venous plexus lie?
In the extradural fat of extradural space.
What is the function of the external vertebral venous plexus?
Drains medullary cavity of vertebral bodies and connects to segmental veins.
Which plexuses surround the vertebrae?
The anterior and posterior external vertebral venous plexuses.
Which plexus lies within the vertebral canal?
The internal vertebral plexus.
What are the layers that a lumbar puncture go through?
Skin, superficial fascia, supraspinous ligament, interspinous ligament, ligamentum flavum, extradural space, dura mater, arachnoid mater and subarachnoid space.
Where is a lumbar puncture performed?
Between L3/L4 or L4/L5.
Why is the lumbar puncture performed where it is?
Spinal cord ends at L1/2 in adults and cauda equina nerve roots suspend in CSF.
