week 1 Spinal cord and spinal pathway Flashcards
how many cervical verterbrae?
7
how many thoracic verterbrae?
12
how many lumbar verterbrae?
5
how many sacral verterbrae?
5
how many cocygeal verterbrae?
1-4
how many cervical spinal nerves are there?
- 1 more than the amount of cervical verterbrae
where does the phrenic nerve arise from?
C3,4,5
where does the 1st cervical nerve run?
below the base of the skull and above the the 1st cervical vertebrea
do all spinal nerves run above there corresponding verterbrea?
no only cervical vertebrae 1-7 do
At what point do the spinal nerve run below there corresponding verterbea?
from C8 as that runs over T1 vertebrea. Therefore T1 spinal nerve is underneath T1 vertebrea. Undreneath the pedicles
where exactly does spinal nerve C2 to C7 arise?
above the corresponding pedicle. So C2 spinal nerve above pedical of C2 vertebrea
What occurs at C8?
transition in nomeclatures of nerves?
On the spinal column there is two enlargements where?
Cervical and lumbar enlargments
why are there enlargments at the cervical and lumbar region?
Brachial plexus form at the cervical
Sciatic nerves form at the lumbar region.
Need to be enlarged as more and larger nerves are being formed
what type of information does dorsal rootlets contain?
sensory
what type of information does sensory rootlets contain?
motor
what is the name of the tip of the spinal column?
conus medullaris
at what verterbral level is the tip of spinal column? (conus medullaris )
L1/L2
what is Cauda equina?
bundle of rootlets that carry on from the conus medullaris.
what is Filum terminale?
fine thread of pia matter–> remnant of the spinal cord
is the dura matter one layer or double in the spinal cord?
there is no periosteal layer just a meningeal layer
describe the structure of the dura matter?
Tough, fibrous “sleeve”, separated from bone by fat-filled epidural (extra) space
- Only one layer, unlike double layer around brain
describe the structure of the Arachnoid mater
Thin, delicate layer pressed against dura by CSF
describte the structure of Pia matter?
Thin layer attached to surface of cord
Forms flat denticulate ligaments
how does CSF surround the spinal cord?
CSF enters subarachnoid space around cord by leaving the apertures of the ventricular system – lateral and median
what happens to the periosteal layer surrounding the brain?
it becomes the periosteum of the skull
what does subdural space seperate?
arachanoid matter and dura matter
what are denticulate ligament ?
they are extensions of the pia matter laterally that attach to the vetebral canal for stability and prevents rotation of the spinal cord.
Blend with the arachanoid matter
what do dorsal root ganglion contain?
primary sensory fibres–> long axon to the ganglion then short to the CNS
what is the relationship between the dura matter and the ventral/dorsal rootlets?
they do not pierce the dura but become covered by the dura for protection
does epidural pass through the dura?
no it does not specific to that spinal root
does spinal pierce through the dura?
yes it does so can affect all the spinal nerves –> depending on the patients position depends where in the spinal colunmn is affected
what does Cauda equina contain?
Dorsal and ventral roots of lower lumbar, sacral and coccygeal segmental spinal nerves
where is lumbar puncture done?
at the cauda equina –> withdraw CSF
why is it safe to do lumbar puncture at the cauda equina?
there is no spinal cord there
when a fetus what is the relationship of the spinal cord to the verterbal column?
the spinal cord runs along the primitive vertebral column
how does the positioning of the spinal cord to the verterbal column change with time?
verterbral column grow faster than spinal column and also you straighten up so at birth the spinal cord is shorter than the vertebral column –> level L3 –> at adult hood goes to L1/2