Spinal cord + nerves Flashcards
describe how many vertebra there are in the spine
7 C T 12 5 L 5 S fused 3-4 coxxyc
what is the function of the spinal cord
reflex centre
conduction pathway
what is the start and end of the spinal cord
medulla oblongata (from foramen magnum) veterbral levels L1-2 at the conus medullaris
which occurs in the spinal cord anatomy after its termination
terminates at conus medullaris which gives of caudal equina
filum terminale - extension of the pia mater to coxccyv
dural sac extension
describe the anatomy of the spinal nerves in the spine
31 paired nerves 8 cervical 12 T 5 L 5 S 1 C
what is the lumbar cistern
subarachnoid space between filum terminale and dural sac which contains CSF
what is cervical enlargement
brachial plexus C1-8
what is lumbosacral enlargement
L1-S4
how do spinal nerves C1 to C7 leave the spinal cord
and C8
above their respected vertebrae ie superior C1 above CI
C8 leaves above T1 as only C7 vertebrae
how do spinal nerves from T1 onwards leave the spinal cord
from below their respected vertebrae
what are denticulate ligaments
extension of the pia mater which attach the spinal cord laterally
as spinal nerves leave the cord what happens to the meninges
leave with the nerve and go on to form epineurium a protective connective tissue
what type of space is spinal epidural space
it is real space not potential as it is filled with fat
what is the difference in cranial vs spinal dura mater
cranial is double layer
spinal is single layer
describe how spinal roots show disparity between their segmental attachments
development - dural sac grows along vertebrae but not spinal cord - VC grows more rapidly and SC regresss upwards leaving lumbar cistern space below
describe the process of a lumbar puncture
inserted into lumbar cistern (between L3 and 4)
no damage due to corda equinea
why do we have lumbar punctures
test CSF for meningitis or epidural aesthetsia
what are the three main arteries of the spinal cord
one anterior artery in the anterior median fissure from the vertebral arteries
two posterior spinal arteries which run in the posterior lateral sulci
where do the two posterior spinal arteries originate from
posterior inferior cerebellar artery
give examples of supporting spinal arteries
segmental spinal arteries such as
radicular arteries which supply nerve rootlets
deep cervical arteries
lumbar arteries
describe the structure venous drainage in the spinal cord
three anterior and three posterior spinal veins
valveless anastamoses
what is the process of venous drainage in the spinal cord
drain into internal (epidural) and external (outside VC) vertebral Plexi which in turn drain into systemic segmental veins
what two structures does the internal vertebral plexus drain into
dural venous sinuses superiorly and systemic segmental veins
describe the disparity of white matter and gray matter in the brain and spinal cord
in brain gray matter on outside
in spinal cord gray matter on the inside
what occurs in these sections of the spinal cord: ventral white commissure dorsal horn ventral horn lateral horn
white matter fibres cross to opposite side of the cord
nuclei of sensory afferents from the body entering through dorsal horn
nuclei of motor efferent from the brain
nuclei of neurones fro autonomic nervous system
describe the difference in ventral roots vs dorsal roots
ventral - efferent fibres from the ventral horn and lateral horn (somatic motor from ventral and visceral from lateral)
dorsal afferents fibres to the dorsal horn
how does the reflex arc work in the spinal cord
uses an interneuron which connects sensory to related motor which removes need from information to go to the brain for interpretation
what happens to white matter as you ascend the spinal cord
increase
what is found above segment T6
2 dorsal columns on each side of the midline
gracile fascile medially - carrier’s sensory information from lower limbs
cuneate fasciae laterally - carries sensory information from upper limbs
what happens to the cuneate fascicle after T6
disappears
how is spinal grey matter organised
into regions known as rexed laminae after rexed 1952
sites of sensory or motor nuclei with specific functions
