Vertebral Column Flashcards
what vertebrae does the SC travel through?
base of skull to about L2
what developmental issue causes the need for long spinal nerves at the base of the SC?
vertebral column grows faster than SC so the SC is forced higher and nerve roots have to lengthen to get to their corresponding foramen
what two sections of the SC have longer nerve roots?
lumbar and sacral/coccygeal
what is the collection on nerve roots around L2 that hosts the nerve roots for the rest of the SC?
cauda equina
what is the cauda equina?
collection of nerve roots in inferior portion of the SC
what is the end of the SC called that tapers off?
conus medularis
what is the filum terminale?
a vestigial remnant of the caudal spinal cord that was the tail
what are the two portions of the filum terminale?
internal and external
what is the role of the internal filum terminale? where does it extend to?
extends from conus medullaris to the dural sac
what is the role of the external filum terminale? where does it extend to?
extends from tip of dural sac to sacrum/coccyx and helps anchor the SC
where is the tip of the SC?
L1 or L2
where are the two enlargements of the SC?
cervical and lumbosacral
why are there enlargements of the SC at the cervical and lumbosacral places?
because there are extra neurons for innervation of the extremities
how many cervical nerves are there?
8
do cervical nerves traverse above or below their respective vertebral body?
superior to it
where does C8 nerve travel through?
C7 and T1
other than cervical nerves, where do other spinal nerves traverse their respective vertebra?
inferior to the body
what is the name of the membranes that surround the SC?
spinal meninges
name the three spinal meninges
dura mater
arachnoid mater
pia matter
what is the outermost membrane of the SC?
dura mater
what does the dura mater do to protect the spinal nerves as they go out of the SC?
extends laterally into the intervertebral foramina to form dorsal sleeves
what is the intermediate layer of the membranes around the SC?
arachnoid mater
what is the innermost layer of the spinal meninges?
pia mater
where does CSF lye in the spinal meninges?
the subarachnoid space
what are the denticulate ligaments? where do they originate from?
lateral extensions of the pia mater between dorsal and ventral roots
what is the role of the denticulate ligaments?
help anchor the cord laterally
what lies between the dura mater and the vertebral canal edges?
epidural space
what is within the epidural space?
adipose tissue and internal venous plexus
what are the two components that give arterial supply to the SC?
vertical/longitudinal and horizontal
name the three vertical/longitudinal arteries
an anterior spinal artery
two posterior spinal arteries
what arteries help communicate and feed the SC along with the vertical arteries?
segmental/horizontal
how many segmental/medullary arteries are there?
about 8-10
where do segmental arteries enter the SC?
intervertebral foramen
name the largest segmental artery of the SC
great anterior segmental artery…artery of adamkiewicz
the artery of adamkiewicz usually arise from what side? and supplies where on the SC?
arises from the left (intercostal artery) and supplies the inferior 2/3 of the SC
describe the venous drainage into the internal epidural venous plexus
from both the anterior and posterior spinal veins into the epidural venous plexus
what does the internal epidural plexus connect with? describe the flow
connects to the external venous plexus through the basivertebral veins..
what do the basivertebral veins drain? where are they located?
drain the vertebrae…located in the body of vertebrae
how are the interconnecting vertebral venous plexuses connected? what does this allow?
without valves…so blood can flow up or down
what is another name for the interconnecting vertebral venous plexus
Batsons plexus
what other sites doe batsons or vertebral venous plexus communicate blood with?
cranial cavity
pelvic veins
posterior thoracic wall
what do the connections that Batsons plexus has allow for?
potentially metastes
what three ligaments in order do you go through for a spinal tap?
supraspinous
interspinous
ligamentum flavum
name the six tissues in order to get to the subarachnoid space
skin supraspinous ligament interspinous ligament ligamentum flavum epidural space dura mater arachnoid mater
what does the posterior longitudinal ligament have that allows for herniated discs?
lateral portions that dont cover or support the entire part of the disc
with a herniated disc, what portion of the disc is protruding?
nucleus pulposus
where do disc herniations usually occur?
posterolaterally where anulus is think and poorly supported by the posterior longitudinal ligament
what two sites do 95% of herniated discs occur at
L4/L5 and L5/S1
if you have herniated disc at L4/L5, which nerve root will be impinged? what is this trend?
L5..anytime you have herniation between two vertebrae the higher number vertebrae will be the nerve that gets impinged
