Lumbar Spine Structure And Disorders Flashcards
How many vertebrae are in the lumbar Spinal region
5
What are the most mobile regions of the spinal cord
Cervical and lumbar
What are the functions of the spinal cord
- support the skull, pelvis, upper limb and thoracic cage
- protects the spinal cord and cauda equina
- allows for movement
- haemopoiesis
why is the thoracic region relatively immobile
as the ribs articulate with these vertebrae restricting movement
how many vertebrae make up the spinal column
33
what are the movements of the spinal cord
- flexion and extension
- lateral flexion
- rotation
what type of bone is the vertebral body mostly made up of and why
cancellous bone as its light weight, can resist compression (as the body is the main weight bearing part) and also can carry out other functions like haemopoiesis
why does the size of the vertebral bodies increase as you go inferiorly
as there are greater compressive forces
what is a laminectomy
removal of the spinal processes and lamina to relieve compression of the spinal nerve
what makes up the vertebral arch
lamina and pedicle
what is the type of joint found between the superior and inferior articular processes
facet/plane joint
what strengthens the facet joints
ligamentum flavum
what are the advantages of the design of the facet joints
the interlocking design prevents anterior dislocation and determines the amount of flexion and rotation
what are intervertebral discs made up of
70% water, 20% collagen and 10% proteoglycans
what happens to the height of the IV discs with age
they become shorter as the repair of the proteoglycans decreases so they hold less water
what 2 regions do IV discs consist of
- nucleus pulposus
- annular fibrosus
describe the structure of the annular fibrosus and its function
- made up of outer lamellae (type 1 collagen) and inner lamellae (fibrocartilaginous)
- acts as a shock absorber and is resilient under compression
what is the nucleus pulposus
centre of the IV disc made up of type 2 collagen and is gelatinous
changes in size through the day and with age
what are the main ligaments of the spine and where are they found
- anterior longitudinal = covers the vertebral bodies and prevents hyperextension
- posterior longitudinal = covers vertebral body facing the spinal canal and prevents hyperflexion
- ligamentum flavum = between lamina of vertebrae
- interspinous = unite spinous processes
- supraspinous = join the tips of adjacent spinous processes
true or false - the posterior longitudinal ligament is stronger than the anterior
false - the anterior is stronger
why is the ligamentum flavum yellow
due to the elastic fibres
how many fused vertebrae make up the sacrum and coccyx
sacrum = 5 coccyx = 4
which parts of the spine are the lordoses regions
cervical and lumbar
what is the primary curvature
the kyphosis (C-shaped) curvature of the fetal spine
what is the secondary curvature
when the lordoses develop
when does the cervical lordosis develop
when the child begins to lift its head
when does the lumbar lordosis develop
when the child starts to walk
what happens to the vertebral column in old age
primary curvature is re-established and there is senile kyphosis
what happens to the curvature of the spine in pregnancy
exaggerated lumbar lordosis
where do lumbar punctures usually occur
in L4/5 as the spinal cord is finished and the cauda equina started so theres less chance of neurological damage
what structures does the needle pass through in a lumbar puncture
skin, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural fat, dura matter
what is marginal osteophytosis
development of osteophytes on the edges of the joint
what are the 4 stages in a slipped disc
- disc degeneration = discs dehydrate and bulge
- prolapse = protrusion of nucleus pulposus with slight impingement
- extrusion = nucleus pulposus breaks through and remains in disc space
- sequestration = nucleus pulposus breas through and separates from main body
where do slipped discs most commonly occur and why
L4/5 as this is where the spine is most compressed
why do slipped discs herniate posterolaterally
this is where the posterior ligament finishes so is an area of weakness
what is the most common type of disc prolapse
paracentral - which causes impingement of the nerve root below
what is sciatica
compression of the nerve roots (L4,L5,S1,S2 and S3) which contribute to the sciatic nerve
where would the affects of sciatica be felt if L4 was compressed
medial lower leg
where would the affects of sciatica be felt if L5 was compressed
lateral lower leg
S1
sole of foot
what is cauda equina syndrome
compression of the cauda equina due to complete filling of the spinal canal by the IV disc giving bilateral sciatica, perianal numbness, painless urine retention
what is lumbar canal stenosis
narrowing of the spinal canal
what 3 things cause lumbar canal stenosis
- bulging of the disc
- facet joint osteoarthritis (osteophyte formation)
- ligamentum flavum hypertrophy
what is claudication
pain in legs when walking either due to narrowing of the blood vessels or nerves
what is venous engorgement
when the vein is compressed so the lack f blood flow causes the area of vein beneath the compression to expand so much that is impinges the arteries supplying the nerves causing claudication
what is spondyloisthesis
slip forward of the vertebra above
what are the 3 main types of spondylolisthesis
- dysplastic = abnormality in the shape of the facet joint
- isthmic = stress fracture of the par interarticularis
- degenerative = arthritis in the facet joint
what does iscthmic spondyloidthesis present with
back pain as the arch is not intact so cant compress the spinal canal
what does degenerative spondylolisthesis present with
claudication as the arch is still intact so a stenosis develops
