vertebral column Flashcards
functions of vertebral column
support+ protection- holds body weight, transmits forces evenly, supports head and upper limbs, and protects spinal cord
movement- extrinsic muscles to upper limbs and ribs attach to vertebral column, intrinsic muscles within column needed for postural control
regions of column and area of weakness
C1-7, T1-12, L1-5, S1-5, and C1-3/5 (33), with transition from lumbar to sacral region area of weakeness, as column goes from vertical to take a sharp turn coccygeal bones are fused into one, as well as sacral
curvatures DIAGRAM- primary and secondary
there are primary and secondary curvatures primary curvatures are present from the foetus which are concave pointing anteriorly (interior of curve pointing forward), secondary curvatures point posteriorly- they are added in from fetus to adult as you start to stand up primary are thoracic and sacral, secondary are lumbar and cervical
situations where curvatures change
pregnancy- women start to lean back to counteract baby growing anteriorly obesity can lead to problems due to the excess curvature need to stand upright
types of curvatures- EXCESS kyphosis and lordosis DIAGRAM
laterally, excess kyphosis is curvature of lumbar region pointing anteriorly= hunchback
excess lordosis (like a lord’s belly) is curvature pointing posteriorly
types of curvatures- scoliosis DIAGRAM
curvature is normal laterally, but not anteriorly/posteriorly (ie abnormal LATERAL curvature)- curvature leading to an S shaped curve is scoliosis- can compress organs of chest, and cause severe pain
they never exist during birth but occur young
palpable landmarks of vertebral column
not anteriorly, only posteriorly (spinous processes)
different vertebrae and shapes DIAGRAM
top 2 are 1st two cervical vertebrae, next is standard cervical, with vertebral arteries going through (will then go through foramen magnum to circle of willis), then thoracic, then lumbar, then sacral thoracic is heart shaped, lumbar is kidney shaped
typical vertebrae DIAGRAM- arch, body, lamina, pedical, processes
weight bearing vertebral body and vertebral arch, composed of the lamina, which extend posteriorly to form spinous process, and the 2 transverse processes vertebral arch forms vertebral canal (spinal cord goes through), and pedicles anchor arch to body superior articular process faces upwards, and articulates with inferior articular process of vertebra above, which faces downwards
atypical vertebrae- 1st cervical vertebrae : include holesDIAGRAM
important as allow movement of head/neck- often fractured in road accidents atlas (C1- called this as holds head) missing vertebral body- body is present in vertebra below to create joint to allow movement of neck doesn’t have spinous process, has 4 holes- one for spinal cord, one for body of 2nd cervical vertebrae, and 2 (transverse foramina) for vertebral arteries- other vertebrae don’t have this, as vertebral arteries start at neck
atypical vertebrae- 2nd cervical vertebrae DIAGRAM
on top of vertebral body is the vertebral body of the 1st vertebra, called dens- allows rotation of C1 and C2 to give joint greater range of motion
joints DIAGRAM
joint between C1-2 is atlanto-axial joint- known as NO joint as allows ROTATION to shake your head joint between skull at C1 is atlanto-occipital joint- known as YES joint as allows flexion/extension to nod your head
ligaments DIAGRAM
ligaments joining skull to C1/2 and going across the C1/2 are collectively known as cruciate ligament- supports joint between skull and vertebrae whilst giving flexibility
alar ligament connects C2 to skull
ligaments 2 + function DIAGRAM
anterior and posterior longitudinal ligaments run in front of and behind vertebral bodies supraspinous ligaments run along spinous processes, interspinous ligament run between them ligamentum flavum runs between adjacent lamina these ligaments give strength and reduce flexion/extension
intervertebral discs DIAGRAM
fibrocartilaginous joints form between vertebrae, with nucleus pulposus inside, and anulus fibrosis on outside nerves emerge from the intervertebral foramen
spinal nerves and relation to vertebrae
C1-7 nerves emerge from above their vertebrae, but C8-coccygeal emerge from below their corresponding vertebrae- occurs as C8 vertebrae not present, but C8 nerve is nerves come out almost horizontally from spine at top, but become more vertical as you go down, as spinal cord smaller- thus the distance between where the nerve comes out from the spinal cord, and where it comes out from the vertebral column becomes greater as you go down
below L2 no spinal cord present- this is where spinal anaesthetic or CSF for lumbar puncture given
prolapsed intervertebral disc DIAGRAM
this is where nucleus pulposus spills out and becomes herniated- goes into foramen where nerve emerges from- causes back pain- occurs more as you go down spine
movements of spine
extension/flexion, lateral flexion and rotation oblique muscles help with flexion and rotation erector spinae make spine straight
spinal cord layers and extradural space
spinal cord surrounded by pia, then arachnoid, dura extradural/epidural space filled with fat and veins, where catheter inserted for anaesthetics/analgesics during eg labour
range of motion of cervical spine
cervical spine (neck)- 45 degrees either side for extension and flexion or lateral flexion either way, 80 degrees for rotation
epidural space in cranial cavity vs vertebral column DIAGRAM
periosteal layer is lost as it passes down foramum mangum to spine, hence there is epidural space in vertebral column, NOT cranial cavity
epidural anaesthesia
lamina of last few sacral vertebrae not present, so don’t form spinous processes, so there’s a hole at bottom of spine called sacral hiatus- around DURA where needle injected for anaesthetic- often used for pain due to disc herniation, or labour
spinal anaesthesia
pia mater adheres to spinal cord and ends at L2, dura and arachnoid go further down the column from till S2 subarachnoid space is where needle injected- often used when general anaesthetic not use
supraspinous ligament
for C7 to skull, ligament becomes triangular and sheet like to become the ligamentum nuchae
sulci and fissures of spinal cord
anterior median fissure
posterior median sulcus
posterolateral sulcus- one of side where dorsal roots enter
meninges and denticulate ligaments
dura- continuous with inner meningeal layer of cranial dura mater at foramen magnum- forms sheath for pial part of filum terminale, and also forms part of filum terminale
arachnoid- thin membrane separated from dura by subarachnoid space
pia mater- firmly adheres to spinal cord: forms denticulate ligaments which position spinal cord into centre of subarachnoid space
