Anatomy of the vertebral collumn Flashcards
How many vertebrae are there in the back?
33
30 if you count coccyx as one
How many regions are there in the spine, and what are they called?
5
- cervical
- thoracic
- lumbar
- sacral
- coccygeal
How many vertebrae are there in each region of the spine?
CERVICAL - 7 THORACIC - 12 LUMBAR - 5 SACRAL - 5 COCCYGEAL - ~4
Which vertebra is most prominent?
C7
How much of the vertebral column is made up of inter-vertebral discs?
1/4 of the length
What features are there on the vertebral arches? (2)
- pedicles
- lamina
How many articular facets are there on each vertebra?
Four
- 2x superior
- 2x inferior
How many transverse processes are there on each vertebra?
2
How many spinous processes are there on each vertebra?
1
Where are the vertebral notches located?
Superior and inferior to the pedicles.
What do adjacent vertebral notches form?
Intervertebral foramen.
What passes through intervertebral foramen?
Spinal nerves.
How do typical cervical vertebrae vary from normal? (3)
- small body
- bifid transverse process
- foramina in transverse processes
Why do cervical vertebrae have bifid transverse processes?
Muscle attachments
|»_space;wide range of movement
What passes through the foramina in cervical vertebrae?
Vertebral artery and vein
-except C7
Why is dislocation of cervical vertebrae relatively likely?
Flat articular surfaces.
What are the different severities of a cervical vertebra dislocation?
- Flexion sprain
- Sublaxation
- Complete dislocation
Which 2 cervical vertebrae are atypical?
- Atlas (C1)
- Axis (C2)
Which cervical vertebra has no spinous process or body?
Atlas (C1)
What does the atlas consist of posteriorly and anteriorly?
Posterior & anterior arches
What do the posterior and anterior arches of the atlas (C1) contain?
A tubercle and a lateral mass.
Where does the transverse ligament connect to the atlas?
Tubercle on the medial surface of the lateral mass.
What is the function of the transverse ligament (atlas)?
Holds the dens of the axis in place.
What are the 2 large flat surfaces on the superior surface of the axis called?
Superior articular facets.
-atlas rotates upon them
What is another name for the dens?
Odontoid process.
What holds the dens in place, and what does this prevent?
The transverse ligament of atlas.
-prevents horizontal displacement
Why is the dens prone to fracture?
Less dense bone.
What causes dens fractures?
- Hyperextension
- Hyperflexion
What shape is a thoracic vertebral body?
Heart-shaped
What does the thoracic vertebral body contain superiorly and inferiorly?
Costal demi-facets.
-for articulation with head of rib
Describe the spinous process of throacic vertebrae.
- Long
- Extends postero-inferiorly
What feature does the transverse process of thoracic vertebrae contain?
Costal facet.
-for articulation with tubercle of rib
Which direction do thoracic articular facets face?
SUP»_space; posteriorly.
INF»_space; anteriorly.
Which costal demi-facets do ribs articulate with?
SUPERIOR demi-facet of corresponding vertebra.
INFERIOR demi-facet of vertebra above.
Describe the body, transverse processes and spinous process of lumbar vertebrae.
BODY - large
SPINOUS PROCESS - short & sturdy
TRANSVERSE PROCESSES - small (don’t articulate with ribs)
Which direction do the articular facets of lumbar vertebrae face?
SUP»_space; medially
INF»_space; laterally
What runs through the sacral canal?
Spinal nerves.
-but not spinal cord
What passes through anterior sacral foramina?
Anterior (ventral) rami of spinal nerves.
What passes through posterior sacral foramina?
Posterior (dorsal) rami of spinal nerves.
What are the lateral projections of the sacrum called?
Ala.
What do ala (sacrum) articulate with?
Ilium (pelvis).
|»_space;sacroiliac joint
How many vertebrae form the coccyx?
4 vertebrae.
- fuse into 1
What 3 structures hold vertebrae together?
- Zygapophysial joints
- Intervertebral discs
- Ligaments
Where are zygapophysial joints located?
Between superior and inferior articular processes of adjacent vertebrae.
What is the outer ring of intervertebral discs called?
Annulus fibrosis.
What is the annulus fibrosis?
Outer fibrocartilage ring attached to the epiphysial rim of vertebral body.
What is the inner ring of intervertebral discs called?
Nucleus pulposus.
What is the nucleus pulplosus made of?
Gelatinous substance.
-acts as a shock absorber
How does the thickness of intervertebral discs affect their flexibility?
Thicker discs»_space; increased range of movement.
What are the 3 main ligaments of the vertebral column?
- Ligamentum flavum
- Post longitudinal ligament
- Ant longitudinal ligament
What is the function of ligamentum flavum?
Binds lamina of adjacent vertebrae.
Where does the posterior longitudinal ligament run?
C2 to sacrum.
What is the function of the posterior longitudinal ligament?
Prevents posterior herniation of intervertebral discs.
Where does the anterior longitudinal ligament run?
Occipital bone & C1 to sacrum.
What is the function of the anterior longitudinal ligament?
Only ligament to resist hyperextension of the vertebral column.
-all others resist hyperflexion
What other ligaments exist in the vertebral column? (3)
- Interspinous ligament
- Supraspinous ligament
- Intertransverse ligament
What is whiplash?
Hyperextension of the cervical neck.
-e.g. car crash
Which ligament is torn in whiplash?
Anterior longitudinal ligament.
What can happen with severe whiplash?
Part of vertebral body is avulsed & vertebrae dislocate.
|»_space; spinal cord compression
What affects movements of the vertebral column? (2)
- Thickness of discs
- Orientation of zygapophysial joints
What curvatures of the spine are present in a foetus?
Primary.
-secondary develop later
What is another name for a primary curvature?
Kyphosis.
Which regions of the spine have kyphosis (1* curvature)?
Thoracic
Sacral
What is another name for a secondary curvature?
Lordosis.
Which regions of the spine have lordosis (2* curvature)?
Cervical
Lumbar
What is scoliosis?
Abnormal twisting and curvature of the spine.
What is osteoporosis?
Bones become brittle and fragile from loss of tissue.
|»_space;compression fracture
Who is osteoporosis most common in?
Post-menopausal women.
-lack of oestrogen
What are the effects of ageing on vertebrae?
Loss of bone density
» concave vertebral bodies
» increased force on rims
»osteophytes develop
What are osteophytes?
Bony projections associated with degeneration of cartilage.
What is a possible consequence of ageing on intervertebral discs?
Herniation of nucleus pulposus (‘slipped disc’).
- normally posterolaterally between L4/L5 or L5/S1
What can herniation of the nucleus pulposus lead to?
- Lower back pain/sciatica
- Cauda equina syndrome
