the back Flashcards
what are the 5 sections of the vertebral column?
7x cervical vertebrae
12x thoracic vertebrae
5x lumbar vertebrae
5x sacral vertebrae
1-4x cocygael vertebrae
what are the functions of the vetebral column?
protection
support
axis- upright posture
movement
what is the primary and secondary curvature of the spine?
primary = kyphoses (concave anterioly) - remains in the thoracic and sacral region
secondary = lordosis (concave posteriorly) appears when infant lifts its head
why is babies movemnt uncooridinated?
because babies use unmylinated nuerons
what does the vertebral arch form?
an enclosed hole called the vertebral foramen which encloses the spinal cord.
pedicles
connect the vertebral body to the transverse arch
lamina
connects the transverse and spinous processes
articular processes?
forms a joint between one vertebra and its superior and inferior counter parts
what is unique about the cervical vertebrae?
- transverse formamen transmits the vertebral arteries to the brain
- bifid spinous process (the spinal process bifurcates at the distal end)
atlas
C1
- no body
- the superior articular facets will articulate with the occipital condyles
what joint does rotation of the head and neck happen at?
atlanto axial joint
which part of C2 will articulate with anterior arch of the atlis?
the dens
what is unique about the thoracic vertebrae?
- allow rotation
- long transverse processes with a costal facet for articulation with the tubercle of the ribs
- they have 2 costal demi facets for upper and lower articulation with the ribs
- their spinous process is long and points inferiorly
what is unique about the lumbar body vertebrae?
- largest body
- no transverse foramen, costal facet with a short spinous process
what does the size and orientation of the lumbar vertebrae allow?
the size and orientation allows needle access to the spinal canal and spinal cord eg - lumbar puncture
what is unique about the sacrum?
it is a fusion of 5 bones
what is the sacral promontory?
the anterior projection from S1
what is unique about the coccyx?
a small bone that articulates with the apex of the sacrum
- has no vertebral arches, therefore no vertebral canal.
what are 2 congenital abnormalities associated with the sacrum?
1- lumburisation = seperation of S1 from the sacrum
2- sacrilisation = fusion of L5 to the sacrum
lwhat are the different types of ligament in the vertebral column?
what type of joint is it between the articular processes?
zygapophyseal joint - synovial joint
what type of joint is it between the spinous processes?
symphysis/ secondary cartilaginous joint
2 partS of the iNTERVERTEBRAL disc and their function?
1- nucleus pulposus (middle) - absorbs compressive forces between vertebrae, 70-90% water, collagen content will increase with age.
2- anulus fibrosis (outer bit) - strong concentric lamellae of fibrocartillage, attached and kept in place by anterior and posterior longitudinal ligaments
THEY CONTRIBUTE TO THE SHAPE OF THE SPINAL CURVATURES, FORM 20-25% OF THE LEGTH OF THE COLUMN.
WHAT ARE THE SEPERATE NUTRIENT SUPPLIES OF THE INTERVERTEBRAL DISC?
- the periphery of the disc is supplied by neighbouring capillaries
- the centre is nourished by diffusion from the body of the vertebrae
what is a herniated disc?
the nucleus palposus may herniate or prolapse to compress - there will be nerve compression
why are most disc herniations posterolateral?
due to the central position of the posterior longitudinal ligament means that most disc henriations are posterolateral, towards the intervertebral formamen.
function of the anterior and posterior longitudinal ligament?
anterior - limits extension
posterio - resists hyperflexion
what is the tectorial membrane?
it extends between the formane magnum and C2
it continues downwards as the posterior longitudinal ligament
function of the ligamenta flava and intertransverse ligaments?
- the ligamenta flava is between the vertebral laminae and limits sudden flexion and supprts curvatures
- the intertransverse ligament is between all transverse processes
where is the supraspinous ligaments?
between tips of ths spines and runs between sacrum to c7, CONTUNOUS with the ligamentum nuchae
what is the ligamentum nuchae
interspinous ligament?
between all spinous processes
what makes up the curcuate liagement
1- the transverse ligament - keeps the dens close to the anterior arch
2- longitudinal fascicles (superior and inferior)
Prevents excessive movement between the axis, atlas and occiput.
what is the vascular supply?
- arteries form anastomostic rings that arise from vertebral arteries and posterior intercostal and lumbar branches of aorta
- internal and external venous plexus come together and drain to veins equicvelant to the arteries.
describe the extrinsic muscles of the back?
- superficial
- involved with movement of the upper limbs and thoracic wall
- innervated by anterior rami of spinal nerves
describe the intrinsic muscles of the back?
- deep etween spinous processes
- adapted to provide support and movement
- moves the vertebral column
- innervated by the posterior rami of spinal nerves
- arranged in 3 layers
trapezius
accessory nerve
lat dorsi
thoracodorsal nerve
red = levator scapula (scupular elevation)
Green/blue= rhomoid major and minor (scapular retraction and elevation)
pruple/blue = serratus posterior superior and inferior (superior = inspiration inferior = expiration)
top layer, intrinsic muscles?
acting togehter= extend the neck
acting alone = rotate and laterally flex
3 erector spinae muscles (intermediate layer)
what 3 muscles make up the transversospinalis?
1- rotatores
2- multifidus
3- semispinalis
what makes up the sub-occipital triangle in the neck?
- obliquus capitis superior
- obliquus capitis inferior
- rectus cepitis posterior major
They transmit vertibral arteries, veins and suboccipital nerve
What unites in the sacrum?
Spinous, articulate and transverse processes
What is the intervertebral foreman?
Where the spinal nerves emerge formed by the superior and inferior vertebral notches
How is the annulus fibrosis attached and held in place?
By anterior and posterior longitudinal ligaments
When may intervertebral discs deform?
To allow movement between the intervertebral bodies.
Deforming may put pressure on the nucleus palposus and annulus fibrosis. They may degenerate and weaken.
Serratus posterior inferior movement
Expiration
Serratus posterior superior
Inspiration
Rhomboid ajar and minor movement
Scapular retraction and elevation
wHat does the ligamentum nuchae do
Limits flexion and provides muscle attachment
Alar ligaments
Prevents excessive rotation- from side of dens to side of foramen magnum
