Spinal Column And Cord Flashcards
What is the primary role of the spinal column
- weight bearing and locomotion
- protection of the spinal cord
What is the spinal cord composed of
7cervical vertebra 12 thoracic vertebra 5 lumbar vertebra 5 sacral vertebra (fused to become sacrum) 1 coccyx (2 or 3 bones fused)
What are the protruding points on an individual vertebrae called
- transverse process - goes out to the side
- articular process - goes upwards (superior) and downwards (inferior)
- spinous process - sticks out in front
What structure connects the facets of the vertebra to the body
-the pedicle
What structure connects the facets to the midline and spinous process
-the lamina
What is a distinguishing feature of a thoracic vertebra specifically for the points of articulation
-articulates with the ribs in two places
- the head of the rib to the vertebra body
- the tubercle of the rib at the anterior aspect of the transverse process
Give the distinguishing features of a cervical vertebra
- smaller because it carries less weight
- bifid spinous process (from C1 to C6)
- vertebral foramina (vertebral artery passes through this)
Which cervical vertebral does not have a bifid spinous process
-C7 (only has a single tip)
What is the first cervical vertebra called and what does it do
- atlas
- it supports the weight of the skull
What is the second cervical vertebra called and what does it do
- axis
- provides an axis which the neck can rotate
Where is the odontoid peg found
- C2 the axis
- a peg like structure projecting from the axis
- it represents the body the 1st cervical vertebra fused with the body of the 2nd cervical vertebra
What is the ligament that lies behind the odontoid peg called
-the transverse ligament
How many curvatures are exhibited in an adult spine and list them going from cervical to lumbar
3
- cervical bending forwards - lordosis
- thoracic bending backwards - kyphosis
- lumbar bending forwards - lordosis
What is a scoliosis
-sideways bend of the spine
What connects the vertebra of the spines to each other
- intervertebral discs (they connect the body of each vertebra)
- synovial joints (between the articular processes)
Ligaments
- anterior spinal ligament (runs dow the front of the vertebral bodies)
- posterior spinal ligament (runs down the back of the vertebral bodies)
- ligamentum flavum (connects the lamina of each vertebral body, has high amount of elastic tissue which shows up yellow)
- interspinous ligament (connect the spinous processes of the vertebral bodies)
- supraspinous ligament (connects the tips of each spinous process of the vertebral bodies)
What type of joint is the intervertebral disks and what is it composed of
- secondary cartilagenous joint
- so in order goes bone (vertebral body), hyaline cartilage, fibrocartilage (makes up majority of the joint), hyaline cartilage, bone (vertebral body)
Describe the two structures within the vertebral bodies
- liquid center (nucleus pulposus)
- fibrous rings (annulus fibrosis)
What are flavanoids
-early pigments which were yellow
Give the 5 ligaments associated with the vertebral bodies and what they do
- anterior spinal ligament (runs dow the front of the vertebral bodies)
- posterior spinal ligament (runs down the back of the vertebral bodies)
- ligamentum flavum (connects the lamina of each vertebral body, has high amount of elastic tissue which shows up yellow)
- interspinous ligament (connect the spinous processes of the vertebral bodies)
- supraspinous ligament (connects the tips of each spinous process of the vertebral bodies)
How can bending to lift a heavy weight compress a spinal nerve
- bending forward might cause a tear in the posterior spinal ligament and annulus fibrosus
- and cause the liquid nucleus pulpous to bulge through the annulous fibrosus into the intervertebral foramina and compress a spinal nerve
What is the difference between the exiting and tranversing spinal nerve root and how they can be compressed
- existing spinal nerve root is on the spinal level that the compression occurred (usually posterior rupture of the annulus fibrosus)
- tranversing spinal nerve root is on the spinal level below where the compression occurred (usually a rupture of more central annulus fibrosus)
Where would a spinal anaesthetic usually be given
-in the lumbar or sacral region
What is the conus medullaris
- where the spinal cord ends
- identified by it finishing in a tube of pia mater (this tube is the philum termnalis)
What is the continuation of the conus meduallaris all the way to the coccyx
-the philum terminalis (the tube of pia mater)
Why are the dorsal root ganglia at risk of compression from a slipped disc
-they lie within the intervertebral foramina
How does an epidural anaesthetic work
- needle into the spinal canal but alongside the dura
- anaesthetic diffuses and paralyses cell bodies in the dorsal cell ganglion causing that area to become numb
Above which vertebral level are the spinal nerve root that exit there named after them
C1 to C7
-thoracic and lumbar exit below their numbered vertebra
Give the difference between an axon and a dendrite
- mircoscopically identical
- axon takes electrical impulse away from the cell body
- dendrite carries electrical impulse to the cell body
In which aspect of the spinal cord is the intermediate horn only found and why
- the thoracic spinal cord
- the cervical, lumbar and sacral spinal cord do not have any sympathetic nerves exiting from them
What does the intermediate horn of the spinal cord contain
-cell bodies for components of the sympathetic nervous system
Give a brief description of the journey of the descending pathway tracts and where they pass into the anterior horn of the spinal cord
Lateral corticospinal tract - 85% deccussate and synapse on anterior horn of contralateral side
Ipsilateral corticospinal tract - 5% passed down ipsilaterally and synapse with same side of body as the side of the brain they originated
Ipsilateral ventral corticospinal tract - 10% pass down ipsilaterally then deccusate when they reach their spinal level to synapse on anterior horn of spinal cord
Is the lateral corticospinal tract contralateral/ipsilateral to the motor cortex and contralateral/ipsilateral to the muscles it supplies
- contralateral to the motor cortex
- ipsilateral to the muscles it supplies
Is the ventral corticospinal tract contralateral/ipsilateral to the motor cortex and contralateral/ipsilateral to the muscle it supplies
- ipsilateral to the motor cortex
- contralateral to the muscles it supplies
Does the dorsal spinocerebellar tract travel in the spinal cord contralateral/ipsilateral
-ipsilateral
Does the ventral spinocerebellar tract travel up the spinal cord contralateral/ipsilateral
-contralerally
Describe the rotation, flexion and extension of the thoracic and lumbar region
- rotation is maximum at the thoracic region but flexion and extension is limited because of the rib cage
- rotation is limited in the lumbar region
What is the nucleus pulposus made of
- proteoglycan
- collagen
- cartilage cells
What is the annulus fibrosus attached to peripherally
- the vertebral bodies
- the posterior longitudinal ligament
Where does a prolapsed intervertebral disc usually occur
L5/S1 in the lumbar region
C6/7 in the neck region
Give the clinical significance of Bateson’s veins
- these are veins in the vertebral venous plexuses
- they contain no valves and communicate freely with intercostal veins and pelvic veins including veins draining the prostrate
- so can be a route of metastasis for prostate and breast cancer
Detail where the 31 spinal nerve are derived from
- 8 cervical nerves
- 12 thoracic nerves
- 5 lumbar nerves
- 5 sacral nerves
- 1 coccygeal
