Spinal cord and meninges Flashcards
What is the spinal cord?
major reflex center and conduction pathway between body and brain
Where does spinal cord begin and end?
begins at medulla oblongata and extends up to L1/L2 level
in newborn- L2/L3
where does brachial plexus come from and supply?
comes from cervical region and supplies upper limb
where does lumbosacral plexus come from and supply?
sacral and lower limb
how many pairs of spinal nerves are attached to spinal cord?
31 pairs ( 8 in cervical, 12 in thoracic, 5 in sacral and 1 coccygeal spinal nerve)
where does spinal nerve exit from thoracic region downwards?
for e.g. thoracic 1 spinal nerve will be passing through intervertebral foramen just below thoracic 1 vertebral body
in cervical region - one extra spinal nerve and c1 spinal nerve goes over vertebra
what is conus medullarise?
conical inferior end of spinal cord
what is cauda equina?
The bundle of spinal nerve roots in the lumbar cistern of the subarachnoid space prior to termination of spinal cord resembles a horse tail
What is filum terminale?
continuation of pia mater
What is dural cistern?
Dilated dural sac, ends at s2 vertebral level
What is H shape in spinal cord made out of?
Grey matter- Cell bodies of neurons
What is white matter made up of?
axons
what are parts of the grey matter?
anterior horn
anterior median fissure
lateral horn
posterior horn
nissl bodies- rough endoplasmic reticulum ( protein machinery of neurons)
Components of spinal nerve
posterior root of spinal nerve- receives afferent/sensory fibres which carry sensation of touch, pain , temp from periphery
dorsal root ganglia- cell bodies
anterior roots of spinal nerves - contain efferent/ motor fibres which supply skeletal muscle.
anterior horn-cell bodies of motor neurons
what does anterior and posterior root of spinal nerve unite to form?
spinal nerve- mixed in nature (sensory and motor components)
What does dorsal/ posterior rami supply?
facet joints
deep muscles of back
skin of back
what does anterior rami supply?
supplying anterolateral part of trunks and limbs
What is in the epidural space?
internal vertebral venous plexus with some fat and connective tissue
What are arachnoid trabeculae?
avascular
thin structures that connect arachnoid matter with pia matter
Describe pia matter?
Blood vessels which supply spinal cord
What is the space between the pia and arachnoid matter?
sub arachnoid space - contains cerebral spinal fluid
Describe denticulate ligament?
ligament in pia matter that goes from side to side and supports spinal cord to hang inside sub arachnoid space
where do dural sac terminate?
at level of s2 vertebral level and attached to tip of coccyx by filum terminale externum
Where is thoracolumbar/ sympathetic outflow of sympathetic NS?
t1-l2 segment maybe till l3
cell bodies of sympathetic neurons are located at lateral horn of grey matter and will synapse into sympathetic ganglia on either side of spinal cord
