Organisation of the Spinal Cord Flashcards
What is the spinal cord
- This is the connection between the brainstem and the spinal nerves
what makes up the peripheral nerves in the body
- The spinal and cranial nerves make up all the peripheral nerves in the body
what are the 3 meninges in the spinal cord
- Dura mater – tough and thick fibrous layer
- Arachnoid mater – looks like a spidner web
- Pia mater – innermost layer this is on the brain or on the spinal cord itself
what are the spaces in the spinal cord
- There is a big space between the dura mater and the spinal cord this space is filled with fat, this is called extra or epidural space
- Between the dura mater and arachnoid mater there is the subdural space
- Between the arachnoid and pia mater there is the subarchanoid space
where is the CSF in
subarchanoid space
what is the aim of a lumbar puncture
aim to take a sample of CSF, therefore the needle is inserted into the subarachnoid space, this is used in diagnosis of meningitis
what is the aim of an epidural
aim to anaesthetise spinal nerves, this diffuses across the spinal nerves
describe the structure of motor neurones
- Cell body at one end of the neurone
- Dendrites stick out of the cell body and the nucleus is within the cell body
- There is a long axon and then axon terminals at the end
- Covered by a myelin sheath
describe the structure of sensory neurones
- Dendrites at one end,
- Long axon
- Cell body sticks out of the edge of the axon
- Then you have the axon terminates
- Axon is covered by a myelin sheath
where is the grey and white matter in the spinal cord
- The grey matter is a spinal cord is arranged internally whereas the white matter is towards the outside
describe the structure of the grey matter
- There are posterior and anterior horn of grey
- in the thoracic region of the spinal cord there is a lateral horn of grey – this is where the sympathetic nerves leave the spinal cord therefore it is only in the thoracic region
describe the structure of the white matter
posterior, lateral and anterior funcilus
why is there larger anterior horn in the spine
- Sensory neurones travel towards the posterior part of the spinal cord whereas the cell bodies of the motor neurone are towards the anterior horn of the spinal cord, therefore there is a larger anterior horn of the spine as this is where all of the cell bodies of the motor neurones originate here
where does information going to the brain go up in
- goes up or down the spinal cord in the white matter then it synapses in the anterior part of the grey hour with a motor neurone
describe where the grey and white matter is in the brain
- Grey matter is on the outside of the brain and makes up the cerebral cortex, whereas the white matter is on the inside of the brain
what is in grey matter
cell bodies and synapses
what is in white matter
myelinated axons
how many pairs of spinal nerves are there
31