Organisation Of Spinal Cord Flashcards
Layer of meninges outer to inner
Dura mater
Arachnoid mater
Pia mater
Where is the epidural space
Outside dura mater
Where is the subdural space
Potential space beneath dura
Where is the subarachnoid space and what does it contain
Between arachnoid and pia
Csf
Where is a lumbar puncture inserted
L3 subarachnoid space
Where is epidural inserted
Epidural space
Spinal cord funiculi
Posterior
Lateral
Anterior
Is grey matter outermost in the spinal cord or brain
Brain
How does a nerve enter the spinal cord
Sensory nerve enters dorsal horn
Synapses with interneuron
Travels with motor neuron to central horn of grey
Axon of motor neurone travels ventrakly to muscle
what do the ventral root and dorsal root form when they meet
mixed spinal nerce
Two major arteries supply the brain
vertebral arteries and internal carotid arteries
what do the vertebral arteries form when they meet
basilar art
anterior spinal art
posterior spinal art
what blood vessels supply the spinal cord
anterior spinal art
posterior spinal art
radiculospinal arts
how many pair of spinal nerves
31
how many cervical spinal nerves
8
how many thoracic spinal nerves
12
how many lumbar spinal nerves
5
how many sacral spinal nerves
5
how many coccygeal spinal nerves
1
are spinal nerves named after the vertebra above or below them
cervical below,
thoracic above
which vertebral level does the spinal cord end
L2/3
what are the 2 enlargements of the spinal cord
cervical and lumbar
what is the cauda equina
bundle of lumbar nerves below spinal cord
dermatome
area of skin which receives its sensory supply from a single spinal nerve
C4 dermatome
shoulder
C6 dermatome
thumb
C7 dermatome
middle finger
C8 dermatome
little finger
T4 dermatome
nipples
T10 dermatome
umbilicus
L1 dermatome
inguinal ligament
L3 dermatome
medial knee
L5 dermatome
big toe
S1 dermatome
little toe
S3 dermatome
gluteal
S5 dermatome
anal canal
how how proportion of white and grey matter change travelling down the spinal cord
white decreases
grey increases
3 major sensory spinal cord tracts
spinothalmic
dorsal column medial lemniscus
spinocerebellar
major motor spinal tract
corticospinal
what does spinothalamic transmit
crude touch, pain, temperature
what does DCML transmit
vibration, proprioception, discriminative touch
what does Spinocerebellar transmit
subconscious proprioception
spinothalamic tract course
Sensory nerves synapse in dorsal horn of grey (second order neuron), travels across (decussates) the midline to the other side (right side of brain controls left side of body and vice versa). Travels into white mater to the spinothalamic tract. Synapses again in the thalamus (third order neuron) and then travels via the internal capsule to the primary somatosensory cortex.
DCML course
first order neuron doesn’t synapse in spinal cord but travels to the brainstem. It synapses with the cunate or gracile nucleus respectively, then decussates to reach the medial lemniscus. Then 🡪 thalamus
spinocerebellar course
second order neuron enters the ipsilateral spinocerebellar tract and travels up to the cerebellum.
corticospinal course
First order neuron is in primary motor cortex, axon projects down internal capsule to reach brainstem. Neurons run anteriorly in brainstem (in medullary pyramids). Majority of fibres decussate to enter CT. Synapse with second order neurons in ventral horn of grey 🡪 ventral root.
where is the spinothalamic tract
below and lateral to ventral horn
where is the DCML
between dorsal horns
where is the spinocerebellar
lateral edges of cord
where is the corticospinal tract
between dorsal and ventral horns
