Neuroanatomy Flashcards
What is a spinal nerve root?
Connects spinal nerve
to segment of spinal cord
What are the two types of spinal nerve roots?
Dorsal root
Ventral root
What does the dorsal root carry?
Sensory fibres
What is the dorsal root ganglion?
Collection of cell bodies of afferent sensory neurones
What does the ventral root carry?
Motor and autonomic fibres
What are spinal nerves?
Merging of dorsal and ventral roots
contain both sensory and motor fibres
Where are spinal nerves located?
As they pass though the intervertebral foramen
What is the significance of the spinal nerve passing through the intervertebral foramen?
Marks the division of the CNS and PNS
How many spinal nerve roots are there?
31
How are the spinal nerve roots numbered?
Depending on the level at which they leave the vertebral column
Where does the spinal cord begin?
Inferior margin of medulla oblongata
Where does the spinal cord end?
Conus medullaris
at L2
Are spinal cord segments vertically aligned with their corresponding vertebrae?
Not really
How do lumbar, sacral, coccygeal nerves exit?
Long spinal nerve roots
descent down in cauda equina
then exit at their own intervertebral foramina
Where do C1 - C7 nerves exit?
Above their corresponding vertebrae
Where does C8 exit?
Above T1
Where do T1-L5 exit?
Below their corresponding vertebrae
Where do S1-S4 exit?
4 pairs of sacral foramina
Where do S5 and Co1 exit?
Posterior sacral hiatus
What do spinal nerves divide into?
Anterior rami
Posterior rami
What do the posterior rami divide into?
Medial branch
Lateral branch
What do posterior rami supply?
Dorsal trunk - DEEP muscles
Dorsal trunk - skin
What do the anterior rami do?
Enter plexuses
What do anterior rami supply?
Upper limb - muscles and skin
Lower limb - muscles and skin
Ventral and lateral trunk - muscles and skin
What is the meningeal branch?
Branch off spinal nerve
Where does the meningeal branch run?
Re-enters vertebral canal through intervertebral foramen
What does the meningeal branch supply?
Vertebrae
Ligaments
Blood vessels
Meninges
What are the rami communicantes?
Branch off spinal nerve
join the sympathetic chain of the ANS
What are the divisions of the spinal cord?
Anterior
Posterior
What are the functions of the anterior cord?
Sensory and motor
Light touch
pinprick
pain
What are the functions of the posterior cord?
Vibration sense
Proprioception
How can the anterior motor part of the cord be divided up?
Central tracts
Lateral tracts
What is the function of the central tracts?
Move arms
What is the function of the lateral tracts?
Move legs
What is anterior cord syndrome?
Injury to the anterior part of the spinal cord
What are the general consequences of anterior cord syndrome?
Loss of sensation
Loss of movement
What do the specific consequences of anterior cord syndrome depend on? Give some examples
The level of the injury
Cervical affects both arms and legs
Thoracic affects legs only
What is central cord syndrome?
Injury to central part of spinal cord
What are the consequences of central cord syndrome?
Loss of upper limb sensory and motor function much more compared to lower limb
What is posterior cord syndrome?
Injury to posterior part of spinal cord
What are the consequences of posterior cord syndrome?
Loss of vibration sense
Loss of proprioception
How do patients with posterior cord syndrome present?
Loss of co-ordination
What is a neural level?
Last functioning level in terms of sensory and motor power
