Neuroanatomy: Spinal Cord and Spinal Nerves

Question 1

What are the dorsal and ventral rami and what do they supply?

Answer 1

These are branches going anteriorly and posteriorly from the mixed spinal nerve leaving the spinal cord
made up of both dorsal and ventral rootlets mixed together

Dorsal rami - muscles and sensation to the back
Ventral rami - muscles and sensation of the anterolateral trunk and limbs

Question 2

What is the functional difference between dorsal and ventral nerve roots?

Answer 2

Dorsal nerve roots = somatic and visceral sensory

Ventral nerve roots = somatic and visceral motor

Question 3

Where do the dura and arachnoid mater terminate inferiorly?

Answer 3

Around the S2 level

Question 4

What is the lumabr cistern?

Answer 4

the area between the end of the spinal cord and the termination of the dura and arachnoid mater

Question 5

What surface landmark can be used to determine betwen L4/5, the point of entry for an epidural

Answer 5

Supracristal plane

line between peaks to both iliac crests

Question 6

Why is there more white matter as you ascend the spinal cord?

Answer 6

Cervical spinal cord has the most white matter

in order to achieve fine finger control, more myelinated axons are required (white matter

Question 7

Is the spinothalamic tract somatotopically mapped?

Answer 7

yes, divisions for arm, trunk and leg

for secondary neuron to run in