NETTER - Neuroscience Flash Cards

Spinal Cord: Cross-Sectional
Anatomy In Situ
1. Ventral ramus (intercostal nerve)
2. Spinal nerve
3. Dorsal root (spinal) ganglion
4. Dorsal root
5. Rami communicantes
6. Ventral root
7. Sympathetic ganglion
8. Epidural space with epidural fat
9. Dura mater
10. Subarachnoid space
11. Filum terminale
12. Cauda equina
Comment: The dorsal root ganglia contain primary sensory cell
bodies whose axons, when greater than 1 to 2 μm in diameter,
are myelinated by Schwann cells in the peripheral nervous system,
including the proximal portion that extends to the dorsal root entry
zone of the spinal cord, and are myelinated by oligodendroglia once
they enter the central nervous system. For thoracolumbar segments,
the distal white ramus communicans contains axons from autonomic
preganglionic neurons that will synapse in the sympathetic chain
ganglia or continue through a splanchnic nerve to synapse in a
collateral ganglion. The medially located gray ramus communicans
contains the postganglionic axons (mostly unmyelinated) that
distribute to target effector tissues of the autonomic nervous system.
The bulk of the ventral root contains axons from lower motor neurons
in the spinal cord, destined for synapsing on skeletal muscle fibers
for that myotome.
Overview of the Nervous System See book 5.5