Spinal Nerves Part 1 Flashcards
How many spinal nerves are in a typical person?
62 spinal nerves (31 pairs)
How many coccygeal nerve pairs are there typically?
1 pair
How many sacral nerve pairs are there typically?
5 pairs
What kind of axons are carried by the anterior roots of the spinal cord?
efferent axons
Which roots of the spinal cord are considered motor roots?
anterior (ventral) roots
Where are the cell bodies located of the axons carried by the anterior roots?
in the anterior (ventral) or lateral horns (if present)
How are the anterior roots of the spinal nerves attached to the spinal cord?
by a series of rootlets
Where are the cell bodies of the axons carried by posterior roots of the spinal nerves?
cell bodies are located in the dorsal root ganglion
What are the other acceptable names for the dorsal root ganglion?
posterior root ganglion or spinal ganglion
Where do the rootlets of the posterior root attach to the spinal cord?
posterolateral sulcus
Which roots of the spinal nerves can be considered sensory roots?
posterior (dorsal)
Where are spinal ganglia typically located?
either inside or just medial to the intervertebral foramen, beyond the dura mater
Where are the C1 and C2 spinal ganglia located?
on their respective vertebral arches
Where are sacral spinal ganglia located?
within the vertebral canal
Where are the coccygeal spinal ganglia located?
inside dura mater
Shortly after combining into a mixed spinal nerve, what branch is given off?
meningeal (aka recurrent meningeal or sinuvertebral) branch
Where are the cell bodies of the meningeal branch located?
in sympathetic trunk (postganglionic sympathetics)
What does the sinuvertebral branch supply?
the disc
At what levels are sinuvertebral branches present?
all levels
Meningeal branches re-enter the vertebral canal through the IVF and divide into what?
ascending, descending and transverse branches
The meningeal/sinuvertebral branches supply what kind of info to the dura, and periosteum in the anterior/lateral portions of the canal?
somatosensory and sympathetic supply
What kind of info is supplied by the meningeal branches to the blood vessels, ligaments and intervertebral discs of the anterior/lateral portions of the canal?
somatosensory and sympathetic
What two primary rami does the mixed spinal nerve divide into?
anterior and posterior ramus
T/F: The posterior ramus of the mixed spinal nerve divides into lateral and medial branches at every level of the spinal cord.
False; no C1
Where are the only places that the anterior ramus is smaller than the posterior ramus?
C1, S4, and S5
Which ramus supplies motor innervation to the deep back muscles?
posterior (dorsal) ramus
Which ramus supplies sensory innervation to the skin on either side of the spine?
posterior (dorsal) ramus
T/F: both the anterior rami and the posterior rami are mixed nerves.
True
Which ramus supplies motor innervation to the anterior and lateral trunk muscles?
anterior (ventral) ramus
Which ramus supplies motor innervation to skeletal muscles in the extremities?
anterior (ventral) ramus
Which rami contribute to the great plexuses?
anterior rami
Which ramus supplies sensory innervation to skin of extremities as well as anterior and lateral trunk?
anterior (ventral) ramus
