spinal nerves Flashcards
which root carries efferent axons cell bodies located in the anterior or lateral horn
anterior (ventral or motor) root
how many pairs of spinal nerves are there
31 pairs, 8 cervical, 12 thoracic, 5 lumbar, and 5 sacral and 1 coccygeal
which root attaches to the spinal cord as a series of rootlets
anterior root
which root carries axons from cell bodies located in the dorsal root (spinal ganglion)
posterior (dorsal or sensory) root
how does the posterior root attach to the cord
as a number of rootlets that attach to the posterolateral sulcus
where are the spinal ganglion located
inside or just medial to the intervertebral foramen, beyond the dura mater
where are C1 and C2 ganglia located
on their respective vertebral arches
where is the sacral ganglia located
within the vertebral canal
where is the coccygeal ganglia located
inside the dura mater
after the anterior and posterior roots combine what is the first branch to come off
the meningeal (recurrent meningeal, sinuvertebral) branch
where can the meningeal branch be found
all spinal levels
what is the path of the meningeal branch
it re-enters the vertebral canal trough the IVF and divides into ascending and descending and transverse brnaches
what type of information is provided by the meningeal branch
somatosensory and sympathetic supply to the dura, blood vessels, periosteum, ligaments, IVD in the anterior and lateral portion of the canal
what does the mixed spinal root break into
Posterior (dorsal) and anterior (ventral) ramus
the posterior ramus splits into lateral and medial branches at all spinal levels except
C1
the posterior ramus is smaller than the anterior ramus at all spinal levels except what level
C1, S4, and S5
what is the motor innervation of the posterior ramus
motor innervation to the deep back muscles
what is the sensory innervation of the posterior ramus
the skin on either side of the spine
what is the motor innervation of the anterior ramus
the anterior and lateral trunk muscles, and to skeletal muscles in the extermities
the anterior ramus contributes to what plexuses
the great plexuses
where is the sympathetic chain located?
at or just medial to the bifurcation of the mixed spinal nerve
Where can myelinated axons of the white ramus be found?
in the lateral horn cells at cord level T1-L2
Preganglionic sympathetic fibers enter the sympathetic chain and go where?
1- synapse
2- pass through splachnic nerve
what carries unmyelinated postganglionic sympathetic axons from cell bodies in the sympathetic chain to the spinal nerves?
gray ramus communicans
