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
what suboccipital muscles are the motor supply from C1?
- rectus capitis posterior major and minor
- obliquus capitis superior and inferior
- semispinalis capitis
what are the two branches of C2?
medial (greater occipital nerve) and lateral branch
the greater occipital nerve innervates what?
sensory innervation to the posterior neck and scalp
what is innervated by the lateral branch of the C2?
motor supply to semispinalis capitis, longissimus capitis, spenius capitis muscles
What are the two branches of C3?
the medial (least occipital nerve) and lateral
what is innervated by least occipital nerve
sensory supply from skin of posterior neck
what is supplied the lateral branch of C3?
motor supply to semispinalis capitis, longissimus capitis, splenius capitis
what is innervated by the medial branch of C4-C8?
sensory supply from the skin of the posterior neck
what is supplied by the lateral branch of C4-C8?
motor supply to iliocostalis cervcis, longissimus cervicis and capitis
