exam 2 UNIT 5 Flashcards
how many cervical pairs of spinal nerves?
8 PAIRS
how many lumbar spinal nerve pairs?
5 pairs
how many thoracic spinal nerve pairs?
12 Pairs
how many spinal nerves?
62
31 pairs
how many sacral nerve pairs?
5 pairs
how many coccygeal nerve pairs?
1 pair
what are the characteristics of the anterior root?
- carry efferent axons from cell bodies in the anterior or lateral horns
- attached to spinal cord by a series of rootlets
what are the characteristics of the posterior root?
- carry axons from cell bodies in posterior root (dorsal root gaglion)
- root separates into a number of rootlets that attach to cord at posterolateral sulcus
- spinal ganglia
where are spinal ganglia typically located?
either inside or just medial to the intervertebral foramen, beyond the dura mater
what are the three spinal ganglia location exceptions?
- C1 and C2 ganglia located on their respective vertebral arches
- sacral ganglia located within the vertebral canal
- coccygeal located inside dura mater
shortly after the anterior and posterior roots combine into a mixed nerve, what is given off?
a meningeal (recurrent meningeal, sinuvertebral) branch
after a meningeal (recurrent meningeal, sinuvertebral) branch re-enters the vertebral canal through the IVF, what does it do?
divides into ascending, descending, and transverse branches
a meningeal branch also provides somatosensory and sympathetic supply to what?
dura, blood vessels, periosteum, ligaments and intervertebral disc, in the anteior and lateral portions of the canal
at what levels are meningeal branches present and how do they re-enter the vertebral canal?
present at all cord levels and re-enters through the IVF after branching off of a mixed nerve
the mixed spinal nerve divides into what two rami?
posterior primary rami
anterior primary rami
what are the characteristics of the posterior primay ramus?
- splits into lateral and medial branches
- smaller than anterior ramus
- motor innervation to the deep back muscles
- sensory innervation to the skin on either side of the spine
the posterior ramus splits into lateral and medial branches except for what cord level exception?
C1 does not split
the posterior ramus is smaller than anterior ramus except for what exceptions?
C1
S4
S5
what are the characteristics of the anterior primary ramus?
- motor innervation to anterior and lateral trunk muscles
- motor innervation to skeletal muscle in the xtremities
- sensory innervation to the skin on either side of the spine
which ramus division contributes to the great plexuses?
the anterior rami
which ramus division is motor innervation to the deep back muscles?
posterior rami. only muscles it innervates
where is the sympathetic chain located?
either at or just medial to the bifurcation of the mixed spinal nerve
which division of the sympathetic chain carries myelinated axons?
white ramus communicans
white rami communicans are associated with what cord level nerves?
T1-L2
white ramus communicans carries myelinated axons from cell bodies located where?
located in the lateral horn cells at cord levels T1-L2
preganglionic sympathetic fibers associated with white ramus enter the sympathetic chain and do what two things?
synapse at their entrance level
pass through to splanchnic nerve
which division of the sympathetic chain carries unmyelinated postganglionic sympathetic axons?
gray rami communicans
which division of the sympathetic chain is associated with all cord levels?
gray rami communicans
what type of axons are carried by the gray rami communicans, connecting the cell bodies of the sympathetic chain to the spinal nerve?
unmyelinated postganglionic sympathetic axons from the cell bodies in the sympathetic chain to the spinal nerve
the cervical posterior rami of C1 is known as?
suboccipital nerve
what muscles are innervated by the posterior rami of C1?
1) rectus capitis posterior major and minor
2) obliquus capitis superior and inferior
3) semispinalis capitis
the posterior medial branch of C2 is known as?
greater occipital nerve
what does the (Greater occipital nerve) C2 medial posterior branch innervate?
sensory innervation to the posterior neck and scalp
what does the lateral branch of C2 innervate?
motor supply to the semispinalis capitis, longissimus capitis and splenius capitis muscle
what is the posterior medial branch of C3 known as?
third (least) occipital nerve
what does the (third (Least) occipital nerve) posterior medial branch of C3 innervate?
sensory supply from the skin of the posterior neck
what does the posterior lateral branch of C3 innervate?
(motor supply same as C2)
semispinalis capitis, longissimus capitis and splenius capitis muscle
what do the posterior medial branches of C4-C8 innervate?
sensory supply from the skin of the posterior neck
what do the posterior lateral branches of C4-C8 innervate?
motor supply to iliocostalis cervcis, longissimus cervicis and capitis
what forms the cevical plexus?
formed by anterior (primary) rami of C1-C4 spinal nerves
what do the nerve roots of the cervical plexus form?
a series of communicating loops
the cervical plexes and the inferior vagal ganglion communicate with the?
loop formed by C1 and C2
the cervical plexus communicates with the accessory nerve thorugh what?
loops formed by C2 and C3 and with C3 and C4
what type of information do fibers of the accessory nerve that communicates with the cervical plexus carry?
proprioceptive information
what spinal nerve does the sternocleidomastoid communicate with through the cervical plexus?
C2
what spinal nerves does the trapezius communicate with through the cervical plexus?
C3 and C4
usually gray rami communicans carry what type of information in postganglionic sympathetic fibers to the loop between C1 and C2 and Roots of C3 and C4
vasomotor
sudomotor
pilomotor
what type of fibers carry vasomotor, sudomotor, pilomotor information to the loop of C1 and C2 and Roots of C3 and C4?`
three gray rami communicans carry postganglionic sympathetic fibers
what are the superficial branche sof the cervical plexus?
lesser occipital nerve
great auricular nerve
transverce cutaneous
medial, intermediate, lateral supraclavicular nerves
the lesser occipital nerve carries fibers from C2 and occasionally C3 to supply?
skin on the superior 1/3 of the auricle as well as the skin behind the ear
what other nerves does the lesser occipital nerve communicate with?
greater occipital nerve
great auricular nerve
the lesser occipital nerve may be implicated in cases of?
cervicogenic headache
the great auricular nerve carries fibers from which spinal nerves?
C2 and C3
as the great auricular nerve enters the parotid gland what does it do?
divides into anterior and posterior branches
the anterior branch of the great auricular branch combines with the facial nerve to supply what?
skin over the parotid gland
what does the posterior branch of the great auricular branch supply?
supplies the skin over the mastoid process
