3.21 Spinal Region Lecture 1 Flashcards
demarcation of peripheral nervous system
between DRG and rami (not encased in bone)
What’s in the spinal region?
- spinal cord
- dorsal root
- ventral root
- spinal nerve (briefly)
- meninges
Where does the SC run?
medulla » L1/L2
What’s in the SC?
- cauda equina
- filum terminale
cauda equina
long roots that exit L2-L5 spaces
L2-L5 spaces
intervertebral foramina
filum terminale
connection of SC to coccyx
landmarks on anterior SC
- median fissure
- 2 anterolateral sulci
median fissure for:
blood supply (2/3)
anterior sulci for:
exiting ventral roots
landmarks on posterior SC
- median sulcus
- 2 posterolateral sulci
posterior median sulcus for:
blood supply (1/3)
posterior sulci for:
entering dorsal roots
spinal nerve =
all sensory and all motor for one SC segment
Which of these is closest to the SC?
rootlets
roots
nerves
rootlets
relationship between rootlets, roots, and nerves
- rootlets combine to form roots
- roots combine to form nerves
Rexed’s lamina
histologically and funcionally distinct regions of the gray matter
How many pairs of spinal nerves?
31
What are the spinal nerves?
C1-C8
T1-T12
L1-L5
S1-S6
naming of spinal nerve segments
named for intervertebral foramen they exit
i.e. T6 segment: exit T6 intervertebral foramen
C1-C7 exit (above/below)
above
C8-S6 exit (above/below)
below
After exiting the spinal column, what do spinal nerves split into?
rami
dorsal rami innervate
- paravertebrals
- overlying skin
ventral rami innervate
musculoskeletal and cutaneous areas of
- limbs
- anterior lateral trunk
white matter organized into:
columns (somatotopically arranged)
gray matter organized into:
horns
What are the gray matter horns?
- dorsal
- ventral
- lateral
dorsal horn contains:
sensory cell bodies
ventral horn contains:
motor cell bodies (largely LMN)
lateral horn contains:
autonomic cell bodies (preganglionic cell bodies)
Where are lateral horns located?
only in T1-L2
