Spinal Cord and PNS Pt. 1

myelinated

most peripheral nerves are

Schwann cells

myelinating cells in the PNS are also called what?

epineurium

surrounds the entire nerve

perineurium

surrounds each fascicle

endoneurium

surrounds each nerve fiber

motor endplate

the postsynaptic membrane of a neuromuscular junction

ganglion

cluster of cell bodies in PNS

plexus

network of nerves

cervical and lumbar

the spinal cord is wider at what two levels of the spine?

L1-L2

at what level does the spinal CORD end

8

how many pairs of cervical spinal nerves are?

12

how many pairs of thoracic spinal nerves are there?

5

how many pairs of lumbar spinal nerves are there?

5

how many pairs of sacral spinal nerves are there?

1

how many pairs of coccygeal spinal nerves are there?

intervertebral foramen

where do spinal nerves exit?

brachial plexus

lumbosacral plexus

dorsal root

the sensory branch of each spinal nerve

POSTERIOR

ventral root

the motor branch of each spinal nerve

ANTERIOR

ventral ramus

the anterior division of spinal nerves that communicate with the muscle and skin of the anterior and lateral trunk

motor and sensory innervation in the front of the body

plexuses derive from here

ventral

which rami is larger? ventral or dorsal?

dorsal ramus

motor and sensory innervation of the back of the body

SMALLER

dorsal rootlets

dorsal root

B

dorsal root ganglion

A

ventral rootlets

ventral root

spinal nerve

sensory and motor neurons

dorsal ramus

ventral ramus

gray ramus

communication between ANS and spinal nerves

white ramus

communication between ANS and spinal nerves

sympathetic ganglion

cervical nerves

thoracic nerves

lumbar nerves

conus

cauda equina

sacral nerves

coccygeal nerves

shingles

lives in the DRG

wakes up because of: mental stress, immune system deficiency

causes nerve pain

17-18 in

length of adult spinal cord

9 in

length of child spinal cord at birth

5 in

length of spinal cord in a fetus is about

C4-T1

where does cervical enlargement of the spinal cord occur?

T11-S1

where does lumbar enlargement of the spinal cord occur?

L1

where is conus typically located on the spinal cord? what level?

filum terminale

fibrous extension of the pia mater; anchors the spinal cord to the coccyx

cauda equina

"horse's tail", a fan of nerve fibers below the termination of the spinal cord

at about L1/L2