Ch. 14 Flashcards
average individual spinal cord length
45 cm long and 0.5 max width
spinal cord goes down to
L1 L2
spinal cord stops growing after age
4
very end of the spinal cord is called
conus medullaris
root to stabilize conus medullaris
filum terminale
inferior nerve roots on spinal cord
cauda equina
spinal nerve amount
31 pairs
posterior surface of spinal cord groove
posterior median sulcus
anterior surface of spinal cord deep
anterior median fissure
center of spinal cord hole
central canal contains cerebrospinal fluid
spinal cord gray mater forms
butterfly
gray matter is where you see
clusters of cell bodies and interneurons
horn that is in the top left corner
posterior dorsal gray horn
below the posterior dorsal gray horn is the
lateral intermediate gray horn
what type of neurons does posterior dorsal gray horn have
sensory nuclei
lateral gray horn does
motor nuclei that are autonomic, cardiac smooth muscle
front of horn gray matter
anterior ventral gray horn
anterior ventral gray horn nuclei
skeletal muscle signal
the most superficial of the meninges is the
dura mater
dura mater means
hard durable mother
dura mater is
tough tissue fibrous ct
space above or on top of dura mater
epidural space
middle layer of spinal meninges
arachnoid mater
minimal space between spinal meninges
arachnoid mater and dura mater
when you die arachnoid mater and dura mater
seperate and make subdural apace
space after arachnoid mater is
subarachnoid space
subarachnoid space is where
cerebrospinal fluid flows
subarachnoid space is filled with
elastic fibers and collagen
deepest layer of spinal meninges
pia mater
pia mater attachment
very tight with neural tissue
pia mater includes
blood vessels to help nutriate
BOTH spinal and epidural anesthesia involve injecting anesthesia near
spinal cord, patient is awake, avoid risks of general
most spinal and epidural differences have to do with
location of needle
spinal anesthesia, needle penetrates through to
dura mater, arachnoid mater, into the subarachnoid space
with epidural anesthesia it only penetrates
through skin, muscle, and ligaments in epidural space
spinal anesthetic can only be injected
inferior to L2, spinal cord stops there
pain relief anesthesia quickly with
spinal, it is closer to nueral tissue
epidural pain relief time
10-15 minutes
no muscular block with
epidural
epidural anesthesia leaves you with an
catheter to add more
the spinal nerves come off in
dorsal root and ventral root
multiple rots are
rootlets
key diff between dorsal and ventral root
dorsal root is swollen called dorsal root ganglion
dorsal and spinal def
dorsal: sensory
ventral: motor
spinal nerve passes through
intervertebral formana
spinal nerve splits into
dorsal ramus, ventral ramus
dorsal ramus
supply neck and back
ventral ramus
supply ventral body and limbs
dorsal and ventral rami are nerves that
mixed
rami communicantes connects spinal nerve to
sympathetic ganglia
white ramus communicans
myelinated prepanglionic fibers
gray ramus communicans
unmyelinated postganglionic fibers
what part of body is supplied by what nerve is called
dermatome
complex nerve networks
nerve plexuses
plexuses form due to
skeletal small muscles fusing into larger muscles
make ability to send signals with multiple routes
nerve plexuses
cervical plexus arises
c1-c5
cervical plexus innervates muscles
skin of neck, shoulder, and diaphragm
nerve that innervates diaphragm is
phrenic nerve
phrenic nerve formed by
c345
cervical plexus supplies
CN XI= accessory
CNXII hypoglossal
brachial plexus innervates
upper limbs, shoulder, thorax
brachial plexus ranges
c5-T1
brachial plexus nerves
axillary
musculocutaneous
radial
median
ulanr
how many spinal nerves give rise to the plexus
5!!!
lumbar plexus begins and ends
t12-l4
lumbar plexus innervates
abdomen, genitals, thigh, and lower leg
nerves of lumbar plexus
femoral and obturator nerves
lumbar plexus femoral nerve supplies
interior thigh muscle, foot
obturator nerve lumbar plexus supply
adductor muscles of thigh
sacral plexus arises
L4-S4
sacral plexus innervates
genitals, gluteal, thigh, and lower leg
sacral plexus nerves
sciatic and pudendal nerves
sciatic nerve fun fact
largest single nerve in body
a reflux is an
immediate involuntary motor response to specific stimulus
reflex arc is
complete neural pathway
step 1 for reflex
have to stimulate receptor
step 2 reflex
stimulated receptor conveys signal across sensory neuron to spinal cord in brain
step 3 reflex
CNS processing stimulus if it is worth responding too
step 4 reflex
activate motor neuron (efferent), away from spinal cord
step 5 reflex
response by effector
classify development reflexes
reflexes learned or
genetically determined
development reflex example
saliva with food (innate reflex)
acquired (increase saliva)
response reflexes
somatic: skeletal responds
visceral: smooth and cardiac responds
processing site reflexes
spinal reflex: in spinal cord
cranial reflex: in the brain
complexity circuit reflexes
monosynaptic: 1 synapse
polysnaptic: multiple (2-100)
synapse is electrical to
chemical then back to electircal in postsynaptic neuron
more synapses the more
you have to convert, longer it takes
monosynaptics responses take
shorter time but have to be simple
most relfexes in body are
polysynaptic reflex
patellar reflex is
monosynaptic/ stretch reflex
when patella hit
pulls patella, quads, which stretches anterior portion of thigh is stretch
what detects stretch
muscle spindles
crossed extensor reflex is what type
complicated polysnaptic
pain receptors are
noiciceptor
crossed extensor reflex pathways are
divergence followed by serial processing
aka parallel processing
