Test 4 - Ch. 17 Flashcards
What are we talking about when we say peripheral nervous system?
EVERYTHING distal to spinal Nerves
Where are peripheral cell bodies located?
dorsal root ganglion
What are the peripheral anterior ramus in charge of?
house axons that feed arms and legs in front of me
What are the peripheral posterior ramus in charge of?
sensory and autonomic in back of me
What happens with damage to spinal N?
dermatome loss
many Mm weak
What happens with damage to peripheral N?
Dermatomal loss of Median N supply
Paralyzed motor loss of Mm served by that peripheral N
What is the order of connective tissue wrapping a peripheral axon?
axon > endoneurium > perineurium > epineurium
end - right around axon
perineurium - fasciculus - bundle of axons - around N
epi - gathers all fascicles
What group of axons are efferent extrafusal that contract big Mm?
A-Alpha
What group of axons are afferent proprioception sensory?
1a, 1b, II
What group of axons are afferent exteroception, temperature, visceral receptors?
A-Beta
What group of axons are efferent – intrafusal muscle spindle sensitivity
A- gamma
What group of axons are afferent – pain, temperature, viscera (Sharp and stinging that alert us to move)
A-delta
efferent – presynaptic autonomic axon group
B pre gang
afferent – pain, temperature, viscera dull aching, chronic pain axon group
A
efferent – postsynaptic autonomic axon group
C post gang
Which is the only plexus that has parasympathetic nervous fibers?
L4-S4 - sacral
One peripheral N gets input from —-?—– spinal N
One spinal N branches out to —?—- peripheral N
many
multiple
What does A-alpha motor neurons leak a little bit of when m is at rest?
ACl
What kind of atrophy occurs when peripheral N is cut?
atrophy of denervation
What is the order of sensory loss with compression
Con cold fast heat slow
What are some autonomic changes with peripheral dysfunction?
loss of sweating
loss of shunting
loss of capacitance - orthostatic hypotension
What are some motor changes with peripheral dysfunction?
paresis
paralysis
atrophy of denervation
fibrillations
What are trophic changes after denervation due to?
Blood supply changes
Loss of autonomic innervation
Loss of sensation
Loss of movement
What are the three classifications of neurozpathesis and describe them.
Mononeuropathy (one) -ONE NERVE SICK -UNILATERAL CARPAL TUNNEL SYNDROME Multiple mononeuropathy (several) -MULTIPLE SINGLE NERVES -BILATERAL CARPAL TUNNEL SYNDROME Polyneuropathy (many) -MANY NERVES AFFECTED AT ONCE -STOCKING AND GLOVE (DIABETES) -TOES, FEET, ANKLE, LEGS/ FINGERS, HANDS, WRIST AND FOREARM -MULTIPLE DERMATOMES AND MULTIPLE PERIPHERAL NN
Describe the feeling of traumatic myelinopathy.
CROSSING LEGES AND FOOT FALLS ASLEEP – SQUEEZE COMMON FIBULAR N – ISCHEMIC- ALL AXONS FELL ASLEEP
- TEMPORARY ISCHEMIA
- RETURN BLOOD FLOW
- AXON WAKES UP
- PROLONGED ISCHEMIA – MYELIN MAY DIE AROUND IT
IF MYELIN DIES, PROGNOSIS IS NOT AS GOOD
Traumatic Axonopathy
= peripheral neuropathy
Axon dies and degenerates distal to point of injury.
Prognosis good. Recovery in weeks to months (1” per month).
severance
Axon and connective tissue tube is cut off, Proximal axon will try to regrow but may not connect to correct tube
prognosis - guarded
Polyneuropathy
Many nerves sick
Typically symmetric involvement of sensory, motor and autonomic
Stocking and glove neuropathy
-typically develops distally to proximmaly
-diabetic neuropathy the smallest most distal fail to distribute blood
cannot feel stimulus that would otherwise damage – cause of ulcers
Lost of sensory in many nerves (ulnar, median and radial)
Myasthenia Gravis
Degeneration of Ach receptors on postsynaptic-cleft
Where A-alphas come down
When ACl receptors disappear from neuromuscular jx
Esterase come closer to surface and Acl is eaten up before it can bind to a receptor
Mm contraction starts out strong then fades
Botulism
Impaired release of Ach from presynaptic - cleft
Inject this into M that is over-active
Causing M to not contract
Ca++ not coming in then Acl will not be outputted
Pt with injury to brain
BS hyperactive
Mm tonically contracted
Inject with Botox – brain is still sending messages but Mm not responding
Stretch and allow ROM to remodel M and brain for norm fx
Typicallly lasts a month
