Ch. 12: Peripheral NS Flashcards Preview

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Flashcards in Ch. 12: Peripheral NS Deck (29):
1

Peripheral Nerve

-distal axon projections
-After nerve leaves spinal canal

2

Cervical Plexus

-C1-C4
-motor, sensory, sympathetic to neck and tops of shoulders

3

Brachial Plexus

-C5-C8, T1
-Motor, sensory, sympathetic to arms

4

Sacral Plexus

-L4-S4
-motor, sensory and parasympathetic to back and bottom of legs

5

Damage to spinal nerve causes:

-minor weakness to 1+ muscles
-(b/c Mm are innervated by more than one spinal level)

-sensory loss in dermatomal pattern

6

Damage to Peripheral Nerve Causes:

-paralysis to 1+ Mm
-(b/c a muscle is only supplied by one peripheral nerve)

-sensory loss in peripheral pattern

7

Spinal Nerve at risk from:

-bulging disc
-collapse of intervetebral foramen

8

Lumbar Plexus

-L1-L4
-motor, sensory, sympathetic to front of legs

9

Principles of a plexus

-one peripheral nerve gets axons from many different spinal levels
-one spinal level sends axons to many different peripheral nerves

10

Spinal Nerve

-joining of one spinal level
-all sensory, motor and autonomic
-dividing line between central and peripheral NS
-dermatomal/myotomal pattern when damaged

11

Rami

-ventral
-dorsal
-communicating

12

Axon Connective Sheaths

-endoneurium
-perineurium
-epineurium

13

Nerves and movement

-nerves love blood, space and movement
-Movement increases blood flow, facilitates gliding of N, and axoplasmic transport
-nerve axons have wrinkling in endoneurium to allow movement

14

If nerves can't move:

the axons stick to connective tissue and shorten

15

Dysfunction of peripheral Nn

-Sensory changes
-Motor changes
-Autonomic changes

16

Autonomic changes
(peripheral nerve damage)

-decreased function
-decreased sympathetic function

(there is no parasympathetic in peripheral nerves)

17

NMJ

-EPSP only
-atrophy of denervation if axons die

18

Sensory Changes
(damage to pheripheral nerve)

-location depends on where it's damaged
-depends on how much damage
-Anesthetic/Analgesic or both

19

Motor damage
(to peripheral nerve)

-location depends on what's damaged
-severity depends on how much damage

20

changes following denervation

-fibrillations
-trophic changes (to nerve, muscle, skin)

21

Traumatic Axonopathy

-axon and myelin degenerate, but connective tissue tube remains
-Wallerian degeneration distal
-Recovery: good

22

Axon regrowth rate

1 inch/month

23

Multiple mononeuropathy

-involves 2+ discrete Nn in different body parts

24

Classification of peripheral neuropathies

-mononeuropathy
-multiple mononeuropathy
-Polyneuropathy

25

Traumatic Myelinopathy

-temporary disruption of conduction along axon membrane
-axon intact
-demyelination possible
-Recovery: excellent
- +Tine's sign (b/c demyelinated areas upregulate mechanoreceptors)

26

Severance

-axon/myelin degenerate and connective tissue tube is severed
-wallerian degeneration distal
-Recovery: fair
-axons may not find connective tissue tube (can form neuroma)
-may go into other tube and become nonfunctional

27

Polyneuropathy

-decreased sensory, motor, autonomic starting distal and working to proximal
-no peripheral or dermatomal pattern

28

Causes of Polyneuropathy

-diabetes
-Alcoholism (nutritional deficiencies)
-autoimmune (guillain barre)

29

Mononeuropathy Levels

-traumatic myelinopathy
-traumatic axonopathy
-severance