Exam 2 Study Guide 5

Question 1

Demarcation between PNS and CNS

Answer 1

CNS: encased in bone
PNS: not in bone

Question 2

How are peripheral nerves constructed?

Answer 2

parallel bundles of axons surrounded by 3 sheaths

Question 3

3 sheaths

Answer 3

• endoneurium
• perinerium
• epineurium

*mesoneurium outside of that

Question 4

What supplies blood to the peripheral nerves?

Answer 4

Arterial branches that enter the nerve trunk

Question 5

What structures are supplied by peripheral nerves?

Answer 5

• visceral

- somatic structures

Question 6

somatic peripheral nerves

Answer 6

usually mixed, consisting of sensory, autonomic, and motor axons

Question 7

cutaneous branches of peripheral nerves supply

Answer 7

• skin

- subcutaneous tissues

Question 8

muscular branches of peripheral nerves supply

Answer 8

• muscles
• tendons
• joints

Question 9

4 nerve plexuses

Answer 9

• cervical
• brachial
• lumbar
• sacral

Question 10

movement and nerve health

Answer 10

promotes flow of blood through nerves and axoplasm

Question 11

nerve movements and sheaths

Answer 11

• fascicles glide within the nerves

- nerves glide along with other structures

Question 12

myopathy

Answer 12

disorder intrinsic to muscles

Question 13

What remains intact with myopathies?

Answer 13

• sensation

- autonomic function

Question 14

When is coordination, muscle tone, and reflexes affected with a myopathy?

Answer 14

only when atrophy is so severe that muscle activity can’t be elicited

Question 15

pins and needles sensations increase with

Answer 15

severity of neuropathy

Question 16

signs of damage from neuropathy result from

Answer 16

hypoactivity or hyperactivity of neurons

Question 17

When does severance occur?

Answer 17

when nerves are physically divided by excessive stretching or a laceration
- axons completely interrupted

Question 18

What happens immediately with severance injury?

Answer 18

• loss of sensation
• muscle paralysis

in area supplied

Question 19

When would severance result in regrowth/repair?

Answer 19

• if proximal and distal nerve stumps are apposed and

- scarring doesn’t interfere

Question 20

focal compression of a peripheral nerve causes

Answer 20

traumatic myelinopathy

Question 21

repeated mechanical stimuli may cause

Answer 21

focal compression

Question 22

Where does collateral sprouting occur for repair of nerve injury?

Answer 22

proximal stump

Question 23

What must be the case for regeneration to occur?

Answer 23

PNS only

cell body must be intact

Question 24

What do Schwann cells do for regeneration?

Answer 24

• myelinate axons
• secrete chaemotactic factors that promote growth and axon guidance
• secrete neurotrophic factors

Question 25

axon rate of regrowth

Answer 25

1-2 mm per day

Question 26

What happens if the NMJ fails to function?

Answer 26

- no depolarization occurs - weakness - atrophy

Question 27

MG

Answer 27

- affects NMJ - damages ACH receptors - repeated use of a muscle leads to weakness

Question 28

botulism poisoning causes interference with

Answer 28

release of ACH from motor axons

Question 29

botulism poisoning causes:

Answer 29

- acute progressive weakness - loss of stretch reflex - sensation remains intact

Question 30

some types of peripheral nerve damages

Answer 30

- sensory changes - autonomic changes - motor changes - trophic changes

Question 31

types of sensory changes in response to peripheral nerve damage

Answer 31

- allodynia - dysesthesia - paresthesia - hyperalgesia

Question 32

3 types of peripheral neuropathy

Answer 32

- mononeuropathy - multiple mononeuropathy - polyneuropathy

Question 33

types of traumatic mononeuropathies

Answer 33

- axonopathy - myelinopathy - severance

Question 34

neuropathy vs. myopathy

Answer 34

neuropathy: disorders dealing with damage to axon, myeline sheath, or both myopathy: disorder intrinsic to muscles themselves

Question 35

What is a muscular dystrophy? (general)

Answer 35

progressive weakening and wasting of muscle