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Flashcards in Pathology Deck (43)
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1
Q

What is a lesion?

A

A zone of localized dysfunction within the nervous system

2
Q

What are the 2 classifications of lesions?

A
  • Anatomic: Structural

- Physiologic: Dysfunction, but no structural lesion

3
Q

What are symptoms?

A

Subjective sensations resulting from a disorder

4
Q

What are signs?

A

Objective abnormalities detected on exam.

5
Q

Is a headache a symptom or sign?

A

Symptom

6
Q

Is hyperreflexia a symptom or sign?

A

Sign

7
Q

What is a syndrome?

A

A constellation of signs and symptoms associated with each other, suggesting a common origin

8
Q

What are negative and postive neurological manifestations of lesions?

A

Negative: Loss of function
Positive: Result from inappropriate exciitation

9
Q

What neurological senses are required for gait?

A
  • Sensory
  • Cerebellar
  • Visual
  • Vestibular
10
Q

Do neurogenic diseases tend to be more distal or more proximal?

A
  • Distal
11
Q

What type of distribution do neurogenic diseases tend to have?

A
  • Glove/ stocking distribution
12
Q

What are the 2 types of neurogenic diseases?

A
  • Motor neuron

- Peripheral neuropathies

13
Q

What are the 2 signs/ symptoms of neurogenic disease of the motor unit?

A
  • Fasciculation (visible)

- Fibrillations (not visible)

14
Q

What are “diseases of the muscle” called?

A

Myopathies

15
Q

What is the primary problem of myopathies?

A

Muscle weakness

16
Q

Do myopathies tend to be proximal or distal?

A

Proximal

17
Q

What are muscular dystrophies?

A

Myopathies with special characteristics such as:

  • Heredity
  • Progressive weakness and wasting
18
Q

Which muscle system tends to cause death in myopathies?

A

Respiratory system

19
Q

What is a myotonic disorder?

A

An abnormality of the muscle fiber membrane

20
Q

How is the muscle affected by a myotonic disorder?

A
  • Marked delay in relaxation

- Increased stiffness for an extended period of time

21
Q

What is the pathogenesis of Myansthenia Gravis?

A
  • Autoimmune disorder where antibodies attach the acetycholine receptor
22
Q

What is the progression of Myasthenia Gravis?

A
  • Slow, progressive
23
Q

How are the muscles affected by Myasthenia Gravis? What are the 2 major symptoms?

A
  • Weakness is patchy, and not related to the distribution of any single nerve
  • Weakness fluates
  • Decreased muscular endurance
24
Q

What age and gender are affected by Myasthenia Gravis?

A
  • Any age

- More common in females

25
Q

What is it called when the eye is half open (common in Myasthenia Gravis)?

A

Ptosis

26
Q

At what level is the motor unit affected by Myasthenia Gravis?

A

The synapse

27
Q

Describe the 4-step process of Wallerian Degeneration.

A

Less than 24 hours: Neurofilaments break up; axons break up into short lengths
Within 10 days: Myelin sheath breaks down into lipid droplets around axon
Within Month: Myelin denatures
Within 3 Months: Macrophages from endoneurium invage myelin sheath and axis cyclinder and phagocytize everything

28
Q

Where are fat droplets found in relation to the lesion in Wallernian Degeneration?

A
  • Distal to lesion

- One or 2 nodes proximal to lesion

29
Q

What is chromatolysis?

A
  • When an axon is damaged, the cell swells, nucleus swells, and protein substances move to one side producing protein, and sending it down to the site of injury
30
Q

How are muscles and nerves affected when healing of an axon begin?

A
  • Muscle is no longer innervated and atrophies

- Nerves synapsing on axon atrophy

31
Q

What type of injury will cause Wallerian Degeneration/ Chromatolysis?

A

Axonotemesis

32
Q

What must occur before healing of a nerve begins in the periphery?

A
  • Degeneration/ myelin removal
33
Q

What protective coating must remain for nerve eregeneration to occur?

A

Neurolemma

34
Q

What are the structures that sprout from proximal nerves in a damaged peripheral nerve during healing?

A
  • Filopodia
35
Q

How do filopodia help a nerve regenerate?

A
  • The filopodia attach to the schwann cell and provide a scaffolding for other filopodia to grow
  • The filopodia then become myelinated
36
Q

At what rate do nerve regenrate?

A

1 mm/day

37
Q

What are 2 methods of neural plasticity in an axonal/ neuronal injury?

A
  • An axon may shoot a collateral to plug a hole

- A glia cell may plug the hole

38
Q

What is apoptosis?

A

Orderly, genetically programmed cell death

39
Q

What synaptic stripping?

A
  • Synaptic terminals withdraw from neuron, and are replaced by processes of glia cells
40
Q

What substance from schwann cells attract neurons?

A
  • Chemotropic factors
41
Q

Why may a neurolemma or cell die in the periphery?

A
  • If the filopodia do not reach a schwann cell
42
Q

What inside the perineurium can prevent the regenerating axons from going astray?

A

Inhibitory molecules

43
Q

What 4 factors contribute to poor central NS regeneration?

A
  • Glial scars
  • Growth inhibition from Oligodendroglia
  • Do not have trophic factors required for regeneration
  • No neurolemma sheath