Pathology

Question 1

What is a lesion?

Answer 1

A zone of localized dysfunction within the nervous system

Question 2

What are the 2 classifications of lesions?

Answer 2

• Anatomic: Structural

- Physiologic: Dysfunction, but no structural lesion

Question 3

What are symptoms?

Answer 3

Subjective sensations resulting from a disorder

Question 4

What are signs?

Answer 4

Objective abnormalities detected on exam.

Question 5

Is a headache a symptom or sign?

Answer 5

Symptom

Question 6

Is hyperreflexia a symptom or sign?

Answer 6

Sign

Question 7

What is a syndrome?

Answer 7

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

Question 8

What are negative and postive neurological manifestations of lesions?

Answer 8

Negative: Loss of function
Positive: Result from inappropriate exciitation

Question 9

What neurological senses are required for gait?

Answer 9

• Sensory
• Cerebellar
• Visual
• Vestibular

Question 10

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

Answer 10

• Distal

Question 11

What type of distribution do neurogenic diseases tend to have?

Answer 11

• Glove/ stocking distribution

Question 12

What are the 2 types of neurogenic diseases?

Answer 12

• Motor neuron

- Peripheral neuropathies

Question 13

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

Answer 13

• Fasciculation (visible)

- Fibrillations (not visible)

Question 14

What are “diseases of the muscle” called?

Answer 14

Myopathies

Question 15

What is the primary problem of myopathies?

Answer 15

Muscle weakness

Question 16

Do myopathies tend to be proximal or distal?

Answer 16

Proximal

Question 17

What are muscular dystrophies?

Answer 17

Myopathies with special characteristics such as:

• Heredity
• Progressive weakness and wasting

Question 18

Which muscle system tends to cause death in myopathies?

Answer 18

Respiratory system

Question 19

What is a myotonic disorder?

Answer 19

An abnormality of the muscle fiber membrane

Question 20

How is the muscle affected by a myotonic disorder?

Answer 20

• Marked delay in relaxation

- Increased stiffness for an extended period of time

Question 21

What is the pathogenesis of Myansthenia Gravis?

Answer 21

• Autoimmune disorder where antibodies attach the acetycholine receptor

Question 22

What is the progression of Myasthenia Gravis?

Answer 22

• Slow, progressive

Question 23

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

Answer 23

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

Question 24

What age and gender are affected by Myasthenia Gravis?

Answer 24

• Any age

- More common in females

Question 25

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

Answer 25

Ptosis

Question 26

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

Answer 26

The synapse

Question 27

Describe the 4-step process of Wallerian Degeneration.

Answer 27

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

Question 28

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

Answer 28

- Distal to lesion | - One or 2 nodes proximal to lesion

Question 29

What is chromatolysis?

Answer 29

- 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

Question 30

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

Answer 30

- Muscle is no longer innervated and atrophies | - Nerves synapsing on axon atrophy

Question 31

What type of injury will cause Wallerian Degeneration/ Chromatolysis?

Answer 31

Axonotemesis

Question 32

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

Answer 32

- Degeneration/ myelin removal

Question 33

What protective coating must remain for nerve eregeneration to occur?

Answer 33

Neurolemma

Question 34

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

Answer 34

- Filopodia

Question 35

How do filopodia help a nerve regenerate?

Answer 35

- The filopodia attach to the schwann cell and provide a scaffolding for other filopodia to grow - The filopodia then become myelinated

Question 36

At what rate do nerve regenrate?

Answer 36

1 mm/day

Question 37

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

Answer 37

- An axon may shoot a collateral to plug a hole | - A glia cell may plug the hole

Question 38

What is apoptosis?

Answer 38

Orderly, genetically programmed cell death

Question 39

What synaptic stripping?

Answer 39

- Synaptic terminals withdraw from neuron, and are replaced by processes of glia cells

Question 40

What substance from schwann cells attract neurons?

Answer 40

- Chemotropic factors

Question 41

Why may a neurolemma or cell die in the periphery?

Answer 41

- If the filopodia do not reach a schwann cell

Question 42

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

Answer 42

Inhibitory molecules

Question 43

What 4 factors contribute to poor central NS regeneration?

Answer 43

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