Nerve and muscle degeneration and re-innervation

Question 1

What would happen if a motor neurone in the PNS was damaged?

Answer 1

It has terminally differentiated
Permanent injury results in cell death
No mitosis = no replacemetn

Question 2

Describe the nerve fibres found in type 1 muscle

Answer 2

Slow motor fibres (70m/s)
Small ~70microm
Excitability has low threshold
alpha2 neuron

Question 3

Describe the nerve fibres found in type 2 muscle

Answer 3

Fast motor fibre (120m/s)
Large ~100microm
Excitability has a high threshold
alpha1 neuron

Question 4

What happens in the soma of an axon?

Answer 4

Protein synthesis

Question 5

What is the survival of cytoplasm dependent on?

Answer 5

Interaction with the nucleus

Question 6

What protects peripheral nerves?

Answer 6

Schwann cells
Endoneurium
Perineurium
Epineurium

Question 7

How many spinal nerves are there?

Answer 7

31

Question 8

How many cranial nerves are there?

Answer 8

12

Question 9

What does damage to the cell body result in?

Answer 9

Neuronal death

Question 10

What is a dead neurone replaced with?

Answer 10

Fibrous tissue

astrocytes/fibroblasts

Question 11

What does damage to the axon result in?

Answer 11

Possibility for recovery

Question 12

What is the first stage in repairing a neuron?

Answer 12

Neuronal degeneration