L12: Degeneration And Regeneration Of Nerves

Question 1

In the somatic nervous system what is the effector

Answer 1

Skeletal muscle

Question 2

In the autonomic nervous system what is the effector

Answer 2

Cardiac muscle
Smooth muscle
Secretory glands

Question 3

What is the Seddons classification

Answer 3

The 3 classes of responses expected from a neurone after damage

Question 4

What is seddons 3 classes

Answer 4

Neuropoxia
Axonotomesis
Neurotmesis

Question 5

What are the 3 layers of the axons

Answer 5

Endoneurium
Perineurium
Epinineurim

Question 6

Which layer is the most superficial

Answer 6

Epiniurium

Question 7

Which layer is the deepest

Answer 7

Enoneurium

Question 8

What is neuropraxia

Answer 8

When the myelination of a neurone is disturbed

Question 9

Is the loss of function in neuropaxia permanent

Answer 9

No it is temporary and function is normal after recovery

Question 10

What is axonotmesis

Answer 10

When axons with myelin sheath is damaged

Question 11

In axonotmesis does the 3 layers of the neurone remain intact

Answer 11

Yes

Question 12

What is axonotmesis a result of

Answer 12

Severe crush

Question 13

What happens during axonotmesis

Answer 13

Wallerian degeneration

Question 14

What is neurotmesis

Answer 14

When the entire nerve is completely injured

Question 15

What layers become damaged in neurotmesis

Answer 15

Axon and connective tissue

Question 16

Does recovery occur in neurotmesis

Answer 16

Not fully if the damage is close to the cell body

Question 17

From the seddons classification what is the most sever class of injury

Answer 17

Neurotmesis

Question 18

Which factors are released when there is a damaged neurone

Answer 18

Myelin forming cells
Astrocytes
Microglia

Question 19

What are myelin forming cells

Answer 19

Oligodendrocytes

Schwann cells

Question 20

What do oligodendrocytes do

Answer 20

Myelinate up to 250 axons at the same time

Question 21

What do Schwann cells do

Answer 21

Demyelination of one axon

Question 22

What do astrocytes do

Answer 22

Create environment for neurone

Question 23

What do microglia do

Answer 23

They are activated and start to digest material around by contracting around injury

Question 24

What happens to a damaged neurones minutes after injury

Answer 24

Neurone stops conduction AP
Two ends will be exposed and leak into extracellular fluid
Two ends cut and seal and swell apart

Question 25

What happens to a damaged neurone hours after

Answer 25

Synaptic terminal degenerates by macrophages and phagocytosis
Astrogliua surrounf the synaptic terminal for further degeneration

Question 26

What happens to a damaged neurone days after

Answer 26

Cell body undergo chromatolysis
Volume of cell body increases due to protein production
Nucleus is pushed to the side of the body
Injured nerve forms a neuroma

Question 27

What is chromatolysis

Answer 27

Breaking up of a cell in a colourful way

Question 28

What happens to a damaged neurone weeks after

Answer 28

Distal stump of axon undergo wallerian degeneration and is removed by phagocytosis
Tissues are preserved
Regenerating axons form many sprouts into Schwann cells

Question 29

Which nervous system is oligodendrocytes found in

Answer 29

Central nervous system

Question 30

Which nervous system is Schwann cells found in

Answer 30

Peripheral nervous system (PNS)