Neural Degeneration

Question 0

Neurons don’t die unless you have a

Answer 0

Pathology or injury

Question 1

Cells do age causing

Answer 1

Dendritic and axonal connection processes to slow, in general

Question 2

Cns neurons are less capable of regeneration than other

Answer 2

Types of cells in the body

Question 3

The pre and post synaptic membranes must be well-nourished or

Answer 3

The cell body will degenerate

Question 4

Axon degeneration or death affects not only that neuron but

Answer 4

The other neurons which used to be connected to the now dysfunctional/damaged axon

Question 5

The axon MAY be able regenerate to some degree

Answer 5

But glial cells disrupt this process in the cns

Question 6

While groups of neurons may die off at once

Answer 6

Even if only a few are injured such as of it Alzheimer’s

Question 7

Once a neuron in the cns is gone. It’s gone forever

Answer 7

Excerptions- olfactory epithelium and hippocampus

New research-implant stem cells to encourage new neurons (pd)

Question 8

Although the network itself may reorganize its efforts called

Answer 8

Neuroplasticity

Question 9

Axons MAY be able to regenerate if

Answer 9

The cell body is intact

Question 10

Primary neuronal cell death-necrosis

Answer 10

Immediate death/degeneration
As a direct result of some type of trauma, injury, disease, anoxia
Cell body

Question 11

Secondary neuronal cell death

Answer 11

Occurs hours/days/weeks after the primary trauma/injury
In strike secondary cell death occurs in region near primary trauma/injury
Variable processes and or outcomes

Question 12

Secondary neuronal cell death continued

Answer 12

Depends on blood flow, edema, inflammation, and the integrity if the BBB
If swelling/bleeding then new wave if cell death, unexpected

Question 13

Necrosis

Answer 13

Death of cell

No longer exists, or can no longer function

Question 14

Causes of primary cell death

Answer 14

Anoxia/ total lack of oxygen
Hypoxia/ insufficient oxygen
Trauma-focal
Toxic/metabolic poisoning/disrupts cellular mechanisms

Question 15

Trauma/focal

Answer 15

Damage to cytoskeleton, intracellular organelles
Damage to BBB
Damage to axon causing death

Question 16

Axonal (retrograde) reaction - secondary cell death

Answer 16

• Changes and/or death to the cell body
• initial trauma but cell body remain intact
• but axon no longer maintain action potential, disruption extends back into cell body itself
• as a result to damage to the axon

Question 17

Process of cell death

Answer 17

Internal changes to cell body take place
Cell body swells
Nucleus becomes displaced
Disruption of BBB and deterioration of cytoskeleton occur
Cell body disintegrates, explodes

Question 18

Process of cell death continued

Answer 18

Macrophages take over to liquify the mess of necrotic tissue
Phagocytes work to remove the dead mass tissue
May take several months to years
Tissue removal will leave a cavity in the brain-take months to years

Question 19

Wallerian (anterograde) degeneration

Answer 19

Degeneration to the distal part of the axon away from the site of the actual injury

Question 20

Process of wallerian

Answer 20

The distal part of the axon will swell within 24 hours
Within days, the muscles which were previously Innervate by this axon will become denervated- see changes in muscle tone-atrophy

Question 21

Wallerian process

Answer 21

Within 1 week the axon and it’s myelin are disintegrated
Macrophages and phagocytes take over to liquify and remove dead tissue
May take months to years to remove everything
In rue meantime macrophages and phagocytes block the site of injury

Question 22

Axonal damage/death affects

Answer 22

Receiving (post synaptic) and transmitting (presynaptic)

Question 23

The resulting impact depends on the

Answer 23

Extent of involvement this axon had with its region/network