23 Cells of nervous system - neurons and glia

Question 1

List all the glial cells.

Answer 1

PNS: Schwann cells, satellite cells in sensory ganglia

CNS: astrocytes, oligodendrocytes, microglia

Question 2

What are the changes in Nissl bodies after injury?

Answer 2

Chromatolysis of motor neurons after axonal injury, therefore nissl bodies are indicators for injury in the nervous system

Question 3

What are the 2 configurations of synapses?

Why is there such feature?

Answer 3

1. Between axon terminal and dendritic spine
2. Between axon terminal and shaft of dendrite

• spines increase the surface area for contact of dendrite with axons

Question 4

What is the clinical significance of the dendritic spines?

Answer 4

Changes in number and morphology of dendritic spines occur in many physiological (e.g. learning and memory) and pathological processes (dementia, Alzheimer’s disease)

Question 5

What are the functions of astrocytes?

Answer 5

1. wrap around blood vessels: BBB
2. wrap around synapses: removal and recycling of NT and modulate synaptic activity
3. secrete growth factors for neuronal growth and activity

Question 6

What are the functions of oligodendrocytes?

Answer 6

1. form myelin sheath
2. saltatory conduction
3. inhibits CNS regeneration after injury

Question 7

Which of the below is incorrect about microglia?

A. They are active sensors of the environment
B. They phagocytose degenerating neuronal debris , acting like brain macrophages
C. They decrease in number and size in injured processes
D. Development of chronic pain is due to glial cells synthesizing cytokines to further excite injured neuron

Answer 7

C

Injured CNS: Increase number and size (cell bodies) and have stouter processes