Cells Introduction

Question 1

What are the cellular components of the NS?

Answer 1

=Neurones (electrical cells) 
=Glia (supporting cells) 
-Astrocytes
-Oligodendrocytes
-Schwann cells
-Microglia

Question 2

What are the types of neurones?

Answer 2

=Unipolar (intervebrates)
=Multipolar (archetypal)
=Bipolar (classical sensory neurone)
=Pseudounipolar (once Bipolar eg. Sensory ganglia)

Question 3

What are the components of a neurone?

Answer 3

=Dendrites
=Cell body
=Nucleus
=Axon Hillock
=Axon
=Presynaptic cell
=Myelin sheath
=Synaptic terminals
=Synapse
=Postsynaptic cell

Question 4

Describe neurone cell bodies

Answer 4

High energy requirement so lots of mitochondria

Neurotransmitter synthesis and packaging in cell body

Question 5

Describe the pre-synaptic terminal

Answer 5

Microtubule
Neurofibrils
Synaptic vesicles

Question 6

Describe the axon

Answer 6

Nucleus of Schwann cells
Microfilament
Microtubule
Axon
Filament structure supports axon integrity and synaptic vesicle trafficking

Question 7

Describe Axonal Transport

Answer 7

Anterograde transport= takes neurotransmitters and other products down towards the synapse
- Kinesin (heavy chain and light chain)

Retrograde transport= bringing materials back

• Dynein (heavy and intermediate/light chains)
• Dynactin

Railway tracks of scaffolding= microtubules
Cargo= vesicles, cytoskeletal proteins

Question 8

What are the key concepts of synapses?

Answer 8

• Chemical synspase for cell-signalling (neurone to neurone or neuro-muscular junction)
• Slow (diffusion), can induce gain
• Drugable

Question 9

Describe electrical transmission

Answer 9

Two neurones connected tightly through gap junctions via connexion proteins (channels)
Fast connectivity but does not induce gain

Question 10

Describe sensory neurones

Answer 10

Free nerve endings
Specialised nerve endings (pacinian corpuscule= pressure)
Specialised nerve cells (hair cell from ear to detect fluid movement/ photoreceptor in eye)

Question 11

Describe oligodendrocytes

Answer 11

Insulation
1:n ratio with axon (many axons)
CNS

Question 12

Describe the astrocyte

Answer 12

Star shaped
Central to BBB (blood brain barrier) integrity so protects NS from blood
Evolving understanding of multiple cell-cell roles
End feet wrap around blood vessels and stop components of blood diffusing into the NS

Question 13

Describe microglia

Answer 13

Resident macrophage of CNS

Complex roles in development, immune surveillance, disease response and tissue repair