Cells of the Nervous System 1 & 2

Question 1

Recall the major structural compartments of a neuron and what their functions are:
Axons

Answer 1

Output information
No rough ER or free ribosomes
1mm to 1m long

Question 2

Recall the major structural compartments of a neuron and what their functions are:
Presynaptic terminals

Answer 2

No microtubules
Synaptic vesicles
Mitochondria
Synaptic cleft

Question 3

Recall the major structural compartments of a neuron and what their functions are:
Soma

Answer 3

Nucleus
Organelles for protein synthesis and processing
Mitochondria

Question 4

Recall the major structural compartments of a neuron and what their functions are:
Dendrites

Answer 4

Receive information
Can have thousands of synapses
Dendritic branches form dendritic trees
Convergence

Question 5

Describe the methods used to visualise neurons

Answer 5

-Nissl stain - neurons vs glia
-Golgi stain - highlights some neurons
-Immunohistochemistry - antibodies
-Retrograde tracers - cell body location
-Electron microscope - synapses and organelles

Question 6

Recall the different structural classifications of neurons

Answer 6

-Sensory neurons - afferent, info from periphery into CNS
-Motor neurons - efferent, info from CNS out to periphery

Question 7

Describe, with examples, how neuronal structure relates to function

Answer 7

Unipolar e.g. dorsal root ganglion
-reliable relay of information
-small area for receiving synaptic input -therefore highly specialised

Bipolar e.g. retinal bipolar cells
-reliable relay of information
-small area for receiving synaptic input –therefore highly specialised

Multipolar e.g. purkinje cell
-Large area for receiving synaptic input
-High levels of convergence

Question 8

Recall the different glial cell types, their location and function within the nervous system

Answer 8

-Astrocytes - CNS, control the environment surrounding neurons, store glycogen

-Microglia - CNS, macrophages of the CNS

-Oligodendrocytes - CNS, form myelin sheaths of CNS axons

-Shwann cells - PNS, form myelin sheaths of PNS

Question 9

Explain what myelin is and how it ensheaths neuronal axons.

Answer 9

-Myelination is insulating, creating nodes of ranvier, enabling saltatory conduction
-Oligo cytoplasm wraps around axon
-Cytoplasm squeezed out of layers by compaction