Cells of the nervous system

Question 1

What are the functions of the neuron

Answer 1

Generation and conduction of electrical signals

Communication with one another via synapse

Question 2

What cells are neurons supported by

Answer 2

Neuroglia

Question 3

What contributes to the large diversity in neurons

Answer 3

Differences in number and shape of their processes

Question 4

What factors contribute to CNS conditions

Answer 4

Size, location, function and metabolic activity

Question 5

What are the ultrastructural features of neurons

Answer 5

Large nucleus
Abundant RER
Free ribosomes
Well developed golgi
Abundant mitochondria
Highly organised cytoskeleton

Question 6

What are dendrites

Answer 6

Extensions that act as a major area of incoming information e.g. sensory neurons.

Question 7

What is the significance of the highly branched nature of dendrites

Answer 7

Greatly increases surface area

Question 8

How many axons usually are on a cell

Answer 8

one

Question 9

Describe the structure of the axon

Answer 9

Emerges at the axon hillock and conducts impulses away from the cell body

Question 10

Give a difference between axons and dendrites

Answer 10

Axons may branch but they stay the same diameter, while dendrite branches decrease in diameter

Question 11

Which cytoskeleton elements are most prominent in axons

Answer 11

micro-tubules and neurofilaments

Question 12

What are the domains of axon

Answer 12

Node, paranode and junta para-node

Question 13

What is the terminal arbor

Answer 13

The area where axons branch extensively close to the target to form synaptic terminals

Question 14

What are the two types of axon terminals

Answer 14

Boutons and varicosities

Question 15

What is the difference between the two types of terminal

Answer 15

boutons = swelling at the end
Varicosities = multiple swellings along the axon e.g. in smooth muscle

Question 16

Why are synapse cells abundant in mitochondria

Answer 16

Needed for ion pumping and synaptic transmission (45%)

Question 17

What are the synaptic cells sensitive to

Answer 17

Oxygen deprivation

Question 18

What is neuronal integration

Answer 18

Competing inputs are integrated in the postsynaptic neurone

Question 19

What are the types of synapse

Answer 19

Axo-dendritic (excitatory)
Axo-somatic (inhibitory)
Ax-axonic (modulatory)

Question 20

What are the cytoskeletal elements of neurons and what are their functions

Answer 20

Neurofilaments - determining axon caliber

Micro-tubules - very abundant

Question 21

What is fast axonal transport

Answer 21

Transport of membrane associated materials as vesicles are moved down the axon with associated motors

Question 22

What are the morphological subtypes

Answer 22

pseudounipolar
Bipolar
Golgi type I multipolar
Golgi type II multipolar

Question 23

Describe pseudo unipolar cells

Answer 23

Sensory neurons have 2 fused processes

Question 24

Give an example of a bipolar cells

Answer 24

retinal bipolar cells

Question 25

Describe golgi type I multipolar neurons

Answer 25

Highly branched dendritic trees
Axons extend long distances
Pyramidal cells of the cerbral cortex
Purkinje cells of the cerebellum 
Anterior horn cells of the spinal cord
Retinal ganglion cells
Most vulnerable to degeneration

Question 26

Describe golgi type II multipolar neurons

Answer 26

Short axons
Axons terminate quite close to the cell body of origin
Stellate cells of the cerebral cortex and cerebellum

Question 27

Give an example of golgi type II mutipolar

Answer 27

Cerebral cortex

Question 28

What are the functional subtypes

Answer 28

Sensory, motor and interneurons

Question 29

What is the role of interneurons

Answer 29

modification, coordination, integration, facilitation and inhibition of sensory inpu

Question 30

What are oligodendroglia

Answer 30

Cells that produce and maintain myelin sheaths. They have very few other processes

Question 31

What are the ultrastructural features of oligodendroglia

Answer 31

Prominent ER and Golgi and small spherical nuclei

Question 32

What is myelin

Answer 32

A lipid rich insulating membrane that wraps many times around the axon, giving up to as many 50 lamellae

Question 33

Give examples of myelin disease states

Answer 33

Multiple sclerosis

Adrenoleucodystrophy

Question 34

Where do the microglia derive from

Answer 34

The bone marrow

Question 35

What are the functions the microglia

Answer 35

Involved in immune surveillance
Presentation of antigens
First cells to react to infection or damage
Tissue modelling
Synaptic stripping

Question 36

What are the functions of Schwann cells

Answer 36

Myelin producing cells of the peripheral nervous system. Each cell makes one myelin sheath