Neurons & Glial cells

Question 1

What is the CNS composed of?

Answer 1

Brain

Spinal cord

Question 2

What is the PNS composed of?

Answer 2

Nerves that connect the body’s muscles, organs and tissues to the CNS

Question 3

What are the 5 basic components of the neuron?

Answer 3

Dendrites (dendritic spines)
Cell body/ soma
Axon hillock
Axon
Presynaptic terminal

Question 4

Function of dendritic spines? (2)

Answer 4

Increase SA

Basis of memory & learning

Question 5

What are the 3 functional classes of neurons?

Answer 5

Afferent (sensory)
Interneurons
Efferent (motor)

Question 6

Define nerve fibre

Answer 6

A single axon

Question 7

Define nerve

Answer 7

Bundle of axons bound together by connective tissue

Question 8

What do kinesins do?

Answer 8

Anterograde

Carry nutrients from cell body to axon terminal

Question 9

What do dyneins do?

Answer 9

Retrograde

Carry (waste) substances from axon terminals back to cell body

Question 10

What myelinates axons of the CNS?

Answer 10

Oligodendrocytes

Question 11

What is the composition of myelin?

Answer 11

70% lipid

30% protein

Question 12

What myelinatyes axons of the PNS?

Answer 12

Schwann cells

Question 13

How many axons can an oligodendrocyte myelinate?

Answer 13

Up to 40 - lots

Question 14

How many axons can a schwann cell myelinate?

Answer 14

One

Question 15

What are nodes of Ranvier?

Answer 15

Spaces between adjacent sections of myelin where axon is exposed to ECF

Question 16

Purpose of myelin?

Answer 16

To increase speed of conduction along axons

Question 17

Are myelinated or unmyelinated axons thicker?

Answer 17

Myelinated

Question 18

What are two ways of increasing the speed of conduction?

Answer 18

1. Increase axon diameter (but limitations)

2. Insulation (myelination)

Question 19

Microscopic differences between chemical and electrical synapses?

Answer 19

Chemical: synaptic cleft, presynaptic vesicles, postsynaptic density

Electrical synapse: electron density on pre- and post-synaptic membranes

Question 20

Functional differences between chemical and electrical synapses?

Answer 20

Chemical: one way transmission, inhibitory/excitatory, neurotransmitter

Electrical: two way transmission, gap junctions join pre- adn post-synaptic membranes

Question 21

Function of astrocytes (star-like)? (4)

Answer 21

• Regulate composition of ECF (remove K+ and neurotransmitter)
• Convert glutamate –> glutamine
• Stimulate formation of tight junctions
• Form BBB (foot processes)

Question 22

Where are protoplasmic astrocytes found?

Answer 22

In grey matter

Question 23

Where are fibrous astrocytes found?

Answer 23

In white matter

Question 24

Where are radial glia found?

Answer 24

In developing brains (not found in adults)

Question 25

Function of radial glia?

Answer 25

Guide developing neurons

Question 26

Where are Bergmann glia found?

Answer 26

In cerbellum

Question 27

Function of Bergmann glia?

Answer 27

Supoort purkinje cell dendrites and synapses

Question 28

Function of microglia?

Answer 28

• Macrophage-like cells that perform immune functions in CNS

- Contributre to synaptic plasticity

Question 29

Function of ependymal cells? (2)

Answer 29

• Line ventricles of the brain and spinaln cord

- Rgulate flow & production of CSF

Question 30

Epilepsy is a disease of?

Answer 30

Neurons

Question 31

Motor neuron disease is a disease of?

Answer 31

Neurons & glia

Question 32

Depression is a disease of?

Answer 32

Neurons & glia

Question 33

Alzheimer’s disease is a disease of?

Answer 33

Neurons & glia

Question 34

Multiple sclerosis is a disease of?

Answer 34

Neurons & glia (oligodendrocytes are attacked)