Brain and Nervous System 2

Question 1

What supports neurons in their job

Answer 1

Glial cells

Question 2

where does the word glia come from

Answer 2

greek word for glue

Question 3

4 main functions of glial cells

Answer 3

-support and hold neurons in place
-nourishment = supply O2
-insulate neurons electrically
-protect from pathogens

Question 4

What do blood vessels contain

Answer 4

Continuous capillaries

Question 5

What are capillaries made up of

Answer 5

mosaic of endothelial cells
tight binding between cells

Question 6

what determines capillaries permeabiltiy

Answer 6

how well endothelial cells fit together
(like jigsaw pieces)

Question 7

how well do enothelial cells fit together in capillaries in the brain

Answer 7

fit very well
creates blood brain barrier

Question 8

What reinforces connections between neurons and blood vessels in the brain

Answer 8

Sticky feet of astrocyte projections

Question 9

what are astrocytes

Answer 9

star shapes glial cells in brain and spine

Question 10

What are the types of glial cells

Answer 10

Astrocytes
Schwann
Oligodendrocytes
Microglia

Question 11

What do astrocytes do physically

Answer 11

-support and protect neurons
-contribute to blood-brain barrier (BBB)

Question 12

What do astrocytes do to protect the body

Answer 12

-protects brain from toxins/drugs in blood
-role in inflammatory response

Question 13

what do astrocytes do with other neurons

Answer 13

-astrocytes projections contact capillaries and neurons
-control and coordinate other glial cell types

Question 14

Are astrocytes in periphery or CNS

Answer 14

CNS only

Question 15

what does an astrocyte look like

Answer 15

smaller cell body than neuron, no axon
very long dendrites that connect capillary and neuron
only has cell body that contains nucleus

Question 16

what is the blood brain barrier made up of

Answer 16

-cell membranes

Question 17

is the BBB permeable or impermeable

Answer 17

permeable to fat-soluble substances
anaesthetics, alcohol cross BB easily
rapid effects on CNS

Question 18

WHat system (periphery or CNS) are schwaan cells contained in

Answer 18

periphery

Question 19

what are schwaan cells made out of and what do they produce

Answer 19

-rich in lipids
-produce myelin

Question 20

where are schwann cells

Answer 20

wrap around axons
provide myelin sheath around axons

Question 21

how does the myelin sheath benefit the neuron

Answer 21

-myelin provides electrical insulation
-enhances speed of electrical conductance
-impulses jump between nodes of ranvier

Question 22

what type of conduction is produced from schwann cells

Answer 22

Saltatory conduction

Question 23

what do schwann cells look like

Answer 23

wrap around axon looks like string of sausages

Question 24

what system are oligodendrocytes contained in

Answer 24

CNS only

Question 25

What do oligodendrocytes produce

Answer 25

produce myelin in CNS

Question 26

describe structure of glial cells

Answer 26

-highly branches -contact to several axons and myelin sheaths

Question 27

how much myelin do oligodendrocytes produce

Answer 27

1 ODC produces myelin for several axons

Question 28

what do oligodendrocytes look like

Answer 28

like spiderweb formed between different axons

Question 29

what is the role of oligodendrocytes

Answer 29

form myelin sheath around axons in CNS

Question 30

what happens if oligodendrocytes are damaged

Answer 30

leads to diseases like 'Multiple Sclerosis'

Question 31

what is damaged when someone has multiple sclerosis

Answer 31

autoimmune disease destroys myelin sheath loss of saltatory conduction

Question 32

symptoms of multiple sclerosis

Answer 32

pins and needles loss of motor function visual disturbance

Question 33

what determines how severe the disease is

Answer 33

location of disease nature of symptoms vary severity of demyelination

Question 34

what is the myelinating cell for the CNS and periphery system

Answer 34

CNS = oligodendrocyte Periphery = schwann cell

Question 35

How are the different myelinating cells connected to axons

Answer 35

**CNS** 1 oligodendrocyte -> many axons **Periphery** 1axon -> many schwann cells

Question 36

What are microglia

Answer 36

Immune cells of CNS

Question 37

Microglia main role

Answer 37

-detect and respond to damage or infection in brain and spine

Question 38

How do microglia respond and work

Answer 38

-scavenge CNS looking for debris and bacteria to engulf and digest

Question 39

what type of defence are microglias

Answer 39

primary immune defence within CNS

Question 40

why are microglia important

Answer 40

few antibodies can cross blood brain barrier (BBB), so microglia acts as brains first (primary) defence

Question 41

What do microglias work alongside

Answer 41

Astrocytes

Question 42

Summarise function and location of all glial cells

Answer 42

**Glial Cell** *Location* -Function **Astrocyte** *CNS* -Support BBB -Control other glial cells **Oligodendrocyte** *CNS* -Myelination **Schwann** **cell** *PNS* -Myelination **Microglia** *CNS* -Immune/inflammatory function

Question 43

What do astrocytes do after CNS injury

Answer 43

-divide and become **reactive** -invade injury site (surrounding it) -attract microglia to contain damage

Question 44

Why do astrocytes respond this way

Answer 44

limits the spread of the injury protects remaining CNS

Question 45

What do astrocytes do after invading injury site

Answer 45

Create physical and chemical barrier: -Form glial scar (plaque/cyst) -Release chemicals that blocks axon regrowth

Question 46

Why is it bad that astrocytes form a physical and chemical barrier

Answer 46

Neurons can't reconnect CNS damage is permanent and debilitating

Question 47

How does the PNS differ from the CNS in terms of repair

Answer 47

PNS has fewer specialised support cells BUT **Can** repair and regenerate

Question 48

Why can the PNS regenerate

Answer 48

Lacks glial scarring and has supportive cells (Schwann cells) that promote axon regrowth