Cells of CNS (other than neurones)

Question 1

Neurones account for only half of the cells in the CNS the rest are

Answer 1

GLIAL CELLS

Question 2

What do glial cells do

Answer 2

surround the soma (Cell body), axon and dendraites of neurones and provide them with physical and metabolic support

Question 3

Function of Oligodendrocytes

Answer 3

Myelinating cells of the CNS

also provide metabolic support for axons, they are able to transport metabolic products directly into axons

myelinate multiple axons

Question 4

Function of schwann cells

Answer 4

myelinating cells of PNS

only myelinate single axons

Question 5

(1) Function of astrocytes (star like)

Answer 5

help regulate comp of extracelluar fluid In CNS by removing K+ ions and neurotransmitters e.g. (glutamate) around synapses

Question 6

How do astrocytes carry out their function (1)

Answer 6

take up glutamate then convert it to glutamine and release it then neurones can take it up and convert it back to glutamate for reuse

Question 7

(2) Function of astrocytes (star like)

Answer 7

Stimulate formation of tight junctions between the cells that make up the walls of capillaries found in the CNS –

this forms the BLOOD BRAIN BARRIER, which is a much more selective filter for exchanged substances that is present between the blood and most other tissues

Question 8

(2) How do astrocytes carry out their function

Answer 8

help form the blood brain barrier by foot processes closely applies around capillaries

Question 9

(3) Function of astrocytes (star like)

Answer 9

sustain the neurones metabolically e.g. providing glucose and removing ammonia

Question 10

cells are protoplasmic mean?

Answer 10

found in grey matter

Question 11

What does cells are fibrous mean

Answer 11

found in white matter

Question 12

3 specific types of astrocyte

Answer 12

1 radial glia
2 muller Glia
3 bergmann glia

Question 13

Function of Radial Glia

Answer 13

Crucial in guiding developing neurones

these only developmental not found in adult brain

Question 14

Function of Muller glia

Answer 14

specialised radial glia of the retina

Question 15

Function of Bergmann glia

Answer 15

found in the cerebellum, support purkinje cell dendrites & synapses

Question 16

Function of microglia

Answer 16

specialised macrophage-like cells that perform immune functions in the CNS

Proliferate at sights of injury - phagocytic
migrate to sights of damage
Phagocytose debris/microbes

contribute to synaptic plasticity i.e. microglia can eat unwanted dendritic spines

Question 17

What are microglia derived from

Answer 17

progenitors that migrate into CNS from periphery

Question 18

how are the microglia different in the cortical grey matter

Answer 18

more ramified (Branched)

Question 19

How an microglia be bad

Answer 19

being too sensitive and causing excessive inflammation & destruction of dendritic spines

Question 20

Function of Ependymal cells

Answer 20

line fluid filled cavities within the brain (i.e. ventricles) and spinal cord and regulate the production and flow of CSF

provide barrier between CSF and brain

Question 21

Features of Ependymal cells

Answer 21

have cilia, microvilli and desmosomes