cells of the central nervous system

how many types of glial cells are there

4

what are the 4 types of glial cells

• ependymal cells

• astrocytes

• microglia

• oligodendrocyte

what are glial cells important in

important in physiology and pathophysiology

what are the most abundant cells in the CNS

astrocytes

what is the dynamic role of astrocytes

communicate with each other (gap junctions and chemical signal) and with neurons

what other support do astrocytes provide

• structural suport

• including scaffold during development

do astrocytes pass the blood brain barrier

yes

what do astrocytes form for repair

scar tissue

what maintenance are astrocytes important in

• maintenance of extracellular environments

• they have membrane transporters that allow uptake of neurotransmitters

• important in extracellular K+ regulation- ensures the neurons dont depolarise

what do astrocytes modulate

• synapse function

• formation, maintenance, modification of neurotransmitter release

what type of cells are microglia

• immune cells of the CNS

• macrophages of the CNS

• scavengers

• release of cytokines

what are the 2 types of microglia

• resting

• activated

what is the structure of resting microglia

• highly ramified

• homeostatic

what is the structure of activated microglia

• motile

• start to retract their processes

• pro-inflammatory- release pro-inflammatory cytokines

what other role are microglia involved in

neurodegenerative diseases

what do oligodendrocytes form

form the myelin sheath around neuronal axons- white matter

what type of cells are ependymal cells

• epithelial cells

• line the cavities fluid-filled cavities of the CNS (ventricles)

what do ependymal cells secrete

cerebrospinal fluid (CSF)

are ependymal cells ciliated

yes

do ependymal cells cross the blood brain barrier

yes