glial cells Flashcards
what system are glial cells apart of
the nervous system, along with neurons
types of glial cells
astrocytes, oligodendrocytes, microglia
neural stem cells
guide neurons to their final destination through radial glial cells, which form the path along which neurons move
neural stem cells
oligodendrocytes and astrocytes form from these
how do neuronal stem cells work?
neurons develop from the stem cells, attach themselves through the radial glial cell, which they can move along to their final destination before detatching and forming neuronal connections
why are radial glial cells important
important for development and making sure cells are where they need to be
astrocytes
small to medium sized glial cells with lots of extensions
what is the role of astrocytes (3)
maintain homeostasis and equilibrium between different substances in the brain, regulate chemical concentration, and contribute to neuronal repair
why is equilibrium between substances in the brain important
the concentration of ions and neurotransmitters have to be exactly right for neuronal cells to function properly
how do astrocytes work
take up substances from extracellular space if it gets too high or release substances if it gets too low
how do astrocytes contribute to neuronal repair
form a glial scar around the area
blood brain barrier
protects the brain from being exposed to harmful substances
why are astrocytes important for the blood brain barrier
they make the blood brain barrier tighter and more secure, by forming feet which cover blood vessels so its more difficult for substances in the blood to penetrate the vessel into the brain space
oligodendrocytes
form myelin sheets around neurons, snake around the neuron axon to form a tight insulation barrier
why are oligodendrocytes important
help increase the speed of information along the axon
microglia
first line of defence against infections in the brain
how are microglia created
bone marrow
why are microglia used instead of white blood cells
the blood brain barrier keeps white blood cells out of the brain
how do microglia work
change their shape and become ‘activated’, help eat away at harmful substances through active surveillance and phagocytosis
phagocytosis
cellular process for englufing and eliminating particles, such as dead cells
why are microglia important
limiting damage inside the brain, stop harmful substances from dying cells affecting other neurons
peripheral nervous system glial cells
satellite cells, schwann cells
