The neuroglia cells are the supporting cells of the nervous
system.
The neuroglia which is phagocytic is microglia cells.
Microglia cells are derived from the monocytes.
They enter the infected tissue from the blood.
They migrate to the site of infection and are also called as
macrophages of the central nervous system.
They engulf the microorganisms and destroy them . Also they eat
cellular debris by phagocytosis.
The astrocytes forms the blood brain barrier.
These are star shaped neuroglia cells.
Astrocytes form blood brain barrier and regulates entry of
substances from blood into the brain.
The processes of the astrocytes cover the nerve cells . They
sends processes towards the blood vessels of the brain and
capillaries and form the tight junction.The tight junction is
called as blood brain barrier.