cells of the NS Flashcards
what are astrocytes?
cells of the NS that form the blood brain barrier
What type of cell supports and protects neurons
neuroglia or glial cells
what is the structure of an atrocyte?
feet that cover the surfaces of neurons and blood vessels and the pia mater
what is the fn of an astrocyte?
by producing chemicals that promote tight jncts, astrocytes form the blood-brain barrier to regulate what substances reach the CNS from the blood; also helps regulate extracellular spinal fluid composition
what type of NS cell supports and protects the neurons?
glial cells or neuroglia
what does the blood-brain barrier do?
it protects neurons from toxins, allows exchange of nutrients and waste products between blood stream and neurons
what type of NS cells regulate the extracellular brain/spinal fluid composition?
astrocytes
what do ependymal cells do?
line brain ventricles and spinal cord central canal
specialized versions of what type of NS cell form the choroid plexuses?
ependymal
what type of cells in the NS form the blood-brain barrier?
astrocytes
what type of cells regulate extracellular brain fluid composition?
astrocytes
what does the choroid plexus do?
secretes cerebrospinal fluid
cilia move the fluid through the cavities of the brain
where is the choroid plexus located?
certain regions of ventricles
what type of cell is the microglia?
specialized macrophages
what brain region secretes and moves cerebrospinal fluid and is made of specialized ependymal cells?
choroid plexus
ependymal cells of the___________ secrete cerebrospinal fluid
choroid plexus
what do microglia do?
respond to inflammation
phagocytize necrotic tissue, microorganisms and foreign substances that invade the CNS
what are the specialized macrophages of the NS?
microglia
what type of NS cell responds to inflammation?
microglia
microglia are responsible for phagocytizing
necrotic tissue
microorganisms
foreign substances
what do oligodendrocytes do?
form myelin sheaths around portions of 1 or more axons
what type of NS cell forms the myelin sheaths?
oligodendrocyte
what are neuroglia?
non neuron cells that work to support the nervous system (myelin sheath, macrophage, blood-brain barrier)
compare and contrast oligodendrocytes and neurolemmocyte?
both form myelin sheaths by wrapping around neurons
both form protection from current of AP which makes the AP propagate more quickly (saltatory)
oligodendrocytes are only in CNS (brain, spinal cord)
neurolemmocytes are in the PNS
what type of cell forms the myelin sheaths of neurons in the CNS?
oligodendrocyte
what is another name for neurolemmocyte?
schwann cell
what is myelin made of that makes it so insulating?
lipids (80%)
how is a myelin sheath formed?
oligodendrocytes or neurolemmocytes wrap many times around an area of a neuron up and down the entire length of neuron, creating nodes of ranvier in between
what is the fn of satellite cells
surround neuron cell bodies in the ganglia to provide support and nutrients
what type of cell surrounds neuron cell bodies in the ganglia to provide support and nutrients
satellite cells
what is myelin’s purpose?
to insulate axons from each other and to speed transmission (saltatory propagation)
what is gray matter made of?
unmyelinated axons
what type of neurons do not have oligodendrocytes or neurolemmocytes wrapped around them?
unmyelinated axons (gray matter)
