Neurons Flashcards
where do APs propagate from on a neuron
axon hillock
what stain stains myelin
luxor fast blue
what stain stains Nissl (RER)
cresol violet
what colour does eosin stain proteins
red
what colour does haemotoxylin stain nucleic acids
blue
what are the 3 functional classes of neurons
afferent
efferent
interneurons
Where are interneurons
found within CNS
lie entirely within CNS
what do afferent neurons do
convey info from tissues/ organs to CNS; sensory receptors on peripheral ends so respond to physical/ chemical changes in environment by generating signals in the neuron
what do efferent neurons do
convey info away from CNS to effector cells
have cell bodies/ dendrites within CNS
what do interneurons do
connect neurons within CNS
what is the composition of myelin
70& lipid
30% protein
highly compacted
20-200 layers of modified plasma protein wrapped around axon by nearby surrporting cells
where are oligodendrocytes found
CNS
where are Schwann cells found
PNS
what are nodes of Ranvier
where plasma membrane of axon is exposed to extracellular fluid
where are myelinated axons mainly found
somatic nerves i.e. fast sensory/ motor systems
where are unmyelinated axons mainly found
post-ganglionic autonomic fibres, fine sensory fibres, olfactory neurons and interneurons
what is the difference in thickness between myelinated and unmyelinated axons
myelinated are thicker
what are the 5 types of glial cells
oligodendrocytes schwann cells astrocytes microglia ependymal cells
describe oligodendrocytes
glial cells of CNS
myelinating cells that myelinate multiple axons
Provide metabolic support for axons
describe Schwann cells
glial/ myelinating cells of CNS
myelinate single axons
what are the differences between oligodendrocytes and Schwann cells
CNS v PNS
myelinate multiple axons v single axons
what is the name of astrocytes in grey matter
protoplasmic
what is the name of astrocytes in white matter
fibrous
where are protoplasmic astrocytes found
grey matter
