Nervous System Flashcards
two major types of cells in the nervous system are what?
neurons (transport electrical impulses) and glial cells (support cells for neurons).
collection of neurons in the PNS are what?
ganglion
unipolar neuron is what? bipolar (rare but where is one present?) multipolar (most common)?
a neuron with one process
a neuron with 2 processes (IN THE RETINA)
a neuron with many processes (more than 2)
two types of sensory neurons?
unipolar/bipolar
what type of neuron is multipolar?
motor
What is a perikaryon?
cell body or soma
do neurons have large amounts of mitochondria?
YES. highly active in protein synthesis, lots of euchromatin.
axon hillock is the point where what occurs?
axon originates and where initiation of AP occurs.
mylenation is the wrapping of what kind of cell around the axon?
glial cells.
nissl bodies are what?
dark stained mitochondria
what produces myelin in the CNS? PNS? is mylenation found in all neurons?
oligodendrocyte in CNS
schawnn in PNS
NO. usually in vertebrate neurons though.
neurofilaments correspond to what system? neurotubules?
intermediate filament system (structural and organization) microtubule system (transport highway)
type of tissue in neurons?
neuronal or nervous tissue
how can you tell the difference between a nucleus and nucleolus in a neuron image? difference between axons and dendrites?
nucleus is white due to high amount of euchromatin nucleolus is dark
cant tell the difference between these unless labelled.
what are the four types of synapses?
- axosomatic synapse (axon synapsing on cell body)
- axoaxonic synapse (axon synapsing on axon)
- axodendritic synapse (axon synapsing on dendrite)
- axospinous synapse (axon synapsing on specialized part of dendrite called a spine)
any neuron terminating on muscle, the part innervating the muscle is called what?
neuromuscular junction OR motor end plate
neurons contain alot of which organelle?
mitochondria (located in al parts of neuron)
junctional folds are characteristics of what?
motor end plates in muscle cells. they are invaginations of the PM of muscle cells.
Neurotransmitters are transmitted in what structures? released by? they then act on what? which opens what? and further activates? there can be two types of actions which are?
vesicles exocytosis receptors (not all hormones need receptors because they are lipophillic) ACh channels 2nd msg systems inhibitory or stimulatory
what is the postsynaptic density?
underlies PM and helps hold receptors in place (can be soma, dendrites etc).
what are low MW transmitters?
non protein, small.
what is the low MW transmitter used at all NMJ?
acetylcholine
low MW transmitters such as dopamine are located where? serotonin? glutamate? GABA? where are all low MW transmitter synthesized?
horizontal and amacrine cells in retina CNS and photoreceptors photoreceptors (main one they use) horizontal and amacrine synthesized in terminal
high MW transmitters are what? made where? can be released from which cells in retina? where are they all synthesized? they then must what?
proteins, made on RER
can be released from amacrine and ganglion cells in retina
all synthesized in soma, they then must be transported down the axon terminal
what are two types of axonal transport?
anterograde: bringing product from soma to terminal
retrograde: bringing product from terminal to soma (reuptake of nt and needs modification)
schawnn cells are mylenating cells in which system?
PNS
satelite cells are a type of what? where are they located?
glial cell
around soma
what are the two types of glial cells in PNS? 3 types in CNS?
satelite and schawnn.
oligodendrocytes (mylenating ones), astrocytes (support cells, largest glial cells) and microglia (macrophages)
astrocytes have what unique feature?
end feet: important in the BBB
what are mueller cells? what type of specific glial cell are they?
long glial cells extending from inner retina surface to just below ELM
oligodendrocytes
what forms the ELM and ILM in retina?
end feet from mueller cells
what glial cell helps form the BBB?
astrocytes (with end feet)
function of ependymal cells? in ventricles of brain what are the ependymal cells called?
lines ventricles of brain and spinal cord.
tanyctyes
what happens in MS disease? lateral sclerosis? alzeihmers?
demyelination of motor neurons.
motor neurons degenerate
loss of neurons in cortex (forms amyloid plaques- filled with protinaceous substance)
