Neurophysiology Flashcards
What is an action potential
brief electrical impulse resulting in membrane potential being momentarily reversed
where is the site of initiation of the all or none action potential in a neuron
axon hillock
describe a unipolar neuron
1 neurite
peripheral autonomic neuron
describe a pseudounipolar neuron
1 neurite that bifurcates
dorsal root ganglion
describe a bipolar neuron
2 neurites
retinal neuron
describe a multipolar neuron
> =3 neurites
motor neurons
LMN
What is the overall ion movement in upstroke in an action potential
Na influx
What is the overall ion movement in downstroke in action potential
K efflux
what is membrane resistance
holes/channels that allow for ion leakage
What is length constant
distance a passive process travels
high membrane resistance means there are no leakages, true or false
true
higher the membrane resistance, the higher/lower the axoplasm resistance, the higher/lower the length constant
higher the membrane resistance, lower the axoplasm resistance, higher the length constant
increasing axon diameter increases/decreases axoplasm resistance
decreases
adding an insulating material increases/decreases membrane resistance
increases
myelinated axons conduct faster than non-myelinated axons, true or false
true
2 ways of increasing passive current spread
decrease axoplasm resistance with thicker axons
increase membrane resistance with myelin
What types of synapses exist
axodendritic - commonest
axosomatic
axoaxonic - least common
What is the major excitatory neurotransmitter
glutamine
in the excitatory synapses, what are the properties of the receptor
cation, selective, ionotropic, glutamate receptors
what are the major inhibitory neurotransmitters
GABA
glycine
in the inhibitory synapse, what are the properties of the receptor
anion, selective, ionotropic, GABA/glycine receptors
Of which ion is there an influx in epsp
Na+ influx
Of which ion is there an influx in ipsp
Cl- influx
What types of gating are present in neurotransmitter receptors
direct gating
indirect gating
What receptor is involved in direct gating
ionotropic receptors
What are ionotropic receptors and how fast is transmission
receptors that are also channels
rapid transmission
What receptor is involved in indirect gating
metabotropic receptors
What are metabotropic receptors and how fast is transmission
receptor with NO channel
slow transmission
NMDA receptors are permeable to which ions
Ca, Na, K
Non-NMDA receptors are permeable to which ions
Na, K
