intro to neurons/conduction/synaps Flashcards
where would you find a unipolar neurone
peripheral autonomic neurone - single neurite
dorsal root ganglion has what type of neurone
pseudounipolar - single neurite that bifurcates
retinal neurone is what type
bipolar (2 neurites)
lower motor neurone is of what type
multipolar (3+ neurites)
4 functional regions of neurone
input > integration > conductile > output
Na+ and K+ channels are ____ activated
voltage
upstroke, what moves & where to?
Na+ moves in (fast)
downstroke, what moves & where to
K+ moves out (slowly)
value for threshold
- 60mV
different membrane potentials during action potential
- 70 (resting) > -60 (threshold) > +40 (overshoot) > -80 (undershoot)
time taken for an action potential
2 milli secs
an action potential has ___ amplitude
constant
makes myelin in CNS
oligodendrocytes
makes myelin in PNS
schwann cells
oligodendrocytes and schwann cells are both types of
macroglia
other than location, what is the difference between myeline from schwann and oligodendrocytes
oligodendrocytes cover many axons, where multiple schwann cells will cover a single axon
ri
rm
ri - resistance of axoplasm
rm - resistance of axon membrane
how can you increase passive current spread in axon
increase rm (axoplasm resistance) by insulating (myeline) decrease ri (membrane reistance) by increasing axon diameter
in CNS most common excitatory neurotransmitter is
glutamate
most common inhibitory neurotransmitter in CNS is
GABA - gama aminobutyric acid or glycine
glutamate activates what type of receptor
postsynaptic, CATION selective, ionotropic, glutamate receptors
GABA or glycine active what receptors
postsynaptic IONOTROPIC , GABAa, or glycine receptors
amino acid neurotransmitters include
GABA, glycine, glutamate
the binding of inhibitory neurotransmitter to receptor results in
membrane potential becoming even more negative
examples of amine neurotransmitters (5)
ACh dopamine histamine noradrenaline seratonin
amino acid and amine neurotransmitters are released from ___ vesicles
synaptic vesicles
secretory vesicles realease what type of neurotransmitter
peptide
All, except ___ , can also activate metabotropic G protein-coupled receptors.
glycine
which type of receptor binding leads to relatively slow neurotransmission
G protein coupled
Glutamate, GABA, glycine, acetylcholine, and 5-HT can activate _____ ion channels (LGICs). These mediate ____ neurotransmission
1) ionoptopic ligand-gated
2) fast
which neurotransmitters must be synthesised by specific enzymes
GABA and all amines (ACh, dopamine, histamine, noradrenaline and serotonin)
enzymes that synthesise GABA and amines are made in ___ and transported to synapse via _____
in cell body
via axoplasmic transport (along microbes)
enzymes synthesise neurotransmitter from ___
precursor
