action potentials and synaptic transmission Flashcards
characteristics of action potentials
self propagating, all or none and one direction travel
action potential
self propagating biochemical disturbances that generates an electric field of dipole
what is the ratio for sodium potassium pumps
3 :2
absolute refractory period
time period after the threshold has reached that caused the AP until the sodium inactivation is reset
relative refractory period
time after the sodium inactivation mechanism is reset and while there is still an outward potassium current
propagation
AP occurs at one local place along the axon
-local current created at a specific place
what does it mean for AP strength with propagation
it is the full strength at each occurrence
synaptic transmission
chemical messengers carry info from one cell to another
-AP reaches terminal bouton
-Ca channels are opened
-neurotransmitters are trigger to be released
-NT find receptor sites
what are neurotransmitters
amines, amino acids and neuropeptides
examples of neurotransmitters in the CNS
glutamate, GABA and glycine
example of neurotransmitters in the PNS
acetylcholine
5 steps in a chemical synaptic transmission (NT role)
synthesis of NT in presynaptic endings and soma, concentration and packaging of NT in vesicles, release of NT into synaptic cleft, bidning of NT to receptor molecules in postsynaptic membranes, and termination of NT action by uptake/degeneration or diffusion
reabsorbed NT can be ________ for use again
recycled
two types of transmission
EPSP and IPSP
excitatory postsynaptic potential (EPSP)
depolarization of the postsynaptic cell
