Lecture 2 Flashcards
neurophysiology
study of life processes of neurons
anion
negatively charged
cation
positively charged
microelectrode
used to show the interior was mroe negative than exterior in membrane
resting potential inside membrane
-50 to -80 mV
ion channels
allow ions to pass through
leaky potassium channels
open all the time
neurons are
selectively permeable
diffusion
movement along concentration gradient
electrostatic pressure
movement of ions to oppositely charged areas
sodium potassium pump
3 sodium out for 2 k+ in
equilibrium potential
electrical charge that balances the opposing forces –> concentration gradient and electrostatic potential
axon hillock
membrane potential originates just after here
hyperpolarization
increased membrane potential –> charge moves even further from zero
depolarization
interior becomes less negative
graded response
change in potential –> greater the stimulus the greater the response
local potential
as potnetial moves further away from point of stimulation, it decreases
threshold
depolarization to about -40 mV that triggers action potential
all or none porperty
action potential either fires or it doesn’t –> amplitude of action potential is not relates to stimulus size
after potential
small changes in membrane potential after action potential
voltage gates channels
change shape and open in response to changes in charge *like depolarization
absolute refractory period
no action potentials can be produced
relative refractory phase
only strong stimulation can produce action potential
conduction velocity
speed of propagation of action potentials vary with axon diameter
myelin
insulation around axon, formed by glial cells that speed conduction
nodes of ranvier
gap in insulating myelin sheath –> channels are here
saltatory conduction
potential traveling inside axon jumps from node to node
postsynaptic potentials
breif changes in the membrane potential in reponse to neurotransmitters
excitatory postsynaptic potentials
thing that push post synaptic neuron closer to action potential
inhibitatory postsynaptic potential
pushes cell further awawy from theshold –> like Cl- ions
spatial summation
summing of all potentials that reach axon hillock from locations across the body
temporal summation
summing of potentials that reach the axon hillock based on time of arrival
closer together in time the potentials the greater their imapct and likelihood of producing action potential
synpatic delay
delay ebtween action potentail reaching axon terminal and creating postsynaptic potential
ligands
molecules that fit into receptors and activate or block them
acetylcholine
curare and bungarotoxin
block acH receptors
nicotine
mimics aCH receptors
degradation
rapid breakdown and inactivation of transmitter by an enzyme
reuptake
trasnmitter is cleared from teh synapse by being absorbed back into the. presynaptic axon terminal
transporters
special receptors that bring transmitter back insdie
axo dendritic
axon terminal synapse to dendrite
axo somatic
axon and cell body
axo axonic
axon and axon
dendro dendritic
between two sdendrites
EEG
recording of spontaneous brain potentials
ERPS
EEG response to strong stimulus
epilepsy
brain disorder characterized by seizures
seizure
abnormally schronous electrical activity
grand mal seizure
abnormal EEG activity throughout brain
petit mal seizure
seizure activity for 5-15 seconds and may occur several times a day
complex partial seizure
do not involve entire brain and preceded by unusual aura