Neuroscience 1 Flashcards
how many neurons are in the brain
about 100 billion
receptive zone
part of the neuron that recieves signals
transmission zone
part of the neuron that passes signals on
dendrites, cell body, nucleus
receptive zone
node of ranvier, acon, myelin, axon terminals
transmission zone
action potential
firing of neurons, all or nothing event
selective permeability
preferentially allowing certain ions across the membrane
resting potential
-70mv,
electrostatic force
Na+ keeps Cl- primarily outside of the cell
diffusion
sodium flows in very small amounts into the cells
leaky K+ channel
a major contributor to resting potential
voltage-gated K+ channel
important player for action potential
steps of action potential
1) reaching the threshold
2) the rise
3) the peak
4) the fall
the rise
1) sodium channels open and Na rushes into the neuron, increasing charge in neuron
2) K+ voltage-gated channels open allowing K+ to rush out
the peak
once reached about -40mv sodium channels close, Na+ stops entering but K+ continues to rush out
The fall
- continues to fall and overshoots to about -100mv
- voltage-gated K+ channels close
- slowly returns to -70mv
restoring resting potential
- Na+/K+ pump
- moves slow
- uses a lot of energy
- pumps 3 Na+ out
pumps 2 K+ in
saltatory conduction
the movement of the action potential down an axon
myelin
CNS- ologodendrocytes
PNS- shwann cells
frequency of action potentials
how neurons communicat messages
strong action potential means more frequent
synapse
not a direct physical connection
vesicles
small intracellular containers that as AP teaches the terminals in fuses with the membran of ppresynaptic neuron releasing the contents (neurotrasmitters)
synaptic cleft
space between two neurons
receptors
along membrane of post synaptic neuron to take in neurotransmitters released by presynaptic neuron
