Neurons

cell body

contains nucleus and organelles

dendrites

receive incoming signals; direct to cell body

axon

direct signals to axon terminals

myelin sheath

speed up signal

axon terminals

contain neurotransmitters (signals to be released)

nodes of Ranvier

gaps between myelin; contain channels to help signals travel correctly

synapses

spaces between neurons where signals are passed

pre-synaptic neuron

neuron that sends signal

post-synaptic neuron

neuron that receives signal

ligand-gated channel

located on dendrites and cell bodies; open/close due to neurotransmitter

mechanically gated channel

located on dendrites/cell bodies; open/close due to mechanical deformation (stretch, vibrations, pressure)

voltage-gated channel

axon and axon hillock; open/close due to changes in membrane potential

leaky channel

located everywhere; always open —> allows ions to pass freely. Allow for ion concentrations to reset to normal

membrane potential

difference in electrical charge or concentrations of ions in/outside of a neuron

resting membrane potential

-70 mV

depolarization

increase in charge (becoming more +)

repolarization

decrease in charge (becoming more -)

hyperpolarization

further decrease in membrane potential (past resting)

threshold potential

-55 mV; triggers opening of voltage gated channels