pscl 101 exam 1: neurons and signaling (lecture 4)

somatic nervous system

bodily sensation and movement

sympathetic nervous system

"fight or flight," mobilization to manage threat

parasympathetic nervous system

"rest and digest," "brake pedal" on SNS

action potential

a neural impulse; a brief electrical charge that travels down an axon

sodium-potassium pumps

maintain concentration of Na+ and K+ inside and outside of cell membrane

all or none law

-an action potential either fires fully or not at all

-in a given neuron, all action potentials have the same strength and speed

firing rate

-# of action potentials per second can vary

-in a given neuron, the ap firing rate may differ from moment to moment depending on current input

synaptic potential

the outcome of a synapse for the postsynaptic (receiving neuron)

excitatory synaptic potential

raise cell voltage -> encourage ap firing

inhibitory synaptic potential

lower cell voltage -> discourage ap firing

after binding to receptor, neurotransmitter may experience

-reuptake

-degradation

-diffusion into extracellular spacfe

reuptake

reabsorbed and repackaged

degradation

broken down and deactivated

diffusion

into extracellular space