Neurons and Nervous Systems Flashcards
Dendrite
branch-like projections of neurons that receive messages
Soma
cell body
Axon
tail of neuron, electrical messages carried through
Myelin Sheath
protects axon and increases speed of message
Terminal Button
knobs at end of axon where neurotransmitters are released into synapse from vesicles
Afferent Neurons
sensory neurons (Approach brain): senses—>brain
Efferent Neurons
motor neurons (Exit brain): brain—> muscles
Interneurons
connects afferent and efferent in spinal cord (*reflexes)
Mirror Neurons
activated while watching, not while actually mimicking (*sympathy)
Resting State
neuron is off
Firing Threshold
minimum amount of stimulus that neurons react to
Action Potential
once stimulated, neuron will fire regardless of how much stimulus there is
All or Nothing Principle
process of electrical message being passed through axon
Sodium-Potassium Pump
necessary for action potential to work
Refractory Period
recharging, neuron cannot fire again immediately
Synapse
space b/t cell (electrical message cannot cross so neurotransmitters are necessary)
Lock + Key Model
certain neurotransmitters will only bind to specific receptors
Agonists
mimic; same shape as neurotransmitter and fit into receptors, increase activity.
Antagonists
reduce effect of neurotransmitter
Excitatory vs. Inhibitory Messages
excitatory rev up; inhibitory slow down
Re-Uptake
unneeded neurotransmitters taken out of synapse
Sympathetic vs. Parasympathetic NS
part of autonomic NS.
sympathetic = excitatory
parasympathetic = inhibitory
Somatic NS
voluntary muscles
Autonomic NS
involuntary muscles
