The Neuron
- Cell body: contains neucleus; neucleus produces neurotransmitters
- Axon = nerve fiber, conducts neurotransmission
- Dendrites: gets neurotranmitters from terminal buttons (via synapse)
- Terminal buttons: stores and releases neurotransmitters
- Myelin sheath: covers axon; speeds up conduction of neurotransmission
Glial cells: forms myelin sheath; protect cells
Synapse: (1) aka synaptic gap/cleft (2) presynaptic membrane: terminal buttons (3) postsynaptic membrane: dendrite (4) is not a part of the neuron (5) neurotransmitters floating in this gap can be reabsorbed back to the terminal button (aka reuptake)
Receptor site: sits on post-synaptic membrane; neurotransmitters bind to receptor sites, which makes the neuron fire under the "all-or-none" principle
All-or-none principle: a neuron is either stimulated enough (by neurotransmitters) to fire, or it doesn't fire at all; there is no strong or weak firing, it's 1 or 0
Resting potential: the "default" state, inside is negatively charge (-70mV)
Action potential: a rapid change of potential (positively charged) across membrane when the threshold is reached (sufficiently stimulated by neurotransmitters binding to receptors); aka depolarization; aka neural impulse (electrical in nature)
Refractory period: after depolarization, there is repolarization (absolute refractory period) and the inside of axon becomes negatively charged again (relative refractory period), during which the neuron cannot fire again (not ready to fire too frequently)