Neurons Flashcards
When the cell becomes even more negative,
… the neuron is LESS likely to fire (IPSP). This is a graded potential.
Soma
Cell body
Flow of information in a neuron
- Dendrites receive information
- Cell body processes information
- Axon sends information via terminal buttons
Saltatory Conduction
Faster to travel along the myelinated neuron
Glial cells
Support neurons. Insulate neurons by enclosing in a myelin sheath
Dendrites vs. Axons
- Dendrites not myelinated
- Dendrite branching pattern can change through life, where axons remain stable through aging
- Dendrites can regenerate, axons cannot
- Dendrites receive information, axons send information
Conduction within the neuron is…
Conduction between neurons is…
… electrical
… chemical
Stages of action potential
- Resting potential
- Depolarization
- Actional potential
- Hyperpolarization
Resting potential
Negative. More potassium inside and more sodium outside. This is maintained by the sodium-potassium pump.
Depolarization
Stimulus causes membrane potential to increase threshold potential.
Action potential spike
Membrane becomes positive as sodium ions rush into the cell.
Absolute refractory period.
Repolarization
Potassium ions leave the cell and negative charge is restored.
Hyperpolarization
Cell becomes even more negative than it is at resting potential.
Relative refractory period. Really strong stimulus has to occur in order for another action potential to happen.
Axon hillock
Point where action potential originates. Where axon meets cell body. Graded potential converted into all-or-nothing potential of axon.
Chemical transmission between neurons
- receptor sites - binding
- remain in cleft
- reuptake
Postsynaptic potential
When NT binds to receptor site on dendrite, generates electrical charge (PSP)
1. EPSP: more likely to fire
2. IPSP: less likely to fire
These are GRADED. Vary in intensity.