Cells in the nervous system
Neurons
Neuroglia/ glial cells
CNS glial cells
- Ependymal cells line compartments and produce CSF
- Oligodendrocytes form myelin sheaths, which insulate and increase propagation speed
- Microglia serve as immune cells
- Astrocytes are responsible for nutrient provision and blood flow
PNS glial cells
- Schwann cells form myelin sheaths in the peripheral nervous system
- Satellite cells provide structure and nutrients
Neuronal activation
- Resting membrane potential is -70mV, maintained by channels that pump out Na+ and bring in K+
- Stimulus causes Na+ channels to open and depolarization, meaning potential becomes more positive. Leads to Action Potential (AP) at a certain threshold
- Once AP reaches peak, Na+ channels close and voltage-gated K+ channels open
- K+ rushes out of the neuron resulting in repolarization
