Cells of the Nervous System
The cellular cast
Neurons and glia
The nervous system contains neurons and glial cells. Neurons carry information using electrical and chemical signals. Glia do not simply provide support; they help nourish neurons, shape communication, protect the brain, and regulate the environment around nerve cells.
Neurons vs. glia
Neurons
- Send rapid signals
- Form networks for communication
- Use electrical impulses and neurotransmitters
Glia
- Support and regulate neurons
- Maintain chemical balance
- Help with insulation, defense, and repair
Helpful analogy
Neurons are like messengers, while glia are like the maintenance crew, supply system, and security team all at once.
Major glial types
In the central nervous system, astrocytes help regulate the chemical environment, oligodendrocytes form myelin, and microglia act as immune-like cells. In the peripheral nervous system, Schwann cells also form myelin around axons.
Main cell types
| Cell type | Main role |
|---|---|
| Neuron | Information processing and signaling |
| Astrocyte | Chemical support and regulation |
| Oligodendrocyte | Myelin formation in the central nervous system |
| Microglia | Immune defense and cleanup |
| Schwann cell | Myelin formation in the peripheral nervous system |
Which cell type forms myelin in the central nervous system?
Oligodendrocytes wrap axons with myelin in the central nervous system.
Correct answer: Oligodendrocytes
Name one type of glial cell and one thing it does.
Many answers are possible if they correctly pair a glial cell with its function.
Correct answer: astrocyte helps regulate the chemical environment