2. Organisation of the Nervous System
- Divided into the Central Nervous System (CNS) — brain and spinal cord — and the Peripheral Nervous System (PNS) — all nerves and ganglia outside the CNS.
- Basic functions: sensation (detecting stimuli), transduction (converting stimuli to impulses), integration (processing/comparing information), and response (generating an appropriate action).
- Voluntary responses are controlled by the somatic nervous system; involuntary responses by the autonomic nervous system.
Glial Cells (Neuroglia)
Six types support neurons — four in the CNS, two in the PNS:
|
CNS Glia |
PNS Glia |
Basic Function |
|
Astrocyte |
Satellite cell |
Support; controls chemical environment |
|
Oligodendrocyte |
Schwann cell |
Insulation / myelination |
|
Microglia |
— |
Immune surveillance, phagocytosis |
|
Ependymal cell |
— |
Produces cerebrospinal fluid (CSF) |