# Nervous System
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The **nervous system** is an [[organ system]] made up of [[neural tissue]] that coordinates, processes and reacts to all the the information information that we sense, be it external or internal, perceptible or imperceptible.
## Anatomy
The anatomical division of the nervous system is between the [[central nervous system]], or **CNS**, and the [[peripheral nervous system]] or **PNS**. The PNS receive signals from various receptors, and then sends those signals to the CNS for processing. Once done, the CNS sends "instructions" back the PNS to be enacted upon.
```mermaid
flowchart TD
A[The Nervous System] --> B[CNS]
A --> C[PNS]
B --> D[brain]
B --> E[spinal cord]
C --> F[motor neurons]
C --> G[sensory neurons]
F --> H[autonomic]
F --> I[somatic]
G --> H
G --> I
H --> J[sympathetic]
H --> K[parasympathetic]
```
## Physiology
Another general division is between the [[afferent nervous system]] and the [[efferent nervous system]] of the PNS. The afferent, or sensory division *receives* information from receptors and the efferent, or motor division receives information from the CNS and sends those signals to effectors.
There are many different organizations of systems; some function independently, and some interact with other systems closely.
Some sections of nervous system are completely separate, their own ecosystem, disconnected from the rest. These are exclusively %%I think%% part of the autonomic nervous system.
- the [[enteric nervous system]] runs along the GI tract and regulates those functions.
## Problems with the Nervous System
- Signs and symptoms that indicate a problem with the nervous system tend to be... [[neurological assessment]]
- pain
- seizures
- dizziness/vertigo
- visual disturbances
- muscle weakness
- abnormal sensation
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