General Biology/Tissues and Systems/Nervous System

From Wikibooks, the open-content textbooks collection

Nervous System

Composed of tissues designed to integrate sensory information and direct a coordinated response to the environment.

Basic unit of the nervous system is the neuron, a highly specialized cell that uses both electrical and chemical processes to communicate. Neurons "listen" to sensory organs (see next chapter) or other neurons, and can simultaneously "hear" from 1 to hundreds of inputs simultaneously. Likewise, a neuron can "talk" to other neurons or cells that can create an action, like muscle cells or glands.

Neurons are outnumbered in the nervous system by glia. Glia were once thought to only play a supportive role in helping neurons survive; today we know that they also are important participants in the communication process.

Neuron structure

Action potential

Synapses

Neurotransmitters

Example : Neuromuscular synapses

Circuits / Nuclei / Ganglia

CNS

PNS / ANS

Drugs

Stroke

--Darren 04:30, 28 January 2006 (UTC)