Nervous System

Nervous System

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The internet of the human body. The nervous system provides the fastest way for cells and tissues from all over the body to communicate with each other, by sending electrical impulses through a vast network of nerve fibers. It's composed of a central nervous system (CNS), holding 99% of the body's neurons, and a peripheral nervous system, holding the rest. The central nervous system is composed of the brain and the spinal cord. The peripheral nervous system is composed of many branching nerves, which reach to every corner of the body.

Neuron (Nerve Cell)

A typical neuron is composed of a cell body, around 10,000 highly branched receptive tentacles called dendrites (although some nerves have no dendrites at all), and a single long thin tentacle called an axon or nerve fiber, which branches possibly along its course and at its ends.

Transmitting Messages

The dendrites contain receptors that respond to various physical or chemical changes in its immediate vicinity. When one of these receptors is activated, it causes charged ions to travel across the cell's membrane, either by activating an ionic pump or by opening channels though which ions can travel pulled by their own magnetic charge. If enough of these receptors are activated, together they will induce an action potential, a significant difference in charge between the inside and outside of a nerve cell. Once this action potential reaches a certain threshold, a chain reaction is initiated that travels down the length of the nerve's axon. This is an electrical nerve impulse. Once this impulse reaches the end of an axon branch, it causes chemicals called neurotransmitters to be released from the axon's branch. These neurotransmitters are the chemicals that activate the receptors on the next neuron. This induces another nerve impulse, which induces another and another, etc.

User's Manual

Participate in sports that require coordination between different muscles and quick thinking. Activities like this can train certain muscle groups to harmoniously work together to produce smoother more coordinated movements. These activities will also exercise the ability of your central nervous system to make quick decisions or quick reactions. An improved coordination and quick reaction time can help you prevent injury in your day to day activities.

Anything good for the brain is good for the nervous, so check out the brain user manual.

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  • Anatomy Topics

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Amazing Facts

  • Nerve impulses travel up to 250 miles per hour.
  • Some nerve cells are over a foot long.
  • A nerve's axon can be 5000 to 10,000 times longer than the width of the nerve's cell body.
  • For every 1 neuron traveling toward the CNS (central nervous system), there are 10 neurons traveling away from the CNS, and 200,000 neurons traveling within the CNS!
  • Certain neurons in the brain are hit with over 100,000 different synapses (the junction between an axon branch of one neuron and the receiving surface of another neuron).
  • One of the teams in a nation-wide improvisational comedy act called Comedy Sports is named after the dendrites of a neuron.

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