Sympathetic nervous system

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The sympathetic nervous system is part of the autonomic nervous system has the following functions:

The autonomic nervous system
Blue = parasympathetic
Red = sympathetic

• Diverts blood flow away from the gastro-intestinal (GI) tract and skin via vasoconstriction.
• Blood flow to skeletal muscles, the lung is not only maintained, but enhanced (by as much as 1200%, in the case of skeletal muscles).
• Dilates bronchioles of the lung, which allows for greater alveolar oxygen exchange.
• Increases heart rate and the contractility of cardiac cells (myocytes), thereby providing a mechanism for the enhanced blood flow to skeletal muscles.
• Dilates pupils and relaxes the lens, allowing more light to enter the eye.

See also

• Adrenergic receptor

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