View source for Sympathetic nervous system

== Overview ==
The [[Sympathetic nervous system|sympathetic nervous system]] (SNS) is a component of the [[Autonomic nervous system|autonomic nervous system]] (ANS), which regulates the body's unconscious actions. The SNS is responsible for the body's 'fight or flight' response, preparing the body for action during times of stress or danger.

[[Image:Detail-45505.jpg|thumb|center|A close-up view of the human nervous system, focusing on the spinal cord where the sympathetic nervous system is located.|class=only_on_mobile]]
[[Image:Detail-45506.jpg|thumb|center|A close-up view of the human nervous system, focusing on the spinal cord where the sympathetic nervous system is located.|class=only_on_desktop]]

== Anatomy ==
The SNS is primarily composed of [[Neuron|neurons]] that originate in the [[Spinal cord|spinal cord]], specifically the thoracic and lumbar regions. These neurons connect to various [[Organ (anatomy)|organs]] and [[Muscle|muscles]] throughout the body, allowing the SNS to exert control over a wide range of bodily functions.

== Function ==
The primary function of the SNS is to stimulate the body's 'fight or flight' response. This involves a range of physiological changes, including increased heart rate, blood pressure, and metabolic rate, as well as dilation of the pupils and bronchial tubes. These changes prepare the body for action, either to confront a threat or to flee from it.

== Neurotransmitters ==
The SNS primarily uses the [[Neurotransmitter|neurotransmitters]] norepinephrine and epinephrine to transmit signals. These neurotransmitters bind to [[Adrenergic receptor|adrenergic receptors]] on the target cells, triggering the physiological changes associated with the 'fight or flight' response.

== Pathology ==
Disorders of the SNS can lead to a range of health problems, including hypertension, heart disease, and anxiety disorders. These conditions can often be managed with medications that target the SNS, such as beta blockers and alpha blockers.

== See Also ==
* [[Parasympathetic nervous system]]
* [[Endocrine system]]
* [[Stress (biology)]]

[[Category:Neuroscience]]
[[Category:Physiology]]
[[Category:Human anatomy]]