Sympathetic nervous system

sympatheticsympathetic nervesympathetic nervessympathetic systemsympathetic tonesympathetic activitysympathetic divisionSympathetic innervationsympathetic responsesympathetic activation
The sympathetic nervous system (SNS) is one of the two main divisions of the autonomic nervous system, the other being the parasympathetic nervous system.wikipedia
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Parasympathetic nervous system

parasympatheticparasympathetic nerveparasympathetic nerves
The sympathetic nervous system (SNS) is one of the two main divisions of the autonomic nervous system, the other being the parasympathetic nervous system.
The parasympathetic nervous system (PSNS) is one of the two divisions of the autonomic nervous system (a division of the peripheral nervous system (PNS)), the other being the sympathetic nervous system.

Fight-or-flight response

stress responsefight or flightfight-or-flight
The sympathetic nervous system's primary process is to stimulate the body's fight-flight-or-freeze response.
His theory states that animals react to threats with a general discharge of the sympathetic nervous system, preparing the animal for fighting or fleeing.

Enteric nervous system

neurogastroenterologyentericenteric nervous plexus
(The enteric nervous system (ENS) is now usually referred to as separate from the autonomic nervous system since it has its own independent reflex activity.)
It is capable of acting independently of the sympathetic and parasympathetic nervous systems, although it may be influenced by them.

Autonomic nervous system

autonomicautonomous nervous systemautonomic functions
The sympathetic nervous system (SNS) is one of the two main divisions of the autonomic nervous system, the other being the parasympathetic nervous system. (The enteric nervous system (ENS) is now usually referred to as separate from the autonomic nervous system since it has its own independent reflex activity.)
The autonomic nervous system has three branches: the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.

Acetylcholine

cholinergicAChacetylcholine (ACh)
At the synapses within the ganglia, preganglionic neurons release acetylcholine, a neurotransmitter that activates nicotinic acetylcholine receptors on postganglionic neurons.
Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasympathetic nervous system.

Adrenergic receptor

adrenergic receptorsβadrenergic
In response to this stimulus, the postganglionic neurons release norepinephrine, which activates adrenergic receptors that are present on the peripheral target tissues. The target synapse of the postganglionic neuron is mediated by adrenergic receptors and is activated by either norepinephrine (noradrenaline) or epinephrine (adrenaline).
Many cells have these receptors, and the binding of a catecholamine to the receptor will generally stimulate the sympathetic nervous system (SNS).

Homeostasis

homeostaticequilibriumimmunomodulation
It is, however, constantly active at a basic level to maintain homeostasis homeodynamics.
When core temperature rises are detected by thermoreceptors, the sweat glands in the skin are stimulated via cholinergic sympathetic nerves to secrete sweat onto the skin, which, when it evaporates, cools the skin and the blood flowing through it.

Norepinephrine

noradrenalinenoradrenergicnoradrenalin
In response to this stimulus, the postganglionic neurons release norepinephrine, which activates adrenergic receptors that are present on the peripheral target tissues. The target synapse of the postganglionic neuron is mediated by adrenergic receptors and is activated by either norepinephrine (noradrenaline) or epinephrine (adrenaline).
Norepinephrine is synthesized from the amino acid tyrosine by a series of enzymatic steps in the adrenal medulla and postganglionic neurons of the sympathetic nervous system.

Adrenal medulla

medullamedullary(medulla)
This response is also known as sympatho-adrenal response of the body, as the preganglionic sympathetic fibers that end in the adrenal medulla (but also all other sympathetic fibers) secrete acetylcholine, which activates the great secretion of adrenaline (epinephrine) and to a lesser extent noradrenaline (norepinephrine) from it.
It is the innermost part of the adrenal gland, consisting of cells that secrete epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine in response to stimulation by sympathetic preganglionic neurons.

Chromaffin cell

chromaffin cellschromaffinchromaffin granules
They are in close proximity to pre-synaptic sympathetic ganglia of the sympathetic nervous system, with which they communicate, and structurally they are similar to post-synaptic sympathetic neurons.

Adrenaline

epinephrineadrenaline junkieadrenalin
The target synapse of the postganglionic neuron is mediated by adrenergic receptors and is activated by either norepinephrine (noradrenaline) or epinephrine (adrenaline).
Pharmacological doses of adrenaline stimulate α 1, α 2, β 1, β 2, and β 3 adrenoceptors of the sympathetic nervous system.

Kidney

kidneysrenalkidney disorder
Input from the sympathetic nervous system triggers vasoconstriction in the kidney, thereby reducing renal blood flow.

Superior cervical ganglion

superior cervical gangliasuperior
The ganglia include not just the sympathetic trunks but also the cervical ganglia (superior, middle and inferior), which send sympathetic nerve fibers to the head and thorax organs, and the celiac and mesenteric ganglia, which send sympathetic fibers to the gut.
The superior cervical ganglion (SCG) is part of the autonomic nervous system (ANS), more specifically it is part of the sympathetic nervous system, a division of the ANS most commonly associated with the fight or flight response.

Lateral grey column

lateral columnlateral hornintermediate horn cell
Sympathetic nerves arise from near the middle of the spinal cord in the intermediolateral nucleus of the lateral grey column, beginning at the first thoracic vertebra of the vertebral column and are thought to extend to the second or third lumbar vertebra.
The autonomic nervous system is divided into the parasympathetic nervous system (normal functioning) and the sympathetic nervous system (emergency functioning).

Celiac ganglia

celiac ganglionceliacGanglion coeliacum
The ganglia include not just the sympathetic trunks but also the cervical ganglia (superior, middle and inferior), which send sympathetic nerve fibers to the head and thorax organs, and the celiac and mesenteric ganglia, which send sympathetic fibers to the gut.
Part of the sympathetic subdivision of the autonomic nervous system (ANS), the two celiac ganglia are the largest ganglia in the ANS, and they innervate most of the digestive tract.

Vertebra

vertebraeneural spineneural arch
Sympathetic nerves arise from near the middle of the spinal cord in the intermediolateral nucleus of the lateral grey column, beginning at the first thoracic vertebra of the vertebral column and are thought to extend to the second or third lumbar vertebra.
This is an opening on each of the transverse processes which gives passage to the vertebral artery and vein and a sympathetic nerve plexus.

Cervical ganglia

cervicalcervical ganglionInferior cervical sympathetic ganglion
The ganglia include not just the sympathetic trunks but also the cervical ganglia (superior, middle and inferior), which send sympathetic nerve fibers to the head and thorax organs, and the celiac and mesenteric ganglia, which send sympathetic fibers to the gut.
The cervical ganglia are paravertebral ganglia of the sympathetic nervous system.

Vertebral column

spinespinal columnspinal
Sympathetic nerves arise from near the middle of the spinal cord in the intermediolateral nucleus of the lateral grey column, beginning at the first thoracic vertebra of the vertebral column and are thought to extend to the second or third lumbar vertebra. The shorter preganglionic neurons originate in the thoracolumbar division of the spinal cord specifically at T1 to L2~L3, and travel to a ganglion, often one of the paravertebral ganglia, where they synapse with a postganglionic neuron.
The spinal nerves provide sympathetic nervous supply to the body, with nerves emerging forming the sympathetic trunk and the splanchnic nerves.

Heart rate

heartbeatresting heart ratemaximum heart rate
For example, the sympathetic nervous system can accelerate heart rate; widen bronchial passages; decrease motility (movement) of the large intestine; constrict blood vessels; increase peristalsis in the oesophagus; cause pupillary dilation, piloerection (goose bumps) and perspiration (sweating); and raise blood pressure.
While heart rhythm is regulated entirely by the sinoatrial node under normal conditions, heart rate is regulated by sympathetic and parasympathetic input to the sinoatrial node.

Dopamine

dopaminergic systemDAdopaminergic
The relatively small quantity of unconjugated dopamine in the bloodstream may be produced by the sympathetic nervous system, the digestive system, or possibly other organs.

White ramus communicans

white rami communicanteswhite rami
However, unlike somatic innervation, they quickly separate out through white rami connectors (so called from the shiny white sheaths of myelin around each axon) that connect to either the paravertebral (which lie near the vertebral column) or prevertebral (which lie near the aortic bifurcation) ganglia extending alongside the spinal column.
White rami communicantes contain both myelinated and unmyelinated preganglionic sympathetic fibers, (GVE and GVA).

Esophagus

oesophagusesophageallower esophageal sphincter
For example, the sympathetic nervous system can accelerate heart rate; widen bronchial passages; decrease motility (movement) of the large intestine; constrict blood vessels; increase peristalsis in the oesophagus; cause pupillary dilation, piloerection (goose bumps) and perspiration (sweating); and raise blood pressure.
Its smooth muscle is innervated by involuntary nerves (sympathetic nerves via the sympathetic trunk and parasympathetic nerves via the vagus nerve) and in addition voluntary nerves (lower motor neurons) which are carried in the vagus nerve to innervate its striated muscle.

Postganglionic nerve fibers

postganglionicpostganglionic fiberspostganglionic neuron
From there, the long postganglionic neurons extend across most of the body.

Perspiration

sweatingsweatdiaphoresis
For example, the sympathetic nervous system can accelerate heart rate; widen bronchial passages; decrease motility (movement) of the large intestine; constrict blood vessels; increase peristalsis in the oesophagus; cause pupillary dilation, piloerection (goose bumps) and perspiration (sweating); and raise blood pressure.
The vast majority of sweat glands in the body are innervated by sympathetic cholinergic neurons.