Autonomic nervous system

autonomicautonomous nervous systemautonomic functionsautonomic nervoussympathetic fibersvegetative nervous systemautonomic nervesautonomic responseautonomic responsesautonomic system
The autonomic nervous system (ANS), formerly the vegetative nervous system, is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of internal organs.wikipedia
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Urination

urinateurinatingmicturition
The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal.
Physiologically, urination involves coordination between the central, autonomic, and somatic nervous systems.

Peripheral nervous system

peripheralperipheral nervesPNS
The autonomic nervous system (ANS), formerly the vegetative nervous system, is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of internal organs.
The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.

Hypothalamus

hypothalamicanterior hypothalamushypothalamic hormones
Within the brain, the autonomic nervous system is regulated by the hypothalamus. The hypothalamus, just above the brain stem, acts as an integrator for autonomic functions, receiving ANS regulatory input from the limbic system to do so.
The hypothalamus is responsible for the regulation of certain metabolic processes and other activities of the autonomic nervous system.

Sympathetic nervous system

sympatheticsympathetic nervesympathetic nerves
The autonomic nervous system has three branches: the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.
The sympathetic nervous system (SNS) is one of the two main divisions of the autonomic nervous system, the other being the parasympathetic nervous system.

Parasympathetic nervous system

parasympatheticparasympathetic nerveparasympathetic nerves
The autonomic nervous system has three branches: the sympathetic nervous system, the parasympathetic nervous system and the enteric 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.

Nervous system

neuralnervousneurogenic
Those are then subdivided into other areas and are also linked to ANS subsystems and nervous systems external to the brain.
The PNS is divided into three separate subsystems, the somatic, autonomic, and enteric nervous systems.

Enteric nervous system

neurogastroenterologyentericenteric nervous plexus
The autonomic nervous system has three branches: the sympathetic nervous system, the parasympathetic nervous system and the enteric nervous system.
The enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract.

Orgasm

sexual gratificationfemale orgasmclimax
A more modern characterization is that the sympathetic nervous system is a "quick response mobilizing system" and the parasympathetic is a "more slowly activated dampening system", but even this has exceptions, such as in sexual arousal and orgasm, wherein both play a role.
Experienced by males and females, orgasms are controlled by the involuntary or autonomic nervous system.

Non-noradrenergic, non-cholinergic transmitter

NANCnon-noradrenergic/non-cholinergic (NANC)
Relatively recently, a third subsystem of neurons that have been named non-noradrenergic, non-cholinergic transmitters (because they use nitric oxide as a neurotransmitter) have been described and found to be integral in autonomic function, in particular in the gut and the lungs.
A non-noradrenergic, non-cholinergic transmitter (NANC) is a neurotransmitter of the autonomic nervous system (ANS) that is neither acetylcholine, norepinephrine, nor epinephrine.

Heart rate

heartbeatresting heart ratemaximum heart rate
The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. Autonomic functions include control of respiration, cardiac regulation (the cardiac control center), vasomotor activity (the vasomotor center), and certain reflex actions such as coughing, sneezing, swallowing and vomiting.
The normal SA node firing rate is affected by autonomic nervous system activity: sympathetic stimulation increases and parasympathetic stimulation decreases the firing rate.

Swallowing

swalloweddeglutitionswallow
Autonomic functions include control of respiration, cardiac regulation (the cardiac control center), vasomotor activity (the vasomotor center), and certain reflex actions such as coughing, sneezing, swallowing and vomiting.
The autonomic nervous system (ANS) coordinates this process in the pharyngeal and esophageal phases.

Neuron

neuronsnerve cellsnerve cell
There are inhibitory and excitatory synapses between neurons.
The nervous system is made up of the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which includes the autonomic and somatic nervous systems.

General visceral afferent fibers

general visceral afferentSympathetic afferentafferent fibres
They are considered to be part of the autonomic nervous system.

General visceral efferent fibers

general visceral efferentSympathetic efferentGVE
The term general efferent fibers (GVE or visceral efferent or autonomic efferent) refers to the efferent neurons of the autonomic nervous system that provide motor innervation to smooth muscle, cardiac muscle, and glands (contrast with SVE fibers) through postganglionic varicosities.

Limbic system

limbiclimbic structureslimbic region
The hypothalamus, just above the brain stem, acts as an integrator for autonomic functions, receiving ANS regulatory input from the limbic system to do so.
The limbic system operates by influencing the endocrine system and the autonomic nervous system.

Lung

lungspulmonaryright lung
Relatively recently, a third subsystem of neurons that have been named non-noradrenergic, non-cholinergic transmitters (because they use nitric oxide as a neurotransmitter) have been described and found to be integral in autonomic function, in particular in the gut and the lungs.
The lungs are supplied by nerves of the autonomic nervous system.

Lateral grey column

lateral columnlateral hornintermediate horn cell
The peripheral nervous system is divided into the somatic nervous system (voluntary processes) and the autonomic nervous system (involuntary processes).

Splanchnic nerves

splanchnic nerveleft splanchnic nervesright splanchnic nerves
Most organs receive parasympathetic supply by the vagus nerve and sympathetic supply by splanchnic nerves.
The splanchnic nerves are paired visceral nerves (nerves that contribute to the innervation of the internal organs), carrying fibers of the autonomic nervous system (visceral efferent fibers) as well as sensory fibers from the organs (visceral afferent fibers).

Adrenal medulla

medullamedullary(medulla)
In particular, they are modified postganglionic sympathetic neurons of the autonomic nervous system that have lost their axons and dendrites, receiving innervation from corresponding preganglionic fibers.

Prevertebral ganglia

Prevertebral ganglionpre-aortic gangliapreaortic ganglia
Nerves arising from the lateral horn of the spinal cord are those of the autonomic nervous system.

Vagus nerve

vagusvagalcranial nerve X
Most organs receive parasympathetic supply by the vagus nerve and sympathetic supply by splanchnic nerves. The parasympathetic division has craniosacral “outflow”, meaning that the neurons begin at the cranial nerves (specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve and vagus nerve) and sacral (S2-S4) spinal cord.
It is the longest nerve of the autonomic nervous system in the human body.

Brainstem

brain stembrain-stemback of the skull
The hypothalamus, just above the brain stem, acts as an integrator for autonomic functions, receiving ANS regulatory input from the limbic system to do so.

Homeostasis

homeostaticequilibriumimmunomodulation
In general, these two systems should be seen as permanently modulating vital functions, in usually antagonistic fashion, to achieve homeostasis.
The medulla oblongata then distributes messages along motor or efferent nerves belonging to the autonomic nervous system to a wide variety of effector organs, whose activity is consequently changed to reverse the error in the blood pressure.

Vasoconstriction

vasoconstrictorvasoconstrictivevasoconstricting
Examples of endogenous factors include the autonomic nervous system, circulating hormones, and intrinsic mechanisms inherent to the vasculature itself (also referred to as the myogenic response).

Spinal nerve

spinal nervescervical nervessacral nerves
Branches also exit the spine and go directly to the paravertebral ganglia of the autonomic nervous system where they are involved in the functions of organs and glands in the head, neck, thorax and abdomen.