Autonomic nervous system

Autonomic nervous system

The autonomic nervous system coordinates cardiovascular, respiratory, digestive, urinary, and reproductive functions.

Preganglionic neurons from the thoracic and lumbar segments form the sympathetic division (fight or flight system). Post-ganglionic sympathetic actions in end organs are mediated via noradrenaline acting on adrenergic receptors (with the single exception of sweat glands).

Preganglionic

neurons from the brain and sacral segments form the parasympathetic division (rest and repose system). Post-ganglionic parasympathetic actions in end organs are mediated via acetylcholine acting on muscarinic receptors.

All preganglionic transmission is mediated via acetylcholine acting on nicotinic receptors.

The graphic shown an overview of the effects of the sympathetic and parasympathetic nervous system.