- published: 03 Jun 2014
- views: 76876
The autonomic nervous system (ANS or visceral nervous system or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiratory rate, salivation, perspiration, pupillary dilation, micturition (urination), and sexual arousal. Whereas most of its actions are involuntary, some, such as breathing, work in tandem with the conscious mind. The ANS is located in the medulla oblongata which is then divided into the rcc(respiratory control centre) the ccc(cardiac control centre) and the vmc(vasomotor centre). These then subdivide into other areas. The ccc to parasympathetic and sympathetic, the rcc to inspiratory control centre and expiratory control centre. It is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS). Relatively recently, a third subsystem of neurons that have been named 'non-adrenergic and non-cholinergic' neurons (because they use nitric oxide as a neurotransmitter) have been described and found to be integral in autonomic function, particularly in the gut and the lungs.