<prompt> Noradrenaline is major neurotransmitter in ?Postganglionic parasympathetic fibresPostganglionic sympathetic fibres except in sweat glandsAutonomic gangliaPreganglionic autonomic fibres  <response>: Ans. is b i.e., Postganglionic sympathetic fibres except in sweat glandsNeurotransmitter in all preganglionic autonomic nerves both sympathetic and parasympathetic is acetylcholine A CHNeurotransmitter in all ganglia both sympathetic and parasympathetic is acetylcholine.Neurotransmitter in postganglionic parasympathetic fibres is acetylcholine.In posganglionic sympathetic fibres, the major neurotransmitter is noradrenaline NA except in renal and mesentric vasculature where it is dopamine, in sweat glands, some blood vessels where it is acetylcholine and in adrenal medulla where it is adrenaline.Most of the visceral organs are supplied by both sympathetic and parasympathetic system except;Blood vessels, spleen, sweat glands and hair follicles receive only sympathetic innervation.Ciliary muscle gastric and pancreatic glands receive only parasympathetic innervation.In general sympathetic and parasympathetic systems are antagonistic except :Refractory period of atrial fibres is decreased by both.At almost all organs except hea, cholinergic system has excitatory activity and adrenergic system has relaxing propeies Sympathetic system stimulates Tachycardia, Positive inotropic and parasympathetic system depresses Bradycardia, Negative inotropic the hea. 