Class 11 NEET Biology Neural Control and Coordination

(a) : The blood is supplied into visceral organs by both SNS (sympathetic nervous system) and PNS (parasympathetic nervous system) involuntarily. The sympathetic fibres increase the rate and force of heart beat, constrict most blood vessels and raise the arterial blood pressure. The parasympathetic fibres decrease the rate and force of heart beat, dilate many blood vessels and lower the arterial blood pressure.