How is the anatomy of the ANS?

Efferent neurons consist of two neurons, preganglionic (cell body in CNS) relays in ganglia with postganglionic neuron (cell body in ganglion, non-myelinated ends on effector organ), it is divided into sympathetic and parasympathetic Afferent neurons important in reflex regulation of this system (sensing carotid sinus pressure), and signals to efferent system to respond.