True regarding autonomic system is

Autonomic nervous system -        The highest centre is the hypothalamus. -        Conduction speed is slower in ANS compared to somatic nerves. ANS is non-myelinated. -        Preganglionic parasympathetic fibers are lengthier because parasympathetic ganglia lie closer to the organs. -        Ratios of preganglionic to post ganglionic fibers are 1:20 to 1:100 in sympathetic system.