Complex sentence: Langley also described an enteric nervous system although it has received minimal attention, and most modern textbooks tend to only mention the sympathetic and parasympathetic pathways in the context of the autonomic nervous system.
Split into simpler sentences: Langley also described an enteric nervous system which has received minimal attention. Most modern textbooks tend to only mention the sympathetic and parasympathetic pathways in the context of the autonomic nervous system.