The video explains the parasympathetic nervous system, focusing on its cranial part. It details the functions of four cranial nerves: oculomotor, facial, glossopharyngeal, and vagus. Each nerve's role in controlling specific body functions, such as eye adjustments, salivation, and widespread organ control, is discussed. The video emphasizes the three-neuron system and the importance of ganglia in these processes.

What new insight or understanding did you gain from this video?