Bundle of nerves

Jenny was a good girl, but her friends thought she was just a big bundle of nerves.
Which, I suppose, is fair. Because she was just a big bundle of nerves.
No skin or bones or fat or muscle or anything else.
After her accident, all the doctors managed to save was her nervous system.
Just a brain, spinal cord, and spidery nerves in a jar of electrolytes.
When guys asked her out on a date, she knew it was for her brains, not her body.
Although some liked to wave magnets over her and cause weird sparkly light displays.