Postganglionic nerve

Postganglionic nerves are part of the nervous systems of Bajorans and Humans.

In one of the final oral exams while he was at the Starfleet Medical Academy, Julian Bashir incorrectly identfied a preganglionic fiber as a postganglionic nerve. The error meant Bashir lost the title of valedictorian to Elizabeth Lense and became salutatorian of the graduating class. 

Bashir mentioned his failure in discerning between a postganglionic nerve and a preganglionic fiber to Jadzia Dax, Benjamin Sisko and Kira Nerys when he first met them on the way to, and on, Deep Space 9 in 2369. 

In 2371, while Bashir was in a coma after a telepathic attack by the Lethean criminal Altovar, an imaginary version of the Lethean claimed Bashir gave the wrong answer on purpose. 

In 2376, Simon Tarses misidentified a preganglionic fiber as a postganglionic nerve on medical scan of Ro Laren. Bashir was quick to correct him.