LISTEN: Tig Notaro & Alex Kurtzman Catch Up on the Latest Episode of “Don’t Ask Tig”

Traditional name for personnel access conduits aboard Federation starships, usually to allow hands-on contact to critical circuitry and serve as emergency access in times of power outage.
In 2369, Lt. Cmdr. Nella Darren used a Jefferies Tube junction on the Galaxy-class Enterprise as a concert hall for its acoustics.