A graphic showing the hull pressure compartments on the Enterprise
A hull pressure compartment was a notable section of a Federation Constitution-class starship.
As a member of the this class, the USS Enterprise had several hull pressure compartments throughout the ship, the locations of which were often displayed on computer graphics on the bridge. (TOS: "Day of the Dove")
The hull pressure compartment graphic was created by Production Designer Matt Jefferies. (The Star Trek Auction catalog, p. 21)