There have been several iterations of the Nikon F mount over the years. Originally the Nikon F was an adaption of the early Nikon rangefinders (1948)- but with the mirror and prism on the SLR's, the lenses were extensively redesigned. Originally the Nikons (1959) had the meter in the prism and the lens coupled with the prism through a mechanical linkage (rabbit ears). At the same time there was a flange on the lenses that extended towards the body through 360 degrees around the lens mount. With the later models of the F2 (the F2 had several evolutionary metered prisms extending over its many years 1971-1980) in the 70's, a new lens design was developed that used a meter setting activated via a tab on the body (so called AI lens type). The tab had to rotate through about 60 degrees of arc and needed the space that was occupied by the flange on the earlier lenses.
On the "professional Nikons" (single digit Nikons ie: F3, F4, F5 -with adapter and now F6) the camera body tab is able to flip out of the way so earlier lenses will not interfere with the body. On later amatuer bodies (kind of an arbitrary term on Nikon's part but generally anything more than a single digit Nikon), the tab is not moveable and damage will result to the camera/lens if one is mounted on the body. (There are a few exceptions eg FM, and FE).
For the rest of the later lenses ( including AF), they will mount on the earlier cameras but may not meter correctly depending upon the camera - with the professional/expensive models being more versatile.
The best featured (in terms of lens mount) film camera is probably the F4 which will mount and meter with virtually any Nikon lens (SLR type) right up to the newest types. The F4 has the ability to shoot 6 fps, has 100% viewfinder, choice of matrix, spot and center weighted metering, removable pentaprism, mirror lockup, viewfinder shield (internal). It has a shutter speed range of 30s to1/8000 and flash sync to 1/250. It also features silent film advance and a choice of program modes and the ability to manually rewind your film if desired. It is also the largest and heaviest 35mm SLR (F4E version) I am aware of and rivals a Mamiya TLR Medium format camera in weight.
So yes, Nikon has largely kept with one lens mount over the past 45 years, but it is not as universally useful as the Pentax mount. What has kept it from being more useful (IMHO) is the wide price range between high end models (typically thousands of dollars) and the lower end models (competative with low end Canon, Minolta and Pentax cameras) which haven't got the features to use all the lenses. The result of it all is to "require" several bodies and several lenses to make use of all the features available.
Regards, Phil
Who sometimes can't decide what camera to use when he wakes up and doesn't take a particulary good picture with any of them. But I keep trying!