System apps location on Android Jelly Bean

I chose to pose this question here, since I don't have any Jelly Bean device nearby.

On Android KitKat, system apps are located at /system/priv-app/. On Lollipop and Marshmallow, instead, they're placed under /system/priv-app/name-of-the-app/.

Following a similar fashion, I would like to know the path of those apps which are installed as system apps, on Android devices in a version range going from 4.1.x to 4.3.x (namely, all of the Jelly Bean builds).

Are their APKs located under the /system/app/ folder directly, are they placed in a folder of the same name of the corresponding app, or are they present in a completely different folder?

Thanks in advance.