Gender of קרבן

So in the week's פרשה as well as last's, we dicuss the קרבן עולָה. Why is a קרבן considered feminine? And if it is feminine, why do we refer to a קרבן עולֶה ויורד? That would imply that it is masculine. Is this yet another example of what we have been dicussing a lot recently - the case of the "hidden word?"