Remodeling an addition and I don't know if these ceiling beams are structural. Any help?

Hi all,

We are remodeling an addition and we tore down the drywall from the ceiling. There are some boards that extend accross the ceiling and we want to remove them in order to install some beams in a different way. I dont know if the existing boards are structural and could use some advice.

Here is an IMGur album of the issue: