My coworkers are able to take lunch and other breaks that I am barred from taking in the same way.

I work for a hospital in Ohio as a switchboard operator. I work third shift, 11p-7a. On my shift, I am the only Operator on duty, and, because the switchboard cannot go unanswered - I call in emergency teams, dispatch for codes, etc. - I am prohibited from leaving the office during my shift. First and second shift, however, can and do leave for lunch and fifteen-minute breaks. They also work eight-hour shifts (7a-3p, 8a-4p, and 3p-11p). Nobody is ever required to clock out for their breaks or lunches, and no such breaks are taken out of anyone's paycheck. My question is whether this is legal. It seems I am being denied work breaks to which I am entitled and/or not being somehow compensated for the difference. Am I correct? Thank you.