Why are nurses answering questions doctors should be answering now a days ?

I 'm so sick of it. Nurses pretending to be doctors. Or these nurse practitioners thinking they are doctors ? What's up with this ? I recently had lab work done and a nurse from the doctor;s office calls me and says my doctor wants me to see a hematologist because my blood count is 4.4 and it was 6 point something in Dec. and she says it's because it involves your white count not red. Than she starts talking about bone marrow and how my bone marrow might not be right ? How does she know this. Well I had enough and called back the office and told them I wanted to talk to my doctor. So they put me over to an answering machine to my doctors assistant. So I left a message saying I want to talk to my doctor. Another time when I had to have my colonoscopy I made an appointment , when I got there they had me talk to a nurse practitioner . She took my history, I told her I have a mitra valve prolapse she went on to tell me that I didn't have a mitral valve prolapse because she didn't hear a click with the stethoscope. Boy what a nerve ! I most certainly do. I was going to report her but she called me back and apologized. Boy this practice of patients not be able to talk to a doctor and just discuss their case with a nurse needs to stop. I never did see a doctor prior to my colonscopy. I just don't feel comfortable with this. What do you think about this practice ?