PTA Vs. Receptionist

Do PTAs perform the same job duties as a receptionist/ a secretary? like answering phone and scheduling patients?

I have a rare phobia of answering the phone at work. I don't have any problems making any kind of calls, nor do I have problems with my cell/ home phone. I just seem to dread the formal greeting of customers, too much that I've been avoiding any job that requires phone answering, and settled for a job I hate so much. Then I stumbled across this discussion board, and after reading all the threads, I can say that I can be a great PTA. I love working with people, and I have exceptionally good customer service. I just want to make sure My phone phobia doesn't get in the way as usual.

Is answering the phone with formal greeting a requirement for becoming a PTA?
Any feedback is greatly appreciated.