“Physicians,” “dentists,” “optometrists,” “pharmacists,” “doctors of podiatric medicine,” “veterinarians,” “veterinary surgeons,” “registered nurses,” “naturopathic doctors,” and “physician assistants” are persons authorized by a currently valid and unrevoked license to practice their respective professions in this state. “Physician” means and includes any person holding a valid and unrevoked physician’s and surgeon’s certificate or certificate to practice medicine and surgery, issued by the Medical Board of California or the Osteopathic Medical Board of California, and includes an unlicensed person lawfully practicing medicine pursuant to Section 2065, when acting within the scope of that section.