PA instruction averages 111 weeks, and a typical medical school runs 155 weeks. Physicians also are required to do an internship, and the majority also complete a residency in a specialty following that. PAs do not have to undertake an internship or residency. A doctor has complete responsibility for the care of the patient. PAs share that responsibility with the doctors.
Doctors are independent practitioners.
PAs practice medicine with the supervision of a physician. The physician is generally not required to be on site when the physician assistant is treating a patient. Registered nurses study nursing and PAs study medicine. While some areas of education overlap, nurses focus on nursing assessment and patient care issues. A PA is taught to diagnose and treat illnesses using the medical model.