When you hear that an individual is an assistant to a professional, what image springs to mind? Someone who answers the phone and schedules appointments? Someone who takes care of other administrative tasks so that the professionals can devote their time to working directly with the customers/clients/patients? In a doctor's office, would you assume that "physician's assistant" and "medical assistant" mean the same thing?

That would be a mistake. The healthcare system has done a poor job of titling people involved in patient care who aren't doctors or nurses. Consider physician's assistants (PAs).

PAs are supervised by doctors, and as one staff member in a local orthopedics office told me, "The PAs can do everything the doctor does except perform surgery!" And in fact, they may assist in surgery.

According to the American Academy of Physician Assistants (AAPA), "PAs perform physical examinations, diagnose and treat illnesses, order and interpret lab tests, perform procedures, assist in surgery, provide patient education and counseling and make rounds in hospitals and nursing homes. All 50 states and the District of Columbia allow PAs to practice and prescribe medications."

To become a physician's assistant requires having an undergraduate degree including a number of heavy-duty science courses, and then typically 24-27 months of graduate study based on a framework consistent with that used in medical schools and leading to a master's degree.

How easy is it to get into a physician assistant master's program? Recent numbers from three programs in Arizona tell the tale: 20-25 times as many people applied as the schools had slots for. In other words, only 4-5 percent of the people who applied were admitted and enrolled. In fact, it is harder to get into an Arizona PA master's program than it is to get into Harvard College (where this year almost 6 percent of applicants were admitted).

About half of the time in typical PA master's programs is spent in classes. Examples of topics covered are anatomy, physiology and pharmacology. Students also learn how to take a medical history and examine a patient, how to make an accurate diagnosis, and so forth. They learn about areas such as pediatrics, psychiatry, women's health and emergency medicine.

The other half of the time consists of clinical rotations - gaining hands-on experience in areas such as emergency, family and internal medicine, mental health and surgery.

But graduating from the program isn't enough to allow the newly trained professionals to practice. Graduates must pass a national certification exam - and then apply for state licensing.

According to the federal Bureau of Labor Statistics, nationally the average salary for a PA is about $92,500 per year. The AAPA reports that PAs' services are covered by virtually all insurance programs, at rates ranging from 85 percent to 100 percent of the rates paid to doctors in the same area for the same services.

And what are medical assistants (MAs)? The Arizona Medical Board says, "A medical assistant (MA) is an unlicensed person who assists in the medical practice under the supervision of a physician, physician assistant or nurse practitioner. An MA does not diagnose, interpret, design or modify established treatment programs."

MAs may handle tasks such as drawing blood and giving shots; collecting information such as height, weight, blood pressure and temperature and noting the reason the patient is being seen; updating medical records with the results of medical tests; and providing information to patients about treatments, medicines, and doctors' orders. They may perform dozens or hundreds of other tasks needed to keep medical practices running smoothly, as instructed by doctors and other practitioners.

Generally, MAs are expected to complete an approved training program, which may typically take 30-60 weeks and result in either a diploma or an associate's degree. It is left to their supervisors to ensure that MAs have completed appropriate training. While certification is not required, some MAs do get certified, which is a plus. Nationally, the Bureau of Labor Statistics reports that a typical medical assistant earns about $30,500 a year.

What's the bottom line? It helps to understand the roles of different players in your doctor's office. You may get better results by being seen promptly by a physician's assistant than by waiting six weeks to see the doctor.