As used in sections nine C to nine K, inclusive, the following words shall have the following meanings:
''Approved program'', a program for the education and training of physician assistants approved by the board.
''Board'', the board of registration of physician assistants.
''Health care facility'', any hospital, nursing home, extended care facility, state health or mental institution, clinic, physician's office or health maintenance organization licensed or otherwise operating legally within the commonwealth.
''Physician assistant,'' a person who is duly registered and licensed by the board.
''Physician assistant trainee'', a person enrolled in an approved program.