Most of their training is in their own area, and modern medicine is very finely sub-divided into specialties. Surgery, for example, is sub-divided into eight or nine sub-specialties including cardiology and neurology.
由於他們接受的訓練是以本科為主，而現代的醫學分科又很細，光是外科就有心臟外科、神經外科等八、九個次專科。