Women’s programs

You might notice that once we get to the Women’s programs, the term firming is used versus mass gains or strength. Is there any real difference in the mechanisms at the level of the neural system or muscle that is different between men and women? In other words, if I have both a man and a woman use a 5 pound weight for biceps curls, is there anything going on that is different between men and women per the changes in the muscles and/or CNS? Explain your answer.