When is a woman most fertile? What are the physical and emotional changes that tend to occur during this cycle, and why do these occur?

Describe menstrual cycle 
From aescribe menstrual cycle n anatomical and physiological perspective, describe the menstrual cycle. Pay special attention to the hormonal changes during the cycle. When is a woman most fertile? What are the physical and emotional changes that tend to occur during this cycle, and why do these occur?
Describe the biological and physiological aspects of the sexual response cycle as described by Masters and Johnson.

Note: Many researchers and sexual health educators feel the response cycle is incomplete. As part of your response, include your thoughts regarding whether the response cycle accurately represents what happens to the human system during sexual activity. Also, comment on the reasons why many researchers and educators feel it is incomplete.