Which Layer Of The Endometrium Is The Functional Layer?

Which Layer Of The Endometrium Is The Functional Layer? The endometrium itself is divided into two layers, the stratum functionalis and stratum basalis. During the menstrual cycle, the stratum functionalis expands and vascularizes and is subsequently sloughed off during the process of menstruation, whereas the stratum basalis remains relatively constant. What is the functional significance