Menstrual flow occurs due to lack of
oxytocin
vasopressin
progesterone
$FSH$
Corpus luteum is the source of secretion of
The secretory phase in the human menstrual cycle is also called
When pregnancy does not occur, the life of corpus luteum is about
About which day in a normal human menstrual cycle does rapid secretion of $LH$ (popularly called $LH$ surge) normally occurs?
Why are menstrual cycles absent during pregnancy ?