About which day in a normal human menstrual cycle does rapid secretion of $LH$ (popularly called $LH$ surge) normally occurs?
$14^{th}$ day
$20^{th}$ day
$5^{th}$ day
$11^{th}$ day
During menstruation the level of progesterone in blood is
Corpus luteum in pregnancy has a long life. However, if fertilisation does not take place, it remains active only for $10-12$ days. Explain.
Corpus luteum is formed in
In girl, the first menstruation begins at puberty and is called .....
Menstrual cycle occurs in