m25

May 28, 2014
304
19
Status
Pre-Medical
Does decreased level of estrogen alone during the luteal phase cause the onset of menstrual flow, or is it the decreased level of both estrogen and progesterone that causes the onset of menstrual flow?
 

tdod

5+ Year Member
Oct 30, 2011
220
21
Status
Medical Student
Does decreased level of estrogen alone during the luteal phase cause the onset of menstrual flow, or is it the decreased level of both estrogen and progesterone that causes the onset of menstrual flow?
I am not sure about this, but my understanding is that E & P are high during the luteal phase b/c they are being secreted by the corpus luteum. however, the corpus luteum eventually dies (unless pregnancy occurs) and ceases to secrete E & P. Progesterone is important for encouraging the endometrium to continue growing; I would assume that, without progesterone, the endometrium is shed.
 

Hadi7183

5+ Year Member
Dec 8, 2013
63
22
NWT
Status
Pre-Medical
@tdod is right. Progesterone is essential for the maintenance of endometrium ; reduced progesterone level --> menstruation.