The blastocyst implants in the uterus on about the ________ day of the 28 day menstrual cycle.At this time,the endometrium is ________ and progesterone levels are _______.
A)21st; thick and secretory; high
B)28th; thick and secretory; low
C)14th; thick and secretory; low
D)7th; thin and proliferating; high
E)1st; thin and proliferating; low

Question

Quizplus · Accepted Answer

The blastocyst usually implants in the uterus on day 21 of the 28-day menstrual cycle. At this time, the endometrium is thick and secretory. This is due to the increased levels of progesterone produced by the corpus luteum during the luteal phase of the menstrual cycle.

The Blastocyst Implants in the Uterus on About the ________