Final answer:
Estrogen and progesterone help maintain the endometrium in a fertilized egg by regulating the growth and development of the uterine lining. During the follicular phase, the released hormones maintain the endometrium to ensure pregnancy. If the egg is fertilized, progesterone is secreted by the corpus luteum to prevent the endometrium from breaking down and maintain the pregnancy.
Step-by-step explanation:
Estrogen and progesterone help maintain the endometrium in a fertilized egg by regulating the growth and development of the uterine lining.
During the follicular phase of the ovarian cycle, the follicles on the surface of the ovary release estrogens and a low level of progesterone. Progesterone maintains the endometrium to help ensure pregnancy.
If the egg is fertilized, the ruptured follicle, now known as the corpus luteum, will secrete progesterone. This hormone prevents the endometrium from breaking down and is essential for maintaining the pregnancy. Without progesterone, the endometrium will break down and be shed, starting a new menstrual cycle.