Distinguish the effect of estrogen and progesterone on:

(A) ENDOMETRIUM:

The role of estrogen is to regeneration and growth of the endometrium prior to ovulation. It leads to thicken of uterine lining during the pre-ovulatory phase of the cycle. One of the progesterone's most important function is to cause the endometrium to secrete special protein during second half of menstrual cycle, preparing it to receive and nourish an implanted fertilized egg. If implantation does not occur, estrogen and progesterone level drops, the endometrium breaks down and menstruation occur.

(B) CERVICAL MUCUS:

The cervix is the lowest portion of uterus. It undergoes hormonally induced changes during ovarian cycle. Under the influence of estrogen during the follicular phase, the mucus secreted by the cervix become clear and thin. This change, which is most pronounced when estrogen is at its peak and ovulation is approaching, facilitate the passage of sperm through cervical canal. After ovulation, under the influence of progesterone, the mucus becomes thick and sticky, essentially plugging up the cervical opening. Sperm cannot penetrate this thick mucus barrier.

(C) MYOMETRIAL:

Progesterone withdrawal or enable to create myometrial contraction. During late pregnancy the progesterone level drop. As progesterone decreases sensitivity is increased to oxytocin.

(D) MAMMARY GLAND:

Estrogen is primary hormone that stimulate breast growth during puberty, progesterone act with estrogen to maintain female reproductive health and female sex characteristics. Progesterone has several effect on breast tissue during puberty, menstruation and pregnancy. It also influences the growth of cancerous tissue in the heart. Progesterone levels begin to rise and peak during menses. Progesterone that occur during menstrual cycle contributes to cause of the characteristic breast tenderness during menstruation. During pregnancy, progesterone promote further development of glandular tissue in breast so that it will secrete milk.

(E) GONADOTROPHIN SECRETION:

The primary mechanism of action of hormonal contraceptives is that they suppress the secretion of gonadotrophins (FSH,LH). A woman receives a combination of progesterone and estrogen or just estrogen. Progesterone and estrogen naturally inhibit gonadotrophins secretion during luteal phase of cycle. The goal is to suppress ovulation.