Estrone and estradiol are both natural oestrogens. Oestrogens are responsible for the normal development of the female genital tract, of the breast and of the female secondary sex characteristics. The pubertal growth spurt is less marked in females than in males, probably because oestrogens have less protein anabolic action than do androgens, although they are as effective in promoting closure of epiphyses.

Blood oestrogen concentrations must be above a critical level for the maintenance of both proliferative and (together with progesterone) secretory phases of the uterine endometrium. If the oestrogen level falls too low then the endometrium can no longer be maintained and uterine bleeding follows. Thus uterine bleeding may be stopped temporarily by giving large doses of oestrogens, or started by abrupt withdrawal (oestrogen-withdrawal bleeding). Bleeding may occur despite a high blood oestrogen concentration if large doses are given for a long time, due to infarctions in the greatly hyper-trophied endometrium. Oestrogens are necessary for the maintenance of normal pregnancy and for the accompanying breast hyperplasia. The vagina is more sensitive to oestrogens than is the endometrium.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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