Anatomy And Physiology

Anatomy Physiology

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Estradiol is a sexual hormone belonging to the group of estrogens. Estrogens themselves are classified in the group of steroid hormones – biologically active substances that form in the human body and that have one common predecessor – cholesterol.

Estradiol’s concentration in the body is directly dependent on the menstrual cycle from the onset of puberty to menopause. This hormone is also playing a role in the male body. Its absence can cause sterility.

The female body produces estrogens mainly in the ovaries during the first half of the menstrual cycle. These hormones affect the manner in which a woman’s body gets shaped and her fertility.

Estradiol and the menstrual cycle

Estradiol is the most active hormone from the estrogen group. The highest concentration of estradiol has been found in the urine of pregnant women and in the placenta. A woman in her fertile years secretes 300 to 700 micrograms of estradiol within a 24-hour period.

In the beginning of the menstrual cycle, the concentration of estradiol in the blood is low. As ovulation approaches, this concentration increases significantly. Once the ovulation ends, the amount of estradiol in the blood starts decreasing gradually.

When a pregnancy occurs, the level of estradiol continues increasing even after ovulation.

The concentration of the hormone is highest as childbirth approaches. Shortly after birth is given, the amount of estradiol in the blood returns to the original values. As a woman ages, the concentration of the hormone decreases to become quite low after menopause.

Function of estradiol in the human body

Estradiol plays very important role in the female body. It is the one responsible for the silhouette that each lady will have. The accumulation of fatty tissue in certain areas of the body is caused directly by estradiol.

The hormone regulates the menstrual cycle and the individual sexual desire of a woman.

Under the influence of estradiol, ova mature in the ovaries. During pregnancy, it increases the size and blood flow to the uterus.

Apart from sexual functions, estradiol controls several other physiological processes. The hormone controls metabolism in bone tissue, making bones grow in length.

High levels of estradiol cause the body to retain liquids and to have high levels of sodium. This is the reason many pregnant women feel swelling in certain parts of the body. The high level of estradiol during pregnancy can also cause mood swings and irritation.

In the male body, estrogens and estradiol in particularly decrease the level of testosterone. These hormones make it difficult for men to build muscle tissue. Estradiol is connected to lower prostate cancer risk.


US National Library of Medicine   The influence of estradiol on nervous system function   Estrogen: Function and synthesis   Hormone levels and fertility bloodwork

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