Saturday, May 29, 2010

0 Hormones & Reproduction

Normal human reproduction involves interactions between various hormones and organs, which is regulated by the hypothalamus (a region in the brain).
In men and women, the hypothalamus produces hormones called releasing factors (RH).

RH walked into the pituitary (a gland located below the hypothalamus) and stimulates the pituitary to release other hormones. Eg gonadotropin-releasing hormones (produced by the hypothalamus) stimulates the pituitary to produce luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
- LH and FSH stimulates the maturation of the reproductive glands and release of sex hormones: the woman's ovaries to release estrogen
- The testes in the male to release androgens (eg testosterone).
Sexual hormones are also released by the adrenal glands, located above the kidneys.

The pattern of release of hormones and hormone levels in the blood is an indication of the stimulation or inhibition in the release of LH and FSH by the pituitary. For example, decreased levels of sex hormones stimulate the pituitary to release more LH and FSH.
Hormones are released every 1-3 hours, because that hormone levels in the blood is usually spotty.


Puberty is early sexual maturation, which is a period in which a child suffered physical changes, hormonal and sexual abuse and able to conduct the process of reproduction.
Puberty associated with rapid growth and emergence of secondary sexual characteristics.

At birth, levels of LH and FSH are high, but several months later declined and remained low until puberty.
At the beginning of puberty, both hormones are increased, thus stimulating the formation of sexual hormones. Elevated levels of the hormone causes:
- Maturation of the breast, ovary, uterus and vagina
- Commencement of the menstrual cycle
- The appearance of secondary sexual characteristics (such as pubic hair and underarm hair).
These changes occur sequentially during puberty to sexual maturity occurs.

In girls, the first change occurs at puberty is usually a protrusion of the breast, which was soon followed by the growth of pubic hair and armpit hair. The distance between the protrusion of the breast with the first menstrual cycle, usually about two years.
Changing body shape and body fat percentage increases. The rapid growth of the body (especially the addition of height) usually begins before the breasts enlarged. Besides, from the vagina out clear or whitish fluid and the addition of wide pelvic bone.

The most rapid growth relative body occurs in early puberty (before the start of the menstrual cycle). Then the growth slows and typically stops at the age of 14-16 years. In the boys are on the contrary, the body's most rapid growth occurred at 13-17 years of age and continue until the beginning of 20 years.

In girls, puberty usually occurs at age 9-16 years. Average daughter undergoes puberty two years earlier than boys.
Age of puberty appears to be influenced by child health and nutrition, as well as socio-economic factors and heredity.
Slightly chubby girls who tend to experience first cycle early, while girls are skinny and malnourished tend to have slower first cycle. The first cycle also occurs earlier in girls who live in the city.


Menstruation is the release of the uterine lining (endometrium), accompanied by bleeding and occur repeatedly every month except during pregnancy.

First menstruation (called menarche) most often occurs at the age of 11 years, but can also occur at the age of 8 years or 16 years.
Menstruation is a sign of the reproductive years in the life of a woman, who started from menarche to menopause.

The first day of bleeding is calculated as the beginning of each menstrual cycle (day 1). Cycle ends right before the next menstrual cycle.
Menstrual cycles ranging from 21-40 days. Only 10-15% of women who have 28 day cycles.
The distance between the longest cycle usually occurs shortly after menarche and immediately before menopause.

Initially, the cycle may be irregular. The distance between the two cycles can last for two months or within one month may be two cycles. This is normal, after a long cycle will become more regular.
And duration of the menstrual cycle can be known by making notes on kalender.Dengan use the calendar, mark your cycle each month. After several months, you can know your cycle pattern and this will help you in predicting future cycles.
Mark each day of the first with a cross, then count to the next cross. Thus you can find out your cycle.

Each month, after day 5 of the menstrual cycle, the endometrium begins to grow and thicken in preparation for the possibility of pregnancy.
Around day 14, there was the release of eggs from the ovaries (ovulation). Tues telulr this into one of the fallopian tubes. Can occur in the fallopian fertilization by sperm.
If fertilization occurs, the egg will go into the womb and begin to grow into a fetus.

At about day-to-28, if no fertilization occurs, the endometrium is released and bleeding (menstrual cycle). The cycle may last for 3-5 days, sometimes up to seven days.
The process of growth and thickening of the endometrium and then started again on the next cycle.


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