domingo, 5 de junio de 2011

Female Reproductive System

The female reproductive system is a collection of organs and other structures located primarily in the pelvic region. Most of the structures are inside the body. The female reproductive system has several functions:
• producing eggs, which are female gametes
• secreting female sex hormones
• receiving sperm during sexual intercourse
• supporting the development of a fetus
• delivering a baby during birth
• breastfeeding a baby after birth
During puberty, a girl develops into a sexually mature woman, capable of producing eggs and reproducing.
Sexual Development in Females
Like baby boys, baby girls are born with all their reproductive organs present but immature and unable to function. Female reproductive organs grow very little during childhood. They begin to grow rapidly and to mature during puberty.
Changes of Puberty
Puberty in girls differs from puberty in boys in several ways, including when it begins, how long it lasts, and the hormones involved. Girls begin puberty a year or two earlier than boys, and they complete puberty in about four years instead of six. In females, the major sex hormone is estrogen rather than testosterone.
During puberty, estrogen promotes growth and other physical changes in females. For example, estrogen stimulates growth of the breasts and uterus. It also stimulates development of bones and contributes to the adolescent growth spurt in height.
Physical Changes in Females During Puberty
Changes in Reproductive Organs
Ovaries and follicles grow
Uterus grows and endometrium thickens
Other reproductive structures grow
Menstrual cycle begins
Other Physical Changes
Breasts develop
Long bones grow and mature
Pubic hair grows
Underarm hair grows
Body fat increases
Apocrine sweat glands develop
Pelvis widens
Mature reproductive organs are primary sex characteristics. Other changes, such as growth of pubic hair, lead to traits that are secondary sex characteristics.
Female Reproductive Organs
Only a few of the female reproductive structures are external to the body. All the main reproductive organs are internal.
External Organs
The external female reproductive structures are referred to collectively as the vulva. They include the mons pubis, the labia (majora and minora) and the clitoris. The labia are the “lips” of the vulva. They protect the vagina and urethra, both of which have openings in the vulva. The mons pubis consists of fatty tissue covering the pubic bone. It protects the pubic bone and vulva from injury. The clitoris, located between the labia minora at their upper end, is a small protrusion that corresponds to the penis in the male. The clitoris, like the penis, is very sensitive to sexual stimulation and can become erect.
Internal Organs
The internal female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries.
The vagina is a cylinder-shaped organ. One end of the vagina opens at the surface of the body. The other end joins with the uterus. During sexual intercourse, sperm may deposited in the vagina. The sperm move through the vagina and into the uterus. During birth, a baby passes from the uterus through the vagina to leave the body.
The uterus is a hollow organ with muscular walls. The narrow part of the uterus where it connects with the vagina is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus expand as the baby grows. The muscular walls of the uterus push the baby out during birth.
The two ovaries are small, oval organs on opposite sides of the uterus. Each ovary contains thousands of eggs. The eggs do not fully develop until a female has gone through puberty. About once a month, an egg completes its development and is released by the ovary. The ovaries also secrete estrogen.
The two Fallopian tubes are narrow passages that open off the uterus. Each tube reaches one of the ovaries. However, the tubes are not attached to the ovaries.

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