Female reproductive system (human)

Overview
The human female reproductive system contains two main parts: the vagina and uterus, which act as the receptacle for the male's sperm, and the ovaries, which produce the female's ova. All of these parts are always internal; the vagina meets the outside at the vulva, which also includes the labia, clitoris and urethra. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the fallopian tube into the uterus.

If, in this transit, it meets with sperm, the sperm penetrate and merge with the egg, fertilizing it. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then implants itself in the wall of the uterus, where it begins the processes of embryogenesis and morphogenesis. When developed enough to survive outside the womb, the cervix dilates and contractions of the uterus propel the fetus through the birth canal, which is the vagina.

The ova are larger than sperm and are generally all created by birth. Approximately every month, a process of oogenesis matures one ovum to be sent down the Fallopian tube attached to its ovary in anticipation of fertilization. If not fertilized, this egg is flushed out of the system through menstruation.

Vagina
The vagina is the tubular tract leading from the uterus to the exterior of the body in female mammals, or to the cloaca in female birds and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct.

The vagina is the place where semen from the man is deposited into the woman's body during sexual intercourse.

Cervix
The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall. Approximately half its length is visible; the remainder lies above the vagina beyond view.

Uterus
The uterus or womb is the major female reproductive organ of humans. One end, the cervix, opens into the vagina; the other is connected on both sides to the fallopian tubes.



The uterus mostly consists of muscle, known as myometrium. Its major function is to accept a fertilized ovum which becomes implanted into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose. The fertilized ovum becomes an embryo, develops into a fetus and gestates until childbirth.

Oviducts
The Fallopian tubes or oviducts are two very fine tubes leading from the ovaries of female mammals into the uterus.

On maturity of an ovum, the follicle and the ovary's wall rupture, allowing the ovum to escape and enter the Fallopian tube. There it travels toward the uterus, pushed along by movements of cilia on the inner lining of the tubes. This trip takes hours or days. If the ovum is fertilized while in the Fallopian tube, then it normally implants in the endometrium when it reaches the uterus, which signals the beginning of pregnancy.

Ovaries
The ovaries are the place inside the female body where ova or eggs are produced. The process by which the ovum is released is called ovulation. The speed of ovulation is periodic and impacts directly to the length of a menstrual cycle.

After ovulation, the ovum is captured by the oviduct, where it travelled down the oviduct to the uterus, occasionally being fertilised on its way by an incoming sperm, leading to pregnancy.

The Fallopian tubes are often called the oviducts and they have small hairs (cilia) to help the egg cell travel.