A sex organ or primary sexual characteristic, as narrowly defined, is any anatomical part of the body involved in sexual reproduction and constituting the reproductive system in a complex organism, especially the external sex organs; the external sex organs are also commonly referred to as the genitalia or genitals.
Mosses, ferns, and some similar plants have gametangia for reproductive organs, which are part of the gametophyte. The flowers of flowering plants produce pollen and egg cells, but the sex organs themselves are inside the gametophytes within the pollen and the ovule.Coniferous plants likewise produce their sexually reproductive structures within the gametophytes contained within the cones and pollen. The cones and pollen are not themselves sexual organs.
The Latin term genitalia, sometimes anglicized as genitals, is used to describe the externally visible sex organs, known as primary genitalia or external genitalia: in male mammals, the penis and scrotum; and in female mammals, the clitoris and vulva.
A woman is a female human. The term woman is usually reserved for an adult, with the term girl being the usual term for a female child or adolescent. The term woman is also sometimes used to identify a female human, regardless of age, as in phrases such as "women's rights". "Woman" may also refer to a person's gender identity. Women with typical genetic development are usually capable of giving birth from puberty until menopause. In the context of gender identity, transgender people who are biologically determined to be male and identify as women cannot give birth. Some intersex people who identify as women cannot give birth due to either sterility or inheriting one or more Y chromosomes. In extremely rare cases, people who have Swyer syndrome can give birth with medical assistance. Throughout history women have assumed or been assigned various social roles.
The spelling of woman in English has progressed over the past millennium from wīfmann to wīmmann to wumman, and finally, the modern spelling woman. In Old English, wīfmann meant "female human", whereas wēr meant "male human". Mann or monn had a gender-neutral meaning of "human", corresponding to Modern English "person" or "someone"; however, subsequent to the Norman Conquest, man began to be used more in reference to "male human", and by the late 13th century had begun to eclipse usage of the older term wēr. The medial labial consonants f and m in wīfmann coalesced into the modern form "woman", while the initial element, which meant "female", underwent semantic narrowing to the sense of a married woman ("wife"). It is a popular misconception that the term "woman" is etymologically connected with "womb", which is from a separate Old English word, wambe meaning "stomach" (of male or female; modern German retains the colloquial term "Wampe" from Middle High German for "potbelly"). Nevertheless, such a false derivation of "woman" has appeared in print.
The female reproductive system (or female genital system) contains two main parts: the uterus, which hosts the developing fetus, produces vaginal and uterine secretions, and can pass sperm through to the Fallopian tubes; and the ovaries, which produce the female's egg cells. These parts are internal; the vagina meets the external organs at the vulva, which includes the labia, clitoris and urinary meatus. 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, a single sperm can enter and merge with the egg, fertilizing it. Corresponding equivalent among males is the male reproductive system.
During the reproductive process, the egg is not a passive recipient, but rather an active participant in the fertilization process. It releases certain molecules that are essential to guiding the sperm which allow the surface of the egg to attach to the sperm's surface. The egg can then absorb the sperm and fertilization begins. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. A zygote will then divide over enough generations of cells to form a blastocyst, which 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.
