The female genital apparatus, in organisms anfigonici is the set of organs and structures that allow the reproduction and mating in female animals.
The external evidence may have different anatomical aspects, with the orifice positioned at the opening of the excretory system, integrating with the external outlet of the excretory system (genitourinary tract), integrating with the outlet end of the digestive system (cloaca), disgiungendosi completely (eg gonoporo in crustaceans and other arthropods), and is covered by protective structures, such as the epigino of spiders or totally lacking external opening in organisms such as traumatic insemination, as some hemipterans heteroptera.
The female genital apparatus consists of two main parts:
internal genitalia, uterus and adnexa (fallopian tubes, ovaries)
external genitals, vulva and outbuildings.
The ovaries are paired organs, small, located on the side walls of the small pelvis. The ovaries are formed by ovarian follicles that release the mature egg cells: they descend into the fallopian tubes where fertilization occurs (if the environment is favorable and there are active sperm). If the egg is not fertilized within 24 hours, is removed by menstruation, but if it is fertilized, the egg descends into the uterus where the zygote forms.
Schematic front view
Salpinge
Trumpet or fallopian tube.
Uterus
The uterus is an organ uneven, hollow, muscular. Resembles the shape of an inverted pear. It is located between the rectum and the bladder. The cavity of the uterus is divided into three parts:
body, in relation to the bladder and defines the space or hollow bladder-uterine;
neck;
isthmus;
The uterus is formed by three different fabrics:
outer tunic or perimetrio, represented by peritoneum;
muscle layer or myometrium, consisting of bundles of smooth muscle;
uterine lining, or endometrium, a cylindrical epithelium monostratificato.
Vagina
The vagina is the canal in front of the uterus and, in the sexual relationship, is the organ that receives the male genitalia (penis). The vagina is the place where you can prevent mechanically or chemically fertilization by inserting systems, eg. the diaphragm and the intrauterine device or I.U.D. (Intra Uterine Device), which are close to the mouth of the uterus and / or inhibit fertilization.
External genitalia
Anatomy of the vulva, from the top (groin) to bottom (vaginal orifice):
- Pubes - Mount of Venus
- Clitoral prepuce
- Clitoral glans
- Large lips
- Small lips
- Urethral orifice
- Hymen
- Vaginal orifice
- Perineum
- Ano
Vulva [edit]
It is an area disposed in a vertical direction and consists of different parts:
Mount of Venus
clitoral prepuce
clitoris
labia
labia minora
urethral orifice
hymen
vaginal orifice.
Activities of the female genitalia
The female genital apparatus has in reproduction and endocrine functions:
reproductive function produces female gametes;
endocrine function: producing female hormones, like estrogens and progestogens.
Embryonic and fetal development of the genital tract
Males and females evolve from an ordinary asexual / hermaphroditic with the external genitalia of female type with a relatively large clitoris. In the male the labia minora and the major ones fuse to form the scrotum. The vestibule of the clitoris elongates and forms the penis. In women, the growth of the labia minora and labia majora is much higher than the evolution of the clitoris, which remains small.
In the body of the embryo and fetus, there are 4 conducted with the form of very thin tubes, called by the eponym of their advisers: two Mullerian ducts and two of Wolff.
In the male the Wolffian ducts develop to form the ejaculatory ducts, the epididymis, the vas deferens and prostate. The sketches at the beginning of the testes are located much higher up the sides of the bladder, above the groin (more or less where they are the ovaries in women), gonadal glands in childhood that will go down in the inguinal canal (protected from the sack consists of the cremaster muscle) and accompanied by the spermatic cord to be already present in the scrotum (10 years) before the start of puberty (11-12 years).
For more, see Male reproductive system.
In women, while the Wolff ducts atrophy, Müller ducts merge along an axis that will train for 1/3 the vagina to the uterus and another third for the other third will remain similar to the original Mullerian ducts forming the fallopian tubes. In the early stages of the embryo there is only the anus, the vagina is located inside the abdomen, behind the bladder, but slowly approaches the groin in order to operate a fissure and become a cavity only partially open to the outside, remaining a membrane more or less thin and cribrosa consists dall'imene.
The fallopian tubes does not come into contact with the ovary during ovulation if not, when approximating it to induce ovulation.
At birth all the main structures are present, vary only in size, thickness and trophism of the mucosa, depending on the type of active hormone in that moment.
