The vulva begins over the pubic bone and extends between the legs of the woman far back to only a short distance from the rectal opening. In young girls or some women the vulva begins fairly far up at the lowest part of the belly. As the pubic bone grows during maturing, the vulva is often pushed further downwards between the legs.
The parts of the vulva that are most easily seen are the outer genital lips, called the great lips or the Labia majora. Between the upper parts of the lips lies the clitoris, a knob-like structure with a hood like the penile foreskin. Beneath the clitoris and continuous with the clitoral foreskin are the small or inner genital lips, the Labia minora. These surrounds a deepened area called the vaginal vestibule. The urethra opens in the vaginal vestibule and just beneath the urethral opening is the vaginal opening.
THE GENITAL LIPS AND THE AREA BETWEEN THE LIPS
The Labia majora join each other at the lower part of the belly, just over the pubic bone and extend backwards between the woman's legs where they also also join each other. The inner lips, the labia minora, vary much in shape and size. They may extend out from the great lips or lie fully within the area of the great lips.
The inside of the genital lips excrete an oily fluid from sebaceous glands, and there are also sweat glands that deliver salty secretions. This fluids blend with fat-rich skin cells rejected from the inner surface of the lips and friendly bacteria to make a whitish substance called sebum. The sebum has a protective and lubricating function.
THE URETHRA AND PARAURETHRAL GLANDS
The urinary opening is situated between the inner lips in the vestibule some distance from the clitoris, sometimes it is placed even at the upper rim of the vaginal opening. At each side of the urethra there is a gland that secrete the same kind of fluid as the male prostate, the paraurethral glands or Skene's glands. The glands tend to empty themselves before and during orgasm and can this way contribute to the phenomenon called female ejaculation.
THE VAGINA
The vaginal opening lies just below the urethral orifice. In Jung girls it is mostly closed by a thin membrane called the hymen. The hymen will at some time rupture and leave only residuals at the rim of the vaginal opening. The vagina leads up to the womb or uterus.
The inner vaginal wall consists of an epithelium over an elastic connective tissue sheet and around that there is a sheet of muscles. In the walls of the vagina, there are a lot of glands that secrete a lubricating slime. This secretion tend to increase just before and during puberty. It occurs all the time, but increase during sexual excitement.
The vaginal wall do not have much nerves that can recognize sensations but nerve endings controlling the glands an the muscles.
On both sides of the vagina fairly far back there are situated two glands, the Bartholin's glands, that secrete a slime, especially just before the female orgasm. Also this secretion may contribute to female ejaculation.
THE CLITORIS AND THE ERECTILE BODIES
The clitoris has a hood like the penis and this hood can be continuous with the minor lips or extend downwards at both sides of the minor lips so that it look like the women has even one more pair of lips. The visible clitoris has the ability to become blood-filled, engorged and erect just like the penis.
It has a set of erectile bodies that do not only lie within the clitoris but extend inside the structures of the vulva, so that the whole vulva has the ability to get blood-filled and engorged.The erectile bodies are a mesh of very elastic blood vessels in a framework of elastic connective tissue.
In the lower part of the clitoris lies the erectile body corpus bulbospongiosus. This body divides itself into two branches, the bulbs of vestibule, that continue as two great bodies at each side of the vaginal vestibule and frame the urethra and vagina, These bodies are partly surrounded by a muscle called the bulbospongiosus muscle.
In the upper part of the clitoris are the erectile bodies corpora cavernosa at both sides that each extends inside as two bodies, called the crura of clitoris or legs of clitoris. These go along the inner rim of the pubic bone under each of the great lips. These bodies are also partly surrounded by a muscle, the ischiocavernosus muscle..
The clitoris has a very rich density of nerve endings through the whole structure. Many of these lies inside small connective tissue bodies that are capable of transmitting and focusing impulses like pressure and vibration towards the nerve endings.
THE G-SPOT AND INNER SENSUAL AREAS OF THE VULVA
From the clitoris down at both sides of the urethra towards the upper vaginal wall, goes a sensitive structure with a swampy appearance because of a meshwork of blood vessels. This structure can be stimulated from the clitoral side by pressure and vibration or from within the vagina. The part of this structure laying nearest the vaginal wall is often called the G-spot.
When a women has orgasm, sensations in both the clitoris and the whole structure down to the vaginal wall play a role.Sometimes most of the sensations are registered at the clitoris, and the orgasm is then called a clitoral orgasm. Other times most of the sensations are registered in the area over the vaginal wall, and this type of orgasm is called G-spot orgasm or vaginal orgasm.
THE INNERVATION AND BLOOD SUPPLY OF THE VULVA
The clitoris and the central portions of the vulva are innervated by the perineal nerve which is a branch of the pudendal nerve, a nerve that control many important functions in the pelvic region. The peripheral parts of the vulva is controlled by branches from the posterior femoral cutaneus nerves which also controls the surfaces of the thighs. These nerves contain fibers to transmit sensations, fibers to control voluntary muscles in the vulva and parasympathetic fibers that control glands, blood vessels and involuntary muscular functions.
Much of the blood supply to the vulva comes from the internal pudendal artery on both sides. This artery has branches that go towards the labia, towards the clitoral region towards the rectum and other places in the pelvic area.
