Chapter V - Female Reproduction
Fallopian tubes or oviducts
The Fallopian tubes, also known as oviducts and uterine tubes, are two very fine tubes leading from the ovaries of female mammals into the uterus.
There are two Fallopian tubes, attached to either side of the cranial end of the uterus, and each terminating at or near one ovary forming a structure called the fimbria.
When an ovum is developing in an ovary, it is encapsulated in a sac known as a ovarian follicle. On maturity of the 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. Occasionally the embryo implants into the Fallopian tube instead of the uterus, creating an ectopic pregnancy.
Ovaries are egg-producing reproductive organs found in female organisms. Ovaries are two almond-shaped glands placed on each side of the uterus, attached to the fallopian tube, suspended with the help of broad ligaments to the uterus. The main function of ovaries is to produce the female reproductive cell called ova. The ovaries contain a large number of immature ova called primary oocytes, which are sur-rounded by nutritive follicular cells. Every month, (at each menstrual cycle), one of these oocytes develop into a Graafian follicle. The Graafian follicle ripens and becomes distended with fluid. Increasing tension within the Graafian follicle causes it to rupture and ovum is released from the ovary into the opening of the uterine tube. (In the ovary; numerous Graafian follicles are present in different stages of development.) The ovaries also produce two hormones called estrogen and progesterone. These hormones play an important role in the menstrual cycle, secondary sexual characteristic development, and preparation of the endometrium of uterus for implantation of a fertilized ovum.
The Bartholin's glands (also called Bartholin glands or greater vestibular glands) are two glands located slightly below and to the left and right of the opening of the vagina in women. They secrete mucus to provide lubrication, especially when the woman is sexually aroused, thus facilitating sexual activity. Bartholin's glands are homologous to Cowper's glands in males.
The Gräfenberg spot, or G-spot, is a small area in the genital area of women behind the pubic bone and surrounding the urethra. It is named after German gynecologist Ernst Gräfenberg. It is the same as, or part of, the urethral sponge, the site of Skene's glands.
Stimulation of the G-spot (through the front wall of the vagina) is said to promote a more vigorous and satisfying orgasm, and is possibly the cause of female ejaculation from the Skene's glands, contained in the urethral sponge. Such stimulation requires a somewhat opposite thrust to that required to obtain maximal clitoral stimulation via the penis, called "riding high".
The stimulation of the G-spot is thought to be more intense for women beyond their thirties, because of changes in tissue structure inside the vagina allowing easier access to the G-spot. Some women believe their thirties are their sexual peak because of this reason.
The hymen (also known under the slang names cherry and maidenhead) is a membrane, which completely or partially occludes the vaginal opening in human females. The term comes from a Greek word meaning "membrane", and is also the name of the classical Greek god of marriage.
Because sexual activity would usually tear this membrane, its presence has been considered a guarantor of virginity in societies that place a high value on female chastity before marriage. However, the hymen is a poor indicator of whether a woman has actually engaged in coitus, because the tissue may be torn or stretched through masturbation, or tampon use and other non-sexual acts before having sexual intercourse. Also, some females with intact hymens have had sexual intercourse.
The size and shape of this opening (or openings) vary greatly from person to person. Some women are born with no hymen at all, while others have a closed or imperforate hymen. These women may require a gynecologist to perform a medical procedure called a hymenotomy to allow menstrual products to escape. Still other women have unusually thick hymens that may require a hymenotomy to prevent pain for the woman during sex.
Some other common forms of hymen are:
Annular – in which the hymen forms a ring around the vaginal opening.
Septate – in which the hymen has one or more bands extending across the opening.
Cribriform – in which the hymen stretches completely across the vaginal opening, but is perforated with several holes.
Parous Introitus – which refers to the vaginal opening which has had a baby pass through it and consequently has nothing left of its hymen but a fleshy irregular outline decorating its perimeter.
Labium majora and minora
Labia majora (large lips, literally) are two thick and fleshy folds which form the sides of vulva. They contain fat and have sweat and sebaceous glands. After puberty, they become covered with thick hair. Situated between the upper parts of labia majora are two small folds of skin which surround the opening of the vagina and urethra and are called labia minora (small lips, literally). The opening of the vagina is called introitus. The two labia minora meet at the clitoris in front. The color of the outside skin of the labia majora is usually close to the overall skin colour of the individual, although there is considerable variation. The inside skin is often pink or brownish.
In human anatomy, the Skene's glands (also known as the lesser vestibular or paraurethral glands) are glands located on the upper wall of the vagina, around the lower end of the urethra. They drain into the urethra and near the urethral opening. The location of the Skene's glands is also known as the Gräfenberg spot or G-spot; the general area is the urethral sponge. The Skene's glands are homologous with (that is to say, the female equivalent of) the prostate gland in males.
Some believe that the Skene's glands are the source of female ejaculation.
In anatomy, the urethra is a tube, which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes, to pass urine to the outside, and also a reproductive function in the male, as a passage for sperm.
The external urethral sphincter is a striated smooth muscle that allows voluntary control over urination.
Men have a longer urethra than women. This means that women tend to be more susceptible to infections of the bladder (cystitis) and the urinary tract. The length of a male's urethra, and the fact it contains a number of bends makes catheterization more difficult.
In the human female, the urethra is about 1-1.5 inches (2.5-4 cm) long and opens in the vulva between the clitoris and the vaginal opening. In the human male, the urethra is about 8 inches (20 cm) long and opens at the end of the penis.
The urethra is divided into three parts in men, named after the location:
· The prostatic urethra crosses through the prostate gland. There is a small opening where the vas deferens enters.
· The membranous urethra is a small (1 or 2 cm) portion passing through the external urethral sphincter. This is the narrowest part of the urethra.
· The spongy (or penile) urethra runs along the length of the penis on its ventral (underneath) surface. It is about 15-16 cm in length, and travels through the corpus spongiosum.
Medical problems of the urethra:
· Hypospadias and epispadias are forms of abnormal development of the urethra in the male, where the opening is not quite where it should be (it occurs lower than normal with hypospadias, and higher with epispadias). A chordee is when the urethra develops between the penis and the scrotum.
· Infection of the urethra is urethritis, said to be more common in females than males. Urethritis is a common cause of dysuria (pain when urinating).
· Related to urethritis is so called urethral syndrome
· Passage of kidney stones through the urethra can be painful and subsequently it can lead to urethral strictures
Endoscopy of the bladder via the urethra is called cystoscopy.
The external genital organs of the female are collectively known as the vulva (or pudenda).
In human beings this consists of the labia majora and labia minora (while these names translate as "large" and "small" lips, often the "minora" can be larger, and protrude outside the "majora"), clitoris, opening of the urethra (meatus), and the opening of the vagina. The main functions involving the vulva are urination, sexual behavior, menstruation, and childbirth.
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Chapter V - Female Reproduction