The reproductive system of the female is far more complex than that of the male. Females have monthly period (rhythmic menstrual cycle) and produce egg cells, but after fertilization of the egg by a sperm the female reproductive system also nourish, carry (for 9 months) and protect the developing embryo (fetus).
The function of the female reproductive system is to form the ovum (egg) and after fertilization to protect the foetus until it is able to live independently. The other function of the female reproductive system is sexual pleasure.
FEMALE REPRODUCTIVE SYSTEM
The female reproductive system is divided into three groups:
· The external organs of reproduction (vulva)
· The internal organs of reproduction
· The mammary glands (breast) are also considered part of the female reproductive system
The external genitalia, known as vulva, consist of:
· The mons pubis
· The labia majora
· The labia minora
· The vestibule
· The greater vestibular gland
Let us first view the external organ. Click on the diagram for enlarge image.
THE LABIA MAJORA (corresponding to the scrotum in made reproductive system)
The labia majora are two rounded folds of skin containing abundance of adipose (fatty) tissue, sebaceous glands and sweat glands. At the top, the two folds meet to form the elevated fatty portion called mons pubis. At puberty the mons pubis and the outer aspect of the labia become covered with hair.
THE LABIA MINORA
The labia minora are two folds of mucous membrane which lie within the labia majora. Unlike the labia majora, the labia minora do not have pubic hair and fatty tissue but contain a few sweat glands.
The clitoris is a small, cyclindrical mass of erectile tissue and nerves. It is located at the upper junction of the labia minora. A layer of skin called the prepuce (foreskin) is formed at the point where the labia minora unite and covers the body of the clitoris. The exposed portion of clitoris is the glans. The clitoris corresponds to the penis of the male in that it is capable of enlargement upon stimulation and assumes a role in sexual excitement of the female.
|Tip of clitoris is cut for female circumcision
The hymen is a thin membrane which partially covers the opening of the vagina and may vary in thickness. Insertion of an erect penis during intercourse results in some tearing of the hymen. The hymen can also be torn during vigorous exercising.
|The presence or absence of a hymen is not a reliable indicator of virginity or non-virginity.
The vestibule is a smooth almond-shaped area lying between the labia minora. Within the vestibule are the hymen, vaginal orifice (opening), urethral opening and the opening of several ducts. The vaginal opening occupies the greater portion of the vestibule and is bordered by the hymen. The urethral opening is below the clitoris and above the vaginal opening.
THE GREATER VESTIBULAR GLANDS
The greater vestibular glands lie in the labia majora, one on either side at the commencement of the vagina. They are about the size of a small pea and are covered with dense fibrous tissue. There are ducts which lead from the glands and open into the vestibule. The glands secrete mucus which lubricate the vulva. This mucus secretion supplement lubrication during sexual intercourse.
MAMMARY GLANDS / BREAST (Diagram C)
Mammary glands are modified sweat glands that lie externally over the pectoralis major muscles and are attached to them by a layer of connective (tough) tissue.
View the diagram to have a better understanding.
Internally, each breast consists of 15 to 20 lobes or compartments separated by adipose (fatty) tissues. The amount of adipose tissue determine the size of the breast. However, the breast size has nothing to do with the amount of milk produced. In each lobe are several smaller compartments called lobules, composed of connective tissue in which milk-secreting cells called alveoli are embedded (buried).
The alveoli convey the milk through the tubules into the mammary ducts. As the mammary ducts approach the nipple, they expand to form sinuses (opening/space) called ampullae where milk may be stored. The ampullae continue as lactiferous ducts that terminate in the nipple.
The circular pigmentation area of skin surrounding the nipple is called areola. It appears rough because it contains modified sebaceous gland.
At birth, both male and female breast are underdeveloped and appear as slight elevation on the chest.
With the onset of puberty, the female breast begin to develop, the ductile system matures, extensive fat deposition occurs, and the areola and nipple grow and become pigmented. These changes are correlated with an increased output of oestrogen (a female hormone) produced by the ovary.
Further breast development occurs at sexual maturity with the onset of ovulation (release of egg by the ovaries).
During adolescence, increased levels of progesterone (another female hormone produced by the ovaries) cause the alveoli (milk secreting cells in the breast) to proliferate (increase), enlarge and become secretory. Also, fat deposition continues, increasing the size of the breast.
The essential function of the breast is milk secretion and ejection called lactation (associated with child birth).
Well girls, during adolescence the enlargement of breast contribute to our body image.
|Girls are advised to do a monthly breast self-examination soon after the period to exclude any breast lumps.
THE INTERNAL ORGANS OF THE FEMALE REPRODUCTIVE SYSTEM (Diagram D)
The internal organs of the female reproductive system lie in the pelvic cavity and consist of:
· The vagina
· The uterus
· The 2 uterine tubes
· The ovaries
|Female Reproductive System:
|2. Fallopian Tubes
The vagina serves as a passageway for the menstrual flow. The seminal fluid is ejaculated into the vagina by the penis during sexual intercourse. The vagina forms lower portion of the birth canal. The vagina is a fibro-muscular tube connecting the internal and external organ of generation (reproduction). The muscular tube lined with mucous membrane measures about 10cm in length. The vagina is situated between the urinary bladder and the rectum. The vagina has three layers (inner, middle and outer). The outermost layer has folds which can stretch for the birth of the baby.
The vagina is designed to clean itself by periodically shedding mucus and dead cells. Most of the time the surface of the vagina is moist (wet). It secretes slippery mucus during sexual arousal.
The Uterus, also known as the womb, is the site for menstrual blood, implantation of a fertilized ovum,, development of the foetus during pregnancy and labour. The uterus is a hollow muscular organ shaped like an upside down pear. The uterus is a thick walled organ. It provides a nourishing environment for the developing foetus during pregnancy. The inner cavity of the uterus has varying widths in different sections. There are 3 distinct layers of muscle -a thin outer layer called (perimetrium), thick middle layer (myometrium), and the inner (endometrium) which is shed during menstration. The uterus lies in the pelvic cavity in front of the rectum and behind the urinary bladder. Its position is one of anteversion and anteflexion where the uterus leans forward and simultaneously the uterus also bents forward with its upper part resting on the unrinary bladder.
When the body is in the anatomical position (standing erect) Appendix I & II, the uterus lies in an almost horizontal position resting on the urinary bladder Diagram B.
The size of the uterus is 7.5cm in length, 5cm in breath and 2.5cm thick and weighs 40-50 grammes. During pregnancy, the uterus stretches and grows with the foetus.
Visualize your uterus which has the capacity to stretch to house the growing foetus for 9 months during pregnancy.
During pregnancy, the inner lining (endometrium) of the uterus nourishes the fetus. In the non pregnant stage the lining is shed about once a month if an ovum is not fertilized. This shedding is called menstruation.
For descriptive purpose the uterus is divided into three parts:
· The body
· The cervix
· The fundus
The rounded upper part of the body is called the fundus. Just below the fundus the uterine tubes (fallopian tubes) open out on either side. The body tapers down towards the cervix where there is a constricted (narrowed) portion named the isthmus. The cavity of the body is triangular shape.
The cervix is cylindrical in shape and measures 2.5cm in length. The cavity of the cervix is spindle shaped, communicating with the isthmus of the body at a constricted part known as the internal os and opening into the vagina at the external os. The cervix is the entrance to the uterus and contains mucus producing glands. In fertile women, mucus is present in the vagina during intercourse, sperms released by the male will travel through the cervical opening and into the uterus.
|Cancer cervix starts with a change in the shape, growth and number of the cervical cells at the junction of the isthmus i.e.a narrow region between the uterine body and cervix.
Women who are sexually active are advised to do Pap smear screening where the cervical cells are screened/examined for cancer cells.
UTERINE TUBES / FALLOPIAN TUBES
The 2 uterine tubes lie one on each side of the uterus in the folds of the broad ligament. The uterine tubes transport the ova from the ovaries to the uterus through the funnel shaped open distal end of each tube called the infundibulum which lies close to the ovary.
Once a month an immature ovum breaks out from the surface of the ovary near the infundibulum of the uterine tube a process called ovulation. The ovum is swept into the uterine tube. If the ovum is fertilized by a sperm, it usually occurs in the uterine tube within 24 hours of ovulation. The fertilized ovum is transported into the uterus within 7 days.
|One method of permanent contraception is tubal ligation where the uterine tubes are cut and tied. This prevents fertilization of ovum by the sperm thus preventing pregnancy.
The ovaries are female sex glands resembling unshelled almonds in size and shape. The ovaries are positioned in the upper pelvic cavity, one on each side of the uterus. They are maintained in position by a series of ligaments. The ovaries produce ova, discharge ova (ovulation) and secrete the female sex hormones, progesterone and oestrogen which regulate the menstrual cycle and are responsible for the development of female secondary sex characteristics (eg growth of pubic hair). The ovaries are similar to the testes of the male reproductive system. At birth, a girl's ovary contains about 400,000. However, she will probably use about 400 of the ova in her lifetime.
Relax and read again during leisure times to have a better understanding of your reproductive organs.
Reference: Tortora and Anagnostakos Principles of Anatomy and Physiology 4th Edition. Harper & Row, New York