SEX EDUCATION

Anatomy & Physiology

What is Sex?

When this question is raised the first thought that comes to our minds is the sexual act, so commonly called as sex everywhere. In fact, the word sex has such a vast meaning. It is being male or female. Therefore, my sexuality would be the way I talk, the way I think, the way I behave being a male or a female person. We see that the word sex is nothing other than our entire make up as male or female.

We have been created by a God who loves us and who has made us in His own image, male and female, in order to love and to be loved. In this love, like God Himself, we are designed to bring forth new life. Every child therefore, is a gift of love to its parents.

Human sexuality is all about growing up to be a man or a woman with the power to love and to give life. Man finds in woman and woman in man the companion designed by God. Thus, they help each other to achieve the purpose of their creation.

Puberty

Puberty is a transition from childhood to adulthood. As boys and girls grow up, though sexually different, they mix about easily with each other and show no consciousness about the differences in their sexes till the time of puberty. At puberty, there are certain specific physical, emotional and personality changes taking place in them. These changes are caused by certain chemicals in the body called hormones. These changes usually start between 11 and 13 years of age. At first, girls mature faster into womanhood, but later the boys overtake the girls and grow faster and stronger than the girls.

Development In Girls

As girls grow into puberty, under the influence of the female hormone, Oestrogen, they develop the physical characteristics of women. Their hips broaden and their breasts begin to develop, not just with the purpose of giving them a good form, but to prepare them to nourish their new born infant one day. Besides, they also acquire womanly personal qualities like receptivity, affection and tenderness.

Development In Boys

As boys grow into puberty, they also acquire the built and the physical characteristics of manhood, under the influence of the male hormone, Testosterone. Their shoulders broaden, and their voice grows deeper. But even more they develop masculine personal qualities like daring, initiative and farsightedness. Such qualities, however, are not exclusive to either sex and can to a certain degree be seen in both men and women. For example a woman may also show daring, initiative, farsightedness, etc. to a certain extent and a man may also show affection, tenderness, etc. at certain situations and moments.

In fact, because of these differences in both male and female, both the sexes seem to be inclined towards or get fascinated to the complimentary qualities of the other, leading to a sexual attraction. When sexual attraction leads to a desire of complete oneness with just one person of the opposite sex, wanting to blend and share their entire lives through thick and thin as a matter of decision, it leads to the ultimate purpose of sexual attraction, that is marriage, in order to love, to be be loved and to give life.

THE REPRODUCTIVE SYSTEM

Let us now consider the reproductive organs of the two sexes beautifully designed for the purpose of pro-creation.

THE FEMALE REPRODUCTIVE SYSTEM

Vulva: It is made up of the following three structures that surround the entrance to the vagina, each of which has its own function:

Labia Majora (major lips): They are two large folds of skin, the inner surface of which lie in contact with each other and close the vaginal entrance. The outer sides are covered with coarse hair.

Labia Minora (minor lips): They are two delicate flaps of soft skin, one on either side of the vaginal opening. These vary considerably in size and ordinarily their inner surfaces touch each other. At the upper end, they split into two folds to encircle the clitoris. The minor lips are very vascular and become turgid during sexual excitement.

Clitoris (the female equivalent of the penis in the male): It consists of erectile tissue which gets filled with blood during sexual excitement and is extremely sensitive to touch, as it is richly supplied with nerves. It is the most erotically sensitive part of the vulva. Normally, only its tip (glans) and its covering (prepuce) are visible.

Vestibule: It is the cleft between the minor lips. Into it open the urethra, the vagina and the Bartholin's glands.

Urethra: It is the urinary passage.

Hymen: It is a delicate annular fold of membrane which surrounds the vaginal opening. The fold is wider at the lower position, hence it tends to have a crescentic shape. The first sexual act nearly always causes it to tear, with only a slight loss of blood, since it is relatively avascular.

Bartholin's Glands: They are two pea-sized glands, one on either side of the vagina, their secretion moistens the vaginal entrance to help the penis penetrate the vagina without discomfort.

Mons Pubis (Mons Veneris): The eminence formed by the pad of fat which lies over the pubic bone in the female.

INTERNAL GENITALIA

Side View

Front View

Uterus: The uterus of an adult woman (who has not yet borne children) is 3½ inches in length, 2½ inches across at the upper end and 1½ inches at the lower end. It is pear shaped. The lining of the uterine cavity, is called the endometrium (uterine lining). At the lower end it opens into the vagina through the cervical canal.

Cervix: The neck of the uterus is called the cervix. The passage through the cervix is called the cervical canal. The mucus membrane lining the cervical canal extends inwards to form complex pouches called crypts. These crypts secrete an alkaline mucus, that starts flowing about 4-5 days before the actual day of ovulation.

Vagina: It is an elastic muscular canal, 3 inches long, extending from the cervix (mouth of the uterus) to the vulva. It is lined by mucous membrane which has folds that give it a wrinkled appearance. It is the female organ of sexual intercourse. It receives the seminal fluid deposited by the penis during the marital act and it serves as the birth canal, a passage for the baby during birth. At the opening of the vagina is a thin membrane called hymen.

Fallopian Tubes: The upper end of the uterus on either side, is connected to the fallopian tubes (uterine tubes). Each tube is 4 inches in length. It is a muscular hollow tube which allows the ovum (egg) to pass from the ovary to the uterine cavity (space inside the uterus). The outer end is funnel shaped with a number of finger like processes called fimbriae. In the sterilisation procedure called tubectomy, resection of a segment of both the fallopian tubes is done.

Ovary: These are two in number and are the female sex glands. Each one is 4 cms long and 2 cms wide and less than 1 cm thick. It is connected to the uterus with the help of a ligament and lies suspended close to the outer end of the funnel shaped part of the fallopian tube. The ovaries have the following two functions.

1. To produce ova (female sex cells)

A new born baby girl has 2 million primary oocytes in the ovaries. By puberty 400,000 remain. The single ovum lies enclosed in a thin layer of cells called follicle. The ovum is the female reproductive cell containing 23 chromosomes. It is the largest cell in the female body.

At puberty, a message from the Pituitary gland in the brain causes few egg cells or ova to ripen which then secretes oestrogen. Not just the ovum but the entire follicle begins to mature and grow in size. It is not true that only one follicle matures at a time. In fact, you will find that a few follicles begin to mature at the same time, but only one among them reaches to full maturity. Therefore, if we look at the inside of an ovary we'll be able to see the three growing stages of the follicles. They are the Primary, Maturing and Mature Follicles.

Primary Follicles: This is the stage of all follicles at infancy. It contains the ovum in its earliest stages (called oocyte), surrounded by a layer of small flat cells.

Maturing Follicles: At this stage the ovum (still called oocyte because it is immature) becomes larger and the surrounding cells enlarge and multiply forming some more layers. Fluid-filled spaces appear inside the wall of the follicle, thus pushing the ovum to one side.

Mature Follicle: This follicle is the largest, with a large amount of fluid. The follicle is pushed near the wall of the ovary due to the pressure created by the fluid within, just waiting to release the ovum. Only one ovum is released from either the left ovary or the right ovary in a cycle.

The release of an ovum from the mature follicle is called ovulation. Let's learn what occurs in the process of ovulation.

OVULATION

As the mature follicle is pushed near the wall of the ovary, the lining of the ovary overlying the follicle gets thin and it appears as if there is a bulge on the ovary at that end. After a short while, the ovum detaches itself from the side of the follicle and escapes through the burst opened follicle, then through a temporary opening made at that part of the ovary. It is a gradual, slow process taking several seconds or minutes. Once ovulation takes place, the other follicles that were maturing simultaneously stop developing and soon degenerate.

As the moment of ovulation approaches, the outer end of the tube, moves towards the ovary and its finger like processes, cap it. Once the ovum is released it is pulled into the tube by movements of the fringes and the muscular contractions of the tube. The egg moves further into the tube through the contractions created by the tube. Within a span of 12 - 24 hours, the ovum dies out if it is not fertilised. The capping function of the outer end of the tube is necessary so that the ovum is not lost. Infection of the tubes and its inability to cap the ovary is a cause of infertility in some women.

2. To produce the two female hormones, Oestrogen and Progesterone.

Oestrogen is secreted by the growing follicles and is responsible for mucus secretion by the cervical glands and the development of the endometrium. Once ovulation takes place, the follicle undergoes changes, and forms the yellow body or the corpus luteum, which secretes the hormone progesterone. This progesterone further affects the lining of the uterus, developing it and thickening it.

MENSTRUATION

After ovulation, the layer of cells that form the wall of the follicle form the yellow body (Corpus Luteum). The formation of the yellow body takes 5 days, during this time it is already functioning, it continues to produce oestrogen and begins to secrete a new hormone progesterone. Progesterone immediately thickens the mucus and rapidly causes it to disappear. It further acts on the uterine lining. The lining now thickens and towards the completion of this thick lining, tiny lakes of blood appear just under the thickened lining. The yellow body shows maximum activity for the next 3-4 days after which, degenerative changes begin to be seen 4-5 days before the next menstrual period begins. At this time because the yellow body begins to degenerate, there is a drop in the level of the two hormones which it produces. Once the level drops completely, the uterine lining begins to breakdown because their hormonal supports are withdrawn. The lining is shed in pieces. Thus the discharge consists not only of blood but also of the lining, mucus and other cells. The bleeding is called menstruation or menses (Latin word meaning month) and the number of days it lasts is called the menstrual period. As soon as the yellow body dies out, other primary follicles begin to mature and the oestrogen that they release during this process begins to repair the uterine lining which means even before menstruation is over, the repair work is in progress and about 3 days after menstruation the lining is completely restored with thickness of 1 mm

Mucus changes: On an average of 6 days before ovulation, the mucus begins to flow from the cervix under oestrogen stimulation. At the start it is thick, opaque, sticky and non-stretchy. As the oestrogen level rises further, the mucus becomes cloudy, then clear, watery, slippery and stretchy, like raw egg white, which produces a sensation of slipperiness & wetness. After ovulation, as the progesterone level rises the mucus again becomes thick, opaque and sticky which may last for a day or two, followed by dry days.

Temperature rise: There is a rise in basal body temperature following ovulation. The rise is usually by about 0.4º F. (The range is 0.2º F - 1º F) The temperature remains at a higher level till the end of the cycle. Thus the temperature chart shows a biphasic pattern.

Changes in the cervix: After menstruation the cervix feels firm, closed and dry and its level is low in the pelvis. As the time of ovulation approaches the cervix gets progressively softer, its level higher by about an inch, its mouth open and feels wet due to the presence of mucus. After ovulation, the cervix again becomes firm, closed, low and dry.

Pain: A small percentage of women experience pain around the time of ovulation. It is felt in the lower abdomen on either one of the sides, where the ovary lies, but never on both sides. Women describe it as a dull heaviness, or a cramp-like pain that comes and goes, waxes and wanes in intensity.

Slight bleeding: This is a small intermenstrual flow of blood from the uterine lining called "spotting". It is more often seen in long cycles than in average ones. It appears by itself or with the mucus giving it a reddish or brown tinge.

Vulval swelling: At the time of ovulation, women often notice a slight swelling/congestion of the vulva.

MALE REPRODUCTIVE SYSTEM

Testis: It is the male sex gland, which are two in number, each about 1½ inches long in the adult male. The testes have two functions :

To produce sperms: Sperms are the male sex cells. These are the smallest cells in the body of a male. Sperm production in a male begins at puberty and continues right up to old age. Lets look at the single sperm. A sperm has 23 chromosomes. A sperm has three parts viz. head, neck and tail. The head consists of the nucleus, which contains the chromosomes. The X sperm has a rounded head, that is responsible for a baby girl, and the Y sperm has an oval head and is responsible for a baby boy. The neck of the sperm supplies the energy to the sperm and the long tail of the sperm helps the sperm to move ahead. The sperms swim in the thick whitish fluid called semen. After the sperms are produced in the testes they move on to the Epididymis, which is a highly coiled tube. Here the sperms remain for some days till they mature.

To secrete the male sex hormone (testosterone): Testosterone is released in a very high quantity at the time of puberty into the blood stream and this is the cause of the secondary sexual characters like the beard, moustache, hair on the chest and pubic area, broadened chest, etc. It is responsible for the growth and maintenance of the male secondary sexual characters. The testis is placed in a thin, wrinkled bag of skin called scrotum. The temperature inside the scrotum is about 2° lower than the rest of the body, as this is necessary for sperm production.

Vas Deferens: The long tube that connects the testis to the sperm sac (seminal vesicle) is called the sperm duct (Vas Deferens). The sperms travel from the testis to the sperm sac through Vas Deferens. In the sterilization of a male, a procedure called vasectomy, it is the Vas Deferens that are cut and ligated to prevent the sperms from passing through the penis.

Seminal Vesicles: These are two in number, situated at the base of the bladder. The sperms travel through the sperm duct and enter the sperm sac (seminal vesicle). The sperm sacs are meant for mature sperm storage and produce a lubricating substance that facilitates the passage of the sperms.

Prostate Gland: The secretion of the prostate gland nourishes the sperms, gives it mobility and contributes to the liquid portion of the seminal fluid.

Cowper's Gland: They lie one on either side of the Urethra below the prostate. It's duct opens into the urethra. These glands (the equivalent of Bartholins glands in the female), under sexual excitation secrete an alkaline fluid meant to lubricate and neutralize the acidity of the urethra for safe passage of the sperms.

Penis: It is a cylindrical organ, 3-4 inches in length in the adult male, yet differing in size from one man to another. Most of all the function is important and not the size. It consists mainly of erectile (spongy) tissue. It is covered by a loose skin that is continuous with the scrotum. The part of skin that covers the tip of the penis is called the prepuce or foreskin. The foreskin (prepuce) is cut or folded upwards at the time of circumcision. This prevents the smegma (a secretion) from being accumulated and helps in hygiene. It is also noted that the chances of cancer of the penis are greatly reduced in those who are circumcised very early in life.

The penis has two functions

To pass urine through the narrow tube passing through the penis which is connected to the urinary bladder and ends at the tip of the penis. This tube is called the urethra.

To pass and deposit the semen in the vagina during the marital act. For both the above functions, the urethra acts as the common passage. However, both do not take place at the same time i.e. urination and ejaculation (expulsion of semen) due to a sphincter at the base of the bladder.

Ejaculation
At the end of the marital act, the muscular contractions of the sperm sacs, prostate gland and the sperm ducts expel semen into the vagina through the penis. Now when ejaculation is about to take place, a circular muscle at the base of the bladder tightens and prevents the semen from mixing with the urine. Under sexual excitement, the erectile tissue of the penis gets filled with blood, it becomes firm and it increases in length. This condition is called erection, which is necessary to perform the marital act. Males whose penis is unable to function in the manner explained above at the time of the marital act, experience impotency.

After erection of the penis and the penetration of it in the vagina, ejaculation takes place and the semen is deposited in the vagina. At each ejaculation about 300 to 500 million sperms are released.

How does the sperm travel?
After being produced in the testis the sperms are passed into the epididymis. From here, the mature sperms pass through the sperm duct (Vas Deferens) and enter the sperm sac (Seminal Vesicle) getting a bit of the liquid portion from this, it moves towards the prostrate gland. Mature sperms have little movement till they mix with the fluid from the prostrate gland to form the semen. From here it passes on to the urethra through which it passes out of the male's body. Erection and ejaculation, when made to occur deliberately by forcing oneself with provoked sexual excitement is called masturbation. This is a serious sin. It is a self loving act. It affects the individual's personality, making a person timid, guilty and loose his self-confidence etc. Also, a frequent practice of this can lead to spontaneous erection at even a very slight sexual excitement and it may be out of the person's control. This can be embarrassing if it occurs at any time of the day. Sometimes, quite rarely, when sperms are emitted at night, during the person's sleep, without his knowledge, this phenomenon is called night emission or wet dreams. This is a natural phenomenon through which excess of sperms produced in the body are given out as the law of nature permits.