Bodyworks

Understanding Reproduction

Women's bodies

There productive system in women is made up of external and internal organs. These are found in the lower abdomen, the part of the body below the umbilicus (belly button). This area is often referred to as the pelvic area. They include:

The External Organs:

- Vaginal entrance (opening)

- Labia (vaginal lips)

- Clitoris

The Internal Organs:

- Uterus (womb)

- Fallopian tubes

- Ovaries

-Vagina

- Cervix

The female reproductive organs outside the body.

The vulva includes the opening to the vagina, the inner and outer lips (called labia) and the clitoris. The external part of the clitoris is found towards the the front of vulva, it is highly sensitive and when stimulated can make the woman feel sexually aroused and lead to orgasm.

Hormones and eggs- did you know?

- The female sex hormones ESTROGEN and PROGESTERONE, are responsible for female characteristics such as body shape, developing breasts, periods and controlling the menstrual cycle.

- When a woman reaches puberty she will have up to 1 million eggs in her ovaries.

- During a woman's life only about 400-500 eggs will actually be released at ovulation.

- As a woman gets older (over 30 years) the number and quality of her eggs declines making conception more difficult.

- An egg is less than 1/8 of a grain of sand- invisible to the naked eye.

The female reproductive organs inside the body

Ovaries

Women have two ovaries, one on each side of the uterus. Ovaries are the shape of almonds and they contain an ova (eggs) in structures called follicles. The ovaries also produce the two female sex hormones- estrogen and progesterone.

The fallopian tubes

The two fallopian tubes are found on each side of the uterus, near the ovaries. These are tiny tubes only as wide inside as a thick human hair and just 10cm long! The funnel-like ends of the fallopian tubes pick up the egg released by the ovary and carry it to the uterus. Tiny, microscopic hairs line the inside of the fallopian tubes and help move the egg along. The inside of the tube is very delicate and can very easily be damaged or blocked by infection.

The uterus

The uterus is made up of muscle. It is about the size and shape of an upside down pear, hollow and very stretchy. This is where the baby develops if a woman becomes pregnant. The uterus can stretch to hold a baby and shrink more or less back to its pre-pregnancy size after the baby is born.

The cervix

The lower part of the uterus which connects to the vagina is called the cervix. Sperm released by the man during sex swim from the vagina through the cervix to reach an egg.

The cervix contains small glands which produce secretions called mucus. This alters in texture and amount during a woman's menstrual cycle. In her fertile phase (the time of ovulation- when an ovary releases an egg) it changes from being thick, sticky and creamy in colour to being clearer, wetter and more stretchy- like a raw egg white. These changes allow the sperm to pass through the cervix and reach the egg more easily. When a woman is pregnant, the cervix becomes plugged with very thick mucus to protect the developing baby from infection.

Vagina

The vagina ia a muscular tube 7-10cm long which leads from the cervix to the vaginal opening (vulva). The vaginal opening is between the legs, between the urethra (the tube you pee through) at the front and the anus at the back. The vagina tilts up towards the small of the back. It has glads that produce lubricating secretions when women are sexually aroused to help the penis enter the vagina (penetration). Like the uterus, the vaginal walls are stretchy, allowing it to hold a tampon and stretch around a penis during sex, or a baby during delivery.

The menstrual cycle

The menstrual cycle is the process during which an egg develops and is released from the ovaries, and the lining of the uterus prepares for a possible pregnancy. If a woman does not become pregnant the lining of the uterus is shed, as her period.

Theses are the events caused by hormones- chemical messengers which travel around the body in the blood stream.

How long does the cycle take?

- The number of days in the menstrual cycle is calculated from the first day of the period to the day before your next period.

- The average length of the menstrual cycle is around 28 days, although many women have shorter or longer cycles and this is normal.

What happens during the menstrual cycle?

- The first day of the period is known as day one of the cycle. When a woman has her period about 20 eggs start to develop in the ovary.

- The hormone estrogen causes the lining of the uterus (endometrium)to start to thicken in preparation for a fertilised egg. It also causes the mucus in the cervix to become thinner, wetter and more stretchy, allowing sperm to reach an egg more easily.

- Regardless of how long or short a woman's cycle is, ovulation (egg release from an ovary) will usually happen around 10-16 days before the start of her next period. However, the time from the first day of the period to ovulation can vary between women.

- Occasionally, more than one egg is released (if this happens it will occur within 24 hours of the first egg being released). If more than one egg is fertilised it can lead to multiple pregnancy such as twins.

-Ovulation triggers the production of a second hormone, progesterone. This prepares the lining of the uterus even further,ensuring that it is spongy, thick and full of nutrients so a fertilised egg can settle or implant into it.

- After ovulation the cervical mucus goes back to being sticky. If the egg is not fertilised it will be reabsorbed naturally by the body, the level of hormones falls, and this menstrual cycle comes to an end.

- The cycle then begins again. The lining of the uterus breaks down and is shed through the vagina as a period, also called menstruation.

Periods - Did you know?

- Some menstrual cycles can be as short as 21 days and some as long as 40 days.

- Some women have menstrual cycles that vary in length from month to month.

- The amount and quality of cervical secretions will vary from women to woman and also from one cycle to the next.

- The average amount of menstrual blood lost in a period is 3-5 tablespoons.

- A period usually lasts between 3-7 days.

- Women living together often find that they have their periods at the same time.

- Some women have pain around ovulation- "Mittelschmerz" - this means "middle pain".

Men's bodies

Unlike women's reproductive organs, men's reproductive organs are entirely outside the body.

The male reproductive organs

Testicles and scrotum

The testicles (balls) are the male equivalent of a women's ovaries. It is inside these that the sperm are made and important male hormones produced. There are two testicles, roughly the size of small plums, and they are protected in a soft pouch of skin called the scrotum.

The scrotum hangs outside the body just behind the penis and between the legs. This helps the testicles keep cool - the average body temperature (37 degrees celsius) is too hot to produce healthy sperm. They are very sensitive to heat and if they get too hot the scrotum drops down to cool off and when they are cold it shrinks closer to the body to keep warm.

Male hormones

Hormones are just as important for reproduction in men as they are in woman. The testicles produce the male hormones testosterone. It is responsible for sperm production and growth and it is important for male sex drive. It also controls male characteristics such as hair growth and the deepening of the voice.

Sperm

Inside each testicle are about 1,000 tightly coiled tubes. Individual sperm are continuously made in these tubes. The growing sperm travel along the tiny tubes to a larger coiled tube called the epididymis which is the top of the testicle. Here they stay until they're fully mature and ready to be ejaculated.

Ejaculation

At ejaculation sperm passes along the vas deferens (sperm ducts) to the penis and out of the body through the urethra. On the way, fluid from the seminal vesicles and the prostate gland is added to the sperm. This helps nourish and transport them and gives semen (as it is now called) its white creamy appearance. The average ejaculation contains up to 300 million sperm and will fill a small teaspoon.

Sperm- did you know?

- Boys start to produce sperm at puberty, the time when their body goes through changes from a boy to a man.

- It takes about 70 days for a sperm to be produced, but as production is a continuous process process there is always plenty of mature sperm at anyone time.

- Sperm are minute - only 1/25mm long and 1/250mm wide, which is about a hundred times smaller than the female egg. Sperm are made up of three parts, a head containing the sex chromosomes, a middle which gives them the energy, and a tail for swimming.

- On average men produce around 150-1,000 million sperm everyday, so they are unlikely to run out.

- Sperm are excellent swimmers. With the right type of conditions the best swimmers are able to swim through the cervix into the uterus in about 2 minutes.

- Sperm are also survivors and can live for up to 5 days on average inside the woman's body but up to 7 days if the conditions are right.

- Sperm production can be damaged by untreated sexually transmitted infections, excessive heat, alcohol, smoking or recreational drugs.

The penis contains erectile tissue which fills with blood when a man is sexually aroused and causes an erection, making the penis longer and thicker.

To prepare for an ejaculation a small amount of lubricating fluid, known as pre- ejaculation fluid is produced from the Cowper's glands. This fluid leaks out of the penis before ejaculation and may contain sperm. When a man ejaculates, the muscles of the penis contracts forcing semen out of the penis in spurts. Straight after ejaculation the fluid is thick but becomes more liquid after a few minutes - this helps to release the sperm.

Conception (Getting Pregnant)

Conception is a process that begins with fertilisation and ends with implantation. For fertilisation to take place an egg needs to meet a sperm - usually through a man and a woman having sex.

- When the ovary releases the egg, it is picked up by the fallopian tube where it can be fertilised by the sperm. Sperm are able to wait around in the uterus and fallopian tube until an egg is released.

- Small beating hairs and tiny wave-like contractions help the egg travel along the fallopian tube where it may meet a sperm within minutes or hours of being released from one of the ovaries. The egg only lives for up 24 hours so it increases the chance of pregnancy if the sperm are ready and waiting. If you have sex 2-3 times a week you will help ensure that there is always sperm waiting.

- Only a smaller number of sperm will actually survive the trip to the fallopian tubes and finally only one sperm will actually enter the egg.

- The sperm attaches itself to the egg and produces a special substance which dissolves the outer coat of the egg. Once it has entered,a quick repair of the egg coating means that no other sperm can get in.

- Once the sperm is fully inside the egg fertilisation has taken place.

-The fertilised egg is wafted down the fallopian tube to the ready- prepared uterus. Here, the embryo settles and over a few days attaches itself to the thick,nutritious lining. Implantation has now taken place, conception is complete and the pregnancy begins. The time from ovulation to implantation is around 10 days.

- Once the pregnancy has begun, the pregnancy hormone human chorionic gonadotrophin (hCG) begins to be produced.

Sometimes a pregnancy develops outside of the uterus, usually in the fallopian tube. This is called an ectopic pregnancy.

Conception-did you know?

- Conception is a process that starts with fertilisation and ends with implantation.

- It takes about 3 hours for the sperm to fully enter the egg.

- The egg can be fertilised by sperm that have been ejaculated up to seven days before.

- The egg has special places on the outside coat that attract the sperm.

-It takes a couple an average of 3-6 months to conceive, if they are having sex frequently (2-3 times per week) during their fertile time.

- Women over 30 years may take longer to conceive.

- Women who are either ver underweight or very overweight may have more difficulties conceiving.

- An average pregnancy lasts 280 days.

Pregnancy

The Pregnancy Test

The earliest and most reliable sign of pregnancy for women with a regular menstrual cycle is a missed period. Sometimes women who are pregnant have a shorter or lighter period than normal.

A woman can carry out a pregnancy test from the first day of a missed period. Some tests suggest that pregnancy tests can be carried out earlier than this, but the effectiveness of this varies. For women who don't have regular periods, the earliest time to do a test is 21 days from the last time they had unprotected sex. For some women the test does not show positive until their period is a week late.

Pregnancy tests look for the pregnancy hormone hCG which is found in the urine of pregnant women. A positive test is almost always correctly, even though they may be pregnant.

It's all in the genes

How a baby looks is determined by the genes it inherits from its parents. Genes are contained in chromosomes - tiny thread like structures - and each chromosome contains thousands of genes. It is these genes that determine your height, build, blood group and hair color. Some characteristics will be inherited from the mother and some from the father.

So how is the sex of the baby decided?

An egg has 22 chromosomes and one sex chromosome know as the X chromosome. A sperm also has 22 chromosomes and one sex chromosome which can either be a X or a Y chromosome. It's the sperm's chromosome that determines the sex of the baby. A simple way to look at this is:

- If the egg is fertilised with a sperm containing an X chromosome

Mother X + Father X = XX = Female

- If the sperm contains a Y chromosome

Mother X + Father X = XY = Male

To date, there is no reliable scientific evidence to support claims made for choosing the sex of the baby, such as when you have sex, sexual positions or diet.

Thank you guys for reading x