The Reproductive System

The Male Reproductive System

The male reproductive system comprises of:

• Sperm
• The prostate
• TestesAlso known as testicles or male gonads.
• The penis

Externally, all you can see of the male reproductive system is the penis and the testes (encased in a scrotum - commonly called the ball bag). This enters the vagina, in what is known as penetrative sexual intercourse.

When a man climaxes, he exerts sperm from the testes, through the urethra and out the end of the penis. This then enters the vagina. For the man, this is biologically all he has to do to reproduce.

Interesting fact: in the animal kingdom, to mate, an octopus will literally rip its penis off, throw it at the female, and grow a new penis.

The System Roles

Let's take a look at the roles of the male reproductive organs:

Sperm: the sperm is what is exerted from the penis upon climax during intercourse. This is a single-cell gamete that finds the ova in the female reproductive system.

Testes: these are what store and create the sperm. There is more on what sperm does in the DNA and Cells section of the website. The testes also creates testosterone, a hormone that allows the man to enter puberty and grow masculine features such as pubic hair, facial hair and gives them a change in voice.

The penis: this is an intromittentAllows for insertion into the vagina. organ that allows for sexual intercourse. It also acts as the urinal duct for a male.

The prostate: a gland that produces seminal fluid that mixes with sperm to make semen. Testosterone controls how the prostate works.

Here is a YouTube video from Don't Memorise on the male reproductive system:

The Female Reproductive System

Females have a more complex system than the males, as they hold the embryo and foetus during pregnancy, and give birth. It comprises of:

• Vagina
• Ovaries
• Oviduct/Fallopian Tubes
• Uterus
• Cervix

The System Roles

Let's take a look at the female reproductive organs:

Vagina: everyone knows this one, and it's the first point of insertion for the penis upon penetration. It is a muscular canal lined with mucus and nerves. It links the outside of the body with the uterus and cervix.

Cervix: a small cavity that links the vagina to the uterus, the cervix houses small hairlike structures called cilia that move the sperm along and further up the uterus to help with fertilisation.

Uterus: also called the womb, the uterus is where a foetus and baby will develop in the three trimesters that it is housed for. It is lined with endometrium, a thick, moist mucus membrane that protects the baby while in the womb. This is also what is ejected from the body during menstruation.

Ovaries: the female reproductive system has two ovaries, and they are connected to the uterus by the oviducts (explained below). The ovaries keep the eggs until ready to release. The eggs are already there, and are there during a mother's pregnancy. It is here that the corpus luteum, named after the Latin name of saffron-yellow, luteus. It enables the production of oestrogen and progesterone. These hormones allow for the change in the uterus to enable fertilisation. If no fertilisation happens, menstruation occurs instead.

Oviducts/Fallopian Tubes: the oviducts, also known as fallopian tubes, are small transport tubes that connect the uterus and ovaries. They allow transport of sperm to the egg, and enable fertilisation.

More About the Female System

In similar fashion to the male system, the female system also has a climax, and will exert fluid during climax. Once the sperm has entered the female reproductive system, they will travel up to the cervixThe lower part of the vagina.. A male can ejaculate up to 200 million sperm each time, but only around 2 million sperm will reach the cervix, as they have to flow through acidic fluid inside the vagina.

The sperm then have to find their way up to the top of the organ, the uterusThe upper area of the vagina., and only around 10,000 make it there. They are continually attacked by white blood cells and absorbed by the phagocyteA white blood cell of the immune system..

By the time they reach the fallopian tubes, there are now just 5,000 sperm left. They have travelled up through the vagina, the cervix, the uterus and now they face their biggest challenge - attaching to the egg. All along the fallopian tube, sperm will have either petered out and given up, or will find themselves attached to the tube itself, as it is covered with a layer of mucus.

So, while all of this happens, each interaction with sperm is undertaken with the white blood cells, and a woman's immune system to fight off infection.

Here is a YouTube video from Don't Memorise on the female reproductive system:

So, Now What?

Well, this is where the one egg, and the one sperm form an embryo and in a few weeks' time, it will be a foetus, which by that point, it will be considered a baby, and the female is pregnant.

Interesting fact: the umbilical cord has 2 arteries and 1 vein, linking the mum with the baby. The vein transports oxygen and nutrients to the baby, and the arteries remove waste material via the mother's kidneys.

It takes 9 monthsThe longest known pregnancy lasted for 375 days, in 1945. to conceive and go a full term in pregnancy. In this time, the baby develops in the womb (uterus), and then when ready, the vagina will dilate to up to 10cm, and allow for passage of the new born baby.

The foetus needs nourishment and time to develop. It also needs other components in order to start growing, such as:

• increases in hormones, estrogen and progesterone
• constant nutrients through the umbilical cord
• a healthy diet and plenty of water intake from the mum
• a stress-free environment - the baby will grow better without the stress piling up

Reproductive Cells

The reproductive system uses two specialised cells that work to create new life. They interact with each other when two people have sex, and can be controlled using contraceptives. The specialised cells are called gametes, which are unique in the fact that they only have one set of chromosome within them. They are as follows:

Sperm: one of the two types of gamete in our body, a male will produce a sperm cell. These are tiny cells that when released into a woman's vagina, fight their way up to an ova, or egg.

Ova (Egg): the egg cell is situated in the woman's reproductive system, and once joined with a sperm cell, allows for the creation of a baby. A woman will have all the eggs she needs to reproduce before she is even born, as during the foetal stage of pregnancy, all the eggs are created then.