Reproductive Organs; What Are They For?

Functions and anatomy of reproductive organs

External Male Reproductive Organs

Reproductive organs are the organs that determine if we are a man or a woman. Some of them can be seen in the mirror, these are called the external ones. For men, this includes the scrotum, which contains the testicles and penis. As you mature, pubic hair will grow around these organs. The surface of the penis has skin that can be moved back, this is also known as the foreskin. It protects the tip of the penis from mechanical damage and drying out. The tip of the penis is a very sensitive part. Touching and stroking it will evoke pleasant feelings. The intensity of these feelings is as a result of many nerve endings in the penis itself. In the center of the tip of the penis, there is a small opening. This opening is the end of the urethra, which is used for urination. In addition to urine passing through the urethra, sperm will also exit the penis this way.
Many boys become nervous, that they may urinate during an ejaculation. Don't worry, it is impossible to urinate while ejaculating because the urethra is closed to urine during an erection.



glans (head)


urethral outlet

Inside the scrotum, there are two egg shaped testicles. One testicle will always be higher up than the other, so they don't rub against each other when you walk. Testicles may also be of different sizes.
The scrotum with the testicles is outside of the body for practical reasons. Production of sperm requires a temperature of about 93 degrees Fahrenheit. This temperature is lower than the temperature of the body and is the temperature that is present just outside of the body! Therefore, having the testicles in a sac, just outside of the body is the perfect solution. The scrotum can also react to fluctuations in temperature. In the winter, the testicles may be pulled up toward the body in order to maintain the optimal temperature. In the summer, the testicles will be slightly lower and further away from the body for the exact same reason. The goal is to maintain a constant and optimal temperature for production of sperm!

The foreskin is connected to the frenulum on the bottom of the penis.

Internal Male Reproductive Organs

Inside the body there are several other internal reproductive organs. Let's discuss them in the order in which sperm travels, this means that we will start where is sperm produced and follow the path it takes through the male reproductive tract to exit the penis.
Sperm are produced in the testicles and they will mature in the epididimys. They will then travel via the vas deferens to the prostate where an additional secrete is added to the sperm. This secretion comes from the seminal vesicles to create semen. The semen or ejaculate will exit via the urethra, which is also a part of the urinary tract, and will exit via the glans of the penis.


seminal vesicles

vas deferens





Narrowing of the Foreskin: Phimosis

Sometimes, the foreskin can be so narrow, that it cannot be pulled over the glans (tip) of the penis. Some cases can be so severe, that the opening of the urethra is hardly visible. This condition is known as phimosis and can be dangerous because without a mobile foreskin, proper hygiene is impossible. The glans will accumulate smegma, which is made up of dead skin cells and products of the sebaceous glands of the penis. Phimosis should be consulted with a pediatrician.

Foreskin pulled over the glans

Narrowed foreskin, which cannot be pulled back past the glans

If the narrowing of the foreskin is severe and cannot be loosened with corticoid creams, your doctor may decide to surgically remove a part of it. Often times, a simple surgery to widen the foreskin is sufficient and it does not have to be removed completely. Removal of a part of the foreskin, or circumcision, is a common practice in certain religions. In this case, the glans of the penis is not covered by the foreskin. Circumcision doesn't reduce fertility or excitability.
Reproductive organs are used mainly for well, reproducing. They transport the male gamete, sperm, from the testicles, through the epididymis and prostate, all the way to the urethra to exit the body.

What do sperm look like and how do they move?

Sperm resemble tadpoles in their shape. They had a head which contains the genetic information from the father and a tail which allows it to swim to the egg. When the sperm attaches to the egg, the tail falls off and only the head will penetrate the egg.

head (carries the genetic information)


tail (allows movement)


The penis contains two cavernous bodies and one spongy body (which also includes the glands) which will fill with blood upon erection. The pressure within these bodies will prevent the blood from flowing out of the penis via veins. During an erection the penis will straighten and “stand up” as well as become longer. It is at this point, that ejaculation is possible.
When the penis is erect, it is longer, wider, and harder. When it is flaccid, it is softer and pointing downward. It is possible for the foreskin to be pulled over the penis during an erection.

Flaccid penis

Erect penis

During puberty, it is perfectly normal to get an erection during the day. This may even happen at the least opportune times! While the situation may seem hopeless, here are some tips to survive with dignity. First try to think of something disgusting. While you're doing this, you can put your hands in your pockets to hide the erection. If you're holding something like a book, try covering the erection with the book, or just turn and face the wall. Basically, just do whatever is most natural for the given situation.

Ejaculation, wet dreams

During an orgasm, the sperm is forced out of the penis via rhythmic movements with the pelvic muscles. An orgasm is the climax of male arousal, which begins with the erection of the penis.
A wet dream is when you wake up wet, but not because of a fever. You are “wet” because while you were asleep, an ejaculation occurred after a spontaneous orgasm. Some boys never experience a wet dream and others have them quite often. The most common question about wet dreams is, if they occur because you were dreaming about something erotic, about sex. This can be the case, but it doesn't have to be. Many boys also think wet dreams occur because they don't masturbate enough. This hypothesis is false. Erections are common during the dream phase of sleep and it's also quite possible that men wake up with erections.

Female Internal Sex Organs

As a girl mature into a woman, her internal reproductive organs will change too. Primary sex characteristics are those that a woman is born with, this includes organs like the ovaries. However, until a girl mature into a woman during puberty, these organs aren't functional. Only during puberty, will an egg mature in the ovary and be released.
The ovaries are female reproductive organs with an oval shape and a length of about 3 cm. They look something like a plum. In addition to providing maturing eggs a place to develop, they are also responsible for production of female sex hormones. Women have two ovaries, one on either side of the uterus.

right fallopian tube


left fallopian tube

right ovary



left ovary

Above the ovaries are the fallopian tubes, also one on each side. The fallopian tube really is like a tube that is oriented toward the top of the ovary. When a mature egg is released, the fallopian tube will be able to “suck it up” and transport it to the uterus. The egg will be gently moved along the tube by small hairs known as cilia. It is in the fallopian tube, that fertilization occurs.
The fallopian tubes lead to the uterus. Careful, there is only one uterus with a fallopian tube and ovary on either side of it! The uterus is a pear shaped muscular organ that is lined by a special layer of cells, called the endometrium. The endometrium will thicken every month in preparation for a fertilized egg. If the egg isn't fertilized, the endometrium will be shed and will exit the body via menstruation.

fallopian tube

released mature egg

follicles or sacs containing the egg

These female reproductive organs, the ovaries, fallopian tubes, and uterus are hidden inside the abdominal cavity. The order described above explains the direction in which the egg moves. Remember, the egg is one of two cells needed for the creation of a new life! When the egg is mature, it will be released from the ovary, caught by the fallopian tube, and will be moved toward the uterus. If it is fertilized, it will implant into the endometrium in the uterus.

Movement of the egg through the fallopian tube with fertilization

Blastocyst 5-6 days after fertilization

Morula 4 days after fertilization

Blastomeres 30 hours after fertilization

Uterine cavity


Fertilization of the egg

implantation of the embryo in the endometrium

egg caught by the fallopian tube

External Female Reproductive Organs

The vagina is a muscular tube that acts as an exit for the female reproductive tract. It is surrounded by the labia majora and labia minora.
Between the labia is the clitoris and under the clitoris we can see the urethra. Behind the vagina we can also see the ending of the digestive tract, the anus.
It is important to realize that all three tracts, by which the body excretes either urine, menstrual blood, or stool, have their own orifice by which the excretions exit the body.
The urethra allows for the exit of urine. Behind the urethra is the vagina which is part of the reproductive tract. It is by this canal, that a baby is born. If fertilization does not occurs, the vagina allows for menstrual blood to flow and exit the body.



labia minora and majora




Behind the vagina is the end of the digestive tract, the anus, which allows for the excretion of feces. Feces contains the undigested components of food.

terminal openings of the urinary, reproductive, and digestive tracts




Menstrual Cycle

As a result of hormonal signaling during puberty, eggs will begin to mature and be released from the ovaries. This process occurs about every 28 days. The egg that is released can come either from the left or right ovary. A mature egg is prepared to fuse with a sperm, this process is known as fertilization, and then implant into the endometrial lining of the uterus. If fertilization does not occur, the egg will die, the endometrium will be shed, and together with blood these components will exit the body. The release of blood together with the endometrium is known as menstruation. Menstruation is repeated every 28 days and the entire 28 day process is called the menstrual cycle. The first day of your cycle is an important one to remember! This date is something your gynecologist and other doctors will want to know.

The egg will be released from the ovary about half way through your cycle. Releasing of the egg is also known as ovulation.
After ovulation, in the second half of the cycle, the egg will travel through the fallopian tube and into the uterus. Meanwhile in the uterus, the lining (endometrium) will thicken, become increasingly vascularized (more blood flow), and the endometrial glands will widen all to make the ideal conditions incase of implantation of a fertilized egg.
If the egg is not fertilized, the egg will die. The death of the egg is a signal for the uterus, that the thick endometrial lining will not be needed this month and it will be released. The release of the lining causes the bleeding and will exit the body by the vagina. In this manner, menstruation will occur again.

Changes in the endometrium during the menstrual cycle

uterus with the released endometrium after the menstrual cycle

endometrium before the next menstrual cycle

endometrium during release

Your First Menstruation, Regularity, and Intensity

Most girls menstruate for the first time between 12-13 year of age. Girls who menstruate later will begin around 15 years of age. If menstruation does not occur by 15 years of age, it is advisable to visit your doctor. The age of menarche, or a girl's first menstrual cycle, varies. The timing can be dependent upon when a girl's mother had her first cycle, but this isn't always the case!
The average menstrual cycle takes about 28 days, with menstruation occurring on the 28th day. A normal range is considered to be anywhere from 21-35 days per cycle.In girls 15 and younger, it is common for their cycles to be irregular. However, after 15 years of age, the menstrual cycle should become regular. If not, you should inform your doctor.
Menses or menstruation or your period can last 3-7 days, most often around 5 days. The intensity of flow may vary. Some girls have such a heavy flow the first few days, that they need to change their pad every hour in school. If your period lasts more than 7 days or is abnormal in intensity, you should consult your gynecologist. A normal blood loss during your period is 1mL/1kg of weight. Heavy flow and excessive blood loss is indicated by the use of 10+ pads/day.
What to Use During Your Period and Period Cramps
When you are on your period, it is especially important to practice a regular intimate hygiene routine. Before and after changing your pad or tampon, you should wash your hands and the external part of the vagina.
During her period, a woman can use pads or tampons, which are single use products. After a girl gets more accustomed to having her period, she can transition from pads to tampons or to a menstrual cup, which can be used repeatedly.
If a girl has severe aches and pains during her period, she should talk to her gynecologist. Often times, a hot compress, herbal teas, or Advil help to ease the cramps. While it may be very uncomfortable to move around, many girls say that light exercise during their period alleviates cramping. Cramps can also go away with addition of vitamins and minerals to your diet, like magnesium or vitamine E. Just be careful not to overdose on your daily intake.
You can track your period using a variety of applications and girls with regular periods can use their normal day planner. If a girl has an irregular period or other abnormalities, she should use a classical menstrual calendar, which will allow her to track the heaviness of her flow (how many pads she used), the discharge, pain, and other important details that a gynecologist needs to know.

Menstruation calendar with marked expected dates of menstruation, heaviness of flow (evaluated by number of pads used): 1. pad= very light flow=1 box, 2-4 pads=light flow= 2 boxes, 5-7 pads= medium flow=3 boxes, 8-10 pads heavy flow=4 boxes, 11-18 pads= very heavy flow=5 boxes P marked in a box=abdominal pain H= headache D=discharge S=sexual intercourse I=infection

I-strep throat

1. day of the cycle

14 day of the cycle, half of the cycle, ovulation

Endometrium during the menstrual cycle