Reproductive Systems
Humans reproduce! We have special organ systems in our body that allow us to reproduce, called the reproductive systems! These organs look different between the male body and the female body, so let's learn about them both!
Here’s a brief overview of how sexual reproduction works in humans:
In order for the conception of an embryo (a fertilized egg), the female egg cell must be fertilized by the male sperm cell. This process typically happens due to sexual intercourse, when the erect penis penetrates into the vaginal canal and ejaculates semen. The sperm cells in the semen then “swim” to the egg, which becomes fertilized. If this fertilized egg is properly implanted into the uterus, pregnancy is achieved! The embryo will then develop in the uterus for 9 months, then it is born.
The Female Reproductive System
The female reproductive system contains external and internal parts. It’s important to understand the structure and functions of these organs, and it’s important to use proper terminology! All of these organs are natural parts of the body, they should not be seen as taboo or inappropriate. Just like you have an arm or a leg, you have a vagina or a penis. Instead of using words like “private parts,” use the actual names for the parts. This will allow the stigma around talking about reproductive organs to start disappearing, so people can become more comfortable talking about their sexual health if they happen to have any problems!
​
Let's start off with the external parts of the female reproductive system:
image source
Vulva: The external organs that make up the female reproductive system.
​
The labia majora: The labia majora surround the other external reproductive organs and protect them. The skin here can start growing hair during puberty and contains oil and sweat secreting glands.
The labia minora: These flaps of delicate skin are just inside the labia majora, and they surround the urethra (urinary opening) and the vagina (the canal that connects the cervix, or the lower part of the uterus, to the outside of the body).
Bartholin’s glands: These small glands on either side of the vaginal opening secrete mucus
Urethra: The urethra is the urinary opening, where urine is disposed after it is stored in the bladder until you are ready to use the restroom!
​
Clitoris: The clitoris is found where the labia minora meet, and it has over 8000 nerve endings! This means that the clitoris is extremely sensitive and can therefore be stimulated to achieve sexual climax (or orgasm) during sex or masturbation. When rubbed or touched, the clitoris can become erect and swollen. It is also sometimes covered by a “hood” of skin called the prepuce.
Note: There is no right way for the external organs of the female reproductive system to look. Some people may have larger labia than others, or have different colors, and that’s okay! Your body is amazing just the way it is!
Now, let's take a look at the internal organs of the female reproductive system!
Fun fact: the labia majora and labia minora translate to “big lips” and “small lips” respectively!
image source
image source
Vagina: The vagina is a canal that leads from the lower part of the uterus (called the cervix) to the outside of the body. Sometimes the vagina is also called the birth canal, because babies are pushed through the vaginal canal during birth!
The uterus (womb): The uterus is a hollow organ that houses the baby during pregnancy! The upper part of the uterus, called the corpus, expands in size when someone is pregnant! The lower part of the uterus, called the cervix, leads out to the vagina and the outside of the body. The canal of the cervix allows for uterine lining and blood to leave the uterus during a period, and for sperm to enter the uterus so that an egg may be fertilized after sexual intercourse.
Ovaries: The ovaries are small glands that are found on either side of the uterus, and they produce eggs (that are also called ova or oocytes) and hormones. Did you know that a female baby is born with as many as 1 million eggs? That’s a lot! During ovulation, which is a phase of the menstrual cycle, the ovaries release an unfertilized egg to the uterus, where it waits for sperm to fertilize the egg.
Fallopian tubes: These are narrow tubes that allow ova (eggs) to travel from the ovaries to the uterus.
Endometrium: This is the smooth mucus membrane that lines the inside of the uterus. When an egg is released from the ovaries to the uterus, the endometrium becomes thicker in order to prepare the uterus for holding a baby. If the egg doesn’t become fertilized, the extra lining sheds through the vagina, in the period! So a period happens when your uterus gets ready for an egg to become fertilized, but when it doesn’t, that lining leaves through the vagina, and the whole menstrual cycle can begin again.
Myometrium: This is the muscular middle section of the uterine wall. It is responsible for the contractions of your uterus, which happen during childbirth to help push the infant out of the uterus. However, smaller contractions can also occur while the lining of the uterus is leaving your body during your period...also known as period cramps!
​
​
Wow! There's a lot going on with the female reproductive system! Next, let's check out the male reproductive system.
The Male Reproductive System
The male reproductive system also contains both external and internal parts. It’s important to understand the structure and functions of these organs, and it’s important to use proper terminology! All of these organs are natural parts of the body, they should not be seen as taboo or inappropriate. Just like you have an arm or a leg, you have a vagina or a penis. Instead of using words like “private parts,” use the actual names for the parts. This will allow the stigma around talking about reproductive organs to start disappearing, so people can become more comfortable talking about their sexual health if they happen to have any problems!
​
First, here are the main parts of the external male reproductive system:
image source
image source
Penis: The penis is the main male organ for sexual intercourse, and it also houses the urethra, through which urine and semen are removed from the body. The penis has 3 parts:
​
-
The root, which is where the penis connects to the lower abdomen
-
The shaft/body, which is cylindrical. During an erection, the shaft of the penis fills with blood, causing it to become hard and erect. This allows for penetration during sexual intercourse. The skin around the penis has to account for the change in size and shape during an erection, so it is usually loose and elastic.
-
The glans or the head of the penis: The head of the penis is usually cone shaped, and it houses the urethra (which dispenses urine and semen -- a fluid that contains sperm). The head of the penis is also covered with loose foreskin, which may be removed during circumcision; however, this doesn’t change the function of the penis, it just removes a bit of extra skin. The penis also has many nerve endings (as many as 4000 in just the head!), which means it is incredibly sensitive. During sexual arousal, when the penis becomes erect, semen can be expelled from the urethra in a sexual climax (orgasm).
-
Fun fact: urine is blocked from the penis when it is erect, so an ejaculation only releases semen, and no urine!
-
​
Scrotum: The scrotum is a loose sack of skin that hangs behind the penis, and houses the testicles (which are also called the testes). The scrotum acts as protection for the testes, and it also has many nerves and blood vessels. Also, the scrotum helps to regulate the temperature of the testes -- the ideal temperature for sperm making is slightly cooler than the rest of the body, so the scrotum has special muscles that can move it closer to or farther from the body. This allows it to manipulate the temperature of the testes!
Testicles/testes: The testicles are a pair of oval organs in the scrotum, and they are responsible for making sperm in a process called spermatogenesis, and also for making the sex hormone testosterone.
Epididymis: The epididymis is a long, coiled tube on the back of each testicle. Its job is to carry and store the sperm cells that are produced in the testes. While the sperm cells are in the epididymis, they mature so they are able to fertilize an egg! During sexual arousal, the epididymis contracts to push the sperm cells into the vas deferens.
​
Let's take a look into the internal organs of the male reproductive system!
image source
Vas Deferens: the vas deferens is a long, muscular tube that connects the epididymis to the pelvic cavity, just behind the bladder (which holds urine before it is dispelled). Mature sperm cells from the epididymis travel through the vas deferens to the urethra, where they prepare to be released during ejaculation.
Ejaculatory ducts: These ducts are the connection between the vas deferens and the seminal vesicles, and they empty into the urethra
Seminal vesicles: These are small sac-like pouches that connect to the vas deferens. The seminal vesicles contain a sugar-rich fluid called fructose that provides sperm cells with energy and allows them to be motile (able to move). This is how sperm cells can “swim” up the vaginal canal to an unfertilized egg! This fluid from the seminal vesicles is what makes up most of the ejaculatory fluid dispensed during ejaculation, also known as semen.
Urethra: the urethra is a tube that connects to the bladder and leads outside the body. It excretes urine, but it also dispenses semen during ejaculation when the penis becomes erect.
Prostate gland: The prostate gland is found in front of the rectum and below the bladder. Like the seminal vesicles, it also contains fluid that nourishes the sperm and is part of the ejaculatory fluid that leaves the body. The urethra runs through the prostate gland!
Bulbourethral glands: These are small glands that are located below the prostate gland, on the sides of the urethra. They produce a clear, slippery fluid that helps to lubricate the urethra, and also to neutralize any acidity that may be left behind in the urethra from urine!
​
​
Awesome! The reproductive systems are so cool!