If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Male reproductive system (humans)

Let's explore the male reproductive system in humans. Created by Mahesh Shenoy.

Want to join the conversation?

Video transcript

please note that this video has sexual health content let's look at the different parts of the male reproductive system and see how it works so let's start with the parts that we can visibly see in our body so one of the part is this skin pouch of skin that hangs from our lower abdomen we call this the scrotum scrotum like I said it's a pouch of skin hanging from the lower button so it must be protecting something inside of it right what is it protecting we'll come to that in a second but another part which we can easily see which is visible to us is the penis now let's go to the organs or the parts that is inside our body which we cannot see so one of the parts that you might already know about is our urinary bladder so this is our bladder the bladder and you might know that this is where the urine gets filled up and eventually when the bladder is full the urine passes through a pipe which enters into the penis and then you urinated outside and this particular pipe is what we call the urethra this is the unit and that's going to be important for us okay now let's come back to this scrotum what is inside of it well the scrotum protects an important organ called the testes so this is the testes you can also call it testicle and we have two of them so the plural would be testes with an e tes tes would be the pur testes testes would be the singular and so what does testes do well the primary job of tests is is to make sperm cells and that's why we call it the gonad gonads are the one that ones that create gamuts so in males the gametes are called sperm so testes the gonad which creates sperms creates sperms now you might also remember that testa secretes a very important sex hormone called the testosterone during our puberty it is because of testosterone that we see physical changes during puberty in males like your beard grows and your voice becomes very your voice cracks and gets a little deeper and we also see behavioral changes like we start to get more aggressive all of that happens you do testosterone that's one of the things causes sexual maturity in males but another thing that testosterone testosterone does is that again it regulates the creation of the sperms inside the testes and a curious question could be why is the scrotum hanging down carrying the test is almost outside of our body well there is a reason for that you see it turns out that the creation of the sperms requires a little cooler temperature than our body about two degrees Celsius cooler so this requires cool temperatures all right and it's for that reason the scrotum hangs below the lower abdomen so it so the testes can be out slightly outside our main body and because of that it's temperature will be lower so the scrotum protects the testes and it also helps regulate temperature it also helps keep it cool by hanging below the abdomen all right once these forms are created they move towards another organ called another organ on top of the testes this is called the EPI dye D mus a little hard to spell and pronounce over there but anyways once the sperm reach over there they start growing and maturing over there just like how our bodies grow and mature the sperms also need to grow and mature that's inside this organ that they grow and mature so let me write that over here the sperms grow and mature so mature sperms are sitting over there sperms sit over there now you don't have to remember these names I'm just gonna put a strike on for our syllabus we don't need to remember the name but the mature sperms are sitting over there all right now what happens to these forms now well if the penis gets stimulated then these palms will get propelled into a tube as we will see in a second and eventually it will come out of the penis but if there is no stimulation for quite a while then the sperms basically get reabsorbed by the body and then the whole process continues this ensures that we don't have any old stock over here we will always have fresh new stock of mature sperms waiting to come out of the penis all right so what's gonna happen if this penis gets stimulated well as the penis gets stimulated like we said the sperms are gonna get propelled from the epididymis into yet another organ a tube like structure called the vas deferens so let me write that so it gets propelled the sperm the mature sperms goes into another tube called the vas deferens and where does this forms go after that well the vas deferens takes the sperms and empties it into yet another duct as you can see over here and then finally the sperms will enter into the urethra the same pipe through which the urine moves out the same urethra and then eventually the sperms can come out of the penis now you might have a small curious question why is the vas deferens empty the sperm into this duct and then it goes into the urethra why not directly into the urethra and answer that in a second but here's one question for us now the sperms once they exit the male body they have to survive for quite a long time in the female reproductive system they require energy because they need to move then acquire nutrition and they also need some help in moving so if the swarms directly come out most of these things cannot happen in the cells may not be able to survive so to help the sperm survive outside our body to give it nutrition to give it energy along with the sperms some extra secretions are need and that those secretions are done by accessory glands I'll tell the names of these glands in a second but it's these gland that secretes some fluids into this particular duct and also into the urethra which mix with the sperm and provides the sperm with all the nutrition and the energy and gives it motility helps in in moving and so these are what we call the sec the accessory glands which produce that secretion and finally the mixture the sperm in this sperm and the the fluid mixture which eventually comes out of the urethra so let's say this is that mixture this now is what we call the semen this is what we call the semen so the semen contains the sperms and it contains all the secretions plus the secretions from the accessary glands all right let's name the glands turns out that most of the secretions of the semen is done by this particular gland which is behind the bladder and so it's this is called the seminal vesicle seminal Vasi cull and the gland below over here also helps in the secretions and this is called the prostate gland again you may have heard of this gland prostate and now this answers why we have this tiny little duct over here so the vast difference empties the sperms into the duct these glands empty their secretions into the duct and this is where most of the semen is formed and this tiny bulb like structure is the third land which also adds its secretion to the semen and since it's the bulb like structure it's connect to you literal it's called the bulbar urethra and gland but I'm not gonna write that because we again don't need to remember that it also has another important job before the semen reaches over here it sends out a secretion which is alkaline which cleans up this passage if there is any urine over there because urine is acidic right and if the semen reaches over there where the urine is present the urine the acidic urine might kill the sperms and that's bad so it just cleans up so you first cleans it up and sends it out and then the sperm comes out of the penis and of course at this point the penis might be erect and stiff which will help it to eject that semen out of the body with a very high speed and then the semen can enter the vagina and the sperms will start their new journey in search of an egg to fertilize again something we'll talk about in the future videos and this particular act of expelling the semen out from the penis is what we call ejaculation and in every Jack elation the semen might contain not thousands but millions of sperms that's because the conditions in the female reproductive parts are very harsh and so most of these forms die the unhealthy ones the ones which are not fit to survive they just die out this is to ensure that only the healthiest of the healthiest of the healthiest sperm can survive and go and fertilize with the egg and finally if you're thinking about what the sperm looks like here is a schematic of the sperm the sperm is a cell you can see the head which contains the nucleus which has the genetic material basically it's this genetic material which is supposed to go into the egg after fertilization it has a tail which helps it swim if it helps it move we can say inside the vagina and inside the uterus and and it requires energy for that and it's for that reason the body of this form contains mitochondria you might know mitochondria is the powerhouse so this is basically what a sperm a human sperm looks like alright that's pretty much it let's quickly go ahead and summarize what we learned so the test is is the male gonad which is responsible for creating the sperms it is protected by the scrotum which is the pouch of skin which hangs below the abdomen this also ensures the low temperature and needed for the testes to create this forms the young sperms now move to the epididymis that's where they will mature and sit for a while and then if the penis gets steamed these poems will get propelled into the vas deferens the vast difference empties the sperms into this tiny little duct and these accessory glands also are in their secretions basically the seminal vesicle and the prostate gland mainly and these secretions help the sperm get their nutrients get their energy and help them in motility and now this forms the semen the semen eventually comes out of the urethra from the erect penis and gets thrown out with a great speed and these sperm contains a head which has the genetic material it has a body which has the mitochondria and it has a tail which helps it move