so in this video we're going to talk very briefly about the testes and sperm production so before we begin just remember that there are two testes and they are around about 4 cm in length 2 and 1/2 cm in width and way around about 10 to 12 G each the purpose of the testes is uh twofold predominantly they are there for sperm production and they are also there for Androgen production now andr are male sex hormones for example testosterone so what we're going to look at here first of all is I've drawn to the best of my ability a testy and you can see that well at least I've tried to cut out a wedge from the testy to see what's happening internally in regards to Eternal anatomy and also some of the physiological processes that occur within the testy so to begin with let's talk about some Anatomy what you can see up here above superior to the testes what we call the spermatic cord and the spermatic cord moves from the testes up into the abdomen so this whole region here is the spermatic cord and within the spermatic cord are a number of different anatomical structures for example there's the ductus difference the ductus difference is sometimes called the Vass Defence and that is a tube that carries sperm that's produced in the testes and carries it up to the rest of the ductal system for the male reproductive tract so that's the ductus Defence is a tube carrying the sperm okay what else is within this spermatic cord is the testicular artery and the testicular arter is obviously going to be a branch of the abdominal aort coming down and going to provide nutrients to the testes so if there's going to be an artery that also means it's going to be a Venus system so a vein now the veins that come back up and out of the testes are actually a plexus so they're like a braiding that comes out now it's not called the testicular artery per se but it's called the pampin form plexus so remember I said plexus is like a braiding remember you've got the various spinal plexuses of the the spinal nerve plexuses and remember it's sort of going to come out like this and then it's going to look a little bit like like that and then come back so this pampiniform plexus so remember you're going to have the aoda sorry the branch of the abdominal aota which is the testicular artery coming down providing warm nutrient rich blood to the testes and then you've got this pform plexus coming up right next door to it now the reason why we have this pampiniform plexus is because this Venus Supply cools the arterial blood coming down why do we want to cool this Blood well test when it comes to sperm production the ideal temperature for sperm production is around about 2 to 3° lower than internal body temperature which means the ideal temperature has to be 2 to 3° lower than the blood that's coming in to feed it so this blood's going to be to form for the testes and so this Venus Supply cools it down that's another reason why the testes are found exterior to the body okay all right what else can we find well we can find a testicular nerve and we can also find the craster muscle now the the creas muscle is a muscle that comes down through the spermatic cord and what does it do well when it's relaxed the testes drop when it contracts the testes lift up again this has to do with temperature regulation so when the body is hot or when the temperature is hot again testes need to be 2 to 3° cooler than the internal body temperature so the creas muscle relaxes and the testes drop if it's cold well the testes need to be warm up contracts lifts the testes up now this is the spermatic cord you've got a couple of different layers surrounding the testes which we won't really go through but it's important that you know that there is a muscular layer surrounding the testes and that muscle is called the datos muscle and the reason why I'm bringing this up is the dartos muscle plays another important role in temperature regul of the testes so when it is cold the dartos muscles contract and wrinkles up the scrotum when it is warm the dartos muscles relax and the scrotum becomes less wrinkly and again has to do with temperature regulation when it's cold and wrinkles up well that means that it holds on to the temperature and vice versa when the temperature increases so what are the two muscles involved in temperature regulation for the testes the creas muscles which raise and lower the testes and the dartos muscles which change the scrotum in regards to wrinkly or less wrinkly okay now let's talk about sperm production now what you can find here is I told you that you've got that ductus Defence which is in the spermatic cord and that ductus deference is attached here and what we're going to find is that this ductus Defence is attached to the epidemis and the epidemis which you can find this part that I'm coloring in here is where sperm is stored and further matures okay the epidemis which I'm coloring in here is where sperm is stored and also further matures now there are some ducks or branches of this it go into the testes and these branches further Branch off into individual loes of the testes so you can see I've drawn individual loes here there's actually around about 200 to 250 loes within the testes and these loes turn into smaller tubules and this is where sperm is produced these tubules are called seminiferous tubules now again let's label a couple of things first of all we've got the Epi dimus where sperm is stored and matures and here we've got seminiferous tubules and this is where sperm is produced and therefore sperm being produced in the seminiferous tubules travels through these ducts into the epidemis and then up into the ductus Defence now what I want to do for the rest of this video is focus on what's happening right here in regards to sperm production so if I were to take one of these seminiferous tubules and have a look that's going to be inside of that tub actually I'll draw it a little bit smaller so that's inside the seminiferous tubule and this is the wall of the seminiferous tubule and then you're going to have all the area outside of the 7 tubule now what you're going to find is that there's a number of different cell types that you need to be aware of first of all you've got cells present around here in the walls of the seminiferous tubules these cells are called sustentacular cells there's another good name sustentacular susten tacular cells which we also call CI cells CI okay what's the importance of satol cells they produce a very important hormone called ABP and we'll talk about that in a sec abbp Androgen binding protein in addition to that there are cells that sit outside of the seminiferous tubal walls so in the inters and therefore these cells are called interstitial [Music] cells so these cells are called interal cells but again they have another name and they're called ladig cells and what do L cells do well L cells produce testosterone okay what else do we have we have stem cells in the walls of these seminiferous tubules sperm stem cells so these can obviously turn into sperm so how does this process occur okay well once a male has reached puberty remember if we look at the brain cerebellum cerebrum cerebellum uh midbrain ponds medala so forth and that right here you've got your hypothalmus and you've got two danglies here which AR the testes but is the anterior and posterior pituitary glands remember that the hypothalmus and the anterior pituitary gland is very important when it comes to sperm production so if we were to draw the hypothalmus up here here's the hypos let's say that this one on this side is the anterior pituitary gland well remember similar to when we spoke about the female reproductive cycle you have gatot tropen releasing hormone which is released by the hypothalamus travels down through the blood supply to the anterior pituitary gland and tells the anterior gland to release two hormones called gatot tropins remember these hormones are follicle stimulating hormone and lutenizing hormone now what happens here is that these two hormones when a male reaches puberty is that they travel to the seminiferous tubules and if we have a quick look what you'll find is that the mole stimulating hormone travels to the satoli cells and stimulates sat cells luteinizing hormone travels to the lading cells and stimulates the lading cells which means what happens when a male hits pubity is that the sustentacular cells or the SAT cells produce ABP so now ABP is released in here into the walls of the seminiferous tubules and luteinizing hormone stimulates the lading cells outside here in the interstitium to produce testosterone and this testosterone moves in as well together these two hormones stimulate these stem cells the name of these stem cells is sperato gonia okay spermatogonia or spermatogonium and together ABP and testosterone stimulate their cell to start producing sperm and so this sperm is and what happens is as this sperm is produced it starts to move towards the Lumen or the hollow inside of the tube so the hollow inside of that tube and as this sperm's being produced and starts to mature a little bit more it then gets into the tubul what do we find we now have sperm within our seminiferous tubules and what did I say happen to those sperm they travel into the epidemis where they further matured and they are stored and then when it's time for ejaculation they'll move up to the ductus difference so just to summarize this particular part here follicle stimulating hormone stimulated satoli cells and the SAT cells released ABP luteinizing hormone stimulated the leig cells and they released testosterone together the stimulated spermatogenesis which is sperm production so if you have any questions pop me an email I hope that made sense