Female Reproductive Cycle | Ovulation

iron engineers in this video we're going to talk about the female reproductive cycle now in this video we're going to talk about the auditory cycle and we're going to discuss the menstrual cycle and see how these two cycles are interconnected and intertwined because that's really the crucial point not just looking at one cycle and all it does but looking at how these two cycles are really really intertwined together okay before we do that let's go ahead and start where this whole pathway begins everything upon which these cycles are working are dependent upon the hormones produced by the hypothalamus okay so let's start up here in the hypothalamus so here's your hypothalamus and in the hypothalamus you have two different special nuclei that are secreting specific types of hormones so for example let's say that this red one over here this red group of nuclei we're going to call these guys we're going to call them the pre optic nucleus and then these orange ones over here we're going to specifically call these guys we're going to call these ones the arcuate nucleus okay so we've got the arcuate nucleus which is the orange one and then we got the pre optic nucleus which is these red ones what these guys are doing is they're secreting a very important hormone that hormone is called look at this what they secrete they secrete what's called go natto tropen releasing hormone what ganado tropen releasing hormone does is it comes down here into the anterior pituitary and in the anterior pituitary there's these cells called gonadotropin these ganado Tropes once they're stimulated by grenada trope and releasing hormone they secrete two chemicals into the bloodstream look at these two chemicals that they're releasing this one is called FSH and this one is called LH FSH stands for follicle stimulating hormone and la stands for luteinizing hormone and they're going to come down here and are going to work in the ovary but before I show what they're doing in the ovary we need to discuss real quick all right so whenever a female's born so at birth she has these special types of stem cells and these stem cells are called oh oh go nians okay so an algo neum now I'll go Neum is a stem cell two diploid stem cells what does it mean when it's diploid it means it's 2n right 46 chromosomes 23 of the maternal 23 paternal what happens is once the female is actually born her Oleg onehans she'll have all the Oleg onehans are stem cells that she'll ever need what happens is while the child is growing up before puberty these o Ogoni ins are getting converted into this follicle right here you see this follicle right here this follicle right there is actually specifically called a primordial follicle so what is this one right here called it's called a prai more deal follicle and again when is this occurring when are you shifting from an elegant which is a diploid into a primordial follicle when is this happening which is still by the way this one here is still diploid so this primordial follicle is still diploid but when is this occurring this is occurring during the childhood pre-puberty so this is occurring pre-puberty so when is this occurring again guys pre puberty but then what happens is when the female reaches puberty and she starts undergoing these specific ovulatory cycles so now she's hit puberty and she has her primordial follicles by the time she hits puberty she has tons and tons of primordial follicles but then look what happens once she hits puberty there's specific local chemicals local chemicals so what kind of local chemicals like local androgens so again what type of chemicals here like specific types of localized androgens these localized androgens not FSH not LH these localized androgens are stimulating some of these primordial follicles at puberty to start shifting and turning into this next follicle right here okay so let me repeat this one more time when you're born you have all the Oleg O'Neill's will ever need which is a diploid stem cell during that pre-puberty time period what happens is you're Oleg onehans get converted into primordial follicles which is still too in meaning is diploid then what happens is it's going to get stimulated by the time we hit puberty all the way until you reach menopause right there's going to be localized androgens that are going to stimulate the conversion of some of the primordial follicles into what is this one I hear this one right here is called a primary follicle so this one right here is called a primary follicle okay so we got pre-puberty all the way to this guy which the primordial primordial to a primary follicle one more thing I told you that this is diploid right it's actually frozen in a specific step of what's called meiosis it's actually frozen specifically in prophase one so again this primordial follicle it's diploid but what happens is getting ready to start undergoing meiosis one but it's frozen in prophase one okay now we're at the primary follicle what happens is you see this FSH right here this FSH is super critical for this step right here going from this primary to this next one here let's actually label all of these so they're for example this is a primary follicle how would you describe a primary follicle it's a primary oocytes primary oocytes which means it hasn't undergone meiosis one still frozen in prophase one with a single layer around it of cuboidal or columnar like follicle cells so again a primary follicle is a primary oocytes meaning it hasn't undergone meiosis one and for finish meiosis one and around it has a single layer of cuboidal or columnar like epithelial cells that's a primary then after that look what happens it starts proliferating and makes multiple types of these granulosa cells down these cuboid or columnar this one right here is called a early secondary follicle let's explain something here before we go into each one of these this primary follicle it gets converted into this early secondary follicle how FSH look what FSH does FSH stimulates this step right here look what he does FSH comes right here and he stimulates this step of converting a primary follicle to an early secondary follicle so what's actually happening in this step look what happens in the cuboidal cells they went under will go with a underwent proliferation so we went from just a single layer to multiple layers that's one effective FSH is multiple layers of granulosa cells what else happened a fan stage also stimulates this Oh site to produce this pink glycoprotein membrane around that what does that pink like a protein membrane around it called it's called the zona pellucida okay so FSH is stimulating the proliferation of these follicle cells to multiple layers it's also stimulating this actual OA site to produce a glycoprotein layer called the zona pellucida and look what else that's causing the production off look what else is coming out of this so these cells right here when they're stimulated by this FSH look what they're producing they're producing estrogen okay so let's go ahead and recap this one more time what's this FSH doing to the primary follicle it's stimulating these primary follicles to undergo replication make multiple layers stimulates it to produce a glycoprotein membrane around it called the zona pellucida and it also causes the production of estrogen okay what about LH s LH involved in this step yes he is you see these like a maroon violet like cells around it those are called thecal cells fecal cells let me show you what the equal cells are actually doing these stinkin cells are pretty cool look at these stinkin cells let's say we zoom in on a fecal cell here here's our thecal cell and what happens is the granulosa cells are right next to this fecal cell so if we have a granulosa cell right adjacent to it look what's happening here this is the beauty of it LH is acting on this fecal cell so it's acting on this dqo cell and what's happening in the steagle cells is taking cholesterol and converting it into antigens but who's stimulating this LH LH is actually stimulating the conversion of cholesterol into antigen like and Rothstein's ion but then look at what's right next to this dqo cell what's right next to him these green cells these granulosa cells look what happens to these antigens they move right into this cell and they eventually get converted into estrogen but who's stimulating this mechanism this is the job of FSH so FSH is actually stimulating what he's stimulating the conversion of these androgens that came from the thecal cells into the granulosa cells and he converts it into estrogen that's beautiful so FSH is stimulating the production of estrogen but how you need the presence of luteinizing hormone so luteinizing hormone is actually going to be there how because it's going to stimulate these fecal cells and tell these fecal cells to produce androgens and those antigens will go into the granulosa cell and FSH will stimulate specific enzymes like aroma taste enzymes that convert it into estrogen so it's really important and this step here okay very very nice so now let's go to the next one early secondary follicle FSH and LH are also stimulating this step - so in the same way who else is going to be stimulating this step right here you're still going to have FSH stimulating this step and who's going to be stimulating the thecal cells in this step you're still going to have luteinizing hormone stimulating the conversion of the early secondary to this next one look what else it does so not only does it cause the actual proliferation again of the actual cell layers but look what else it does it starts telling these granulosa cells to start producing follicular fluid what is follicular fluid look at the fluid is actually primarily consisting of what's called hyaluronic acid so it's not only causing again the proliferation of these a granulosa cells not only causing the production of estrogen it's not only causing them to proliferate even more but it's also causing them to produce follicular fluid which is rich in hyaluronic acid so now we produce these pockets of follicular fluid who's responsible for producing these fat pockets a follicular fluid FSH so FSH is doing what he's causing multiple layers of granulosa cells to be made right so in this step what's happening to these granular cells you're making more what else is happening they're producing pockets of follicular fluid which is rich in hyaluronic acid what else would be happening same thing that happened in this step the production of estrogen so you're also going to be producing in this step you're going to be producing estrogen so now that we know how this estrogen is being produced with a thecal cells the LH is stimulated in thecal cells to convert cholesterol to androgens then FSH is taking those androgens that move into the granulosa cells and stimulating their conversion into estrogen we don't need this anymore so now we know this okay so again what is FSH doing to this early secondary follicle as it converts into this next one it's causing proliferation pockets of follicular fluid and the production of estrogen oh man so beautiful should make so much sense guys okay so primary to early secondary FSH and LH is stimulating early secondary into this next one where there's multiple layers pockets a follicular fluid and estrogen production this next one is actually called a late secondary follicle you can tell that because it has more layers in the early secondary and it has pockets of follicular fluid and to continue to keep going with this you know I told you that the primordial follicle was again a primary oocytes the primary follicle is a primary oocyte the early secondary father still a primary oocytes and the late secondary follicle is still a primary oocytes what does that mean it means it hasn't finished meiosis 1 okay it's getting ready to though alright so now look what happens this late secondary follicle it's going to get more stimulation from who from FSH and LH so FSH is going to continue to stimulate what the proliferation of the cells the pockets of follicular fluid and what's the result of actually this you're still going to produce more estrogen okay who else is stimulating this pathway too it's also going to be the presence of luteinizing hormone luteinizing hormones actually going to be stimulating the thecal cells to produce androgens antigens are going to be converted into estrogens by the granulosa cells with the presence of FSH now look what happens here it's stimulating this late secondary follicle into this next one but you see how there was just these little pockets of follicular fluid FSH keeps stimulating these granulosa cells to produce more and more and more powerful Aquila fluid till eventually these two pockets they come together and they coalesce and make one big fluid filled cavity you see this one right there that's your fluid filled cavity this fluid filled cavity here which is going to be rich in follicular fluid and again that follicular fluid is hyaluronic acid this pocket big big huge Lake of follicular fluid that is called the antrum so this big blue structure right here is now called the antrum and what is that antrum how is that answerin formed again FSH is stimulating these granulosa cells to produce those follicular fluid right rich in hyaluronic acid and eventually those pockets of follicular fluid gets so big that eventually they come together they coalesce and make one big fluid filled cavity called the antrum okay next thing you see how this is a late secondary follicle this one is called a graphene or vesicular or tertiary follicle but watch this you know how I've been telling you the whole time that again if we come back over here primordial follicle was what it was a primary oocytes right that here it was a primary oocytes what about a primary follicle it was a primary oocyte what about an early secondary follicle it was a primary oocyte what about a late secondary follicle it was a primary oocytes what about a graafian a graafian follicle is actually going to be a secondary oocytes and before so it actually underwent meiosis 1 so what's meiosis let's actually show you what meiosis is up here so real quickly if I have a diploid stem cell right a parent stem cell and what happens is they undergo meiosis 1 as the result of meiosis 1 I make two haploid daughter cells then those two haploid daughter cells they undergo meiosis two and produce two more haploid daughter cells for a total of four haploid daughter cells all right so when you're going from this diploid stem cell to these two haploid daughter cells this is called meiosis 1 meiosis 1 all right so this is where you had that primordial follicle it's still undergoing my it hasn't completely finished meiosis when it gets converted into a primary follicle primary follicle is converted into an early secondary early secondary to a late secondary and then look look what happens to this late secondary as a result he undergoes meiosis one and produces a haploid daughter cells and then another haploid daughter cells this right here one of them actually becomes what's called a polar body and he undergoes degradation and then he before after he'll actually can undergo meiosis two and produce polar bodies like a third and fourth these want to go degradation also this one I hear it's your secondary oocyte so this one here is called your secondary oocytes go undergo meiosis two but he doesn't finish it he gets stuck in metaphase 2 so this graafian follicle is the secondary oocyte frozen in metaphase 2 okay so we're at that point right now what was this second step here the second step when you're going from these two haploids to four half words is called me closest to all right so we're at that point now okay so the graafian follicle is a secondary oocytes so going from this late secondary to this graafian I underwent meiosis one and produced a secondary oocytes in metaphase 2 I also produced estrogen I formed this lake of follicular fluid and I still have my zona pellucida and I have all these granulosa cells oh real quick if I were to kind of highlight it you see these cells these group of cells want to kind of highlight it in blue here going all the way around them these cells right here that are just directly wrapping around this secondary oocytes rose in a metaphase to these green cells those green cells right they are called corona radiata cells okay so they're just the actual group of cells that are directly wrapping around that second areola site now we need to talk about something real quick okay what is this whole phase here called this whole phase of what I'm going from a prime from technically a primordial to a primary a primary to an early secondary and early secondary to a late secondary and then a late secondary to a tertiary graafian follicle this is called the follicular phase so again what is this here called this is called the follicular phase and again in the follicular phase what am I actually doing I'm going from a primordial follicle to a primary follicle to a early secondary follicle to a late secondary follicle to a graafian follicle okay that's what's happening so in this step let's actually do it again what happens here primordial all the way to a graafian follicle okay and who is stimulating this step primarily primarily it is ask SH but who else is producing produced in a small amount that helps in this process it's also going to be luteinizing hormone what's the product of this reaction or this follicular phase do you remember that you actually undergo mitosis or proliferation so there's mitosis not meiosis mitosis of these granulosa cells making multiple layers what else there's a sturgeon production so estrogen is produced what else is happening you're producing follicular fluid and what else at the end of this follicular phase you go from a primary oocytes all the way to a secondary oocyte okay now we need to talk about something else to this follicular phase is occurring from about days 1 to 14 so again it's occurring from about days 1 all the way to day 14 this is my average not every ovulation cycle is obviously perfect but on average a follicular phase is generally days 1 to 14 so around the mid part of the follicular phase so day 7 8 or 9 right estrogen levels start rising because you're producing a lot of estrogen during this time period so you know where estrogen is actually going it's going into the bloodstream so look it's going into the blood moving into the blood here you're producing it here it's moving into the blood right there right now this estrogen let's follow it look what happens here it's actually going to come through the blood and look what happens to this estrogen levels so as they're rising around mid follicular phase they come over to the hypothalamus and they also go to the anterior pituitary and look what they do to it they exert a negative feedback mechanism okay so as estrogen levels are rising right because it was in the blood and as it rises in the blood what happens it comes up to the hypothalamus and inhibits the hypothalamus from secreting GnRH it also inhibits the anterior pituitary from releasing FSH and LH now when it does that you're not going to make as much FSH and you're not going to make as much LH and then what's going to happen this actual production of estrogen is eventually going to drop but estrogen levels drop if they come back again so now let's actually say that estrogen levels come back up again so at certain levels they get they actually increase not when do they increase again to high high levels around day 14 so let's say that we get to about day 13 day 14 estrogen levels start rising in the blood again so now let's come back over here let's show the second time here as red so when is this time this is around the end of follicular phase and this is when mid follicular phase and then what happens when that happens there exerts a negative feedback mechanism look what happens when it rises again towards the end of the follicular phase does something really really weird oh look at that in that weird guys it stimulates the hypothalamus to produce tons of GnRH it stimulates the anterior pituitary to produce tons of LH now you notice I didn't say a lot of FSH why because you know the graafian follicle is also really special whenever you get to that like the end of the follicular phase it notices this rise in estrogen and it produces a really cool chemical look at this chemical that this guy produces this chemical is called inhibin not technically if we were to be specific as inhibin be look what inhibin b does it comes over here and it inhibits the anterior pituitary from releasing FSH let me repeat that one more time the graafian follicle as a result of this high amounts of estrogen production high amounts of FSH production it releases inhibin b and heaven B then inhibits the anterior pituitary from releasing FSH but what was the high estrogen levels towards the end of the follicular phase doing the high oxygen levels at the end of the follicular phase were promoting a positive feedback mechanism to stimulate the hypothalamus to release gene RH and to stimulate the actual anterior pituitary to produce tons of LH you know what this is called whenever you produce massive amounts of LH it's called the LH surge okay now look what this LH is going to do this LH is actually going to come over here to the graafian follicle and it's going to work in this step primarily so he is primarily going to be working in this step this this whole graphing of follicle look what he does it's actually really cool so you know what he does over here you know there's blood vessels that are supplying this so let's say I draw like a tiny system of blood vessels right here what LH does is is it increases the actual blood flow and permeability to this part of the graphing follicle if it applies a lot of vascular permeability to this part of the follicle what happens you start producing a lot of follicular fluid so this follicular fluid production continues to increase but over here there's not a lot follicular fluid being produced guess what else he does over here he activates special enzymes look at these enzymes look what these enzymes are little scissor enzymes you know what these scissor enzymes are they're called proteases you know what these proteases are going to start doing they're going to start eating away around this tissue of the graafian follicle so it starts eating away and breaking down specific tissue around the graafian follicle so what is this actual always I look in a different view look I'll show you here in a different view let's say here is the OA site and look it's coming up off the surface right there so right here is the OA site popping up off the surface and then what's surrounding it that don't Appaloosa right so there's that zona pellucida surrounding it right here then right around that you're going to have those granulosa cells right so all those granulosa cells are surrounding it now it popped up across the top of the surface here what luteinizing hormone does is he activates specific enzymes these proteolytic enzymes and these proteolytic enzymes start cutting up that little piece you around that area that's keeping it elevated above the surface and it's increasing the blood flow to the antrum over here what eventually happens if you start cutting this little structure way that stigma they call it it pops it out it pops the secondary oocytes out of this graafian follicle so what would that what will happen it look what happens look what comes out of this out of this we have our secondary oocytes who's frozen and what he's frozen in metaphase 2 he has the zona pellucida membrane around him and then directly around that one you have you have those granulosa cells specifically which ones the corona radiata cells what is this step right here call whenever you eject or you pop that secondary oocytes that's frozen in metaphase two out of the graafian follicle this right here is called ovulation when does that usually occur usually this event occurs around mid cycle but like I said it's not everyone has a perfect cycle but it's usually around day 14 or day 15 that's what we assume right so again this is actually going to be called the ovulatory phase okay now the obvious Tori phase like I said is technically assuming a normal cycle about days 14 to 15 anywhere within this time period okay so somewhere in between day 14 and 15 is when the ovulatory phase is occurring and again who is triggering this phase this phase is triggered by the LH surge okay that's the ovule Ettore space now look what else really happens this is really cool females are just intuitive that they know that they need to be able to take this Oh a sight into their fallopian tubes you know what happens right around this time whenever the ovulation occurs this fimbriae see these little fingers here of the fallopian tubes they become really stiff and then they start scraping across the surface of the ovary and when they scrape across the surface of the ovary it creates like little fluid filled currents so there's like some gnarly waves in here that are being produced right and it's kind of kind of like pushing and scooting that little OA site towards this actual fan brea the fallopian tubes so look what happens as a result it starts moving this guy towards the fallopian tubes and it catches it so what happens is it catches the actual secondary oocytes frozen a metaphase - catches it once it's caught it undergoes this little beading mechanism so look what happens in here and here we have these simple columnar cells and these simple columnar cells on their surface they have cilia and this cilia are going to beat that little ol site into this area of the actual fallopian tube so you see this area right here this is called the ampulla of the fallopian tubes okay so it pushes it right into this area and keeps it localized in this area for fertilization to eventually occur right so whenever the sperm cell comes to that vicinity okay so ovulation it ejects the secondary oocyte out the fimbria the fallopian tubes are going stiff and push fluid field currents that push it into the femme Brahe and it catches it and it keeps it in the ampulla until the sperm cell comes and actually tries to fertilize it okay now what else happens okay so we did the IV Latorre phase now we're going to go into this last phase so this last phase here is actually called specifically it's called the luteal phase you'll see why so it's called the luteal phase okay so where were we at we were here at the graafian follicle or dejected that secondary oocytes frozen in metaphase two out what happens is LH is what's stimulated that process but guess what else it stimulates this the structure here becomes filled with blood and it's called the corpus hemorrhagic um when it gets filled with blood LH actually does something again so let's actually represent LH and this color now so LH is actually going to stimulate this step again so not only is going to trigger ovulation but he's going to turn some of these cells these granulosa cells the ones that are still there he's going to specialized them he's going to differentiate them they're going to start accumulating a lot of lipids a lot of cholesterol a lot of fat and it's going to turn yellow you know another word for yellow is is ludia you know so what happens this structure here the graafian follicle luteinizing hormone stimulates him to get converted into this specialized hormone producing factory you know what this hormone producing Factory is called this hormone producing Factory is specifically called the corpus luteum so what is the structure here called it's called the corpus luteum now LH triggers the conversion of the graafian follicle that ruptured into the corpus luteum but you know what else he does so look what happens corpus luteum you know the CC this LH he's going to directly stimulate the corpus luteum and as a result the corpus luteum produces a very very important hormone this hormone is called pro gesture own okay so this hormone is called pro gesture own so LH is stimulating the corpus luteum to not only be converted in from a graafian follicle that ruptured into this corpus luteum but it also stimulates the corpus luteum to produce progesterone now this luteal phase that i told you right so again what's the trigger here this is going to be converting the one graafian into the corpus luteum who's the primary hormone involved in this step the primary hormone involved in this is going to be luteinizing hormone and then what's the result of this luteinizing hormone luteinizing hormone is actually stimulating me corpus luteum to produce what progesterone so it's stimulating the corpus luteum to produce a very important hormone which is called pro just their own that's what luteinizing almost going now the luteal phase is about from now again assuming a normal period I'm sorry I knew a normal ovulatory cycle is from about days 15 to 28 so again on normal the luteal phase is generally approximately about days 15 to 28 all right and the luteal phase is going to be what happens when the graafian follicle that ruptured gets converted to the corpus luteum and then the luteinizing hormone stimulates the corpus luteum to produce progesterone now that will pretty much give us everything that we need to know for the ovulatory cycle okay in the next video we're going to go over the menstrual cycle and see how estrogen and progesterone hormones are going to affect the actual uterus and all the different types of activities that occur there

Channel: Ninja Nerd

Views: 994,742

Rating: 4.8415217 out of 5

Keywords: female reproductive cycle, ovulatory cycle, ovulation

Id: pzgUbyD6mCM

Length: 33min 59sec (2039 seconds)

Published: Mon May 08 2017