Female Reproductive Cycle | Ovulation

All right, ninja nerds. In this video, we're going to talk about the female reproductive cycle. Now, in this video, we're going to talk about the ovulatory 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, but 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 secretreting 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 got the arcuate nucleus which is the orange ones and then we got the preoptic nucleus which is these red ones. What these guys are doing is they're secretreting a very important hormone. That hormone is called look at this what they secrete they secrete what's called gonadotropen releasing hormone. What gonadotropen releasing hormone does is

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 got the arcuate nucleus which is the orange ones and then we got the preoptic nucleus which is these red ones. What these guys are doing is they're secretreting a very important hormone. That hormone is called look at this what they secrete they secrete what's called gonadotropen releasing hormone. What gonadotropen releasing hormone does is

it comes down here into the anterior pituitary and in the anterior pituitary there's these cells called gonadotropes. And these gonadotropes once they're stimulated by gonadotropen 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 follical stimulating hormone and LH stands for luteinizing hormone. And they're going to come down

here and they're going to work in the ovary. But before I show what they're doing in the ovary, we need to discuss something real quick. All right. So, whenever a female is born, so at birth, she has these special types of stem cells. And these stem cells are called ooniums. Okay? So, an oonium. Now, an oonium is a stem cell. It's a diploid stem cells. What does it mean when it's diploid? It means it's 2 N, right? 46 chromosomes. 23 of them maternal, 23 paternal. What happens is once the

female is is actually born, her oagoniums, she'll have all the oagoniums, her stem cells that she'll ever need. What happens is while the child is growing up before puberty, these ooniums 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

primordial follicle. And again when is this occurring? When are you shifting from an oagonium which is a dloid into a primordial follicle? When is this happening? Which is still by the way this one right 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

primordial follicle. And again when is this occurring? When are you shifting from an oagonium which is a dloid into a primordial follicle? When is this happening? Which is still by the way this one right 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 ooniums you'll ever need, which is a diploid stem cell. During that pre-puberty, pre-puberty time period, what happens is your oegoniums get converted into primordial follicles, which is still 2 in, meaning it's 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 right here? 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 is 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 it's 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, for example, this is a primary follicle. How would you describe a primary follicle? It's a primary oasite. Primary oasite, which means it hasn't undergone meiosis one. still frozen in prophase 1 with a single layer around it of cubuidal or columnar like follicle cells. So again a primary follicle is a primary oasite meaning it hasn't undergone meiosis one and or finished meiosis one and around it has a

single layer of cubuidal 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. Now this 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 early secondary follicle. So what's actually happening in this step? Look what happens to the cuboidal cells. They went under we'll go underwent proliferation. So we went from just a single layer to multiple layers. That's one effect of FSH is multiple layers of granulosa cells. What else happened? FSH also stimulates this oasite to produce this pink glyoprotein membrane around

that. What is that pink glycoprotein membrane around it called? It's called the zona palucida. Okay, so FSH is stimulating the proliferation of these follicle cells to multiple layers. It's also stimulating this actual oasite to produce a glyoprotein layer called the zona palucida. And look what else it's causing the production of. Look what else is coming out of this. So these cells right here when they're stimulated by the by this FSH, look what they're producing. they're producing

that. What is that pink glycoprotein membrane around it called? It's called the zona palucida. Okay, so FSH is stimulating the proliferation of these follicle cells to multiple layers. It's also stimulating this actual oasite to produce a glyoprotein layer called the zona palucida. And look what else it's causing the production of. Look what else is coming out of this. So these cells right here when they're stimulated by the 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 to produce a glyoprotein membrane around it called the zona palucida, and it also causes the production of estrogen. Okay, what about LH? Is LH involved in this step? Yes, he is. You see these like uh maroon violet like uh uh cells around it? Those

are called theal cells. Theal cells. Let me show you what theal cells are actually doing. These theal cells are pretty cool. Look at these theal cells. Let's say we zoom in on a theal cell here. Here's our theal cell. And what happens is the granulosis cells are right next to this theal cell. So if we have a granulosis cell right adjacent to it, look what's happening here. This is the beauty of it. LH is acting on this cell. So it's acting on this cell. And

what's happening in the STL cells? It's taking cholesterol and converting it into androigens. But who's stimulating this LH? LH is actually stimulating the conversion of cholesterol into androgens like androstine dione. But then look at what's right next to this theal cell. What's right next to them? These green cells, these granulosa cells. Look what happens to these androgens. 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 theal 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 theal cells and tell these theal cells to

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 theal 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 theal cells and tell these theal cells to

produce androgens. And then those androgens will go into the granulosis cell and FSH will stimulate specific enzymes like aromatase enzymes that convert it into estrogen. So it's really important in 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 too. 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

produce androgens. And then those androgens will go into the granulosis cell and FSH will stimulate specific enzymes like aromatase enzymes that convert it into estrogen. So it's really important in 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 too. 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 theal 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 uh granulosis cells to start producing follicular fluid. What is follicular fluid? follicular fluid is actually primarily consisting of what's

called hyaluronic acid. So it's not only causing again the proliferation of these granulosis cells, it's 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 pockets of follicular fluid? FSH. So FSH is doing what? He's causing multiple layers

of granulosis cells to be made. Right? So in this step, what's happening to these granulosis 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 the theal cells, the

LH is stimulating the theal 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. It 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 of 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 how I told you that the primordial follicle was again a primary oasite, the primary

follicle is a primary oasite. The early secondary follicle is still a primary oasite and the late secondary follicle is still a primary oasite. What does that mean? It means it hasn't finished meiosis one. Okay, it's getting ready to though. All right, 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 hormone is actually going to be stimulating the theal cells to produce androgens. Androgens 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 granulosis cells to produce more and more and more follicular fluid till eventually these two pockets they come together and they coalesce and make one big fluid fil cavity. You see this one right there? That's your fluid fil cavity. This fluid fil 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 antrum formed? Again, FSH is stimulating these granulosis cells to produce those follicular fluid, right? Rich in hyaluronic acid. And eventually those pockets of follicular fluid get so big that eventually they come together. They coalesce and make one big fluid fil cavity called the antrum. Okay. Next thing you see how this is a late

secondary follicle. This one is called a graphion or vicular 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 oite. Let's write that here. It was a primary oasite. What about a primary follicle? It was a primary oite. What about an early secondary follicle? It was a primary oasite. What about a late secondary follicle? It was a primary oasite. What about a graphian? A

secondary follicle. This one is called a graphion or vicular 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 oite. Let's write that here. It was a primary oasite. What about a primary follicle? It was a primary oite. What about an early secondary follicle? It was a primary oasite. What about a late secondary follicle? It was a primary oasite. What about a graphian? A

graphian follicle is actually going to be a secondary oasite. And be so it actually underwent meiosis one. So what's meiosis? Let's actually show you what meiosis is up here. So real quickly, if I have a dloid stem cell, right, a parent stem cell, and what happens is I undergo meiosis one. As the result of meiosis one, I make two hloid daughter cells. Then those two hloid daughter cells, they undergo meiosis 2 and produce two more hloid daughter cells for a total of four

hloid daughter cells. All right. So when you're going from this dloid stem cell to these two hloid daughter cells, this is called meiosis one. Meiosis one. All right. So this is whenever you had that primordial follicle. It's still undergoing my it hasn't completely finished meiosis one. It gets converted into a primary follicle. Primary follicle gets converted into an early secondary early secondary to a late secondary. And then look look what happens to his late

secondary. As a result he under goes meiosis one and produces a hloid daughter cell and then another hoid daughter cell. This right here, one of them actually becomes what's called a polar body and he under goes degradation and then he before after he'll actually can undergo meiosis 2 and produce polar bodies like a third and fourth. These will undergo degradation also. This one right here is your secondary oasite. So this one right here is called your secondary oasite and eventually he'll go

secondary. As a result he under goes meiosis one and produces a hloid daughter cell and then another hoid daughter cell. This right here, one of them actually becomes what's called a polar body and he under goes degradation and then he before after he'll actually can undergo meiosis 2 and produce polar bodies like a third and fourth. These will undergo degradation also. This one right here is your secondary oasite. So this one right here is called your secondary oasite and eventually he'll go

undergo meiosis too but he doesn't finish it. He gets stuck in metaphase 2. So this graphian follicle is a secondary oasite frozen in metaphase 2. Okay. So we're at that point right now. What was this second step here? This second step when you're going from these two hloids to four hloids is called meiosis 2. All right. So we're at that point now. Okay. So the graphine follicle it's a secondary oasite. So going from this late secondary to this graphine I underwent meiosis one and produced a

secondary oasite in metaphase 2. I also produced estrogen. I formed this lake of follicular fluid and I still have my zona palucida 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 I'm going 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 oasite frozen in metaphase 2. these green cells, those green cells right there are

called corona radiata cells. Okay, so they're just the actual group of cells that are directly wrapping around that secondary oasite. Now, we need to talk about something real quick. Okay, what is this whole phase here called? this whole phase of when I'm going from a prime uh from technically a primordial to a primary, a primary to an early secondary, an early secondary to a late secondary, and then a late secondary to a a tertiary or graphion 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? And I'm going from a primordial follicle to a primary follicle to a early secondary follicle to a late secondary follicle to a graphian 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 graphian follicle. Okay. And who is stimulating this step?

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? And I'm going from a primordial follicle to a primary follicle to a early secondary follicle to a late secondary follicle to a graphian 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 graphian follicle. Okay. And who is stimulating this step?

Primarily, primarily it is FSH. 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 here? This follicular phase. Do you remember that? You actually undergo mitosis or proliferation. So there's mitosis, not meiosis, mitosis of these granulosis cells making multiple layers. What else? There's estrogen 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 oasite all the way to a secondary oasite. Okay. Now, we need to talk about something else too. This follicular phase is occurring from about days 1 to 14. So, again, it's occurring from about days one all the way to day 14. This is on average. Not every ovulation cycle is obviously perfect. But on average, a follicular phase is generally days 1 to 14. So around the midpart of the follicular phase, so days

fluid. And what else? At the end of this follicular phase, you go from a primary oasite all the way to a secondary oasite. Okay. Now, we need to talk about something else too. This follicular phase is occurring from about days 1 to 14. So, again, it's occurring from about days one all the way to day 14. This is on average. Not every ovulation cycle is obviously perfect. But on average, a follicular phase is generally days 1 to 14. So around the midpart of the follicular phase, so days

7, 8 or nine, 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. It's 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 midfollicular 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 secretreting G&R. 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 but they come back again. So now let's actually say that estrogen levels come back up again. So estrogen levels they get they actually increase. Now 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 midfollicular

phase and then what happens when that happens 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. Isn't that weird, guys? It stimulates the hypothalamus to produce tons of G&R. 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 graphine follicle is also really special.

Whenever you get to 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 inhib. Now, technically, if we were to be specific, it's inhib. Look what inhib does. It comes over here and it inhibits the anterior pituitary from releasing FSH. Let me repeat that one more time. The graphian follicle as a result of this high amounts of estrogen production, high amounts of FSH

production, it releases inhib. Inhib 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 estrogen levels at the end of the follicular phase were promoting a positive feedback mechanism to stimulate the hypothalamus to release g& 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 graphan 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 graphian 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

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 graphan 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 graphian 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 graphine 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 of follicular fluid being produced. Guess what else he does over here? He activates special enzymes. Look at these enzymes. Look at what these enzymes

here. What LH does is is it increases the actual blood flow and permeability to this part of the graphine 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 of follicular fluid being produced. Guess what else he does over here? He activates special enzymes. Look at these enzymes. Look at what these enzymes

are. Little scissor enzymes. You know what these scissor enzymes are? They're called proteasis. You know what these proteases are going to start doing? they're going to start eating away around this tissue of the graphine follicle. So it starts eating away and breaking down specific tissue around the graphian follicle. So what does this actual oasite look in a different view? Look, I'll show you here in a different view. So let's say here's the oasite and then look, it's coming up off the

are. Little scissor enzymes. You know what these scissor enzymes are? They're called proteasis. You know what these proteases are going to start doing? they're going to start eating away around this tissue of the graphine follicle. So it starts eating away and breaking down specific tissue around the graphian follicle. So what does this actual oasite look in a different view? Look, I'll show you here in a different view. So let's say here's the oasite and then look, it's coming up off the

surface right there. So right here is the oasite. It's popping up off the surface and then what's surrounding it? That's zona palucida, right? So there's that zone of palucida surrounding it right here. Then right around that you're going to have those granulosis cells, right? So all those granulosa cells are surrounding it. Now it's 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 tissue 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 away that stigma they call it. It pops it out. It pops the secondary oasite out of this graphine follicle. So what would that what will happen then? Look what happens. Look what comes out of

this. Out of this we have our secondary oasite who's frozen in what? He's frozen in metaphase 2. He has the zona palucida membrane around him. And then directly around that what do you have? You have those granulosa cells. Specifically which ones? The corona radiata cells. What is this step right here called? Whenever you eject or you pop that secondary oasite that's frozen in metaphase 2 out of the graphine follicle this right here is called ovulation when does that usually occur

this. Out of this we have our secondary oasite who's frozen in what? He's frozen in metaphase 2. He has the zona palucida membrane around him. And then directly around that what do you have? You have those granulosa cells. Specifically which ones? The corona radiata cells. What is this step right here called? Whenever you eject or you pop that secondary oasite that's frozen in metaphase 2 out of the graphine follicle this right here is called ovulation when does that usually occur

usually this event occurs around midcycle 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 ovulatory 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's triggering this phase? This phase

is triggered by the LH

surge. Okay, that's the ovulatory phase. 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 oasite into their fallopian tubes. You know what happens right around this time whenever the ovulation occurs? This fimbra, you 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

surge. Okay, that's the ovulatory phase. 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 oasite into their fallopian tubes. You know what happens right around this time whenever the ovulation occurs? This fimbra, you 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 fil 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 OSI towards this actual frame of 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 oasite frozen in metaphase 2 catches it.

Once it's caught, it under goes this little beating mechanism. So look what happens in here. In here we have these simple columnar cells and these simple columnar cells on their surface they have psyia and the psyia are going to beat that little oasite into this area of the actual fallopian tube. So you see this area right here this is called the ampula 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 oite out the frame becomes stiff and push fluid fil currents that push it into the femre and it catches it and it keeps it in the ampula until the sperm cell comes and actually tries to fertilize it. Okay. Now what else happens? Okay. So we did the ovulatory phase. Now we're going to go into this last phase. So this last phase here is actually called

specifically it's called the ludal phase. And you'll see why. So it's called the lutil phase. Okay. So where were we at? We were here at the graphion follicle where it ejected that secondary oasite frozen in metaphase 2 out. What happens is LH is what stimulated that process. But guess what else? It stimulates this. The structure here becomes filled with blood and it's called the corpus hemorrhagicum. When it gets filled with blood, LH actually does something again.

So let's actually represent LH in this color. Now so LH is actually going to stimulate this step again. So not only is he going to trigger ovulation, but he's going to turn some of these cells, these granulosis cells, the ones that are still there, he's going to specialize 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 what the another word for yellow is is ludia.

You know, so what happens? This structure here, the graphine 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 ludium. So what is this structure right here called? It's called the corpus lutium. Now LH triggers the conversion of the graphine follicle that ruptured into the corpus ludium. But you know what else he

does? So look what happens. Corpus ludium you know see you see see this LH he's going to directly stimulate the corpus ludium. And as a result the corpus ludium produces a very very important hormone. This hormone is called

does? So look what happens. Corpus ludium you know see you see see this LH he's going to directly stimulate the corpus ludium. And as a result the corpus ludium produces a very very important hormone. This hormone is called progesterone. Okay. So this hormone is called

progesterone. Okay. So this hormone is called

progesterone. So LH is stimulating the corpus ludium to not only be converted from a graphian follicle that ruptured into this corpus ludium but it also stimulates the corpus ludium to produce progesterone. Now this ludal phase that I told you right so again what's the trigger here? This is going to be converting the what graphion into the corpus ludium. 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

progesterone. So LH is stimulating the corpus ludium to not only be converted from a graphian follicle that ruptured into this corpus ludium but it also stimulates the corpus ludium to produce progesterone. Now this ludal phase that I told you right so again what's the trigger here? This is going to be converting the what graphion into the corpus ludium. 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 the corpus ludium to produce what? Progesterone. So it's stimulating the corpus ludium to produce a very important hormone which is called progesterone. That's what ludinizing hormone is doing. Now the ludial phase is about from now again assuming a normal period I'm sorry a normal ovulatory cycle is from about days 15 to 28. So again on normal the ludial phase is generally approximately about days 15 to 28. All

right. And the ludial phase is going to be what happens when the graphian follicle that rupture gets converted into the corpus ludium. And then the luteinizing hormone stimulates the corpus ludium 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.