SCB 202 Chapter 28 Female Reproductive System Part 2

0:01 Okay, we're recording now. Okay, so um we're moving on. Okay, so looking at the breasts now, right? So the breasts and the mammary glands. So that they're ducts that basically branch through this fibrous stroma and converge on the nipple. So the mammary glands basically develop during pregnancy. There's 15 to 20 loes. Sashen, can you mute your mic? There's noise coming out of your mic. So 50, there's 15 to 20 loes around the nipple. The lac uh lactoseserous duct drains each lobe. We'll look at those images. These dilate to form the lac

0:48 lactoeras sinus which open into the nipple and these basically end up in these sacks. Right? So if you look at it, let's get to the image. Here we go. Right? So you have obviously this is the fat. The fat makes up the size of the breasts. But now you have these loes. These loes are responsible for generating milk, right? So they help in generating these milk and then they lead into these ducts, right? This is the lact. So think of lactate milk, lacto ferris ducts. So they will all so in here they will each of them make their milk and then they'll all pour into this into this duct collecting the milk right and then once they pour it in they're

1:34 going to go into this area here called the sinus part right and that's how they will lead to the nipple right so all of them collectively join together just like the way we noticed when the photo receptors were taking all the uh the nerves that were coming from the photo receptors and putting them in bundle and sending them to the brain. In the same way, you're collecting all the milk from each lobe, putting them in these ducts and getting them to the sinus so that they can be secreted out of a nipple. Right? So, all of them drain into this last part of the nipple. Right? So, you start off first with the lobe and then the loes obviously drain into the ducts. Right? So, each of them because this area may be making the milk that area

2:19 that area. So they will all make the milk and drain them into the duct which will lead to the sinus over here. So this is how it looks like and that's the fat if you visually look at it. So this is a real life image. So this is a cadaavver of a non-lactating female without obviously all this going on. Right? So just looking at the fats that's why you see the breasts are filled with fat. So of course if you put on weight as I said the breast enlarges well in size because the fat fills up the breast. So if you zoom in to one of the loes as you see over here you zoom in you'll see that this is the type of tissue that's

3:05 there. Right? So obviously here these tissues. So Relle mute your mic. Michelle mute your mic please. So this is how the tissues look like. If you wanted to zoom into the loes, they look like that, right? So these are myoepithelial cells and these are the ones that basically make up um the milk, right? And then obviously they go into the ducts, right? So this is the part of the lactating breasts, right? The ones that when when these loes, right? So this is not the fat. These are the loes that make the milk, right? So milk is made in here. They go into the duct and of course they go into the sinus at the

3:51 end. Breast cancer. So breast cancer occurs in one out of eight or nine American women. It's a lead cause of female mortality. The tumors begin with the cells from the mammary ducts. They can metastasize and these signs basically can include lumps or skin plucking uh changes in the skin texture and drainage from li drainage from the nipples. That's what can give you an indication that an individual may be struggling with cancer. So some of the contributing causes could be the BA one or BA 2. These are the two breast cancer genes and most breast cancer is noneredy. Right? So it could be because of other things like hormones for example like estrogen and so some breast

4:39 cancers are stimulated by estrogen and that's why sometimes the pill you know because the pill supplies constant estrogen so there are questions whether the pill because of this over supply of estrogen over time to create this negative feedback in the body trying not to make a baby right could be connected to some breast cancers. Now, everyone heard that obviously Angelina Jolie was tested uh positive for these genes, these two breast cancer genes. I can't remember if it was one or two, but you know, she had one of the Bracka genes and um and I think she had the type that really definitely would have resulted in cancer of the breast. So, she basically had her breasts removed. So it became obviously a huge thing because obviously

5:25 over the media but people were very proud that she was very vocal about it and um and used that to encourage women that you know they can have if they find out that they have this type of gene they can have their gene that gene removed I mean the breast removed because the bottom line is that if you have that gene because she was tested positive for it. So she had the potential of getting breast cancer because that gene basically is there because I think her mom had it and I believe her mom died of breast cancer or some of her family members and so she was also showing this BA one and two gene or BA one or two gene. The other risk factors that that could contribute to cancer could be aging, exposure to ionizing radiation, obviously carcinogenic chemicals, right? Things

6:12 like bleach, for example, who knows if that's, you know, that could be an issue, right? Because it's carcinogenic, excessive alcohol and fat intake. So, if you're chumping too much in fat, it's been connected to it. Excessive alcohol, um, that as well. And smoking, right? So these are things that have been connected to having high risks of cancer. Over 70% of CA cases lack ident uh identifiable risk factors. So sometimes you know people can't even see the risk factors and before you know it they hear that they have cancer. So tumor discovery usually um can usually be found through self breast examinations which is done every month for women or they encourage women to do it every month. So, of course, as when

6:57 you go and see a gynecologist that they recommend doing every single year to get your papsmear, it's always good to have a gynecologist check to see whether you have breast cancer. Um, obviously, it's a simple test. If you're in the shower, lift your arm over your head and basically use some soap and just rub, you know, in in circular motions around the whole breast and just feel, are there any tissues that are there that are popping up or any foreign um tissue that feels like it could potentially be cancer? Because everyone knows their own breasts and probably um doing a self-examination maybe the best because you know your body really well. So if you've never felt a lump like that before then you know obviously you would bring it to the attention of your gynecologist and say this wasn't there

7:43 before and somehow I feel this this lump right so sometimes when masses grow this uh people don't really know whether something is cancerous or not usually if it's fatlike it could be uh benign if it's fatty and it's soft and it could be moved or squished from side to side but if it's hard like a calcium based thing like if it's hard and you really feel it and you can push on it. Most of the time people want to I mean doctors want to look at things that are tough or hard on your body because they could be um you know maybe potentially cancerous, right? Because they're individuals who sometimes uh confuse growing lumps that are fatty versus something that's hard, right? But again, um most of the time soft

8:29 could be benign fat, but I always recommend having everything checked out. That's usually my my philosophy because you'll never know if something that's fatty eventually composes of some tissues that could end up potentially being hard and become cancerous. So, always a good recommendation to just go and have it checked. Whenever in doubt, just go and have it looked at or um double checked. So, mamograms obviously are breast x-rays and they're done yearly, right? So, of course, because you're using x-rays, they don't want you going every month because obviously x-rays are not good for our bodies. If you're in your late fa uh late 30s, you can have a baseline mamogram. If you're age between 40 to 49, it's done every two years. But if it if you're over 50, it's done yearly, right? Because as you

9:14 increase with age as well, the potential of having it may be greater. So it's important to do it more frequently. Okay. Treatment of breast cancer. So a lumpctomy just removal of the tumor only. A simple masectomy is the removal of the breast tissue only or the so the removal of breast tissue only or breast tissue and some auxiliary lymph nodes and a uh radical maxctomy is a removal of the breasts the underlining muscles the lymph nodes attached to it. This is rarely done as it generally does not improve the outcome. Right? So they tend to try and see if they can just do a simple masectomy. Uh, of course, surgery is followed by radiation or chemotherapy just to make sure if there's any bits of cancer that that's taken away and then

10:00 followup of course because some people tend to uh go back and um so after they've they're survivors some individuals have shown that they can relapse and so back into it again that they actually have the breast cancer. So that constant monitoring is imperative even if you're a survivor just constantly monitor just to see if it you know if it's tried to come back. Uh and of course there's breast reconstruction from the skin, the fats and muscles from other parts of the body. So once if they remove it, they could basically try and build um you know just reconstruct another breast because remember it's mostly made up of fat, right? So and if it's been reconstructed like that, so potentially breastfeeding through that breast probably won't work, right? Because you're just reconstructing at this point with fat and muscle.

10:47 So, if you see over here, right, this is one that's been removed. Okay, here's the other side. Okay, puberty and menopause. So, puberty begins at the age of 8 to 10 for most girls in the United States. Believe it or not, other uh places, and I think it could be diet because other places, other countries abroad, puberty starts a little bit later. for girls here in the US, it starts rather rather early. So, what we're being fed is probably um having an effect on early puberty for young girls, right? Because eight years old is way too early to to start going through puberty, right? Because I mean 8-year-old shouldn't be having these thoughts, right? So, it's it's really really early. Whereas other

11:34 people, other countries, sometimes it starts at 13. Some people start really a really late, 15 sometimes, right? And again, if you're more athletic, it might start later, right? So, if you're usually uh sportive, you know, it might get delayed much later, but here in the US, it's between 8 to 10. That's why they specifically mentioned here for most girls in the United States. uh it's triggered by a rise in um the levels of G&RH because remember G&RH is what stimulates G&RH comes from the hypothalamus which stimulates obviously the anterior pituitary gland remember flat peg to secrete FSH and LH now remember FSH and LH helped us uh or helped the testes basically make testosterone and sperm and so on and so

12:21 forth. Now let's see how they help the female. Right? So again, these are the same hormones that helped the male when they were secreted. Now we're seeing how it helps the females. So the FSH stimulates the follicles, those ovarian follicles, and they then begin to secrete estrogen, progesterone, inhibin, and a small amount of androgen, right? So they help in secretreting. So these FSH help to help the follicles, think F for F, right? So they help the follicles secrete estrogen and progesterone. at PE. Remember what I mentioned the PE? Yeah. So, they help them secrete that the estrogen helps to feminize obviously the body as well, right? To make the body, get the hips um you know like just make the body

13:07 look much more voluuptuous and things like that, right? So, it helps to feminize the body, the effects of the body outside. Sometimes you'll see being indicated estradiol, estrol, right? You'll see it with other names as well. But again, they help the estrogen helps in that sense. Whereas, as you can see, the FSH FSH helps in obviously the um estrogen and progesterone. Whereas, you remember the testosterone was helping with obviously masculineizing the male, the voice, the body, the muscles, you know, the huskiness and so on and so forth. the locker. This is the onset of breast development. Please know these words. There's a reason why I've highlighted them in bold because they'll show up on

13:52 the exam. I will ask you what the lera means. It's the onset of breast development. This is the earliest noticeable sign of puberty when you start to see little breasts starting to poke out. Right? So, this here is the earliest sign that females starting to go through well will begin puberty soon. So estrogen, progesterone and prolactin trigger the development of the ducts and the lo and the lobu what we just saw before in in the female completion of the ducts and the loes is governed by gluccocorticoids and growth hormones. So the growth hormones help to make things grow. Adipost tissue as we saw before the fat help to enlarge the breast. The pop aral this is the appearance of the pubic hairs right so think pp p p p

14:40 p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p pubic hair and auxiliary hair and also with sebaceous glands and auxiliary glands. So these help with you know obviously the androens from the ovaries and the adrenal cortex stimulate this whole process, right? So the hairs can pop up and libido, right? The feeling of wanting to have sex. So again, know these terms, right? So again they're bolded and they're obviously underlined right. So what is that? What is that? So please know these terms. Minara that's the first menstrual period. So again just think Mm. The other one was PP pubic hair right this is the one with the breasts the onset with the breast. So the first menstrual period, right, it

15:28 requires at least 17% of body fat in a teenager. And that's why if you're really athletic as a teenager and you you're a female, it's really you have that mental cycle will come in a little bit later because again, you're burning that body fat and you have much more muscle. Um, and it becomes your the menstrual cycle comes in a little bit later, right? So when you see these young especially like these um you got these track and field runners or these gymnasts right so they normally start a little bit later. So improved nutrition has lowered the age of onset to the age of 12. And as you can see, the more the nutrition, if the nutrition is really, really good, just like here in the United States,

16:14 they pointed out that puberty starts really early, it basically lowers the age to 12, right? And again, in other countries, in Africa, these ages are a little bit later, right? But here in the US, because the nutrition is great, obviously, I mean, the nutrition is great in Africa as well, but there's something about the food that's given here that's creating these onsets to show up earlier than everywhere else around the world. doctor. >> Yes. >> Also account for the obesity because the obesity rate is higher in the United States. >> The obesity. Yeah. The food for sure. Yes. But also the food that's that other countries eat in Africa for example don't have as much um fertilizers and

16:59 they're much more organic. So when you eat more organic food you find that you don't put on as much weight as as over here. And the thing with the US too is that everything is um machine-based from your from elevators to the escalators. There's not much effort in terms of exercise. Whereas overseas, people walk for miles to go and get water, right? So with that as well, you're eating organic food, you're exercising to go and get water. Not that you want the exercise, but you don't have a choice. You don't have a car. So you have to walk miles and miles to go and get water, for example. And then um you're doing a lot of manual labor as well because most uh places are not if obviously if you live in the rural areas you're doing a lot of labor to plant crops and things like

17:45 that needs energy. So you're burning off energy as much as possible. So a combination of poor diet over here, lots of McDonald's, no exercise, going on the escalators is a recipe for disaster, right? Whereas when I was in Europe, um when I was in Austria doing my my uh thesis work out there, I was there for a long time and everyone was biking. People were biking from home to work. Of course, when they got to work, it was a bit different in terms of the uh the sweat and the smell because you're like, "Oh my, you know, this person just woke up in the morning, took a shower, but now they're sweaty because they bike to work." But at the end of it, they maintained some level of physical activity every single day. But for us, it's different. We wake up, we have a huge breakfast, you jump into your car,

18:30 you come, you climb up. Well, thank God at Helenfield students go up the stairs. Other places, everyone's going up escalators. Nobody wants to take the stairs, right? So again, you sit, you have your lecture, sitting down, you're done, you're exhausted, you go back home, you're starving. I mean, go into your car, you're starving, you eat, you get home, you sleep, right? So again, where have we incorporated that much exercise? Whereas in Amsterdam, in the Netherlands, in Europe, for example, people are biking left and right to work and they're exercising every single time. And that's where you'll see they they have much more lean individuals walking around the streets than for us here because we're not putting in the amount of exercise unless you choose it yourself and go to the gym and say, "Okay, I'm putting in that effort to go into the gym." You know, but they're incorporating it all the time. A lot of

19:17 people don't and you know, they care about the environment. They don't want pollution with cars, so they're on their bikes most of the time. So, um, yeah, I I noticed that. So, I tried to get a bike and folks that just didn't work. I ended up on the trains. So, again, you know, it's different lifestyle, but if we are able to incorporate that, it would change our lifestyle a little bit, right? But again, our food as well. Look at the milk when especially when they give the milk to um to the babies. This synthetic milk or the milk from the cows. Those cows have been fed a lot of these antibiotics to keep them a certain way to keep them huge and bulky so we can get more meat from them. The more meat, the more you can feed a huge population. But if these antibiotics and all these

20:04 uh hormones that they give these cows to grow big so they could feed all of us are making them big and they are mammals like us. Imagine what they're making us become. Right? So you'll find that even our young girls have a different type of body type versus other girls who are in Africa. Girls in Africa tend to have a much more slimmer body type. A few in Europe as well have slimmer body types. Here we have much more like larger body types and some of the girls look like like you know young girls are looking like women you and that's why you'll find that some of these men can't even tell the difference that you'll find men are trying to um ask young girls on dates because they think that they they're older right again our onsets so early and again I'm I think it's

20:51 attributed to the food we're eating uh the lack of exercise just so many things. So, if you're going to drink milk from here, try and see. Again, organic milk is a luxury. It's great when there's no antibiotics, but if not, boil it. Maybe that will kill some of those um hormones that are in there because they're protein. So, boil it and cool it down, right? Do that. Yes. Do we have a question? Okay. All right. So um if the body fat and leptin levels drop too low the gonados secretion declines and menstrual cycle basically seizes. So this is just telling you why um if the body fat is less the menstrual cycle

21:37 basically becomes less. The reason why the body the body fat has to be there because it helps that uh that young girl through pregnancy right you can't have this really skinny person or you know like trying to carry a baby becomes much more dangerous. So the fat also is important and that's why we also increase in size women increase in mass size uh in terms of fat adding on some fat so that you're able to sustain that pregnancy period right and so of course if that fat drops biologically it's a way that the body is just trying to protect the individual because obviously if you continue with having um you know releasing a lot of these eggs and um and having trying to have a baby when you're really really as skinniest it becomes a a little bit dangerous, right? So, you

22:23 have to be able to at least accommodate the baby that's coming. Okay. Girls begin ovulating regularly after a year after they begin menrating. Okay. [clears throat] Climaticus. This is the midlife change in hormonal secretion, right? Which is accompanied by menopause. So, you're going through this climatic stage. That's when the menstrual cycle basically sees. So, females are born with about two million eggs. And that [clears throat] peak arrives when things start to go downhill, right? When you have about a thousand follicles left, this is when you're peaking probably in the ages of 45, 40, 45 going up to 50s, you're starting to have less follicles.

23:09 You can start counting them. You have about a thousand left. And from then, it's starting to go down downhill. meaning and then that's why a lot of women start to panic around that stage of a thousand follicles because now they know that they beat they're trying to beat the clock now because obviously they're losing a follicle each month. And if that egg does not fuse at some point with a sperm, it means that there's a possibility you'll have no follicles left or that woman will have no follicles left and basically there's a loss in a chance of having a baby, right? So women obviously try to freeze their eggs now because they know if they're running out of time, right? They'll freeze them and see if later on if they find a mate, they can basically have the um the eggs fused with the

23:56 husband's sperm at that time and have invitro fertilization. But because again, you're running against the cloth and the this um these type of procedures are expensive. They run around $15,000 and sometimes there ads online that tell you, well, you can get it for for 10 and then when you get there, by the time you do everything else, it comes around about 15 to 20 grand. It's a lot. It's expensive. Are cheaper overseas, by the way. I think in Europe it's cheaper. In South Africa, for example, it's a little bit cheaper. So, you know, but again, who's going to fly out there? Do people have relatives out there to allow them to basically do it? So sometimes these places will encourage females to collect their eggs earlier, you know, but which 20-year-old believes that they will not have a partner by the time they're 40, right?

24:42 Nobody's thinking like that. Everyone's hopeful. So everyone thinks, well, by the time I'm 40, I'll be married by 25. And before you know it, it's 30. And then when you're 30, it's like you're 35. And then that clock starts clicking. But they've always said the best eggs are always when the female is younger at the age of 20 versus at the age of 40, right? Because the eggs start to get, for lack of a better word, so excuse the the language, but they get crappier as that time proceeds, right? The best eggs are in the in your 20s and they start to get um they they're not the best as you get older and older. And the reason why it's because obviously when mitosis happens, those old eggs are not really the best when it comes to dividing into half or when you go through meiosis and

25:28 sometimes they'll take on an additional chromosome and you see some autism like disorder starting to develop. Right? So again, these are things that they, you know, nobody thinks of before when they're in the 20s because everyone is hopeful that they'll meet a partner later on, right? But again, that depends on whether the person wants to have kids or not. Okay. So, um the follicles. So, a woman's born with two million eggs. And of course, you have about a thousand left afterwards and then it starts going down now, right? 99 98 I mean 998 and so on and so forth. So, the follicles are less responsive to these gonadotropins. They secrete less estrogen and progesterone. The uterus, the vagina and the breast start to atrophy as well. intercourse becomes uncomfortable. So

26:14 they're just basically mentioning what happens when a woman starts to go through menopause. Vaginal infections are now more common because again remember those the inner lining of those the vagina doesn't probably have as many of those luccoytes macrofasages to do that to protect the skin also also becomes much thinner as well. Cholesterol levels rise so now there's an increase of cardiovascular disease. bone mass decreases, right? So, there's now an increase in osteoporosis, right? Which means bone mass uh basically decreases. Why is bone mass decreasing? Well, if estrogen levels are less, right? They've connected estrogen with bone mass. If you have estrogen, you can

26:59 have stronger bones. But when estrogen levels start to decrease, you end up having uh osteoporosis, right? And that's why women tend to go through osteoporosis really really greatly because there's a decline in estrogen. And the decline in estrogen means bone mass basically declines. Blood vessels constrict and they dilate in response to shifting hormonal balances. That's when you see women having these hot flashes, right? So dilation may produce hot flashes. Spreading sense of heat that's going from the abdomen to the thorax to the neck and face. Right? So they have a lot of hot flashes. Um women can have this hormonal therapy replacement right so hormone replacement therapy this is low doses of estrogen and progesterone right because remember the follicles

27:45 were responsible for secretreting that if you remember PE physical education they were responsible for um secretreting that now that you have no more follicles right you're not producing the estrogen everything's going downhill right so the weight gain body mass basically decreasing I mean the body uh the bone mass decreasing having this osteoporosis is so I mean think about everything just going wrong. It's like such a sad case where women woman once had all this great things going on now all of a sudden with everything's decreasing right vagina uh uterus breast atrophy intercourse becoming uncomfortable and vagina having infections the skin becoming thinner and then obviously cholesterol rising so now this cardiovascular uh disease after having a baby that weight have

28:31 struggling to take it off bone mass basically declining osteoporosis you know so and then the hot flashes, right? It's really really sad that our bodies start to break down at that late age. So, they found that if you try to give um estrogen replacement and progesterone, obviously because the the follicles aren't replacing it, it basically might help, right? So, again, these are still being debated on whether they help or not, but they are trying to state that it could replace or help in terms of the bone mass decline. It could help maybe in these hot flashes because it all started when these follicles basically got you know stop secretreting the estrogen right because again remember when the follicles spit out the ovary I mean the um the egg they will basically

29:19 um the corpus lutium will continue uh putting out estrogen and progesterone. So menopause that's when the menstrual cycle seizes. It usually occurs between the age of 45. That's really early and that sucks if it comes that early. Really, really bad. 45 and 55. Age of menopause has obviously increased in the last century, right? So the menopause was considered complete when they there was no menstrual cycle for a year, right? But say menopause has basically kicked in. So the theory basically was that older women would not live long enough to basically rear an infant to a survivable age. And that's why the system so the theory was that you know there was no

30:05 need for a woman to keep ovulating and making more eggs if back in the days the um the longest they would live was up to about 40 years old. Right? So clearly that lifespan didn't accommodate or take care of the fact that we're living longer now because of medicine, because of food, great food and stuff like that. the world histo you know um the history of it basically is that people would die early at 40 or 50 so you know stop everything by then and that's why they believe that menopause kicked in roughly about then so they've looked at obviously ice age skeletons that showed the um early sort of human skulls that were there and human bodies

30:51 and they found that a lot of them rarely lived past the age of 40 right so menopause may be an artifact of modern nutrition and medicine which is allowing us to live longer than our ancestors. Okay, we're now going to look at or ogenesis and sexual cycle. So the reproductive cycle is a sequence of events from fertilization to giving birth and returning to fertility. So the sexual cycle events that occur every month when pregnancy does not intervene. Right? So this is going to happen every month. So it consists of two interrelated cycles that's controlled by shifting patterns of hormone secretion. So there's the ovarian cycle. These are the events that happen in the ovaries as we saw with those follicles basically um

31:38 you know trying to release the egg and so on and so forth. And then you have the menstrual cycle, right? This is the nursery in the uterus being shredded or getting rid of it because obviously baby has not come along. So these obviously these changes run parallel, right? meaning no fertilized eggs, get rid of the nursery. Oogenesis again notice how I've boldered that name, right? Means egg production, right? So we'll ask you in your exam, what is oenesis, right? So think of genesis as in the beginning, the making, right? Oo is the egg, the o. So oenesis produces hloid gametes by means of meiosis. Why hloid? Why half?

32:25 Hello. >> Because we need the other half from the the father. >> That's right. Yes. So, we produce half because we need the other half coming in from the father. You don't want to send a whole one there. So, as you saw, it was the same thing with the males, right? The males ended up making half. Uh, it's distin distinctively cyclic event that normally releases one egg each month. Yes, we saw that. It's accompanied by cyic changes in hormonal secretion. And um so the uterine changes result in monthly menstrual flow. Okay, let's look at this. Um embryionic development of the ovary. So the female germ cells arise from yolk sacks. They colonize the gonodal regions the first five to six weeks of development. So this is just talking about in the you know after the

33:13 paramisic site is made how do we get this all this going on right? So they differentiate into orgonia and they multiply until the fifth month to six to seven months in six to 7 million in numbers. So they're showing the stages now in how these eggs basically come about. Right? So these eggs will transform into primary oytes. This is early meiosis one. Most of them will degenerate by the time the girl is born. And then the egg or the OAM will be the any stage from the primary oite to the time of fertilization. And then by puberty, we have about 200,000 oites that remain. So

34:00 there's a lifetime supply, but probably they will only ovulate about 480 times. So we're going to go to that image soon. Okay. So this this is what um that um those couple of slides were talking about. So in the beginning so the development of the egg, right? So you start off first with 2 N right? So just like with the male you have the 46 chromosomes and then obviously the primary that egg becomes a primary oite. this primary oasite now. So this is at birth. So you start making a lot of these eggs that live in the follicles

34:48 adolescence to menopause. Now what happens to the eggs? So this primary oite right basically goes under under goes meiosis one. And meiosis one as you know is just splitting the eggs into half. So we're getting rid of half of that DNA. So once that happens basically you'll see that this 2 N just becomes N that becomes the secondary O site right so remember when we saw that primary to secondary to tertiary O site those were the stages that we saw in the follicle I mean in the ovaries but they're just showing you the steps of what's going on in terms of the DNA being haveved. So here as a primary oite it's in the

35:35 here in the follicle in the primary follicle when we spoke about the secondary oite here it is as well right in the secondary oite. So to go from primary to secondary the difference basically and why we call this primary and this one secondary it's because we've gone from the 46 chromosomes to 23. We've h haveved it now. So that's how we went from 46 to 23. That's why you only see n here. So what happened to the other chromosomes? Well, they were put in here in a polar body and that's how they sent them off to die, right? That's how they got rid of the other ones. So this secondary oite, right? So the sec uh so the secondary oite can now fuse with the sperm as you see over here. And once they fuse, right, will go

36:21 through meiosis 2, right? So when they fuse, we'll end up having obviously the zygote. So this here is just showing you that if you don't fuse the sperm with the egg, it dies. But if you fuse it, 23 from the male, 23 from the female will end up giving you the child that has the 46 alto together. And then these are just the steps alongside it what we saw before that obviously ovulation is when the egg comes out and then what's left is the caucus lutium. Right? So what's the take-home me message with this slide? This slide basically is just showing you that at birth you build up those cells, right? Those primary cells that have the 46 chromosomes. And then from adolescence to menopause, meaning

37:06 now when a woman is active now and can have their menstrual cycle, a woman can have her menstrual cycle every month, what happens to the egg? So the egg basically has to get divided into half, right? because you want to be ready in case a sperm arrives to fertilize. And what happens basically is that if the sperm doesn't arrive, it dies, right? And then if basically a sperm comes, it will fuse with a sperm and the sperm brought in 23. The egg has 23 and that's how you end up having 46. And you call that now the zygote. So this is just showing you how the follicles look like. Right? So in the

37:52 beginning these were those primodoro follicles and they ended up becoming the primary oytes, secondary oasite and so on and so forth. Right? So sorry the oite were inside the um the follicles. Okay. A couple of names, right? So follicle genesis means obviously as the name states development of the follicles around the egg that undergoes oenesis right the primodora follicles these were the beginning in early meiosis they're the ones who were um in the be so they're the ones that wait 15 to 30 years before they develop further this is where we're going to pull all the other um follicles from

38:38 primary follicles they are recruited right so So they recruit these primadal follicles. So again, primodoral follicles, primary follicles, secondary follicles, and so on and so forth. That's the trajectory, right? But we've seen this already. This is what I was showing before. Let's just go back. They're just labeling them now. So if you look at the image here, right? Remember these guys, the primodor primodial follicles get converted to primary follicles to

39:24 secondary to tertiary to the mature ores. They're just going in steps to mention what they are. Okay, tertiary oytes, right? They appear after 60 days before ovulation. So mature um oytes, so the mature, sorry, mature follicles, these are the ones that are ready to basically ovulate, right? So these are the ones that are destined to come out and ovulate. So about 20 days before ovulation, one follicle becomes dormant. the other one's destined to ovulate. So

40:10 basically it will come out it captures and holds FSH and um it's about at about 5 days before ovulation it's large enough to be considered a pre-obulatory follicle. Right? So this is the one that's basically going to come out. Okay. So the sexual cycle the sexual cycle averages 28 days. So it varies between 20 to 45 days. The hormones from the hypothalamus regulate the pituitary gland. We know that already. The pituitary gland regulates the ovaries. Remember from flat peg. Ovaries secretes hormones that regulate the uterus. Right? So the PE the pro progesterone and estrogen. The basic hierarchy of hormonal control hypothalamus. So the pituitary gland

40:57 flat peg. When FSH and LH come out, they go to the ovaries. the ovaries get activated and whatever's left in there those um the corpus lutium will secrete progesterone and estrogen to help out the uterus to help out the little baby who's the o the egg who left so that it can go and grow in the area where it's supposed to. So clearly the ovaries exert a feedback control over the hypothalamus and pituitary gland. So there's a feedback that comes from the ovaries to the hypothalamus meaning stop secretreting anything that's going to help ovulation to happen like FSH or LH that may make more release of eggs because this woman

41:42 is pregnant and we do not want to make another baby right so there's a negative feedback where information gets sent so the more and more the ovaries secrete estrogen or progesterone for example like hormones they're going to send a message back to the hypothalamus. I think there's an image, there's a feedback image that Here we go. So, if you look over here, the hypothalamus secretes G&R. So, well, they started here. Okay. So, the maturing follicle secretes estrogen, right? Remember the the follicles are the ones that are going to release the estrogen. So, is the corpus lutium. Bottom line is that they secrete estrogen. These homes secrete estrogen and progesterone, right? And what

42:27 happens basically is that when they secrete that estrogen and progesterone because this egg has been released, meaning that it's got potential to make a baby. Now, we do not want maybe another baby to come about, right? So, you could send a negative feedback to tell the hypothalamus and the pituitary gland, this woman's going to have a baby. We don't want to make another baby. So, hold things on your end. So what can happen basically is that as estrogen gets secreted from the follicle right or the corpus lutium for example it's going to get sent back to the hypothalamus. So estradi or estrogen stimulates the hypothalamus and anterior pituitary gland. So these guys basically they're usually secretreting FSH and LH

43:13 right that's what they secrete and when they secrete that basically it allows so the G&R and estradi stimulate the pituitary gland to secrete that okay we just spoke about that the oasite completes meiosis one this okay this is just showing us that this is the process that happens but if you want to inhibit any more eggs from happening you will have to send a feedback loop to stop this um hypothalamus and the pituitary gland from continuing this process otherwise you'll keep secretreting egg after egg after egg after egg right so you can send a negative feedback loop back to stop this process so I thought this images were showing us that but this is just showing us that um this is the cycle the normal cycle but you can inhibit this cycle as well so we'll look

43:59 at that afterwards okay let's go back okay so the ovaries can secrete can exert a feedback control over the hypothalamus. So the ovaries have the power to do that once that egg has been secreted. Maybe they can send back a message at some point to say stop making uh this woman is pregnant. And that's what the pill works on by the way. The pill takes advantage of that feedback because it knows that the ovaries send message back to the hypothalamus. So what the pill does is by giving more and more estrogen the pill gives a negative feedback by telling the hypothalamus we have enough. we have enough, right? So that we don't keep stimulating egg release, right? And that's why when a woman's on the pill, they're able to basically um they they won't be able to

44:46 ovulate or have uh or get pregnant if estrogen keeps getting supplied because that negative feedback loop happens. And that's what that's what happens during pregnancy. During pregnancy, a feedback loop is sent to the hypothalamus so that you don't make any you don't release any more eggs, right? So the ovaries is telling the hypothalamus, please don't release or please don't send any more additional hormones that will push it pathway into releasing more eggs. I'm pregnant. I'm pregnant. I do not want to make another child while I'm pregnant. Right? So estrogen, the pill does the same thing. It fold it um it tricks the body into believing that the body is pregnant by by giving more and more estrogen so that the hypothalamus doesn't continue this pathway.

45:37 Okay. Um the cycle so here the sexual cycle they're showing the cycle begins with this two week follicular phase. So the men ministration occurs during the first 3 to five days of the cycle. The uterus replaces lost tissue by mitosis and cohorts of uh follicles growth. Ovulation happens around day 14. So folks this is just showing you the path in how basically um the sexual cycle of a female happens right so you have this primary then secondary tertiary right and then you have the ovulation right and that's why here on day 14 ovulation when that egg is out right this is usually regarded as a time where um you have a high chance or woman also has a

46:23 high chance from this period on in having a baby right so after the menstrual cycle Of course, these are known as safe days because obviously the egg has not been released, right? So after the menstrual cycle when you start building brand new eggs over here out of the follicle, this is regarded as the safe period because this is known as the follicular stage. This is a stage where the follicles are growing, right? They're growing so that we can from primary, secondary, tertiary. And what does that mean? We're going from um double the amount of chromosomes to half the amount so that we can spill out the egg. And once the egg comes out, obviously this is the perfect stage because that egg now will be swept into the fallopian tube. Sperm is going to come in and fuse with that egg, right?

47:10 And then after a while the lutil phase now this is a stage where now the corpus lutium will now start secretreting progesterone and estrogen because by then this egg has is starting to dis has starting it's starting to go right down to the um the uterus right and implant itself. You want the body, you want the uterus to keep growing that nursery so that the baby can continue living or living in that nursery because the minute that that nursery stops and there's a baby there, that's how the miscarriages happen. Now, where everything starts to um slosh off because the the lining of the endometrium basically is shredding and of course this corpus lutium gets

47:57 old as you can see and it becomes old like this, right? And then the process starts again where these new follicles start making these promodora follicles start making the primary oy and we continue on right. So here right at ovulation you have a spike of LH the luteinizing hormone. Of course the spike is really high because this is being secreted from the hypothalam I mean from the pituitary gland right? So there's a high spike of LH at this stage. So I wanted to give you a visual with that but let's go back to the images I mean to the wording. So cycle begins with two week follicular stage that's this right. So two weeks means 14 uh 14 days right. So the cycle begins with a twoe follicular phase. Menration

48:43 occurs during the first three to five days of the cycle. Right? So just lost my right. So the first stages right when the woman's menrating ovulation is around day 14 and then the remainder of that follicle becomes the corpus lutium right so the remainder of it once the egg has spilled out becomes the corpus lutium in the next two weeks the lutial phase is about obviously the corpus lutium what's the role of the corpus lutium why did that corpus lutium right what's its responsibility as I head. So that corpus lutium

49:30 that corpus lutium will continue now to secrete progesterone and estrogen. And why is this important? Why does it have to keep secretreting progesterone and estrogen once the egg has gone out? Sorry, I have to keep going back and forth so you could look at the image. So what the corpus lutium does when it secretes progesterone and estrogen is that it stimulates the endometrial the t the the cells there it stimulates them to thicken up. So when they thicken it's preparing the nursery because again remember [clears throat] it's the one that got information that the egg has been released. So it has to send a signal out to the uterus so that the uterus can start creating the nursery because baby is coming and baby has to

50:17 grow in that nursery. So that's the role of the corpus lutium to secrete progesterone and estrogen so that that progesterone and estrogen can make the can make that lining in the nursery start to grow the endometrium start to thicken the uterus to start thickening. If pregnancy does not occur, this lining breaks down in the last two days. And that's what becomes the menstrual cycle because obviously there's information that comes back that I'm sorry, baby's not here. This woman's not pregnant. Get rid of the place. Get rid of uh get rid of the nursery. And that's how ministration cycle uh basically starts again. I mean, the min cycle uh begins and the cycle starts again. and I'll explain and we'll see an image that shows us how do we get the message back

51:04 to back telling us that there's no baby that's there right and that's what you'll hear of hCG hCG is something that heard of that these pregnancy kits test right that's what gets secreted by by the um the baby that's coming about so in yes so there's a question coming up is this a process that happens in miscarriage It could be if there's no feedback getting back to the ovaries telling the ovaries that this baby uh there's a baby here. So if there's no communication with the ovaries because again remember so Marie asked if this is the this is what happens if uh if miscarriage right so is this a process in miscarriage it could be one of them because obviously you'll see when I show

51:50 you that image that would tie it all up together that there's no information going back to the ovaries telling the ovaries that keep secretreting um keep secretreting the progesterone and estrogen because they have to keep secretreting it for the nursery to continue developing as it should. Okay. And then there's the ovarian cycle, right? This is the three principal steps, the follicle stage, the ovulation, and the lutal phase. So this cycle reflects what happens in the ovaries and their relationship to the hypothalamus and the pituitary gland. So, when I was talking about that negative feedback loop, it's just talking about how are they all working together to let the body know this woman's pregnant, don't make any ovaries, don't make any more eggs or

52:35 don't release any more eggs. Um, you know, keep it at a hold for a year. And that's why one doesn't have their period for that whole the whole nine months, right? Because obviously there no eggs being secreted. Therefore, there's no nursery that needs to be broken down. So, the period is not necessary, right? So, you have to it all begins at the hypothalamus, folks. So you have to let the hypothalamus know do not have this process continue because this person is pregnant. Okay. The follicular stage. So when you look at the follicular stage, this is the first. So they're just walking us through this phase right in detail, right? The follicular stage. What happens? So you'll see here you notice there's

53:21 FSH, right? So these are the hormones that are coming from obviously the pituitary gland flat peg remember. So these hormones when the hypothalamus tells the pituitary gland to secrete FSH and over here you see LH spike up here. So these two obviously they're responsible for this process. So when we talk about this follicular stage over here let's talk about it. So this extends from the beginning of the menstrual cycle during or up to ovulation of course. So during ovulation because ovulation happens at day 14. This basically includes the pre o uh ovulatory phase from the end of men uh menration until ovulation. This uh this

54:06 is this most variable part of the cycle. Seldom possible to predict the date of ovulation. So sometimes it's hard but everyone tends to gauge with numbers like from day 14 to day 17 for example or from day 13 right so you ballpark with a couple of of days right never smack in the middle for day 14 always it might shift it might be day 13 or day 15 so always ballpark it as you maybe two plus or two minus on that date. So what does FSH do when FSH arrives? So if you go back again, remember FSH, why was FSH released from the anterior pituitary gland, FSH basically stimulates the follicles to grow, right? As we saw before, the

54:51 you know like we need the follicles to grow so that what can come out the egg can basically get secreted because again remember the follicles have to grow from primary to secondary to tertiary and then spit it out. Right? So FSH stimulates the follicles to grow. And this is why when you don't have these hormones coming from the anterior pituitary gland like FSH, how are you going to end up how is this individual going to end up having a baby? Because you need FSH to start this process of the follicles growing because they don't they don't grow just by themselves. They have to be they have to be told when to grow, right? So every month obviously FSH is released from the from the brain from the anterior pituitary gland that tells the follicles to start growing and

55:37 when they start growing they also release estradi right remember the follicles release estradile and then of course when they become the corpus lutium they're releasing progesterone as well right so these guys are important because their houses or their homes that secrete these hormones So a dormant follicle becomes increasingly sensitive to FSH and LH and estradi. Right? So these guys are obviously sensitive to it. So a dormant follicle has rich blood and a large number of FSH receptors. So it becomes obviously a pre- o um ovulatory follicle. Bottom line folks, it's just telling you that that follicle is waiting for dear life

56:22 once it's asleep. that when that FSH comes along, it's basically going to activate it because it wants to go through primary, secondary, and tertiary. It wants to do this, right? As it should, right? So, it's waiting for that gush of it. So, clearly it has receptors for this FSH. So, we spoke about FSH and FSH is responsible for what? Getting that follicle to grow from primary to tertiary, right? And then spitting it out. What about LH? Right. So, ovulation is the rupture of the mature follicle. So, once that FSH has done its job, that follicle basically goes from primary to tertiary and it's going to get spitted out. Now that it's spat out, right, the release of its eggs, right? It comes out

57:09 typically around this day of around 14 estradile because again remember estradi is coming from the follicles, right? This is going to stimulate a surge of LH. It's going to stimulate LH to basically spike or a lot of it to basically get secreted right by the anterior pituitary gland. So what happens basically is that so let's see if we can draw this. So from the pituitary gland we have two things coming out. FSH and LH.

57:59 So what FSH does is it comes it goes to the follicles and it helps these follicles go from primary to secondary to tertiary until spits out that egg. Right? So let's do a blue egg. Right? Finally it spits it out. So we need the FSH to help those follicles grow so that the egg could come out. And that's why without these without [clears throat] flat peg, without the anterior pituitary gland, a woman cannot conceive. It becomes impossible because you need that FSH to help that follicle to grow from primary to secondary to tertiary to mature thing that spits out the egg. Right? So once it's growing like this, it's also going to be secretreting estrogen. Right? As

58:45 it's growing, it's spooling out estrogen, right? So, estrogen is coming out. I don't know why it's not writing. Okay. Estrogen is coming out as it basically matures, right? So you could see here it says or estradi they call it estradile. So estradiol basically gets secreted from the follicles. Right? Remember it's going to continue secretreting estrogen anyway

59:31 when it becomes a corpus nutium when it gets you know once the egg releases. Right? So here when the egg releases let's draw the corpus lutium. Okay. So once once it comes out it becomes a corpus lutium. Let's see if I can get my marker again. It keeps kicking me out. Okay. So here's the corpus lutium, right? So the corpus lutium and then it becomes a corpus alburn, right? Which is which is old. And remember these guys continue secretreting estrogen. And what's the

1:00:17 other one that the corpus lutium secretes? PE >> progesterone. >> Hello. Progesterone. Yes. So it's continue secretreting estrogen and a new one progesterone. Yes. But in the beginning this follicle has already started that process of secretreting a little bit of estradiol right progesterone because it needs it for this process. So what happens basically is that estradiol then stimulates a surge of LH. So estradiol basically as you know estrogen always goes back to the pituitary gland. That's why I spoke about that feedback loop with the pill right? So estrogen likes to go back. So here, let's pick a color. Let's do that. Yep. So estro estrogen estradi

1:01:04 tells So this estradi tells obviously LH or the pituitary gland to secrete more of this LH, right? So the LH now a gush of it comes in at day 14. That's why you saw that big spike of LH, right? So estradiol stimulates a surge of LH and a lessened spike of FSH by the anterior pituitary gland. So in a way it's almost saying look FSH helped to make the follicle. We made the follicle and clearly we got to the stage where this cell now has basically this follicle has matured over

1:01:50 here. But in the process of it doing that as it was rolling from primary to secondary to tertiary and becoming big, it was secretreting estradiol and that estradi is almost like a messenger that was being sent right. So, let's use a messenger that's been sent to >> the messenger that's been sent to go back and tell the anterior pituitary gland, hey guys, we've reached our final destination right here, right? Because now ovulation has taken place. We have we don't need as much FSH. I've already grown up. Thank you so much. I've gotten to the stage where I've secreted my egg. Now, can you do me a favor? Can you lessen make less of the FSH, please? because I don't need it as much anymore because I'm grown now. Can you make more

1:02:36 of LH? Right. Make more of LH. And now that I'm I'm at this stage over here because I've now spat out that um egg. So here the a bunch of this yellow the LH basically pops up. So what does this LH do? Right. So LH basically helps in just finishing things up, right? So the LH induces se several events. What happens basically is that egg that primary oite completes meiosis one producing the secondary body. So remember how we spoke about going from 46 to basically getting down to 23. Right? So it helps with this process of going down from the 46 to getting it down to

1:03:21 23. Um okay let's move on. So again, what do I need you to know from here? What's underlined? Right? Ovulation, rupture. But I'm going into detail a little bit just to tell you why is it doing that, right? But know that obviously ovulation is the rupture of the mature follicle and release of the egg and the tendon cells. And then estradi stimulates LH, a spike of a huge spike of LH. Where did the estradi come from? Remember the follicle was secretreting it, right? So that's what created the the stimulation of LH to go back to tell the anterior pituitary glands to slow down on the release of

1:04:10 FS but keep producing a lot of LH. Okay. So this is what we just saw before. They're explaining the same thing, right? So the follicles. So again, the mature follicle as it starts to get to the third stage as I was drawing and it's about to spill out that egg, right? It secretes estradile. Estradi comes and tells the um hypothalamus to release obviously because you always have to go to the hypothalamus, right? Or you can go directly to to the anterior pituitary gland. But what it's trying to tell it is listen, I'm already grown now. Please make less FSH and send out more LH. Right? So what's the LH going to help us

1:04:56 with now? Because the FSH was all about follicle. Remember F for F. Right? FSH helps the follicle grow. Right? LH now is about basically. So here the oite completes meiosis one. The follicle rapidly enlarges and then it ovulates. So now it's about basically getting that egg to the stage where it's ready to become half the amount of DNA in it so it could fuse with the other sperm coming in. So this is just the pathway. Ovulation takes only two to three minutes. There's a steep there's a stig uh the stigma steep follicular fluid for one to two minutes. The follicle burst. Yes. Yes. We know that. Good. Let's move on. The uterine tube the fallopian tube catches the oite. it swells up with edema and the the fingers envelope and

1:05:45 caress the ovaries in synchrony with the woman's heartbeat. So every time it goes boom boom sweep boom sweep boom sweep. So they're just telling you how these fingers basically help to sweep um to sweep all the the to sweep the egg to go to the fallopian tube. So couples that are attempting to conceive a child or of course avoid pregnancy may wish to know when ovulation occurs. So the cervical mucus obviously becomes thinner and more stretchy. These are hints right if one is starting to ovulate. The resting body temperature rises right from four degrees from 0.4 degrees CC to 0.6 degrees uh degrees Fahrenheit. That's why you'll find that individuals buy these kits that help to measure their

1:06:31 body temperature so they know when's the best time to basically have intercourse and have that baby because the temperature rises. The best measured first thing in the sorry it's best measured first thing in the morning before rising from bed and it's recorded for several days to see the difference. Mism is the twitches of pain at time of ovelation. So when women sometimes ovulate, they always feel this pain or this twitches and that's how one knows, oh, I'm ovulating. I'm getting closer to having uh my periods afterwards. So ovulation, that pain is a sign that you're ovulating, right? So this is a good signal for times to avoid intercourse if you don't want to have a baby. And of course, it's a time to know that you're ovulating when those pains happen. But they always happen like

1:07:16 right before like maybe two weeks before before um the menstrual cycle, right? So maybe a week and a half towards it. It's an indication, uh oh, I'm I'm going to have my menstrual cycle soon, right? Or that's a time when you know ovulation is basically happening. Please know that word because it's going to show up on the exam, right? Again, know what's underlined, what's bolded because these are signs and potentially what's going to come up on the exam. The best time for conception, it's within 24 hours after the cervical mucus changes and the temperature rises, right? So 24 hours after Okay. So after ovulation you have the lutil phase. This is on day 15 to day 28. That's the last stage that we saw

1:08:02 over here. Okay. That's the last stage. So if pregnancy doesn't occur, events happen as follows. The follicle ruptures. It collapses and bleeds. Right? And then the clotted blood basically is absorbed. The uh ovulated follicle has now become the corpus lutium. Remember because the egg came out, right? It's named for its yellow lipid that accumulates inside it. Now they call it lutein cells, right? That's why the corpus lutium looks like that. So the transformation from a ruptured follicle to the corpus lutium. So once that egg spills out from the follicle to

1:08:47 the lutium is regulated by the LH. Remember that's why we needed that spike of the LH. The LH helped that process of that egg going from from um having double the amount to half the amount because we needed it for the sperm to fuse. And also the LH basically will help the corpus lutium, right? It's going to be responsible for it. So pretty much FSH and LH FSH takes care of the first stage up to day 14 helping the follicles basically mature from primary to secondary to tertiary right and while it's doing that it sends a signal by

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