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BIOL 3324 Human Physiology - 3324_lecture26_1202
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00:02 Yeah. Okay. It looks like turned on. I think so,
00:09 least. Yeah. Hopefully this will lecture record. If you didn't
00:13 lecture from Tuesday, didn't record. go find another older semester. I
00:19 about the same thing every semester. just funniest in this semester.
00:25 um, today's the last day of . Yay. Ah See that's that's
00:32 you get an A in the class you Oh man. Um Just a
00:39 . I know some of you are to forget. So put it
00:41 your phone's turning on the alarm. it triple important. Whatever your views
00:45 due at midnight tonight. Get them . Alright. That's a good way
00:49 lose points that are easy to Right? So get them done.
00:56 , so today, what we're gonna is we're going to talk about uh
01:01 itself. We've spent our time we at the male reproductive system. We
01:06 out what it's supposed to do. is the male reproductive system supposed to
01:11 ? Make sperm deliver sperm? What And then we talked about the female
01:14 system was the female reproductive system responsible everything else, right? Kind of
01:20 real life. Right? And so we're gonna do is we're gonna take
01:24 two systems and understanding them and then gonna look at the process of how
01:28 go about reproducing. And again, just gonna reiterate this is not a
01:31 talk. I mean, this is the extent of the sex talk right
01:35 . The sexual response cycle. And so we talk about this because
01:40 sexual response cycle is how we get this stuff going downhill to happen.
01:46 right. And so when we say response, that's the anatomical and physiological
01:50 that occur that stimulate the reproductive Alright. And so both sexes have
01:57 exact same stages. They go through exact same stages maybe at different rates
02:01 different speeds. All right. But idea is that there's these four
02:05 the first stages excitement. Then Plateau. Is that small period of
02:09 just before orgasm. Then you have and then you have resolution.
02:15 So in essence, to go from to the next, there has to
02:19 some sort of stimulation that's going to you from one to the next.
02:23 right. And so it's this continuous . So you go from excitement to
02:27 . But if you remove the then you'll fall back to excitement and
02:32 eventually to non arousal. And so the idea is that you're constantly moving
02:37 a result sexual stimulation through these stages orgasm is reached. And then you
02:42 into resolution. Now, here's the thing and one of the reasons why
02:47 spend more than 30 seconds just mentioning is that females do not have what
02:53 have. Well, technically, that's , but at the end we have
02:59 resolution period. Men have what is a refractory period. Females do not
03:04 this and what the refractory period is this period of time where in
03:09 , there's no amount of erotic stimulation can cause you to return back into
03:15 sexual response cycle. Right? So a short period of time now,
03:20 period of time Is going to be upon age. So the younger you
03:25 , you can return quicker into the . But as you age, it
03:28 more and more difficult. Which makes because really the reproductive years or the
03:32 years, even though males can reproduce into their 80's and probably even
03:39 Um but the idea here is that basically is this period of time where
03:44 you have orgasm and then you go resolution and you're stuck there and then
03:49 done. Whereas women can actually go orgasm to resolution back to plateau orgasm
03:55 . They can literally stay in that indefinitely. You know? Um So
03:59 just one of these uh unique Now, there's lots of stipulations or
04:05 hypotheses why this occurs. Um and really not important. But if you
04:10 to talk about it, we can what's interesting is that, so what
04:15 can go through these constant cycles that stopped. It's interesting. You
04:20 you know, everyone's like, all , I'm all about orgasm, but
04:23 interesting men, when we go through response, go through great refraction and
04:29 all over again. Each subsequent orgasm a decrease in pleasure, which is
04:34 driving force as to why we do , but also less semen during
04:40 And so there's actually a finite amount semen that's actually reserved. And so
04:45 you do, it's like about four . I think it's like three ejaculation
04:49 how much semen we haven't reserved. it's not like we're going to do
04:53 each ejaculate Instead. It's like you your first the jacket and the next
04:58 like, yeah, we're not gonna you so much sperm this time.
05:00 so you're gonna get like maybe 50% then you're getting 50%. So it's
05:05 even less and less and less as go along now. Why that happens
05:09 ? Well, how long does it to make sperm? About 80 days
05:14 while you're making 80 million a if a normal ejaculate is somewhere between
05:19 and 500 million, you know, gonna take you about three days to
05:24 enough sperm to be able to produce full ejaculate again. So,
05:30 you can kind of think it's a if again, if all the job
05:34 a male is is to make sperm deliver sperm if they're delivering all their
05:38 , then they've lost their jobs. that's kind of the rationale behind
05:43 or at least the biological rationale whether not that's true is something entirely
05:49 All right. So what we're gonna is we're asking the question is
05:53 How do we make a human. so really that sexual response cycle is
05:59 is really there? That's the population that we can bring these two gametes
06:05 . Alright. And so obviously in Mail, we have an ejaculation.
06:09 , you do not need to have orgasm to ovulate. In fact,
06:12 orgasm is kind of a bonus to to sexual congress. I'm gonna use
06:17 word Sexual congress. It's a fun . Picture all these people walking around
06:23 and stuff and harrumphing a lot. right now. All right, So
06:29 is what we're shooting for here. . And so what what we're dealing
06:33 is we're bringing that over, um ovulating over which only occurs once per
06:37 . So, it's a very specific within that 28 day period, when
06:42 oocyte is going to be released. . And what we're gonna do is
06:45 going to try to bring that with sperm and bring them together. All
06:50 . So, we're gonna be restoring deployed number of chromosomes that we brought
06:53 at the beginning. This deployed chromosome going to have either X from the
07:00 or Y from the mail. Always X from the female. So,
07:02 determining sex of the new organism at point, and we're going to initiate
07:06 metadata program. So, there's a bunch of stuff that's going on
07:11 Thanks. Remember how I said things kind of complicated. Alright.
07:15 the first step is we're gonna have activate the sperm which is the process
07:20 that activated sperm is going to have break through these protective barriers that are
07:24 to protect the oocyte. You're going have to have the sperm on the
07:28 side actually recognize each other. They recognize each other, They can't
07:33 And remember in the epidemic we added these proteins so that the oocyte can
07:38 be recognized in the first place. in fact this is one of the
07:42 interesting things. One of the arguments speciation is that if there's this arms
07:47 between the oocyte and sperm because they're constantly mutating these surface molecules. And
07:54 if there's a point where they can't that they can't reproduce or be re
07:58 can't produce offspring. So it's kind this interesting dynamic that's going on then
08:04 you get that recognition then you can the two plasma membranes fuse and then
08:08 gonna have to stop any other sperm coming in because you now have the
08:12 complement of genetic material. So any genetic material would be problematic. So
08:17 got to prevent that from happening. right. And then you're going to
08:22 to remember we were we went through is one because that LH surge we
08:26 the search but we still had Miles to to complete. So we've got
08:29 complete that we got to get rid that excess D. N.
08:32 Outside of the other side. And once all that happens then it's okay
08:36 bring the two pro nuclear together. now you have this new offspring.
08:42 . This new organism. So it's ovum and the sperm that are gonna
08:46 fusing now. I think I'm gonna this in a little bit here down
08:49 road. But I want to point out here because this is a really
08:52 picture. All right this is a sperm and mouse oocyte but it's you
08:57 do this as human. How do know? It's well I thought it
09:01 mouse maybe not. It's hard to you mouth sperm are really easy to
09:06 . Mouse and rat have these Alright so you you've seen the picture
09:09 human sperm and human sperm kind of like a tadpole right? Like so
09:14 sperm they look like elf shoes had weird shape to them. So you
09:21 look at a picture and oh yeah a rodent. That's and then like
09:25 why do they do that? I . All right. But what I
09:33 you to do is you see on this is that oh site. And
09:36 you can see those that that Those are the recognition proteins found on
09:41 surface of the oocyte. This is allows the sperm to recognize what you're
09:46 that oocyte. Alright. And you see it's everywhere except for one little
09:50 there's a bald spot. See the spot that indicates that this offspring is
09:55 to be bald in the future. . No, no, Actually it's
10:01 site that says I don't want the to bind at this particular location.
10:07 do you think is on the other of that bald spot? If you
10:13 to guess if you had to why would I want sperm not to
10:18 in this particular area? You can of look at the list here.
10:25 . Membranes, fused sperm are blocked of diagnosis, nuclei fuse. What
10:34 you think? Huh? The That's right. That's the pro
10:41 And we say pro nucleus because remember a half nucleus. It doesn't have
10:44 full complement of DNA. That's where the female or the oocytes pro nucleus
10:51 located. And so you wanted to able to go through its division without
10:56 interfered with by the sperm. So want the sperm nuclei can be anywhere
11:00 for right here where we're doing a bit of work. And so that's
11:03 it separates it out and that kind neat I think in the meat.
11:08 . Yes, sir. No, they're more or less all round.
11:15 wow, I got that super sound . Yeah, no, they're they're
11:20 or less round. It's the sperm is what's unique and it's not every
11:25 has. It's just there's something about rodents that create that weird shape and
11:29 , I don't know why that I should know. I mean since
11:32 do when you do research on you primarily you're not going around milk
11:35 humans. You're Mhm. Basically getting Alright. Yeah. So he said
11:45 right. Basically it is surrounded. a lot there's lots of different proteins
11:51 the surface but some of them are proteins. In other words, there's
11:53 be proteins specifically located not on the but on the body portion of the
12:01 where that interaction takes place. So recognition proteins are there. We're gonna
12:05 this a little bit later when we the plasma membrane fusion. But they're
12:10 they're so those be that interaction. what we're doing is we're saying you
12:14 interact anywhere on here. So we these proteins everywhere so that wherever you
12:20 through the zona pellucida, there's a of recognition with the exception of this
12:25 little spot right there. So there's . Yes. It's it's private
12:38 So, the answer is kind of . It's part of the cellular
12:42 what they're doing. So they're kind holding the nucleus often reserve until my
12:47 two is complete. And what we're see we never really talked about what
12:50 at the end of my Asus. . So we have my Asus one
12:53 so we're getting this psychokinesis, just you see in mitosis, basically you
12:57 something that gets drawn off, we that a polar body. All right
13:01 you have your cell and all that D. N. A. Goes
13:05 into a polar body. And so your secondary oocyte it still has excess
13:09 . N. A. And so you extrude that excessive D.
13:12 A. That's going to form the polar body and then now you have
13:17 nucleus that's or pro nucleus that's capable being fused with and it's really not
13:23 this point nucleus they're basically it's disorganized you bring the things together and you
13:27 the alignment and then you start doing division my topic division. So and
13:33 in there is a lot of research on this. I mean um and
13:37 like what proteins are available, what . RNA is available. What things
13:41 within minutes. Like minute after minute to minute three. So it's
13:46 of cool but there's there's all these , this machinery in place to ensure
13:50 all the right things are happening in . All right. This is again
13:55 I encourage you before you graduate. you're not graduating it is take a
13:59 class. It is like I said you if you like biology, developmental
14:04 is one of those classes where you're you get blown away going. This
14:07 incredible what goes on. It's a of molecular biology and some other types
14:12 biology that you've already been exploring or least in theory have been exploring.
14:18 I wanna do is I want to kind of talk about capacity ation
14:20 So what we're gonna do, we're gonna kind of walk through this list
14:23 all these steps and really remember one it gets next, which begets the
14:27 begets the next. I have fun this particular page because remember what we
14:31 , we said the sperm gets goes into the vagina. We have
14:35 that fiber network that kind of pace the Sperm to the walls of the
14:40 . And about 20 minutes later the plasma like material, it's called seminar
14:48 basically breaks everything down now the sperm moving and they start moving into the
14:54 and on into the over ducks. . And then what happens is is
14:58 this quiescent period where the sperm are told to just kind of hang tight
15:03 rest up. Alright now this signal actually a signal that's that's coming from
15:09 female reproductive track. And basically it says sperm hang out here, we'll
15:14 you know when it's time to start again. Alright, and this can
15:18 for about five days. Now the process of capacity Haitian really refers to
15:25 all this stuff on within the epidemic then coming into the report of the
15:31 reproductive tract. Alright. And then it again. So it's kind of
15:34 broad period of basically making the sperm , activating them deactivating them. And
15:44 reactivating again. So that's what really . Ation covers all of that
15:49 And what I want to point out is something I think is kind of
15:53 . You know, if you ever a health class in texas, you
15:56 had a coach who taught you that , who probably had a background in
16:02 , right? And I had I've the most interesting conversation with students in
16:06 . It's like one and they're there is never a bad question you
16:10 ask in a class like this one asked said, I was taught that
16:14 dies on the contact with air, that true? And I'm like,
16:19 do you think? And you because again, you gotta think a
16:24 bit like when you hear on the omicron variant, you should stop for
16:28 second and say think, what does mean when it says that it's more
16:32 virulent, you know, more but less dangerous. All right.
16:38 those two words in your mind means something. Right? So you have
16:41 understand, What does it mean to infectious? What does it mean to
16:43 this? So, I asked the said, what do you think that
16:46 ? You think that's true that sperm on contact with their and of course
16:50 was a young woman, she's I don't know. I said,
16:53 right, well let's think about sex a second. Do you think that
16:56 copulation there's air in the vagina? she thinks Bedford says, yeah,
17:01 think so. It's like that's You do not have an internal
17:05 right? There is air everywhere. does sperm die when it goes in
17:09 vagina? And she's like, And I said that's right. It
17:12 die in contact with their sperm can out. You know that's normal.
17:19 in an environment like the vagina it's going to dry out. So what
17:23 it do? Well, we're gonna . But some of that sperm is
17:26 find its way up into the over and they're the female reproductive track.
17:31 tells the sperm this is where you . What did they tell you about
17:35 female reproductive tract it wants and And if it could if it was
17:43 to be pregnant, it is seeking that its purpose is to bring the
17:48 and the ova together. So what doing is we're waiting for an O
17:53 . So sperm can hang out for five days. That's about their lifespan
17:56 they start deteriorating. All right now materials in the acro zone that are
18:05 to destabilize, right? Or the . There's stuff in the reproductive tract
18:10 destabilizes the aca's um So it's getting to become become become reactive prostate
18:15 Remember it's going to suppress that motility And then it's gonna activate it and
18:18 you get the suppression again from the reproductive track and then the female reproductive
18:23 releases a signal that says, okay is the time for you to start
18:27 when you think that is right after by the way, I'm sending an
18:34 to you. So um Wake Alright, here's the fun part.
18:39 think again this is I think is . This is why I get so
18:42 about this. It doesn't just like them all up at the same
18:45 Alright, let's just say you have sperms sitting in your over duct.
18:49 ? It will say. Alright, 20,000 Wake up now, is it
18:53 saying the 1st $20,000? Just sending signal about you know, a quarter
18:57 20% of them start becoming what it's . Hyperactive. Not like a child
19:02 sugar, although more so than they . So they start swimming more
19:09 And what they're like is they are to sharks on a blood trail.
19:15 you ever watch Shark week? All , put blood in the water.
19:20 does the shark doo boom, starts these wide swings and what he's doing
19:24 trying to narrow and where do I the blood sperm is doing the exact
19:28 thing. They become hyperactive. They're a chemical trail to where the oocyte
19:33 . Now if you happen to swim the wrong over duct. Well,
19:36 out of luck. There's not gonna a signal. You're just going to
19:38 of swimming around going I don't know to go, but if you went
19:41 the right one all of a sudden you have a beeline to where you
19:44 to go. And this is what hyper activation is. Notice who's given
19:49 signal? The female. All We did our jobs as the male
19:55 the sperm and delivered the sperm. , it's the female's job to do
19:59 the other work. Sorry. All . So, I like this chart
20:06 it kind of gives you a real . Now, remember we're saying we're
20:09 to use a simple number. We're gonna call 300,000 or 300 million
20:14 Alright, it's an easy number. can be as low as about 180
20:18 about 180, maybe, maybe a bit less. That's when you become
20:24 . Right? And then the top is like 500 million. Alright,
20:29 sperm is gonna be deposited in the here. They're going about 180.
20:32 showing you here. Right. And what you're gonna have to use that
20:35 has to traverse the wall of the . Go through the cervical canal up
20:39 the uterus and along the aqueduct, I already told you is not a
20:42 horn tube, but basically a maze convoluted of convoluted epithelium that kind of
20:49 up and down. So lots and of riga and dead end pathways.
20:52 right. So what happens? Well of that sperm is gonna leak out
20:56 the vagina after copulation. Some are to die in the environment. Some
21:00 not motile motile. In other words they're just nonfunctional in general and then
21:06 aren't even going the right direction You know you're supposed to go this
21:08 but you're going that way because remember not sentient, they don't know what
21:12 doing. They're just swimming. They're and there's parasol tick action that's helping
21:16 moving along. So there's contracts of contractions of the geometry. Um There's
21:21 in the vagina there's contraction along the of the overdose. Each of them
21:25 reverse peristaltic action, drawing the sperm and upward. All right. But
21:33 get to the egg you need to where it is and that's where the
21:36 taxes comes in now for the longest we had no idea what the signal
21:42 . All right. And it turns the signals progesterone in the context of
21:46 oocyte it's releasing progesterone and there are receptors that are located on the side
21:53 the sperm there called the Casper Cat C. A. T.
21:58 c A. T sp er It's a calcium plus sperm receptor and it
22:06 to progesterone progesterone binds it opens up channel calcium flows in. That makes
22:11 sperm get all hunky dory happy and hyper activation alright and it's basically what
22:17 doing is you're following that progesterone Yeah, it's amazing stronger silverback.
22:28 . Take the dice rolling. Better swimmers are going to get further
22:33 deeper. Right? But the argument that is this better genes? It's
22:38 a better it really is the luck the draw. I mean if you're
22:42 sperm that gets deposited pointed the wrong . Right? I mean, good
22:47 . Now. Maybe you get yourself around to go the right direction.
22:50 you you know, know, swim . So there's again, so there's
22:54 there's no signal that directs the initial portion. It's just merely a function
23:01 your position and how you got Right? You can have sperm that
23:06 in circles. That's all they do just swim in circles. All
23:10 Is that a bad? I it might have the best genes,
23:12 it just wasn't correctly built when you the sperm. Right. And that's
23:18 kind of thing. There are 150 chemicals in seaman. Who knows how
23:23 mean, I can't even tell you many different types of proteins are on
23:27 surface. And what sort of But there are a lot of
23:30 The epidemic in length is six m length. If you unwind it and
23:36 making modification along its entire length. lots of stuff going on there.
23:42 the argument we always make right, these are the ones with the good
23:46 . Not necessarily there just the luckiest . All right. The fastest
23:55 Alright. So where you're trying to to is right here, is that
23:58 ? Right? That's just the region different regions um As I as I
24:03 . And so that's the place where takes place is in the ambulance.
24:08 , when you get to the this is what this is what you
24:11 to deal with. All right. , what we're looking at here,
24:14 the oocyte. Alright. You can see this is where the boundary of
24:18 plasma membrane is. Alright. And just outside that there's a barrier proteins
24:24 the zona pellucida? There's actually three in there might be four proteins.
24:29 remember off the top ZP one, two Zp three. And I think
24:33 might be 1/4 1. And they up this protein barrier that serves as
24:37 of like a shell. It's a barrier between the oocyte and the external
24:42 . But when that oocyte was was , it went with it. A
24:48 bunch of granite closest cells that we to as cumulus cells. When you're
24:51 word cumulus, what do you think accumulate? What do you hear?
24:56 of clouds. That's what looks It looks like a bunch of clouds
25:02 the outside. All right. That's they're referred to as a cumulus.
25:05 like a cloud and then they refer this structure as the corona. Radio
25:10 the radiating crown. See you already off life as princesses or Princess.
25:18 see. Right. But what it basically, it's a bunch of these
25:22 and these cells are held together with and there's proteins that they're producing that
25:27 basically allowed to expand. And so happens is the corona radio tas has
25:33 it, a bunch of glycoprotein and starts breaking down. But really when
25:37 breaking down like what you're seeing So all those cells right there,
25:40 are these cumulus cells, you can the sperm kind of in between and
25:45 . But all this clear space in is not clear space. That's a
25:48 of proteins. So you're now a swimming between cells and proteins. Trying
25:54 wiggle your way in up to the pellucida, which is in your
25:59 All this stuff is in your right? It's like the cute
26:02 I'm talking to the guys. It's the cute girl at the front of
26:04 bar that you have to get through crowd and then get through the people
26:09 the bar to be able to talk her. So you guys know what
26:13 talking about. So how do we through the corona radio? Well,
26:21 the tail that hyper activation is what's you through. It's the produces that
26:29 allow you to press through the proteins the cells to ultimately come up to
26:34 zona pellucida. When you get to zona pellucida that ac resume we built
26:38 basically a sack filled of enzymes that responsible for breaking down the proteins of
26:44 zona pellucida. So when it comes contact, there's proteins on the on
26:48 acro zone that recognize the zona pellucida that causes the ac resume reaction to
26:54 the enzymes. And what you do you start breaking it down and that
26:58 the tail start working even harder. so what you're doing is you're acting
27:02 of like a drill to break through proteins. And then what happens.
27:07 this is not showing a good picture it is that once you get in
27:11 escape through. And then what you is you lie inside like this,
27:17 come in that thing because the proteins allow you to recognize the oocyte are
27:23 along the body of that sperm. you get in there and then you
27:29 that connection. You're lying in there then you get fusion of the
27:34 All right. And so now, , the protein of the head of
27:37 . It's the body of the See, I need to change my
27:40 when it's proper Alright. And that's initiate that this reaction. And what
27:45 slide shows units from your book. like look, there's lots of calcium
27:48 stuff like that calcium is like the signal here. You can actually watch
27:51 . It's pulses of calcium that that seeing that are taking place. And
27:56 these calcium uh pulses that are serving signals that help the that basically signal
28:03 process as we move forward. Alright notice we haven't even gotten to the
28:10 down here. We're basically only at point now We only want one
28:19 I don't want to sperm two sperm much d. n. a.
28:22 when you hear the term Paula sperm . It's referring to more than one
28:27 . So that's what we're trying We're trying to block this process.
28:30 called the block to Paula sperm And so what we're gonna have is
28:34 gonna have a what is called the reaction. Now, you can see
28:37 here they're showing you these cortical They're literally lined up along the
28:42 All right. And what these do they contain um materials that cause um
28:51 to do two things first, you the organization of the zona pellucida.
28:57 again, to this day, I don't know how this happens. So
29:01 just have to forgive me. But pretend that the the zona pellucida proteins
29:06 lying this way the coral core reaction us the zona pellucida proteins to align
29:11 this. They change their shape and interaction. And so they're no longer
29:16 by the sperm. So sperm can't through the zona pellucida. But sometimes
29:20 get more than one sperm who break the zona pellucida and now they're actually
29:25 to bind. And so it's whoever to the other side first is going
29:28 be the winning sperm. So what gotta do is once someone crosses the
29:33 line, you've got to make sure no finish line for them to cross
29:37 future ones. Right? So the here is that the cortical reaction pulls
29:42 all the binding proteins on the surface the oocyte. So that once one
29:48 sperm fuses none of the others And it's an incredible reaction to watch
29:53 like it's like a tidal wave that kind of occurs over the surface of
29:58 cell. All right. Now, , the signal here is basically calcium
30:03 that serves as that signal. All . And again, you're getting
30:08 And so it's the when you watch stuff and see it in real
30:12 it's like, oh wow. Each represents something. Yeah. Uh
30:20 Is there a picture of? there's actual videos of it where where
30:26 I'm not sure how they tagged whether the calcium is radioactive or the receptors
30:33 flashing color in response. But you watch the waves of calcium wash over
30:39 cells as they go through their Yes, it's actually it's like I
30:45 , there's I bet you if you you look hard enough, there's probably
30:49 on youtube. But again, it's or not someone was thought this was
30:53 enough to post it on there. . All right. So now remember
30:58 we said, we have to re mitosis. We're just going through the
31:01 so we have to reinitiate reinitiate And so that's gonna trigger that second
31:06 division. Alright. We're gonna shed polar body. So they're trying to
31:11 you the polar bodies here. The one would have occurred after moses,
31:14 at ovulation. The 2nd 1 gets here. Now sometimes you'll see a
31:20 polar body and that usually means that of those polar bodies went through a
31:24 nuclear division. So it went through second biotic event as well. But
31:28 don't care because it's basically DNA that's going to do anything. So sometimes
31:33 see a third one. But that's . Alright. The key thing to
31:37 away from this is because I know asked this question is how many gametes
31:42 from? Oh genesis? Just Right, You start off with a
31:50 that goes through two divisions but you're you're shedding off these things as useless
31:55 For Spermatozoa Genesis. How many Gambians you end up with four.
32:03 now those two nuclei, what we to the pro nuclear because they're happy
32:08 will then come together they fuse and the genetic material then starts beginning the
32:13 process and so this new deployed cell a unique organism. Alright. It
32:19 half the DNA of mom, half DNA of dad. It's not all
32:22 D. N. A. It's completely separate organism. Alright. And
32:27 we do is refer to this at stage as a zygote. All
32:31 So it's a single deployed cell at point. So do we see those
32:37 kind of how we go through All right. There's just a lot
32:40 stuff that happens, but it happens very quickly. And so this is
32:44 occurring. This these last stages from to here is probably about an hour
32:48 so. It's not very long I'm not giving the developmental biology
32:56 I'm just gonna let you know right this is like dipping our toes in
33:02 like nothing. All right. But want to do is I want to
33:06 through and kind of say how do get to that full formed baby?
33:11 right. And in a really really period of time. So what we're
33:14 do is we're gonna, the zygote what's going to go through these nuclear
33:17 . So it's you're gonna see DNA . So this is trying to show
33:20 here's our secondary oocyte. We get . Now we have our oh here's
33:25 two pro nuclear and then we have zygote. And then what we're gonna
33:27 is we're gonna go through my topic . We go from one cell to
33:30 2-4. And then after eight, don't go to 16 at this
33:36 You're already starting to see differentiation of cells. All right. And so
33:41 can see anywhere between 12 and 16 at this point. So, already
33:47 starting to divide the cells up into populations. And again, lots of
33:51 has been done on this. And can actually see which proteins are being
33:55 on, which proteins are being turned . Where does the maternal RNA go
34:00 we turn that stuff and destroy it replace it with the embryonic or the
34:04 RNA? It's again kind of Alright. But I want to point
34:09 here, through all of this, still have a zona pellucida.
34:15 I hate to tell you this at point in your life. You hatch
34:18 that kind of cool. I actually . You're a lizard person.
34:23 Maybe not. All right. And what's happening is that these cells are
34:28 and they can't grow their getting stuck there. So, we get this
34:31 compact structure and it's referred to as . And the the organism at this
34:38 is referred to her is referred to a memorial. Alright. How many
34:42 speak spanish. What sword for Blackberry ? Same route. Right. It's
34:53 latin root moral. More Ebola. take a look at this sucker.
35:00 kind of looks like a raspberry tea blackberry teeth kind of? Yeah,
35:04 that's where he got his name. . Looks like a blackberry.
35:08 Check. Move on. All Now, all these cleavages, look
35:12 they're taking place. None of this taking place in the uterus. It's
35:16 taking place here within the over Again, poorly drawn to show you
35:20 it looks like a trumpet. It's a trumpet. Not. What's interesting
35:26 what keeps it here is the smooth in that initial segment, basically that
35:32 muscles in a contracted state, not contracted, but enough to prevent anything
35:37 going out. And basically what you're is you're holding the more Eola in
35:45 over duct until the uterus is All right. The Ideal Day of
35:51 is seven days post ovulation. Between basically between day seven and day
35:58 . All right. So, you imagine. Let's say you have a
36:01 moving blast it or not blast but basically a fast moving zygote.
36:06 , And this wasn't there wasn't muscle . It would just roll on out
36:10 out here and there is no place it to implant plant. No place
36:14 implant. It's a failed pregnancy. , what you're doing is you're holding
36:21 zygote back until there is an environment allows it to do what it needs
36:29 do. Which is that implantation. right, now, Memorial is going
36:35 continue divide stuck in there. All . And it takes about five days
36:40 all this stuff is going on. , you're gonna get relaxation and that's
36:45 to allow the mortadella really, at point, it's gonna be a blast
36:49 . It's going to be allowed to kind of move out. So when
36:53 enters the uterus, the zona pellucida to degenerate as you can see pictures
36:58 it actually looks like it just kind splits and then the cells kind of
37:03 out and it's like oh look you hatch, it's kind of cool,
37:07 ? And then what you start seeing the early stages of embryo genesis where
37:12 can literally start seeing populations of cells out. And so what happens is
37:17 start seeing this formation of this fluid cavity, It's gonna be called the
37:22 cavity. And what you're going to is there's a population of cells that
37:26 initially inside that moral. And then happens is it gets pushed off to
37:30 side and then that that fluid filled starts filling up and you basically have
37:35 group of cells on the outside. you have a group of cells on
37:39 to the side. So here's a of cells on the outside group of
37:42 on the inside to push to one . Those cells on the outside are
37:47 to as the trophy blast, This is an extra embryonic membrane,
37:52 going to form what is called the a little later on in development.
37:57 . In other words it's not part the embryo proper. It's a protective
38:02 of cells protecting the embryo? The proper is going to come from the
38:09 blast. Which is this inner cell , which is the other words you'll
38:12 hear coming with it. All These are the cells that you could
38:16 in there, pull them out, them apart and then you can create
38:20 cloned organisms from each of those. right. Not for a very long
38:25 of time because they're going to start . But right at this point they're
38:30 all pluripotent. They can all become organisms. Should you want to do
38:34 ? Yeah, it's going to form the trophoblastic. Yeah. And this
38:44 the confusing part about the placenta. forms from female or the mother's tissue
38:50 well as the embryonic tissue. It's a combined organ between the two.
38:58 see that in just a second. , again, posting is a cool
39:01 . I mean, I'm sorry I really giddy in this section. I
39:06 . Right. I mean if your when they teach you about stuff that
39:10 studied and learned, if they don't giddy about it, there's something
39:14 Right? But when they get excited this like, Oh and that's what
39:18 do. When I worked I worked the placenta. What we do is
39:22 we call over to the hospital because was over at MD Anderson.
39:25 We call the texas. Women's. , do you have a placenta that
39:28 can come get Yeah, we've just six births this morning. We have
39:32 placenta ready for you to come and it. You think that will give
39:35 a little tiny step? Oh they give you a bucket filled with
39:39 placenta, 9lb of tissue and all want is like it's take that and
39:46 I can go do my work and let's play with the present. So
39:53 , awesome stuff. Yeah, no, no. Well, so
40:03 right now, let me let me clear here. All right.
40:06 you're you're starting to open a can worms in my brain. That is
40:09 just bad. All right. Remember trophy blast right ourselves that originate in
40:15 embryo. If it's a male embryo what are those cells gonna have in
40:21 ? Y chromosome. Are you ready the front freaky part ladies?
40:26 Many of you will be chimeras after give birth. What is a
40:34 It's an organism that has cells from different sources. All right. It's
40:41 , weird stuff. And you we always learn this real simple biology
40:44 then all of a sudden you find there's freaky things that are going
40:47 So basically during the process of giving there's tearing a blood vessel because you
40:52 a placenta cells enter into the mother's and then we'll find places to just
40:58 of hang out. Right. And I remember reading a story about,
41:03 mean there's, they talked about you go look up timers, humankind
41:07 And there's like stories like women you know, brain tissue where they
41:12 fetal cells from their offspring and how know it was from their offspring because
41:17 xy as opposed to being xx How is that. See if women,
41:27 awesome. You do everything else, . Yeah. No, intersex is
41:37 made up thing. We're not going talk about that. We can later
41:44 after class. I gotta go pick my kids. So but if you
41:47 are inclined to come talk about attractiveness attraction, it's a completely different animal
41:54 completely different field. Which is So question of intersex is deals primarily with
42:01 , right? I'm attracted this or not attracted to that. I'm attracted
42:05 sorts of things. It's attraction. is distinct from sex, which is
42:12 from gender. But we like to it all together and call it a
42:18 milkshake. Yeah. Mm hmm. , I think it's just an artifact
42:26 just the the way that organisms in are made. I mean, so
42:31 have primaries um in all mammals, . But we always think of ourselves
42:36 being pure in whatever we are. know, I remember, And this
42:43 weird. And again, I'm not to get this 100% right? All
42:48 . But I remember seeing a story primary is um where a woman went
42:54 and was trying to do like a you know a just a.
43:02 N. A. Tested. Look parentage right? Like who are my
43:06 ? You know and they came back said your results came back very
43:10 You came back Xy. Which was because she was a mother. You
43:15 So it's like I know I'm X. I know I've I've given
43:20 and you can't do that if your . Y. All right. And
43:24 looked at the tissue and it turned she was chimeric and the tissue sample
43:29 they were taking were male. But wasn't from her child. It was
43:32 her father's D. N. So somehow she got father's D.
43:36 . A. While developing. And you know I read the story I'm
43:42 this is like the weirdest thing So again it's never as simple as
43:46 like to make it out to So what we do is we just
43:50 here's an example of the exception. we like to think in absolutes which
43:55 much easier. Which is why those on your test is which of the
43:59 is the best answer because there's always exception. Sorry. All right.
44:09 again you guys who did the question think I emailed you the few of
44:13 who emailed me and said wait a . I got this question wrong.
44:16 Let's talk about the order. What place during implantation? The first step
44:19 gonna be opposition. I fixed that the quiz. So just making sure
44:23 those of you who didn't email but you saw that? You got
44:26 wrong. You're like what? So the thing I want you to
44:30 is that what we're doing is that that blastocyst is going to work its
44:35 into the wall of the endometrium. . Wall of the uterus is gonna
44:40 its way into the endometrium. And you're going to relax the over duck
44:44 day five. It's slowly gonna work way into the uterus. And why
44:50 window is so valuable is because of is actually occurring the first stages of
44:56 . I want you guys to cup hands like this. All right.
44:59 for the majority of your of the during the cycle, this is what
45:02 uterus looks like. The walls are apart from each other. What opposition
45:06 is bringing the walls close together. , how is that doing that?
45:12 , you're building up the endometrium. so the endometrium are basically pushing
45:16 So now you have this kind of narrow area inside the middle of the
45:21 . Okay. And so what's going ? Is that the that cell is
45:25 in and it's going to find purchase either on the wall that it's coming
45:31 or it's on the other side. would be the roof. Right?
45:34 going to find one or the other it always always always in humans in
45:39 with the embryo blast facing the burrowing . For some reason mice is the
45:47 , right? So what you're doing opposition is the first thing. And
45:51 what progesterone is doing is causing the up of the endometrium so that you
45:56 surface that you can come into contact because they're close up next to each
46:01 , you you're gonna have a you're going to go on this side
46:04 on that side, right? And once you recognize once all the proper
46:10 markers and yes, day seven, when the surface markers starts showing up
46:15 to day seven, the surface markers there? So you're not gonna be
46:18 to implant. And so then what do is you bind to it and
46:23 where adhesion takes place, so opposition adhesion. And then that's gonna cause
46:29 trouble blast cells to start releasing these that literally break the cells open underneath
46:35 . And so you start destroying the and you start creating this monster
46:40 Alright. And you can see it , right? You can start seeing
46:44 up there. Alright, That's called Census EO Trophoblastic. Alright,
46:49 what does the word mean to help remember this? Census you remember is
46:53 sheet, right? So when you science issue and it's like oh there's
46:57 sheet. So this is the census trophoblastic, it's the sheet of trophoblastic
47:02 . And so what it is, not it's it's basically the cells destroying
47:06 cells and incorporating them and becoming a giant blob monster. And what you're
47:11 is you're now burrowing through the connective , creating a bigger and bigger and
47:15 cell. And when you come across blood vessel, you bust it
47:19 And so you end up with these , right? These little tiny
47:23 And here in the lacuna that's where is gonna be, that's maternal
47:28 And it's right up there next to big giants in sitio trophoblastic. Now
47:34 surrounding the embryo. Is this protective ? Alright, and again this origin
47:41 also trophoblastic. And so these are side atrophied blasts. Now again,
47:45 at the words inside of a So cell trophoblastic, you can look
47:48 you can see oh yeah, there's whole bunch of cells there. So
47:51 got this big giant sheet that's basically blob cell with multiple nuclei that gets
47:56 and bigger and bigger and then there's barrier that's around it or underlying
48:01 See if I can draw this So I I see the the I'm
48:04 this thing all right, so here be your sido trophy blast.
48:11 So you can imagine their individual cells your embryo blast. And then you've
48:19 this blob cell that's getting bigger and and bigger. So there's all the
48:23 nuclei in it and it's this that's bigger as it breaks down further and
48:29 and it's allowing this thing to migrate that membrane and eventually it burrows its
48:40 all the way in and then the closes up over it and the cells
48:48 basically until you seal it in. , having said that, I want
48:56 to now think about menstruation for a , what is the purpose of menstruation
49:00 get rid of the endometrium? If this cell that's undergoing division fails
49:06 its developmental process, it's embedded in endometrium. So if you want to
49:14 for pregnancy to occur, you've got get rid of that endometrium. So
49:17 is why we are menstruating organisms because need to get rid of the environment
49:22 implantation occurred. If a pregnancy that kind of makes sense, sort
49:30 Not a lot of fun. It's great. Okay, so I've got
49:33 slough all this stuff off if something happens. But it ensures that you
49:39 a clean environment and a new environment each organism that potentially implants there.
49:48 , so the inner cell, let's if I can circle it again.
49:52 you can see the picture the inner , you can see there's the trophy
49:57 it maintains. And then you get which is the census etorofu blast.
50:02 it's a single large cell with multiple serving like a blob devouring and working
50:08 way downward. This is a little closer, you can kind of see
50:14 little bit better. So by day you're completely burrowed in. That's when
50:18 overlay it with the epithelium. And you've got a nice happy little embryo
50:24 , receiving its nutrients from blood And you start producing HCG human chorionic
50:34 . Now, if you never stopped think about what those words mean to
50:37 out of trope in. All what is the FSH and LH it's
50:41 gonadotropin. What does that devastation LH it signals for the production of estrogen
50:48 progesterone. Right. So really now we have here is we have an
50:53 that's releasing a chemical signal back to ovary that says, hey, guess
51:00 I'm here. And I want you keep making progesterone. And so the
51:07 Lutetia produces tons and tons of And so that's how you maintain
51:15 No pregnancy. No HCG. HcG no progesterone. Stop the cycle
51:24 . It's kind of cool. So complicated. But it all works
51:29 It's kind of nice. The Oh my goodness. Yeah, go
51:40 . It does, but not. there's gonna be a point where the
51:44 takes over and it's it's really at the second trimester where the placenta has
51:50 has become large enough to produce more uh than the the Corporate blue team
51:58 . So you can really think of corpus Blue team as being responsible for
52:01 first trimester and then the placenta is for the hormones of pregnancy for the
52:07 and 3rd prime? Yes ma'am. . Yes, but all right.
52:17 the embryo gets pretty big, doesn't ? Right. It's it's gonna get
52:21 . So what happens is is it there and it begins filling out the
52:24 and the uterus begins expanding. So we do is we look at it
52:27 go oh look it's growing inside the . But really what it's done,
52:31 grown into the cavity from its Alright. I think I have a
52:38 cartoon that kind of shows that All . I mean we'll come back to
52:42 slide but you can kind of see showing that it's growing into the uterus
52:46 this point. Now the uterus is bigger and you can see here is
52:49 placenta and it's out here. What done as you push those trophoblastic
52:55 Remember the trophy blasts are out here this side. So if this is
52:59 embryo and it's growing out this It's pushing this as well. So
53:04 really filling up the uterine cavity. does the korean become? It's that
53:09 outline and then you have the am underneath it that's filled with all the
53:13 that's going to be filled in Okay. Do that kind of answer
53:19 question. Yeah. Ectopic pregnancies. , well what is the definition of
53:27 ectopic pregnancy first outside the uterus. right now the unique characteristic of the
53:34 is one that it goes through massive and hypertrophy, right? During pregnancy
53:41 then after pregnancy, it's going to through the process of evolution. Basic
53:45 back to its original size. You make a fist that's the size of
53:48 uterus, right? Think about a with the placenta and the baby in
53:53 at full term. Big, we're talking about £15 worth of maybe
54:00 worth of material. Right? £9 . That's kind of a big
54:05 Right? Placenta because they're roughly the size. And then whatever the fluid
54:10 . So, it gets nice and . Think about any of your pregnant
54:14 , pregnant family members walking around like , right? You know, And
54:20 it shrinks right back down about the of your fist. Okay. Over
54:24 . And all the other organs in body do not have this characteristic.
54:28 , what is an ectopic pregnancy? right, let's do it on the
54:31 of the over duct. It's going go in there. It's going to
54:33 that over the duck apart. And you're gonna bleed to death. Which
54:37 why That's very bad. Alright, put it on the outside of the
54:40 duct, instead of defend break, know, bringing it in going come
54:43 this way, like somehow find its on the outside. Right, It's
54:47 do the same thing. It's gonna , fill up the pelvic cavity.
54:49 gonna start ripping blood vessels apart. , it doesn't work that way.
54:53 why ectopic pregnancies are so dangerous because working with tissue that can't recover or
55:00 designed for that growth and expansion. the uterus is and there's actually even
55:06 within the uterus that are more beneficial than not. So, you want
55:10 occur here as opposed to over here like say near the cervix.
55:19 Yes. All right. So, is actually this is for those planning
55:23 go on to medical school. This a trick question that you're attending will
55:26 you, they'll go into and uh you'll you'll see um like identical
55:33 And they'll ask the question, is a I can't remember the exact term
55:37 is it single placental or dual Right. And the answer is real
55:42 . If they're if they're if they identical, als they can share a
55:47 . Usually they ask you the question other way, it's like they shared
55:49 placenta, Are they identical or And the answer if they share the
55:54 , they're always gonna be identical. if they have two placentas, then
55:58 likely that they're fraternal okay, because each make their own, right?
56:03 usually with identical. They basically it's get the split while it's inside that
56:08 pellucida. And so they're growing within blastocyst separately. So they start off
56:15 sharing everything. All right. Um , okay, So, coming to
56:22 placenta. Alright, this is we could spend an entire lecture talking
56:27 this and really what I wanted to is an organ of exchange. All
56:30 . And so it's gonna have both and fetal tissue. We saw that
56:35 that that those trophoblastic cells that we in and we're actually starting to penetrate
56:40 and coming into contact with the And it's from that census you
56:45 We're going to start producing these Alright, So, they're coming from
56:50 chorionic tissue. All right now, happening here is there if you're looking
56:55 this, this would be my geometry out here. And what they're trying
56:58 say is over here, this would endometrium. And so you can see
57:02 is the maternal portion. You can the blood vessels of the mom.
57:05 can see the boundary between the mother the fetus, right? But what
57:11 don't remember, we ripped through blood . We created these pools of
57:15 And that's what this stuff represents in . And you can see that there's
57:19 mixing of blood of oxygenated and deoxygenated . So what you have is you
57:23 veins and arteries in contact with his on the fetal side. What you're
57:30 is you're taking those trophoblastic cells that differentiated the Census Bureau trophoblastic, they
57:35 organized and they create these structures that going to be highly vascular rise.
57:40 , what we're looking at here called . and they kind of look like
57:43 tiny invasions that basically are sitting in pools of blood and they're very they
57:49 there's like a thin layer of cells the maternal blood thin layer of cells
57:55 then you have the fetal blood in own blood vessels. And so this
57:59 where the material exchanges taking place. . So what we're looking at here
58:04 we're looking at a boundary that brings blood of both the mom and the
58:09 fetus very close to each other. that gas can be exchanged, nutrient
58:14 be exchanged and waste can be All right. Now, it's also
58:21 pathogens from coming across because you're not be selective of what you're going to
58:24 able to transport. All right. , that's really kind of its primary
58:30 . Secondary role is that it serves an endocrine organ to produce a whole
58:34 of hormones that govern pregnancy. All . And that's what we're going to
58:39 at is what are those hormones. . So, so the thing to
58:44 is that it's a complex dual organ from apart from baby, it brings
58:49 blood close together and then you're getting exchange just like you'd expect when that's
58:55 happening. But the intricate part. so these are gonna be the hormones
59:00 pregnancy we've mentioned. HCG already. know about progesterone we mentioned estrogen.
59:05 we were familiar with these HCG is the one that's produced by the sitio
59:11 cells and it's basically telling the Corpus Team. Stick around. And what
59:15 want you to do. Corporate Blue is I want you to make progesterone
59:17 estrogen. Now, progesterone, you see here's first trimester, 2nd
59:22 you can see projects or here's HCG . Progesterone levels are high estrogen
59:26 Just keep growing up. All And we're gonna see estrogen plays the
59:30 of basically allowing for contractions to occur ultimately um uh labor and delivery.
59:40 right. But basically in the first it's the corpus lutein that's produced in
59:44 progesterone. Alright. You don't really much of placenta. It's a little
59:49 bitsy tiny thing. But you've got massive organ that's pumping out tons and
59:52 of progesterone. But as the baby or the fetus grows. So does
59:56 placenta. And so you end up more mass to produce more progesterone.
60:00 so that's what it does. So corpus lithium uh ends up producing much
60:05 less. It's still there. But not producing enough to be much of
60:09 effect. And by the third trimester overwhelmingly by the placenta. Again,
60:15 still some being produced by the the Latina, but not that much relatively
60:21 . All right. Now, what progesterone do suppresses gonadotropin production, which
60:26 opens from the pituitary. Alright. going to facilitate the growth of the
60:32 and it's going to facilitate memory gland . Alright. Now, why?
60:37 gland enlargement? What's your future after give birth lactation? Right. So
60:45 you're gonna do is you're gonna elaborate tissue that is responsible for milk
60:51 Okay, estrogen, on the other , it still does gonadotropin production downplays
60:56 it relaxes the ligaments. Alright. what it does. It also helps
61:01 prepare the body for labor and ultimately lactation. A couple of other hormones
61:09 have relaxing, promotes angiogenesis. What's ? Making new blood vessels? Why
61:18 I need new blood vessels? Getting and bigger and bigger. All
61:24 According to trump in releasing hormone. , this plays an important role in
61:28 timing of childbirth. Alright. You've about oxytocin is the primary driver of
61:35 , but it all starts when crh the placenta initiates this longer program of
61:43 oxytocin. I mean, so it's way downstream. So it's connected.
61:48 tropic releasing or corticosteroids and releasing hormone does it HP. L. Is
61:53 placental oxygen? It's going to change metabolism. Alright, so what it
61:58 is it says ladies get your fuel your fat. All right.
62:04 Well, I want to make glucose to pass back and forth across that
62:09 for the fetal growth and development. , so I'm consuming fuel primarily to
62:15 direct fuel to the fetus. But gonna store fuel away. So I
62:20 actually have something to consume for It inhibits the effects of insulin.
62:29 , there were a lot more. used to I guess I took a
62:31 bunch of them off. All that's good. All right. Now
62:37 a sean. We're working our way the sun's right Pregnancy. About 38
62:42 from conception. Usually when you go the doctor and you're getting your pregnancy
62:46 . What they do is they want to calculate to your last menses,
62:50 ? And it's like, okay, was the last time you had your
62:52 ? And then they like use that the framework from which to do all
62:55 math. All right. And that's always the best mathematics. But what
63:00 can say is that most pregnancies on run about 38 weeks. Alright.
63:05 you want to do the math 4.3 or 4.3 weeks per month, you
63:10 ? So 38 divided by 4.3 Comes to almost nine. I know that
63:18 we can say nine months of Okay. All right. Now,
63:22 are lots of physical changes that occur pregnancy, as we are probably
63:27 Alright, First uterus is gonna get . We talked about the fist gets
63:31 and bigger and bigger. All the breasts in large. Alright.
63:34 again, what they're doing is they're their ability to produce milk.
63:39 This is where I'm going to have and a little bit with I guess
63:42 a couple of slides weighs about breast . You know? Ladies if you
63:46 know, guys really, really are to breasts. Doesn't matter if they're
63:50 , They're big. They're obnoxiously You know? We just we like
63:54 . And all the guys are sitting staring at because they quit telling our
63:58 . Guys. They know, I mean when we when we walk
64:03 the room and we stare, you , it's like eyes are up
64:07 Yeah, Yeah, We know. right. The thing is, is
64:14 a memory gland which we'll see in seconds is basically a modified sweat
64:19 Alright. So guys were attracted to sweat glands. It doesn't make them
64:24 worse. It's just good to know we're attracted to. All right.
64:29 second thing is that for the most is that they are undeveloped in the
64:34 that they're incapable of producing milk only the right hormones. Are there are
64:40 capable of producing milk? So, we have is primarily uh if you
64:44 if you're not breastfeeding right now, are or you're not pregnant right
64:49 You have what are called rudimentary rudimentary glands, they need to be developed
64:54 to be able to produce milk. right. So, it's predominantly fat
64:58 now is really what I'm trying to at. Alright, So, that's
65:03 I'm talking when I say developed the to produce milk is we've got to
65:06 the machinery inside that breast tissue to it milk producing lactate, herbal.
65:12 there are nutritional requirements increases. Obviously eating for two. So you will
65:17 weight gain blood volume. You actually to have the blood to be able
65:22 produce those material or send those materials the fetus. You breathe more,
65:27 breathing for two Urinary output increases your for two. Everything is for
65:34 Or if you have twins for Right? And we get down to
65:40 tuition. See I mean I literally just jumped over development. Right?
65:45 is labor and delivery. That's what more familiar with calling it. Um
65:49 a couple of things that have to . Remember we talked about the
65:51 Cervix looks like this. It has to it and has an itsy bitsy
65:55 tiny hole. The size of a head is roughly the size of a
65:58 grapefruit or a large orange. I'm not going to fit through
66:04 So we've got to do is we to dilate that. So that's number
66:08 again, it's thick. And so we gotta do is we gotta thin
66:12 and that's what dilation and effacement deal is bringing that size so that you
66:18 now pass through it down into the canal or the vagina. All
66:22 you're gonna have contraction of the uterus Miami atrium. And this is kind
66:26 just showing you what the basic one with oxytocin and stuff and we'll get
66:29 this in just a second. But gonna keep it simple. We're not
66:32 talk about how crh acts on to this downstream event. All right.
66:39 so there's going to be maternal and oxytocin. Oxytocin is the hormone that
66:45 the production of prostaglandins. Prostaglandins are ones that actually do the muscle
66:51 So what's happening is is that oxytocin released from both the fetus and from
66:56 mother and they're gonna act um uh cause the production of prostaglandins which are
67:01 to tell that my mama tree um begin to contract. And it's also
67:05 to tell the cervix to begin to through this process of dilation and
67:14 Now what's happening is that the contractions the mama tree um are pushing the
67:18 against the cervix. You're getting That resistance is detected in the
67:23 Cervix sends a signal up to the says there's resistance produce more oxytocin.
67:29 the hypothalamus produces more october causes the of more oxytocin from the post your
67:34 that causes the production more prostaglandins which further effacement and dilation and further contractions
67:41 keeps pushing the baby and you can how this just becomes a cycle so
67:45 they're getting stronger and stronger and stronger terms of contractions. Now that baby
67:51 gonna go through the cervix until the is ready. I love this
67:56 I think this is the best picture all of picture done Alright because you'll
68:01 it all the time. You hear the Cervix going, you know when
68:04 reached 10 cm of dilation? That's it's going to pass. Well how
68:07 is 10 cm? This picture shows all right. So remember the cervical
68:14 not even a centimeter. It's it's teeny tiny. The size of the
68:18 is about a centimeter Slice of about three cm cracker soda can size
68:25 a bagel is what we're looking Alright, that's how big dilation has
68:32 be in order for a basement or order for the baby to pass into
68:37 birth canal. All right. So dilation happens to be the longest stages
68:41 when you think of someone going through and they're doing the who who he
68:45 stuff right? And there, you , you eat the chips and you
68:49 the ice chips and stuff like They're really talking about this. They're
68:53 through the pressure on the cervix because like get this thing out of me
68:58 there's no path to get out. so that's why the contractions are getting
69:02 and harder and harder Now. I'm gonna pretend I know what that's
69:06 No, no guy is ever gonna they know what this is like,
69:09 well we might say it like oh . You know, we know
69:13 it's like Mhm. Yeah, 10 cm right? But during this
69:21 of time, that's when you are through, when you think about
69:26 This is what you're really thinking The actual expulsion time is not very
69:30 . So once you get dilation and , once you thin that out and
69:34 got this big giant gaping hole, actual giving birth doesn't take that
69:40 Now I saw a paper just a of weeks ago talking about the anatomical
69:45 of the birth canal. And humans the weird species because we have to
69:50 a 90° turn in the birth right? So the baby comes down
69:55 and then turns and then comes out basically shoulders out and then comes
69:59 We're the only organism that does But we're also the only organism that
70:05 upright. And the reason they finally out using models to figure out what
70:11 . And it's basically our upright posture order for us to have us.
70:16 what our birth canal had to If we have slight modifications, then
70:20 gonna be hunched over like chimps. we're going to have to use our
70:24 to help us move like chimps. of course, all right. But
70:29 makes it very difficult, relatively Yes, ma'am. Well, that's
70:36 you can give birth squatting. But , there needs to be an
70:42 So, I've actually seen, I , and you can do this
70:45 I'm sure it's on youtube. You watch a gorilla giving birth. I
70:48 and we we make the joke is you know in the third world you
70:51 you're in the rice paddy and you kind of squat and you give birth
70:54 know you've you've if you've heard those maybe not alright but gorillas literally do
70:59 , it's like okay it's time to birth. They just kind of
71:02 they reach down and they literally give to themselves, they catch the baby
71:08 then they just throw it on their and they keep moving. Humans can't
71:13 that. I mean we we kind joked that they can there needs to
71:17 a significant amount of assistance. Now we be able to do that?
71:21 but notice we are a very social and what happens is is that we
71:27 ask assistance and we get assistance otherwise be killing each other off. I
71:32 up until this century childbirth was the one killer of women go team.
71:39 know? And so I don't know we lay on our backs because it's
71:43 easier but we should be able to and be able to do it.
71:46 again it's you come down sideways and you shift so that you're facing downwards
71:54 in other words you'd be facing backwards and then you have to shift out
72:01 how long this lasts? 30 90 . One of my closest friends um
72:06 went through a 24 hour L. . D. Just took forever.
72:12 know? And finally they were like was she had a doula. It
72:14 gonna be one of those water birds know the whole Granola nine yards No
72:18 . And finally after about 22 hours like get thee to a hospital because
72:23 can't make this happen. So drugs her back the whole thing. All
72:33 my wife Superwoman, I'll never stop about her first pregnancy gave birth to
72:39 girls are two eldest twins In under minutes. I mean the L.
72:44 D. Part was like six hours the expulsion part one boom. Yeah
72:52 never forget my first son coming out he grabbed onto the the attending and
72:58 hung there like a monkey. I like yeah that's about right. All
73:04 . Usually this is where we kind stop and think are right there is
73:07 but we also have a placental The placenta has to be given.
73:10 have to give birth to the placental but no one pays attention to that
73:13 all the hard part's been done. like now I get to hold the
73:16 right? You know and so you're there holding the baby and there's some
73:20 sitting down there going okay dr wayne a placenta you know And that takes
73:26 15-30 minutes because Uterus is still going contractions and it's separating out the placenta
73:32 the Uterine Wall. This is what call the afterbirth. It's just pictures
73:39 it, right? So he knows he is coming down sideways, flipped
73:43 and then shoulder shimmy shimmy and then it comes and then here's the expulsion
73:48 . Right? But you can see this is where the cervix has not
73:52 through dilation right here. You see . You see effacement that birth canal
73:57 very long, is it? Here there's still some length to
74:02 And really what you're doing is you're out and that's why the birth
74:06 It doesn't do that. All so this is the mammary glands.
74:11 but no. Males and females have glands. All right. And when
74:15 not talking I'm not talking structural mammary . Some males do. Yes.
74:20 need to wear bros I think that's Seinfeld. Right. Call him the
74:29 . Alright. But typically with the hormones only in females are they functional
74:36 there is and there is evidence of lactation. All right. But it's
74:40 abnormal thing. It's not like, well you know, we have the
74:44 hormones to kick everything up when we the hormones that are pro lactating.
74:49 prolactin. They have actual different effects our bodies. They don't really actually
74:54 our our mammary glands to develop. I said, modified sweat glands.
74:59 female very rudimentary undeveloped and not undeveloped in size. It's undeveloped as in
75:05 structure that we're interested in. Which is this stuff in here?
75:12 there are about 15 to 25 They radioed to the nipple. There
75:16 duct works that go to the And so what we have is the
75:20 . It's the alveoli that are responsible producing milk in response to the hormone
75:27 . They produce the materials that we milk and then it's the oxytocin and
75:35 prostaglandins that are being produced that cause around the L. V.
75:40 Line along the ducks that allow for ejection. Alright so what we have
75:46 is we have these two hormones. so during gestation you're basically the placental
75:53 . The placental progesterone is helping you those rudimentary mammary glands. Prolactin after
76:00 is starting to be produced and it producing the enzymes that help for milk
76:06 . Alright So That's The 1st Now if you do not breastfeed then
76:11 there's no stimulation then the body just okay I don't need to produce milk
76:16 so you stop producing milk but as as you breastfeed in other words as
76:20 as you're suckling you will produce Now there's a movie caldwell. There's
76:27 that you're probably familiar with the grown right? So it's like I can't
76:32 who the woman was but she basically her four year old son over and
76:36 he's mommy, I'm hungry and she her breasts out and starts breastfeeding is
76:40 four year old kid and everyone's hey you're still breastfeeding. Yeah,
76:44 long as they're still breastfeeding they can it. But the movie I always
76:47 about the Empire of the Sun. an Academy Award winner. None of
76:52 guys know it was long before your . And the emperor, the last
76:56 of china had a milk uh a nurse, milk nurse. I can't
77:02 nurse whatever it is say Good West nurse, thank you blind on brains
77:09 into pudding last day of class talking boobs. You know, I keep
77:17 awake, don't I? Some of right? Had a wet nurse through
77:23 until like the age of 11 or . And that was his comfort
77:26 Right? So whenever he got scared or whatever he called the wet
77:31 and basically would suckle. This is 10 year old child, imagine a
77:35 year old child with westerners. And know. Yeah. So as long
77:42 they're suckling, that's that's what So oxytocin um is there to cause
77:48 prolactin is making milk is the way think about what is oxytocin also
77:53 It also promotes evolution. And what's is that these two hormones together and
77:58 other hormones were not quite clear what are, What they do is they
78:02 ovulation. All right. So typically happens is you give birth you're suckling
78:10 you basically have natural birth control and about you know, Up to about
78:15 months, usually about 12 months That's when you can actually start ovulating
78:21 and again. The reason why this of makes sense. Alright. You
78:24 imagine here I am suckling a I don't want to be pregnant because
78:29 nine months I would have to be two babies and you know,
78:33 we live in a simple, easier . Not simpler, but an easier
78:36 than it was when I say you're chased by tigers across the plains of
78:41 , right? Or surviving all sorts horrible things in the jungles of far
78:46 Asia or wherever you want to right. You're nomadic species. You
78:52 to be able to have one maybe a toddler, maybe an older
78:59 . So on and so forth. wanna be able to create your tribe
79:01 help you take care of stuff. this is that natural birth control.
79:12 all Alright, so where are 2 20. I finished right on
79:19 . Hot dog. Hot dog. diggity dog. All right, so
79:22 have an exam on thursday? You peer reviews do today? I'm gonna
79:27 the button to stop this. This the last lecture. Who's graduating this
79:33 ? Congratulations. You know, get there and scream and yell. I
79:38 recommend doing a handstand. I've have that done on the stage before,
79:42 you better be good at it. . Anyway, that's all I have
79:47 you. Good luck on your Make sure you get your sleep.
79:51 stay up every night all night. welcome often dollars
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