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BIOL 2302 Human Anatomy & Physiology II - 2302_lecture20_0413
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00:02 All right, good morning campers. we are entering into our discussion of
00:10 reproductive systems. Remember this is And what we're going to do over
00:16 course of today is we're going to look at some shared ideas about the
00:23 systems. So we'll look at, example, how we make games.
00:28 right. So, gametogenesis is kind one thing we're gonna cover. Uh
00:33 we'll kind of look at some shared that both males and females have.
00:37 right. But then once we do , we're gonna then move in and
00:39 gonna focus directly on male reproductive And then on Tuesday, Thursday,
00:45 ? On Tuesday, next week, look at the female reproductive system and
00:48 we'll start looking at how those systems regulated through hormones. And then in
00:54 lecture following that, we will then look at how we bring the male
00:58 female reproductive systems together to actually start organisms. All right. And
01:05 we'll be looking at uh placentation, , uh embryogenesis, that sort of
01:11 . Uh So, uh just to of give you the big picture,
01:15 is not a sex talk. So is not like a, a,
01:19 know, a class. This is what are the structures and how do
01:24 work class? OK. And so starting point is to kind of correct
01:30 that has pervaded through. Um I'm not going to, I'm going
01:35 call it social consciousness, but it's . It's, it's even permeated into
01:39 sciences. The difference is between some terms that we use over and over
01:46 over again to describe sex and And the other term is attraction.
01:50 what are the differences and what do words mean? And why do they
01:54 ? Because part of the way that talk to one another means we have
01:58 have a common language, right? in probably in the last 20 years
02:03 so, two words have really been together and they mean absolutely two different
02:08 . All right, we're gonna talk the difference between what sex is and
02:12 gender is as a first step. to start everything off first, to
02:18 humans are sexually dimorphic, right? dimorphic. And what does that
02:25 Well, that means that there are between the two sexes that exist in
02:33 uh humans really. And this is much true in all mammals, all
02:37 . And so what they are, are the characteristics that you can look
02:40 something and say this is this sex it goes beyond just the sexual
02:45 All right. And so here, got a couple of list of things
02:48 you can kind of see here. these are, for example, secondary
02:52 characteristics, right? Sex, secondary characteristics are those features which are inherent
02:57 an organism that distinguish it between one another. All right. So for
03:03 , the male body type is typically now notice I use the word typically
03:08 there is a bell curve in all these things. So if you were
03:11 think of the male uh uh what would the male shape be look
03:18 ? Hm, right? Broad So, so what we term it
03:23 we call it like the carrot All right. So the carrot shape
03:27 broad shoulders and we thin down like . So you can see it's kind
03:31 like a carrot, it's a upside down triangle, right? When
03:35 get older, you add the circle front. So you have the apple
03:38 well, right? And then what the female? What is the typical
03:42 shape? Hourglass? That's an easy because that's one that we hear about
03:46 see about all the time. That's example of a secondary sexual characteristic.
03:49 males have an hourglass uh uh Yes, but it's typical to a
03:54 . Could a female have a carrot ? Yes, but it's atypical.
04:00 right. But this is an example secondary sexual characteristics. Facial hair is
04:04 secondary sexual characteristic, for example, the size weight, anatomical structures.
04:12 so I've actually thrown up here, of the things that you guys have
04:15 about. Um but tangent. So example, this is the ox
04:20 the male and female pelvis are And so when anthropologists dig up
04:27 they look at that, that, skeleton, they say this was a
04:31 that lived during this period of And they know that because the bones
04:35 the female are different than the bones the male, not subtly but
04:40 And this is just trying to, to show you an example of
04:45 There are behavioral and cognitive differences. , when you think cognitive, that
04:50 mean one is smarter than the other some days you might want to make
04:53 case. All right. But for , males are really, really good
04:58 the whole at three dimensional orientation and . So we can take an object
05:04 we can twist it in our brains kind of see three dimensionally what it
05:07 look like. Women struggle with that the whole. But you know,
05:11 you ladies are really, really good is remembering where things are. There
05:16 been studies that have been done like taken maps and said, we want
05:19 to look at this for a minute and here's all these different things on
05:23 , on the picture and then they it away and they say here's a
05:26 , the same picture. But we stuff and added stuff. Can you
05:28 out what it is? Guys stare that. We can't figure out what's
05:31 added or what's been taken away. are like, yeah, these 40
05:34 is what's been added or what's been away. This would be an example
05:38 cognitive differences. Ok. Behavioral Ladies behavior behave differently than men do
05:46 vice versa. Ladies, have you looked at a bunch of guys
05:49 boy, they're a bunch of Yeah, I'm looking at,
05:53 they're, they're laughing because yes, longer you're around the opposite sex,
05:57 more you realize how different they are you. All right. So there's
06:03 these differences can be subtle or they be exaggerated and there is evidence that
06:10 actual sexual selection towards these traits. other words, because you require a
06:16 and a female to reproduce. There favors or, or, or characteristics
06:22 as a organism as a whole, are more attracted to which pushes the
06:29 of that trait being elevated within a organ or society or group,
06:37 So the reason we are, the we are and why we're so different
06:41 because those things resulted, made, those sexes attractive and so they people
06:48 as a function of that and it those particular traits into the population right
06:58 . I said there are a couple terms here that we need to be
07:01 of and I said we have we have gender and we have attraction
07:04 you'll notice I don't even have attraction here. I want you to
07:06 be aware of at least these two . All right, in biology and
07:11 we are as a biology course we refer to as things being,
07:14 a biological sex. All right. this is really the result of the
07:19 or absence of a specific chromosome. Y chromosome being the one that males
07:24 X X being the one that females , right? The type of gonad
07:28 have is an example of something that rise to biological sex. So if
07:33 look at an organism, you see pair of testes and you go into
07:36 and you and you dissect them, go OK, this is a
07:40 right? If you cut into an and you find ovaries, you'd be
07:44 , oh, that's a female because characteristics belong to the biological sex.
07:51 hormones are being produced. And we're to see that there's a lot of
07:54 hormones. But we've already talked a bit about the dominance of certain hormones
07:58 males and females, right? The anatomy, right? External genitality.
08:05 are all ways that we can look an organism for the most part and
08:08 this is its biological sex. And of you are saying that, but
08:11 , Doctor Wayne, I know about . Intersex is a term that we
08:16 to talk about development or it's, , this, I'm gonna get it
08:21 here. It's DS D and uh, the last terms are sexual
08:27 and it's a developmental, sexual In other words, during development,
08:32 didn't go. Right. And so have occurred, right. And abnormal
08:38 mean wrong. It means not within regular population. I want you to
08:43 clear on that. There is also is, what we refer to as
08:47 sex. And this is determined specifically the chromosomes. And so if you're
08:52 X, you are a female, you're X Y, you are
08:56 And again, there are abnormalities within population what we call again, really
09:02 result of that intersect where you have . So you can have things like
09:08 syndrome or Turner syndrome. These are you have extra or too little or
09:12 few of those particular chromosomes. And are a plethora of problems that can
09:19 through the genetic, these genetic All right. So we have biological
09:26 , which is based on anatomical For the most part, we have
09:30 sex, which is based on chromosomal . And then we have gender.
09:35 , gender is a term that that into the lexicon into the biological lexicon
09:41 about 1956 or 58. So it's fairly new term and this term arose
09:48 of a paper that was written by psychologist who was doing this horrific experiment
09:53 humans and I'm not gonna go into it was, but it was,
09:57 , it violates every ethical thing that could possibly imagine. And if I
10:02 you about it you'd be like, can't believe they did that.
10:04 it was 1958 and they didn't have the rules we have now.
10:08 But what gender was, was a taken from the social sciences. And
10:13 it refers to is the differences between and femininity. All right. So
10:20 can have a masculine woman. Do believe that's true. Yeah. Could
10:24 have a, a feminine male? also true. And could you have
10:29 in between? Yes. So what refers to is the degrees of masculinity
10:34 femininity and it refers to a behavioral societal traits and we assign those traits
10:40 on observation, right? So when say guys act like monkeys or
10:46 you know, when we misbehave or bunch of pigs, you, you
10:51 in your mind, there is a behavior, right? And so that
10:55 a masculine behavior, doesn't it? when we say women are dainty and
11:00 and sweet and all the other fun you want to throw in the sugar
11:03 spice and everything nice, right? are we done? What have we
11:06 ? We've assigned traits and saying these feminine. Ok. So gender has
11:15 to do with the external structures of body. That's anatomical. It's
11:22 then there's the third term that you see up here and we're just gonna
11:25 deal with it. That's attraction, ? Attraction simply is what arouses you
11:32 . All right. And so you be masculine, female, be attracted
11:38 a male and you're still what? ? Right? So you have your
11:44 , your gender and your attraction and all different things and they all mean
11:49 things right now, what am I test you? Well, what's the
11:53 of gender? What's the definition of ? We're not gonna worry about attraction
11:57 that's not what this class is Our class is about what are the
12:01 and what do they do? And to understand all these things, I
12:05 you to have that baseline. And , I'll be honest, I'm,
12:09 a real stickler about, about this whenever I see a form that ask
12:13 what my gender is. I actually it out and put sex because they're
12:16 asking me if I'm mascular. If feminine, are they? Yeah,
12:20 know. I'm gonna ask, what I say? All right. So
12:25 you've never taken any sort of let's kind of understand who we are
12:29 a genetic level. All right. so this is baseline, heredity.
12:33 right. First off, we have , which is where all our genetic
12:39 is held and humans have 23 So what we do is we inherit
12:46 chromosomes from mom and we inherit 23 from dad. So that's a
12:50 right? So that's 46 total But we refer to them as 23
12:55 . All right. And so what say is, is that because we
12:58 a pair that is a ploy, many multiplicative of our chromosomes do we
13:05 ? It's not the number. So are diploid. So two die
13:11 So our ploidy is deployed. Most are diploid. All right. And
13:17 when we see this as an abbreviation the text and stuff like that,
13:20 see things like two N and that just refers to. All right,
13:24 not gonna bother counting up the So it's just double whatever the number
13:28 chromosomes we have. So we are times 23. So that's the
13:33 Now, of those 23 chromosomes 22 pairs are what we refer to
13:40 autosome. All right. And so that, what that means is they
13:44 have very little to do with determining sex of an organism. It's the
13:49 , the last pair which are referred as the sex chromosomes and they're identified
13:54 the sex chromosome. Because what they when we first started going through the
13:58 is we started learning, going oh chromosome? When it's present results in
14:02 in and creating a male, when take the y away, you don't
14:06 a male, you get a female so this is why they're referred to
14:10 the sex chromosomes. If you look them and you can see up here
14:13 the picture in that little thing, X chromosome is huge. The Y
14:16 is a little tiny, broken right? And so you can have
14:19 with that lady is like, the Y chromosome is just a little
14:21 X chromosome, right? And the is is there's about 30,000 genes on
14:26 X chromosome. There's about 30 genes the Y chromosome. And of those
14:30 genes, are they all involved in and sex determination? What do you
14:34 ? No, that's, that's a answer. No, most of them
14:37 to do with a whole bunch of stuff. But remember women, you're
14:42 to inherit an X from your mom an X from your dad. So
14:46 have two X chromosomes and males. inherit an X from your mom and
14:51 wife from your dad, right? you have an X chromosome to do
14:55 that autosomal stuff from your mom. then your Y is what's determining your
15:02 sex? All right. Now, said all that, what is the
15:09 here? Well, in order for to reproduce what we need to do
15:13 we need to create a cell that can then merge with another cell.
15:18 right. So we're basically taking these cells, one from mom and one
15:22 dad and we call these cells Right? So mom produces a game
15:27 . Dad produces a game meat. gamete that mom produces is gonna be
15:31 an o site. The game that produces is called a sperm. But
15:35 they were deployed, what would happen , is you'd have two N plus
15:40 N and they'd come together and now have an organism that's four in and
15:44 doesn't work because the next generation would four plus four and then you'd have
15:48 in and then eight in plus eight would be 16 in. And you
15:51 see how this becomes a nightmare. , this is ok in plants.
15:56 fact, oak trees are the weirdest ever. They have like this infinite
16:00 of chromosome sets that they can do you took doctor uh farmer or doctor
16:05 uh uh uh biology class you got it was if you took the general
16:10 , you got to mash down strawberries extract the DNA in the classroom,
16:14 of cool. Right? Strawberries are , you know, so they've got
16:20 and tons and tons of copies of same thing, but that doesn't work
16:24 humans. So, what we had do is we have to come up
16:27 this strategy that allows us to reduce number of, of chromosomes in our
16:35 because the gammy needs to be one . They have to have 23
16:40 not a 23 chromosomal pair, So the process of the reproductive
16:46 and first and foremost is to produce gamm that is then capable of taking
16:52 portion half of the genetic code that parent has and then taking it to
16:57 other gamete and bringing those two gametes to create a unique organism that is
17:04 function. All right. So gametogenesis is the process of making those
17:11 So when the first thing, when think about a reproductive system is
17:14 it is its job is to produce gammy. Now, to help you
17:19 this process, which we're gonna go here, you need to first understand
17:24 . You guys all learn about mitosis one point in your life. If
17:27 took biology at high school or if taken biology here in college, you've
17:32 seen it 1000 times and every time kind of go, I'm going to
17:35 it and OK, check mark and move on, right? It's multiple
17:39 and what you have, you take cell which has, it's, it's
17:43 in number and then it goes through phases of duplicating its DNA,
17:48 So it goes from two N to two N. And then what it
17:52 is it takes those chromosome pairs and them up on the center and then
17:56 splits the cell in half and it the chromosome number or sets equally between
18:02 daughter cells. It splits its nucleus well as the cell. And then
18:06 end up with two clones that look the same as the parent and exactly
18:11 same as each other. All as when the parents started off.
18:16 so that was, that's what mitosis . And so there's the four
18:19 prophase metaphasis and a and then you through the cell division and you
18:23 that's the division of cytoplasm where it's cytokinesis, that's the term that we
18:28 . And then that's how we get cells. And this is kind of
18:31 it looks like right here. All , this is an easier way to
18:33 of look at it. So you see up there if you look at
18:36 top of the picture up here. me find my little thing right up
18:39 . You can see we're, we're this simple, we're only giving it
18:42 chromosomes, right? But it's two . So it's two times two,
18:47 is four. If you count them , it's like, oh yeah,
18:48 see four up there but 22 What do you think the pink belonged
18:54 ? What, what does social convention pink belongs to female? Right?
18:59 those that, that's DNA that belonged mom, they put in green up
19:04 to distinguish it from the background blue normally they use blue, right?
19:09 would be from dad. So you chromosome one and two from mom.
19:12 one and two from dad you can here, I've duplicated each of those
19:16 . I've aligned them. I, separating it out so that each daughter
19:21 gets its own chromosomal set. So you looked at this and counted
19:25 you'll see its same number of And that's why the daughters look exactly
19:29 same as the parent. That's mitosis a nutshell. Right. But as
19:34 mentioned, this doesn't work if you're to reproduce sexually because if I'm taking
19:40 gammy from mom and a game from and they each produce one of
19:44 then the next generation will have twice amount of DNA. And so meiosis
19:52 a solution to the mitosis problem. again, you've probably seen my or
19:59 before. All right. And very when it's taught, they say,
20:03 , look meiosis, you have all same steps and you do and what
20:07 do is you replicate it twice. meiosis one and then meiosis two,
20:10 each have a prophase metas. And , you can go look at those
20:14 what they mean. But if you're paying close attention, you don't see
20:20 you get the, why you need second division. And it's not just
20:24 you just go through mitosis twice. because if you went through mitosis
20:29 you'd have to replicate your DNA at middle step and it doesn't happen
20:34 Instead, what we're gonna do is gonna do something unique in one of
20:39 early stages in pro phase. So going to replicate our DNA like we
20:43 do. All right. But what ? I'm just gonna go to this
20:47 here. All right. Do you the pink and the blue now?
20:55 . So on the left here, we have is we have mitosis,
20:58 ? And so you can see over two in, I've doubled my
21:01 I've lined everything up. There's my , there are two in as well
21:04 here. I'm starting off as two . I'm going to end up down
21:07 at one end. So something unique happening whenever something weird or something
21:11 you have to say, where is happening? And if you look
21:15 if you look here, this is the change is. So I've still
21:19 the DNA. But what's happening is that the chromosome pairs? So like
21:25 and dad's DNA, when it's they all stick together, they form
21:29 is called a tetrad right now. normal circumstances, I pulled a couple
21:34 guys up here and I demonstrate but you're all sitting there looking at
21:37 like, please just get on with . So we're not gonna do that
21:40 . But do you see how, , I have a pair here.
21:43 there's dad's DNA and there's mom's they're not hooked up, they're not
21:48 to each other. They're floating freely of one another. But over here
21:55 connect with each other. And hang with each other. All right.
21:59 that's the tetrad. So when they and you can see up here,
22:03 dad's DNA aligned, there's that same of moms and it's aligned so that
22:08 I divide this, each half of pairs are going to go to the
22:13 over here. Because when I line , what happens is when I split
22:20 in half, I only get either DNA or I only get dad's
22:25 The gamm only gets half, but has two copies of that half.
22:32 so because I have too much I have to go through that second
22:35 and that's why we go through that mitotic step. So I become haploid
22:40 when I go through the division, ? So I go from 2 to
22:45 in but I still have twice the of DNA. Does that kind of
22:50 sense or do you want to visually it visually? See it?
22:55 guess what? I'm gonna have to a couple of you up here.
22:59 right. So I need two So you are, you guys are
23:02 in the splash zone and I need young women who are going to come
23:07 here. You want to see So you get to see it.
23:11 right. Come on actually. No way. Uh OK. Come
23:18 , Jalen. All right. We're make this easy. We just come
23:22 to the stage. All right. the men are quick you guys to
23:26 what chromosome are we gonna be? can't be not sex. Chromosome
23:34 All right. So here is dad's number one. Do you see
23:37 Excellent. No, now we're gonna you way over here because you don't
23:40 yet. All right. And then need Chomos number one from mom.
23:43 you see that? Look at We got a mom chromosome and a
23:46 chromosome, chromosome number one, OK. So what's gonna happen?
23:50 gonna do mitosis first. So the thing that happens in mitosis, we
23:54 our DNA. So when I duplicate DNA, see we're connected together and
24:01 duplicate our DNA and, and then we're gonna do is we're going to
24:07 along the center. So we're gonna the back over here and then we
24:12 in the center. All right. then what we're gonna do is we're
24:18 divide the cell cytokinesis and look, get two daughter cells copy of
24:25 sorry. And a copy of copy of mom, copy of dad
24:28 is easy, right? OK. where we start, dad's DNA,
24:35 DNA make a copy, make a and then we make a tetrad,
24:45 all connected together. Now, notice can imagine there's 22 other chromosomes,
24:51 all lined up, right? This this, they can't separate from each
24:54 because they're all connected. So when go through the first cytokinesis. Look
24:59 happens. One cell gets two copies dad's DNA, but they're connected.
25:07 ? And the other one gets two of mom's DNA. This doesn't
25:12 right? So what do we have do? We have to go through
25:14 second cell division. So we end with four daughters, each one with
25:22 copy. So they're haploid. All . And these are gays. Thank
25:28 so much. You understand, you are winners. So that's what you're
25:34 here. It's that tetrad that that allows us to then go through
25:40 second division and reducing the total copies chromosomes that we have. This process
25:48 gametogenesis is a shared um process between males and females. All right.
25:56 all the steps are going to be same in males and females, the
26:01 is gonna be different and the timing going to be different. So when
26:05 think of go to Genesis, I , OK, I'm starting off with
26:09 cell and then at the very end , that's deployed. And at the
26:12 end, I'm going to end up a haploid cell. Now, in
26:16 for this to happen, the first that we need to do is we
26:19 to make lots and lots and lots gas, right? So in order
26:23 do that, we have to create very large pool of gas. So
26:27 first step of al gametogenesis is Let's make lots all we got to
26:32 is just duplicate, duplicate, duplicate. And so that's what that
26:35 step is. Right. That's a step. And during this step,
26:38 is where you're gonna see the game . All right. And that's just
26:41 word that says the, the, prefix just tells you the generic.
26:45 a game I'm making games. But cell that I'm producing the gonia part
26:50 you that I'm in mitosis. All . So you can imagine, I'm
26:55 tons and tons and tons and tons gamines. Now again, it's gonna
26:59 different in males and females. What , what that translates into the second
27:04 is the myotic step. So what going to do is we're going to
27:08 one of these gam eats. All . So you can see here,
27:11 basically making lots of these, but of them is going to come out
27:14 differentiate and once it differentiates, it's to go through these meiotic steps to
27:19 that haploid gam meat. So that's second step and the second step.
27:24 so these type of games are called . So the, the, the
27:30 C Y T E tells you it's in nature. And then the third
27:35 is this step of modification. So see here, I did the three
27:40 right mitosis meiosis modification. The third here, what we're doing is we're
27:46 that game that Gammy that we made it's not quite ready to actually go
27:52 and fertilize or join up with another . Instead, something has to
27:57 some sort of change needs to This is that modification step. And
28:02 uh what we're gonna do is we're to change things and what we refer
28:06 this as is a tid. So you see T ID at the end
28:09 the world, that just means, , I'm still in the stages of
28:13 . All right. So it doesn't if you're looking at spermatogenesis or o
28:17 , these three steps exist and you're to see something gonia. So,
28:22 , in males, it would be . In females, it would be
28:26 oh gonia. All right. So see a mitotic step. You'll see
28:30 meiotic step, you'll see a modification in all three. And so our
28:34 point is the easier one. Can say something that's kind of offensive?
28:39 that all right? What do you you can tell me now?
28:43 OK. I can't. All She said no. So I can't
28:47 anything offensive now. OK. They're with it. All right. So
28:53 gonna use this because I think this the easier one to learn first and
28:58 take this as the model and then it to oh Genesis. I'm
29:04 I can't help it. I've I've got to be rude. One
29:08 the things I'm gonna try to prove the next three days is this
29:14 So just get ready to be OK? Men are simple. Women
29:18 complicated. OK? I'm gonna try prove that this is the first step
29:27 me trying to prove it. Women , men are simple. Women are
29:31 . All right. If after three , I haven't proved that point.
29:34 can come in my office and yell me perfectly. OK? With
29:38 it's never happened, but I'm All right. So first step,
29:44 looking at spermatogenesis from first step of is going to be the mitotic
29:50 All right. And so what you see up here is that we are
29:53 off with the progenitor sperma. There's stages here and we're not going to
29:57 hard on this type A type B . It actually even gets weirder.
30:00 type a dark type, a pale yada yada yada. But the idea
30:04 is I'm starting off with a population cells and I need to make lots
30:08 them. OK. Now, I you to think about, I
30:12 we haven't talked about this yet. there's a lot of jumping forward and
30:16 back in the male ejaculate in The average ejaculate contains about 200 million
30:23 400 million spermatozoa. So there's a of cells there. All right,
30:30 you didn't have the mitotic set uh steps, you can imagine the number
30:35 copulative events, the number of times uh a male could engage in sex
30:39 they ran out is probably incredibly All right. So you need mitosis
30:45 that you can constantly produce sperm. we're gonna see here that men produce
30:51 a lot. That is primarily our . Men are simple. We make
30:57 . Ok. So, first step , we're going to make tons and
31:01 of that. All right. So the sperma goa that you're producing here
31:04 they're going down, this is just , look, I'm going to pull
31:07 out that is in this process of . And then once I get
31:10 I'm just going to keep amplifying. I can get tons of these cells
31:13 then each of these cells that I are then going to go through the
31:17 steps. So this is meiosis, ? And so you start with the
31:21 gonia and it switches and becomes a spermatocyte right now site. Remember we
31:27 deals with meiosis and we have a one and a meiosis two. So
31:32 means it's in meiosis one, it through those steps that we just described
31:36 haploid and divides. Now you're in two. So you're now a secondary
31:44 and then the secondary spermatocyte has to uh go through that division again,
31:52 ? So it's first division, second . And then now the product of
31:57 second division is entering into the third . The modification stage which we call
32:04 . Notice spermatogenesis is the whole process little step is spermiogenesis. And what
32:09 doing is we're taking a sperma tid we're going to modify it so that
32:13 becomes the thing that we're most familiar . And you can see up here
32:17 the picture here we have a sperma and you can see what is,
32:21 round and it's also connected to the cells. And then when you think
32:28 a sperm, your entire life, is sperm supposed to have looked
32:32 When you think of a picture of sperm, what does it look like
32:34 you? A fish tadpole is another I hear. All right. So
32:39 got to turn that round cell and it a swimmer. So this is
32:43 modification process, right? And so where we get to the spermatozoa.
32:47 , spermiogenesis allows us to go through modification so that we get the spermatozoa
32:53 there's quite a few modifications that take . Now, spermatogenesis and again,
32:59 knowing the anatomy is going to take in a very specific location which we're
33:02 to get to by the end of class, it takes place in what
33:05 called the seminiferous epithelium. All So when we get to that,
33:09 just say, look back a couple slides to know where we're taking
33:12 This picture shows you the Seminis This is within the gonad, within
33:18 testis. All right. And so this is showing you is that this
33:21 a big giant tube. This is basement membrane. So the wall of
33:25 tube and here you can see the . So we start off down here
33:30 the spermatogonia. And then as you through these become spermatocyte and ultimately sperma
33:35 , those sperma tis then develop and and work their way up to the
33:40 and then are released into the lumen the seminiferous epithelium. This picture over
33:46 just shows you the time scale and of what's going on. So here
33:49 am down here, here's spermatogonia color to sperma tis, color coded then
33:55 sorry spermatic sites, then ultimately sperm and the time it takes, if
34:00 is a graph based on time, takes about 75 days for a spermatogonium
34:06 go through all of these stages and become that sperma tid. All
34:14 Now, we said spermiogenesis is a . So what's going on? We
34:18 off with this round cell and we're to end up with this elongated
34:22 And so we're doing, gonna do couple of things to make this a
34:26 . The first thing is we're gonna so that it creates this packet of
34:30 that allows it to penetrate the protective on the o site, which we'll
34:35 to a little bit later, So the goi apparatus becomes the
34:39 And that's what you're seeing here is formation of an acrosome. All
34:44 you're going to see the formation of flagellum. So those uh basal
34:50 the centris are going to migrate and you're going to get this long tail
34:53 comes out, that's going to be swimming portion, right? You're going
34:57 say, wait a second, we energy to make us a swimmer.
35:01 we're going to start making and multiplying mitochondria and we're going to put them
35:05 the base of the flagellum. And the last thing you're going to do
35:08 you're going to say, well, second and last thing is you're going
35:10 say this nucleus is way too We need to pack it down.
35:13 about you go home over a right? You have all that
35:18 right? You just, you know , oh, I'm just gonna carry
35:21 bags of laundry. No, you it into the suitcases, you tighten
35:25 up like you get those shirts, know what you'd normally fold nice and
35:28 like, I don't care about I'm gonna roll it up into a
35:31 little ball and I'm gonna jam everything the suitcase. That's what we're gonna
35:34 with the DNA because we wanna make lean and mean, we wanna make
35:38 small so that it can be packed and get to where it needs to
35:44 and we got to get rid of excess stuff and that's where we're gonna
35:47 all that cytoplasm. And so this showing you the excess cytoplasm. Uh
35:53 going on here is the packing of nucleus. And so at the end
35:56 all of this process, which if look at this chart takes quite a
36:02 of time, right? I we're looking at almost 20 days to
36:07 that all taken care of so that can finally produce this sperm aid.
36:12 , spermatozoon, spermatozoon is singular. is plural. So when you look
36:18 a sperma zone, this is the that you see, these are the
36:22 important parts, we have the All right, the head is what
36:26 the nucleus, right? Or it's not the nucleus of the nuclear
36:30 It's been repackaged. We have the , remember it's the modified Goldie
36:34 It contains all these enzymes that are going to allow it to penetrate through
36:38 protective layer of the o site. have the mid piece. This is
36:43 all the mitochondria are. And then , you have the long tail and
36:49 the flagella that is responsible for its . Is there anything else that we
36:56 in this cell? No, we've energy, you know, and the
37:03 of the seminal plasma is going to the nutrients, it needs to allow
37:07 sperm to swim. But notice we have an er because we don't need
37:10 make proteins. We don't need any the other machinery of the cell because
37:14 we need is packed right here and is gonna get it to the
37:20 All right. So I'm gonna stop . Does spermatogenesis make sense mitosis biosis
37:27 , spermiogenesis making these changes? Be of what little changes are taking
37:34 Ok. Ready for our genesis For the most part takes place after
37:43 , boy, his puberty, testes , seminal uh epithelium or Seminis,
37:49 grows and expands. It gets It's filled up with the sperm as
37:53 producing. So that's about puberty. begins a little bit earlier. All
38:01 . So, again, osis just gen, I'm producing the female
38:05 All right, we're gonna go through mitotic proliferation. We're going to see
38:09 meiosis and we're gonna see some slight that takes place. But the
38:15 the myotic stages take place out in 20 of female development. So you
38:22 still in utero when the gonads are formed. And as the female gonads
38:28 being formed and the cells that are to make up, the o sites
38:32 being formed. That's where you see taking place. You see this massive
38:37 . So this is week 20 of compared to the male after puberty.
38:42 right. Now, some of this does take place in the male early
38:46 . But really, we're talking the mitotic stages in female. Is that
38:52 ? All right. So week 20 development. All right. And so
38:56 produce roughly between six and seven million sites now, ladies, do you
39:02 on having 6 to 7 million Ok. So you have plenty in
39:07 number, right? But even in process, early on between four and
39:14 million O sites fail to go through properer programming and they die off.
39:21 right. So what you're gonna see as you multiply and divide and create
39:27 big pool, they're gonna all be , hey, don't stop.
39:32 we want you all to enter into and so they all do. They're
39:37 , all right, meiosis. Here we go. They multiply their
39:41 and then because they fail in this , that's where you're gonna lose between
39:46 and five million. All right. two million, anyone here planning on
39:50 two million Children. Ok. So all good. Two million is
39:57 It is. It's enough. OK. You're shaking your head there
40:00 a second. Julie. I, , I don't know. Ok,
40:03 two million, two million, you're , you're not jealous right now.
40:06 million per ejaculate two million cells for entire lives. OK. I don't
40:12 you to be jealous. All Now, what's happened is you've entered
40:16 Myosin one, you've basically multiplied your and you've stopped. All right.
40:22 at this point, what you're gonna is you're going to form what are
40:24 follicles in the ovaries which provide the cells that are going to help
40:30 the O site develop a little bit and then everything stops and then you
40:34 to wait until puberty. So already guys are ahead of males at this
40:40 during gammy development, right? Because entered into meiosis and you're not even
40:46 yet and then nothing happens for a period of time and then you turn
40:49 , into puberty and then what we're to do is at puberty is we're
40:53 to re initiate the process. But , what we're gonna do is it's
40:59 different. All right. Not all cells at once. You're going to
41:02 through meiosis, right? What we're do is based on the presence of
41:07 hormones is we're going to select a of between 10 and 30 cells.
41:13 right, and we're gonna tell those to 30 cells is we want you
41:16 reinitiate meiosis. So remember you're starting with about two million cells at puberty
41:21 every cycle you're selecting 10 to 30 to go through the process of
41:28 Now, generally speaking, when women Children, how many do they give
41:33 to normally per birth cycle? All right, on occasion, you
41:39 get two. So when you hear to 30 something must be going on
41:45 . We're not going and using all to 30 because you are not birthing
41:50 to 30 babies at the same All right. So what's going on
41:56 is we're going through the my All right. So, we
41:59 hey, we, you, you . So we want you to start
42:02 so they go through that first myotic . All right, we're gonna get
42:06 that in just a second. But they're doing is they're continuing the process
42:09 they're gonna start working towards that so they undergo this second division. All
42:15 . So you go through that first and then what you're gonna do is
42:19 now become a secondary O site. right, secondary O site.
42:23 We've moved on, but not every of them makes it that far.
42:28 what happens during this process is some them stop responding appropriately to the hormones
42:35 are being produced in the body. right. So if you're starting
42:38 let's just make it simple. If starting off with 20 what's gonna happen
42:41 , is through a process called dominant selection is that those 20 are winnowed
42:47 to one. And it's that one really kind of makes it to become
42:53 secondary ho site. And then once get and become that secondary O site
42:59 grows and becomes the dominant follicle, the one that's destined for ovulation.
43:07 right. So the other ones are we refer to as becoming a tri
43:11 die away and we'll talk about this a little bit later, but that's
43:15 essence, what's going on. All . So, biosis two is
43:21 we need to become that tid, ? So we've, we've divided once
43:25 it's secondary side, we need a division in order to become the O
43:31 . And then once you have an tid, there's a small maturation process
43:34 this doesn't occur until after ovulation and occurs in response to fertilization. So
43:45 a secondary o site that's ovulated, out. The sperm comes along,
43:51 to the surface of that cell and that is the signal to say,
43:56 um we need to still divide. we go through the second ionic division
44:00 then small modifications take place. So existence of an O tid is
44:06 very small. It's like a couple minutes. And now you have an
44:11 tid and that spermatozoa basically form a organism. All right. So the
44:20 step after that fertilization and after that division and when you see that secondary
44:25 , so what you see here is get that division. So there is
44:29 , your um O tid, you what is called a polar body.
44:33 the extra, the extra DNA. not going to do anything. It's
44:37 let's get rid of this. And now because the sperm is already attached
44:41 the O tid, you get absolute and from that fertilization, fertilized egg
44:48 or that fertilizing process, that's where get the new organism. It has
44:52 DNA. It has um characteristics that gonna be shared from the DNA that
44:58 been that it's getting. So if put it all back together again,
45:02 of having it all separated out and all weird. Well, first off
45:07 that right? Is, are women little bit more complicated? Just a
45:11 bit? Ok. So you can here it's the same thing. It's
45:15 . It's just the timing happens very in mitosis. All right, meiosis
45:21 here at developmental week. 21st division at ovulation. Second division occurs at
45:30 , but all the same things are place. Ok. So that's gametogenesis
45:40 a nutshell. And that wasn't a . What I wanna do is I
45:46 to shift just briefly kind of go the shared structures before we do
45:51 Are there any questions about these Can you see how gametogenesis? The
45:59 basically covers both o genesis and Does that make sense? Yeah.
46:06 the hard part is just what what's unique about them, right?
46:09 there's not a lot of uniqueness other the timing and really how much is
46:15 made. So we're going to cover of this development a little bit
46:22 But I want you to understand that reproductive structures in both males and females
46:27 derived from a common structure. All , what we have is what we
46:32 a bi potential gonad. All And an undifferentiated genitalia. And then
46:39 happens is is that when that program week 20 occurs, that's when you're
46:45 pushed one direction or another. the primary reproductive organs, we refer
46:50 them as gonads, males have females have ovaries. All right,
46:54 have a whole bunch of accessory structures go with these that are unique to
46:59 of the individual sexes. We're gonna our specific type of game, but
47:05 already talked about this, the, mechanisms and those are very, very
47:09 . So, males produce for which we were just gonna call
47:14 Uh Females produce that secondary o site we're just gonna call eggs just to
47:18 our lives easy sometimes. All But it's the, the same
47:23 we're gonna use the similar hormones. gonna be some unique ones in females
47:26 are responsible for pregnancy and stuff. for the most part, the same
47:31 are present and then to bring those together, this is just the process
47:36 copulation. So you need a male a female. They copulate, you
47:40 use another term coitus if you're like , thank you. Right? Or
47:45 intercourse if you want to be prim proper. In fact, the reason
47:49 , you know, I've mentioned the gender, the reason gender became so
47:53 is because in polite company, when say sex, it means something.
47:57 you know what sex are you? , no. Right. So that's
48:01 they started using gender because it sounded polite. It didn't refer to the
48:05 of and that's why it got all . All right. So this is
48:13 perennial. This is external structures. what I want to show here is
48:17 these structures are exist both in males females. All right, we have
48:22 different genitalia, but there are some in general of the perennial. That's
48:27 area between the pubs and the So you can see here we have
48:30 diamond structure. There's the pubic pubic bone down there is the
48:34 There's a toxic on either side, isl tuberosity. So you can see
48:38 there's this diamond and if you draw lines through them, you create two
48:42 . One triangle is referred to as euro genital triangle. The other triangle
48:45 the anal triangle. The anal triangle pretty simple. This is where the
48:49 is found. And you can see we have muscle there. That's the
48:52 anal sphincter. We've talked about that we went through the digestive system shared
48:57 , right? When you go and at the genital triangle, you can
49:00 structurally there's external genitalia is very, different, but the muscles are
49:07 very the same. All right. the genitalia are different because of the
49:12 differences that take place. But in of the muscles, all right.
49:17 let me just say, so you the urethra and the vaginal opening in
49:19 female here, you can see the , uh the penis is being is
49:23 and away but it's basically in the area. All right, it sits
49:27 that pubic bone is. But what idea here is, look at the
49:30 , right. So there's three muscles should be aware of, they're all
49:33 . So this muscle right here All right, that's called the superior
49:38 muscle. You might see it sometimes as the superficial transverse muscle. It's
49:45 term and sometimes you might even see thrown in there as well,
49:49 But transverse means it just crosses and the closest one to you. So
49:54 or superior. All right, then the edges, that's the isco
50:01 So that basically makes the wall of triangle and then along the center,
50:07 the bulb spons. And we start at the structure of the penis,
50:11 going to make, oh OK. understand why it's called that because that's
50:14 bulb of the penis, right? females have the same muscle. All
50:19 . It just lines within the And so you can see it being
50:23 right there. So all muscles are the same within the premium. But
50:31 we want to focus on, as said, today's talk is about the
50:34 reproductive system. And so while there shared structures, there are unique
50:39 And so that's what I want to through. And I said a couple
50:42 minutes ago against your wishes is that are simple. So men are simple
50:51 we have two functions. When it to reproduction, we make sperm and
50:57 deliver sperm. That is our Make sperm delivers sperm. So when
51:01 look at the reproductive systems, if think in terms of, I got
51:04 make sperm and I got to deliver , then each of these structures has
51:08 play a role in that process. . So in terms of those
51:14 we're gonna work our wake. I you at the very beginning that the
51:17 of this unit from, from uh digestive system, onward, tube
51:21 we're going to start with tubes that found in the gonads. These are
51:24 testes. And so we go from testes to the epitome. There are
51:28 that are formed from the epis and . All right. So we're going
51:32 follow the ducts outward. Uh Then going to deal with the penis as
51:36 copulative organ and then we're going to with also the sex glands that allow
51:40 to make the material through which the are going to be delivered.
51:45 these are the structures of importance. are three different sex claims that we're
51:48 talk about and everyone already knows one them because you hear about it all
51:52 time. Prostate, right? So , you've heard of the prostate.
51:59 now we dive into the anatomy and a little complex, right? So
52:06 we have the testis. This is paired structure. We have two of
52:09 , just like the ovary is going be a paired structure. There are
52:11 of them, it's covered by a of tunics. The first tunic is
52:15 the tunica vaginal. That's the outer . It's a serious membrane.
52:19 it produces fluid and it protects the testis from friction and strut
52:25 and damage. All right. And underlying that is the second structure which
52:29 called the tunica Albia. So, the air you can see here is
52:33 tunica vaginal tunica vaginal and then all white stuff that penetrates into the testes
52:39 . That's tunica albinia. And the albinia is what separates the testes into
52:46 lobes and within each of the That's where our first tube is
52:51 This is the semi seminiferous epithelium, one that we said spermatogenesis taking
52:57 it's the sperm factory. And so have many, many, many semi
53:04 , uh sorry, seminiferous tubules within is the epithelium. All right.
53:10 this is what accounts for the mass the testis. So when little boys
53:15 producing sperm, they have very, small testes. All right, they
53:19 puberty. The first thing that grows the testis because you just put,
53:23 it up with a whole bunch of and spermatocyte. It makes up roughly
53:29 of the mass of the testis. right. And the semini first tubule
53:33 going to go to the next tube we'll get to in a second which
53:36 the red testis, which then goes to the epi All right. And
53:39 what this is kind of showing This is only showing you like five
53:42 . Just imagine a couple 100,000 of . All right. And they're converging
53:46 forming another tubular structure called the red . This is a cross section through
53:51 and it's color coded. I don't why they chose Mardi Gras colors,
53:54 they did. OK. So what can see here, the yellow is
53:59 you these mature cells, the purple the immature cells. So those would
54:03 the chromatic sites and the schroon and the green in there is the cell
54:07 makes up the wall of the And this cell is called a certo
54:11 named after the guy that discovered All right. And it's really,
54:15 hard to see in this cartoon Certo because you know, I mean,
54:19 can see the green there but over here, it's like I can't see
54:22 certo cell, I can see all germ cells, but I can't really
54:26 the line that separates these two But if you look at the seminiferous
54:32 , you'll see on the outside, have a layer of smooth muscle.
54:35 are myoid cells and they're just in contraction relaxation mode and they're basically squeezing
54:41 tube to propel the fluid that's in tube containing the mature sperm through the
54:48 . And then you can see I these walls of certo cells in between
54:53 certo cells is where all the germ are. This picture demonstrates a little
54:59 more clearly because they've color coded it it's cartoony. You can see
55:03 this is what a certo cell would . And in between the certo
55:07 you have the germ cells. But there's so many of them, it's
55:11 , really hard to see the certo . But I just want you to
55:15 when I think of the seminiferous the epithelium that lines that tubule are
55:20 certo cells and they're really kind of cells. All right, they create
55:26 blood test as barrier. What that is is that the germ cells are
55:31 from the rest of the body. they are immune privileged means materials aren't
55:39 to get near them. Anything that near those cells has to pass through
55:42 certo cell first. So the sali then must be responsible for delivering any
55:48 that it wants. So nutrients are via the capillary. But cli cells
55:53 that up and says I'm gonna give to you. Now, some of
55:56 cells are going to die just like saw trees in the ovary. We
56:01 really talked about that yet. But you had all those o sides dying
56:05 die all the time too, And the reason they die is for
56:10 reason, they fail to go through process, but you don't want the
56:12 cell sitting around. So the sali will engulf and destroy and act like
56:18 macrophage and remove the broken material. produces this fluid, the semi or
56:25 seminal fluid and part of the production that seminal fluid is that it contains
56:30 protein called A B P androgen binding . And so, one of the
56:35 that certo cells do is they sequester hold testosterone in the testes because it's
56:42 for stuff instead of being out and and it controls ultimately, the rate
56:49 which hermano genesis takes place. So we look at that scale that said
56:53 took 75 days, it's because this sitting there monitoring going OK. Have
56:58 met the requirements to move on to next step? You have OK,
57:02 on to the next step. And what happens is, is those cells
57:05 through these little tiny barriers, this junction and then they progress and move
57:10 towards the lumen. And once they've that point of maturation off, they
57:16 . Now between each of these seminiferous is some space called the interstitium.
57:25 just means the stuff in between. the interstitium has, has a specific
57:29 that you should know about. It's the late cell named after the guy
57:32 discovered it. The latex cell's job to take cholesterol and converted it into
57:41 in response to a hormone called luteinizing . LH. And we're going to
57:46 through that whole process of how it it a little bit later. You'll
57:50 see capillaries and stuff. So this is showing you. So here
57:53 can see here's the semi epithelium or tubule tubule. So this little space
57:58 here that is the interstitium in the out here. That's interstitium. You
58:03 see capillaries over there, there's a . So lots of blood going in
58:10 , you got cells that are making and this seminiferous epithelium is producing the
58:18 that are going into that tubule and traveling along and moving on to the
58:22 testis. So each testes has its duct that are going to converge and
58:30 they converge into their own large duct then that duct continues on for each
58:36 of them. And then those two converge at the prostate and then from
58:41 prostate, it's going to allow materials move out through a single duct.
58:45 when you think about the ducks, are their job? If the gonad
58:48 to make the sperm and the job the male is to make and deliver
58:52 sperm, what do you think the are responsible for delivering the sperm?
58:56 we have to have a place for to be stored. So we're gonna
58:59 this also, we're gonna play a in the maturation because the test is
59:03 went through spermiogenesis and made that's from and then it's gonna be a place
59:09 we're gonna keep it until a copulation ejaculation. And then ultimately, that's
59:14 you move it out of the So the next duct, so here
59:22 have the semi semi thelium. The duct is the red testis, sometimes
59:27 to as the media stum. And you're doing is you're taking all these
59:30 of thousands of tubes and they're converging it into this network or mesh of
59:35 , the R testis which then pass the tubes into the next structure.
59:41 next structure being the epitome. So tubes that go from the red testis
59:45 the epito, they're called the ductus or the Ephron duck jules. All
59:54 , I'm leaving, I'm going away I'm going into a new structure,
60:01 ? So this is just a function getting all the different roads going into
60:06 place where you can think about this up here. 45 2,
60:11 not, not, not, not right there. Uh But you
60:14 right up the street, we have 2, 88 59 all converge at
60:18 same point into this nasty little cluster road, right? That's kind of
60:25 going on here is all these things converging to a single point. That's
60:30 the red testis does. And what trying to do is we're trying to
60:33 a single road on the other So from the red testis to the
60:37 duct, jules in the ephron duct , that's where we're going to form
60:40 duct to ultimately open up into the . Now, every textbook I've ever
60:46 other than the one we're using right fails to describe the importance of the
60:51 . See when sperm are made in testis, they're incapable of fertilization.
60:56 can literally take an O site and a sperm from the testis. Put
61:01 right on top of the O site it just sits there. It doesn't
61:05 anything. It can't recognize the it can't swim, it can't do
61:12 . So the function of the epito to make it so that, that
61:18 can do what it's designed to It's its maturation point. All
61:23 So, while we were able to that tid, there's still more modifications
61:28 need to take place. Now, you look at an, it's this
61:32 structure, if you're actually to stretch this little tiny tube that's just
61:35 wrapped really tight. And it's you know, if you look
61:38 it's probably about this big in But if you were to stretch out
61:42 tube, it'd be somewhere between everyone's little bit different, anywhere between six
61:46 20 ft long. All right. it's a really, really tiny tube
61:50 really compressed down into this little tiny . All right. So there's three
61:55 regions. You have the head, body the tail. Um I,
61:59 I did research on it, I the, the original terms caput corpus
62:03 , but it's the same thing and region is unique and each one is
62:08 for different things. And we're not to talk about what each one is
62:11 for. We're just going to do generic responsible. OK. So the
62:14 thing is that you need to finish off, you have to be able
62:18 make that sperm be able to penetrate the protective barrier of the o
62:23 All right. So that's the first is modify the surface of the cell
62:27 that it can one recognize the oci two penetrate through that barrier. Because
62:33 you can't do that, you're not be able to reproduce. And that's
62:35 end of the species. That's kind important, don't you think?
62:39 OK. Number two, we're told can't swim. So as it moves
62:46 , it's taught how to swim. , don't ask me how I
62:48 it's not like, OK, you're gonna swim forward. But
62:52 if you take sperm from different parts the epi, sperm will spin in
62:56 direction, sperm will spin in that , sperm will spin there go
63:01 It's the weirdest thing ever. There's studies that have been done on
63:04 So it learns how to swim in epitome. All right, kind of
63:09 . And the last thing is you to have a place to store
63:11 And so down here at the coddle . So basically at the tail,
63:17 is where you store up sperm. so sperm basically, it's in this
63:20 and is able to move around and has elbow room if sperm had elbows
63:25 what it does is you take away fluid and it concentrates the sperm down
63:29 that they're all tight and can't move stuff and then they basically hang out
63:35 this coddle region and they're stored there they remain there until they're needed.
63:42 , some of them are going to and so the eps can destroy and
63:46 stuff. But for the most this is where, where things hang
63:50 until it's used. So that's what E is for the maturation of storage
63:57 then copulation, we're gonna just say occurs. All right. And it's
64:02 for ejaculation, ejaculation. You need move that sperm from storage and you
64:06 to move it outward. So the structure is the ductus deference. So
64:11 have the ductus Ephron at the front , at the back end, you
64:14 the ductus deference, you might notice vast deference. And so the vast
64:18 is the tube that takes the sperm storage and moves it to that,
64:23 point where it can be mixed with is called the seminal plasma. And
64:29 you're going to move it and then that si plasma plus the sperm,
64:33 basically allows you to have a liquidity again. And that's going to be
64:38 the ejaculate, which is going to released during copulation. All right.
64:43 that's the role of the ducts, friends. And so if this is
64:46 tube to move from one place to other and you want to get things
64:49 quickly, you need to have a of muscle. And so the ductus
64:52 has a whole bunch of different layers muscles. All right, it has
64:58 longitudinal layer, one concentric layer. so that moves the sperm very,
65:01 quickly from one point to the And you can see it's actually fairly
65:05 . So if this is the bottom the epitome, it comes up and
65:08 the bladder and then joins up to next duct, which is called the
65:12 duct. Now, this thing doesn't it a lot of justice. It's
65:15 like this. It is very, short, but it's a convergence of
65:19 ducts in the same location as what ejaculatory duct is. And so this
65:25 you to mix the sperm with the of the seminal vesicles and the secretions
65:33 the prostate. Ultimately, when you to the prostatic regions of the
65:40 So you see we went from lots tubes down to one tube on each
65:44 and then each of the one side bringing a tube and we're conjoin it
65:49 a single tube and that's the Now, we learned about the urethra
65:55 the renal system, we said the is responsible for the pathway between the
65:59 and the bathroom. And that's absolutely true. But in males, it
66:03 serves as the duct through which the plasma and the sperm which we call
66:09 are ejaculated during copulation. So, are three parts to the urethra that
66:16 need to be familiar with in the . All right. So wrapped around
66:19 urethra and nearest the bladder is where prostate is located. This structure when
66:25 passes through the urethra passes through is the prostatic urethra. We're going to
66:30 more clearly what it looks like when look at the prostate. All
66:35 it has a whole bunch of little holes in it so that these are
66:39 ducts that allow for the secretions of prostate to enter into the urethra.
66:44 then we have this really short region the urethra, which is called the
66:48 region. And this is basically the muscle that serves as the floor of
66:53 abdomen into the pelvis. And so you're doing is basically, that's,
66:58 the that structure through which you're So membranous, it has skeletal muscle
67:03 it. This is where the external sphincter is. So when you're holding
67:07 in and you need to go, , not ladies here. I
67:12 it's true for ladies too, but , what you're doing is you're releasing
67:16 . So notice it's on the other of the um um prostate and then
67:23 spongy urethra. All right. And the spongy urethra is the pathway through
67:31 structures of the penis. All This, this this erectile tissue.
67:37 right. Now, as you move the type of epithelium changes. So
67:43 prosthetic tta has transitional epithelium similar to you saw in the bladder membranous,
67:49 is just going to be that pseudostratified stratified columnar. And then as you
67:54 down where you go from the pseudostratified then ultimately get down to the stratified
67:59 . So the closer you are to outside, the more it looks like
68:03 as you move in, the more looks like elongate epithelium. And then
68:08 get to that weird transitional stuff right? So squamous sort of
68:15 transitional, the opening at the end the penis is called the external urethral
68:26 . All right. And that's through the ejaculate is released. The three
68:35 glands pretty straightforward. We have, have the seminal vesicle. I'm gonna
68:41 you what's in them. I'm gonna you what they do when we talk
68:45 copulation. OK? Because each of things are kind of fun and unique
68:51 they're there for a reason. I'm sorry. All right. It's
69:03 the next one right after class, will, I will move them
69:07 I thought I'd moved them, but suck. So, yeah.
69:12 apparently the last time I taught the I apparently rambled on too much.
69:16 so I didn't get to them. so I had them over into the
69:18 one. I will get them There's five slides. Right.
69:23 if you have to scribble, I'm , we'll get through them. They're
69:27 hard. All right. I apologize this side too. OK. All
69:35 . Seminal vesicle. It looks like rabbit ears. Do you see little
69:38 ears at the top? If you're it out there, it is.
69:41 this is your rabbit there, boom, boom. Actually, this
69:43 kind of looks like a jackal, those are your rabbit ears, Semino
69:47 . All right. These are located here to the bladder. And what
69:51 do is they are merging with the defer. All right. So there's
69:56 region of the vast defer that expands that's called the Aula. Um And
70:00 can see here how this kind of outward right there. That's the
70:05 And then right there is the seminal and they converge. And so the
70:10 vesel is responsible for secreting a portion the seminal plasma, right? The
70:15 similar plasma don't let that be All it is is basically saying the
70:19 that make up semen, right? so a portion of the fluid that
70:22 up semen comes from this structure about half of it. And so
70:27 you have this concentrated seam or sperm then you're joining up with fluids.
70:31 you're giving it elbow room again, you're not just doing that. There's
70:35 whole bunch of stuff that's actually localized this as well. Now again,
70:39 told you, we're gonna come back each of these individual things and why
70:43 important. But I just kind of to give you the big picture first
70:46 . It's viscous and alkaline in All right. So it's alkaline,
70:51 , not acidic, it's the opposite . Very, very basic.
70:58 Here we're going to be secreting a of fructose. And the reason we
71:02 a lot of fructose in the seminal is because sperm use fructose as an
71:08 source. Ok. Third, we this chemical prostaglandins. Have you ever
71:15 of the prostaglandins? Yeah, they a roll and smooth muscle contraction.
71:20 do you think they're called prostaglandins? . Yeah, I couldn't hear you
71:28 they thought it came out of the gland. So I was like,
71:32 , prostate glands. No, it came from this structure. So thank
71:36 they didn't call it vesicular gland or , whatever, but that's where it
71:41 from. All right. Thirdly, there's other, some substances in it
71:45 are gonna play a role in motility aid in the process called capacitation.
71:51 right. Second structure is the prostate . All right. It's fairly
71:55 It's like the size of a So, if you don't know,
71:58 , I promise that it will get to you here right after class,
72:01 can take your picture. That's But all right. So, prostate
72:06 inferior to the bladder. So there's bladder, there's a prostate gland.
72:09 has all these openings, these duct that open up into the prostatic
72:16 So it's not a single duct, basically a bunch of different little tiny
72:19 jules that open up and again, producing a portion of the similar plasma
72:24 the prostate. All right. And there's a whole bunch. Some of
72:28 you may be familiar with. Probably heard of P S A
72:32 Uh This is what you get. I'm talking to the gentleman. Uh
72:34 is what they'll test to see if have prostate cancer because right now you
72:38 very little in circulation. But if get prostate cancer, it's one of
72:42 things that rises. So it's an early detection. Um It's slightly acidic
72:47 nature and that's because there's citric acid it, uh has an antibiotic in
72:51 called seminoma. Um It uh uh P A is a liquefaction has another
72:58 called P A which is a noise zinc. Zinc is a, is
73:04 mineral that plays an important role in sperm generally from oxygen radicals. So
73:11 idea is oxygen radicals, they come , they find DNA and they cause
73:16 to explode. So um you don't that to happen with your sperm.
73:22 one is a bubble urethral gland and are little tiny ones you can see
73:26 , here's the prostate. They sit there in the membranous region of the
73:30 . There's, it's a paired structure named after the guy found it's called
73:36 . But we use buble urethral. they make up a very, very
73:40 portion of seminal plasma and here what does is just prior to copulation,
73:45 begin contracting and they release this mucus fluid that basically coats the urethra just
73:51 to ejaculation. And what it does it, it's very, very um
73:57 . So it neutralizes the acidic urethra basically, uh because mucus in
74:02 it kind of makes it slimy or slippery. And so it basically lubricates
74:07 urethra just prior to ejaculation. So bit, we're gonna deal here is
74:19 copulation or the copulative organ, not the act of copulation. All
74:24 So, structurally, penis is a organ. All right. Uh We
74:30 the sides of the penis. So would be the dorsal side. This
74:34 be the ventral side and it's, in reference to an erect penis and
74:39 lying on your back on the So dorsal matches dorsal, on this
74:45 . This is ventral. Ok. that's why if the penis was erected
74:49 you're lying backwards, that's where the come from. Now, internally,
74:53 , we're gonna have two pictures Sorry. There it is. So
74:57 going to go kind of back and or you could use either picture to
75:00 of look. But we have what called is the bulb. The bulb
75:03 the very tip back here at the end of the penis, right?
75:07 continues with the structure called the corpus , which we'll see in the next
75:12 . Uh We have two structures which called the, the crust. All
75:17 , not crew. I've tried forever pronounce it correctly and I always get
75:20 wrong, but it's the crust and the extension of the uh Corpora two
75:26 two cavernosum. So there's two of , one on each side and you
75:32 see them in this picture here. would be the kra singular cress,
75:37 the bulb. OK. So the extends internally for some distance,
75:48 externally structures the penis that, that see externally is referred to as the
75:54 . The tip of the penis is to as the glands. This is
75:57 the external urethral orifice is located. can see that we structurally, we
76:02 this raised edge or ridge. This referred to as the corona. Whenever
76:07 look at any structure, uh know there's a purpose to it. All
76:12 . So it's in shape like it , it looks like it is not
76:16 it's funky and women dig it or , right? Because I remember I
76:19 sexual selection, it's there because it sexual reproductive success. All right.
76:28 so that, that corona serves kind as a gasket. All right.
76:33 know, the gasket is basically a that divides two halves on either side
76:39 that structure. So like when you're of a piston in a car,
76:43 has a gasket so that when the goes up, the gasses that you
76:49 in your engine don't escape around So you get a good explosion so
76:53 it can drive that piston downward. would be in a car during
76:58 What we're doing here is we're creating compression and rare faction so that we
77:03 keep sperm on one side after ejaculation place. All right. Uh The
77:11 is uh very often. Uh I , you're normally born with uh
77:16 which is called a pre, all . Um Part of the thing we
77:21 here in the States is we basically that off, cut for skin off
77:25 circumcision. So not everyone has but that's you're born with a pre
77:32 in terms of the internal structures, mentioned the corporate cavernosum. Here's a
77:36 through the center you can see. there's the paired and then we have
77:39 corporate spongiosum. These are erectile tissues what they are, they're vascular
77:45 So this is a connective tissue structure the vasculature opens into. And so
77:50 sexual arousal, blood flows into those because the arteries vasodilate the veins constrict
77:57 it causes blood to get trapped into structures, causing the penis to become
78:02 to become erect. We need this down here. The spongiosum. I
78:08 , you'd think all I need are two big ones. The cavernosa.
78:12 , those are fine. That's enough get an erection and hold it.
78:15 you don't want the urethra to collapse that's how sperm is passing out.
78:20 the corporate cav uh the spongiosum becomes to keep the urethra open so that
78:28 can occur. All right. So two superior ones are the cavernosa.
78:33 inferior one is the spongiosum. I two more minutes and we're just gonna
78:39 with. The last little bit is scrotum. All right. Not all
78:46 have scrotum like 40% don't, but remaining do. And the reason for
78:52 is sperm develop at a bed, a uh lower temperature than what the
78:58 is. All right, you like meme, I can see the
79:04 All right. So what the purpose the scrotum is, is to raise
79:08 lower the, the testes to the so that you can maintain the proper
79:15 for sperm development. Now, there's lot of structure here that we need
79:19 deal with. I mean, there's , um but just underlying the skin
79:24 a layer of muscle called the Dartos . And this is a smooth
79:28 And so when the body or when testes become hot. What they do
79:33 the dar tose relax and allows the to relax as well. And so
79:38 testes are moved away from the body that they can cool down. And
79:43 when it gets cold, the dar contracts and it brings the testes close
79:48 the body to keep the testes All right. So that's, its
79:54 function is to maintain the proper balance temperature. Now, dividing the two
79:59 , there's a raf. So the testes are in their own compartment and
80:04 each served by a spermatic cord. the spermatic cord simply is a bunch
80:10 blood vessels, a bunch of connective tissue, some muscle as well
80:14 some of the ducts and they're all in there. Now, the things
80:18 I want you to know about the cord is another muscle. Some textbooks
80:23 about it being involved in temperature It is not, this is the
80:27 master and this is skeletal muscle. do you know about skeletal muscle?
80:32 can control it, right? Smooth . Can you control it?
80:37 that's why Castanza there was going I in the pool, I was in
80:40 pool, right? So the cremaster there to raise and lower based on
80:48 . So you can imagine, for , um you know, men
80:54 do you mean fight? They don't much? But yeah, and so
80:59 of the things you want to protect is the structure through which your reproductive
81:05 is dependent. And so you can pull the testes closer to the body
81:09 a short period of time for the of protection. And just to reiterate
81:13 point, I know it's over Once they become sexually active, alpha
81:18 will chew off the scrotum and eat testes of the beta males. So
81:25 won't have any sexual competition. could you see why it would be
81:29 ? Not that humans do this? do you see why it might be
81:33 to be able to move your testes and forth? Yeah. So that's
81:37 purpose of the Cream master? All . I kept you a minute longer
81:42 I should have. We covered a . I will get these slides up
81:45 I start talking to students. And I think I owe you an
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