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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture06_0614
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00:05 All right. So what you're looking here is the distribution from the first
00:12 . All right. I need to through some numbers here so that you
00:16 are not all panicky because you guys like, oh, I don't
00:21 sheep wolf jumps into the pit. guys freak out sheep have horns that
00:27 hurt wolves, but they don't know . And anyway, so what we're
00:32 at is we're looking at this This is actually a really good
00:35 You guys are like probably looking at , yeah, no, no,
00:39 . You guys hit exactly where I you to hit. I don't know
00:42 to be happy or ecstatic about that that means I wrote a really good
00:47 and you're sitting there, but I like my score. You know,
00:50 like everyone to get above 100 or above 70. But the truth
00:53 I really am shooting for that. , this was like my happy
00:57 Now. I will say, you , I'm not happy when I see
01:00 way down here, but I'm not at you. Part of that is
01:03 because you haven't learned how to study we talked about that and I
01:08 really, really recommend if you are here to really consider doing what I
01:13 you to do in terms of how how to review and how to go
01:16 material because it will make your life in the long run. It's harder
01:21 the front end. But once you how to do it, school becomes
01:24 breeze and you don't really care all much. High score with 96 median
01:30 was around 66. So, right here it I love these type of
01:35 . This is I don't know why happens. There's something about it where
01:40 get in the in the higher you end up with lower scores,
01:44 in the lower ranges within that death , it's always higher. And that's
01:48 in this one. But we can on this on all day long.
01:52 cares? It's one test how many you have for? What's the value
01:57 this one test relative to everything else your class? 20%. So,
02:02 right. Look at it. Get taste out of your mouth, spit
02:06 out. Alright. We care about the button works. We care about
02:11 stuff. Right here. All Now, this is more important.
02:16 again, we don't want to fixate it. All right. If you
02:19 a grade that you didn't like say didn't like that grade, I'm going
02:23 make changes because if you continue doing same thing, you're going to get
02:26 same result. So, you gotta the question. How do I
02:29 All right. But really what we're about is what this looks like.
02:33 remember what I told you is that a science class. We care about
02:37 curve and where the grades are not the numbers are. All right.
02:40 so, what you can see here what happens if we add in the
02:44 hats and the achieves. Alright, , here's that passing grade. All
02:49 . I say 50% in my class the passing grade. So, down
02:53 , if you find yourself down what you're doing is you're not performing
02:56 in the exams. And the reason not performing well on the exams is
02:59 you're not doing the top hats. the achieves those grades pull your grades
03:05 . All right. But you can here. Alright, well, let
03:08 see. Here's our a. For now, that's going to change
03:11 This 90 will change Now if you continually do really well in the
03:16 it won't change, right? But the grades kind of slide down towards
03:20 mean, then the new a will lower than a 90. Alright?
03:25 now, A B starts at a and a quarter. So, if
03:30 have a 78, you have a . Right now. All right.
03:33 don't have a c. don't go panicking home. Alright? I'm doing
03:37 , I could do better, Because if you don't have 100 you
03:42 do better. Alright? We shoot hundreds. And if we hit
03:47 we readjust and try to shoot for 100 again. But if you're aiming
03:50 100 you're more likely to get to . If you instead If you're going
03:53 , I hope I can get a . You're gonna get a C.
03:56 worse. So we got to move from that right now. The seas
03:59 57. You can see it's a broad range of scores and then this
04:03 our d. Range. And what's happen is remember this doesn't include any
04:07 credit. I don't add an extra until the end of the semester.
04:09 I'll calculate all your grades and let's today is the day you get your
04:13 right. And so let's say this the end. I would calculate all
04:16 grades out and I'd say based on scale this is what your grade
04:18 And then I go and take the credit, add it on top and
04:21 I recalculate where you were. So you're sitting over here right and I
04:28 in the extra credit. Look what . It's real extra credit. It's
04:33 that fake extra credit that your english gives you. Everyone gets four extra
04:37 . Yeah garbage real extra credit. I got a bunch of emails
04:42 When's the when's the post exam? credit. Gonna open up. It's
04:45 open up on Wednesday and once you at your exams when they become available
04:49 have one more test outstanding. It occur at Wednesday at one o'clock after
04:53 outstanding exam occurs. That's when the exams will open up and you can
04:57 look at your exams look them find why you missed questions. See if
05:01 wrote any questions where I put down wrong answer. You can tell me
05:05 , that answer is not right. know. See here's the slide that
05:08 otherwise. Hopefully there aren't any of because I usually get rid of them
05:12 quickly. Over time we're not fairly , but over time I get rid
05:16 them so there shouldn't be any. I'm not one of those people says
05:20 questions are always right. I guarantee I've screwed up. You guys grew
05:25 . Okay? So if you can up, I can screw up and
05:27 that's that's okay. Well everyone gets when that happens right? If you
05:31 that particular question. All right. make sure you actually are submitting a
05:36 . But the other thing is ask question. Why did I miss
05:38 Did not study it right. Did did I misunderstand what I was trying
05:42 learn that sort of thing. And that's what that extra credit does.
05:45 says All right. You saw your now you see what your test looks
05:48 . Why did I get the grade I got? And then you just
05:51 and that's just more points. So three points going back to
05:57 So, if you find yourself down , don't panic, come and see
06:01 If you need to say look, don't understand what's going on this.
06:04 don't know why I got this and can walk through it. One thing
06:07 did know when looking at the grades was putting them together is I think
06:10 lot of you still think those top post exam material is is not
06:16 it is required. Remember after class those open questions like can you compare
06:21 ? Did you do this? About of you didn't do those and remember
06:25 are required questions. The only ones aren't required are the ones that open
06:29 on Fridays. Those are just for . If you call it fun.
06:34 right. If you miss them, panic, right? They don't make
06:39 a lot of your grade. You missed one unit and one unit out
06:44 four of which It's only 10% of grade. The total thing is
06:48 So you may have missed maybe a off your final grade. Alright,
06:52 two off off the max. Just okay I didn't understand what I needed
06:56 do. Let me go back and it. So remember after class there's
06:59 top hat questions that you need to back and answer and that's gonna stay
07:04 until the night of the exam. to help you practice and review if
07:09 don't practice, you're not gonna If you don't learn, you're not
07:12 do well on the test which is the if if the homework and stuff
07:15 practiced the test is the practical I don't know that's the idea.
07:22 before I switch off and start talking actual um um science, actual body
07:28 . What questions you guys got. think about this? Can you look
07:33 this and go if you don't understand right now, this is the best
07:36 to say I don't understand the curve wayne. Okay, you don't understand
07:40 curve. Alright. So quite simply curve is simply comparing all the students
07:45 each other. Huh? Yeah. basically I went through and I determine
07:50 great and I basically plotted on this I said, alright, where do
07:54 differ? All right. It's just just a statistical test. All
08:01 So basically I figure out where the is mean is someplace in here.
08:05 you look at the curve is where top of the curve kind of pumps
08:08 then I say, okay, where's boundary from here to the next group
08:11 people? And so there's a mathematical and that's what makes me determine this
08:15 right here and then helps me determine line right there and then I take
08:19 distance and I apply it again but distance is way over here and that
08:22 be unfair because then there'd be no so I can bring it back down
08:25 the north place. Alright, so now and a is a 90
08:29 B 77.2 notice I'm not even talking pluses and minuses because it doesn't matter
08:34 . It doesn't matter after every all classes taking the stuff that's when this
08:38 matters Steve right now is a All right. D. Starts at
08:44 . Always starts at 50. All . Now to answer the question
08:49 All right. Well, what does mean at the end of the
08:52 Let's say you all are really, smart. You guys bring all these
08:54 up in the great and the curve this way or goes this way Then
08:58 will happen is that that 90 stays it is. The 77 goes up
09:02 where the means normally start 80. you. Okay, so, it's
09:06 of shipped up that direction, it goes past 80 because it would be
09:09 to you. Maybe Chemistry does We don't do that in biology.
09:14 Then. Where does where does this ? It'll keep moving this direction until
09:17 hits 70 and then it stops. right. Let's go the other other
09:20 . Let's say you guys start getting by the class because everything we've done
09:25 far is more or less review is catch everyone to get everyone on the
09:28 page. Now, we're gonna start with the new stuff. Right?
09:32 here ever learned about skin before. . So, for you guys to
09:36 . All right. But for everybody is like this is all new
09:39 All right. So, let's say the new stuff you now get a
09:42 bit more challenged and so the curve moving this direction? Well, the
09:47 will start dropping lower. Right? low will it go? Historically?
09:52 lowest I've seen is about an Some of them go very, very
09:56 . So AIDS aren't really helped out curves but they shouldn't be because they're
10:00 the top. Where does this I've seen it go as low as
10:03 72 but it sits around a 77 . Where does this go? This
10:08 where it should be. But I've it go as low as 52.
10:12 ? So do you see what It's not the number that matters.
10:17 where you sit on the curve that . All right. So right now
10:22 not the day to panic about the right now is the day that you
10:25 at this and go where do I if you sit over here, is
10:29 impossible to get over there? that's not hard at all. We
10:33 get there if you sit here, it impossible to get there?
10:37 If you sit here, is it to get there? The answer is
10:39 no, it's not. Maybe after third exam it's really, really
10:44 Mathematically impossible, but you never know if everyone does poorly and you do
10:50 , really well you leapfrog people that's curves are both awesome and sucky at
10:56 same time? Okay. To answer question, you're good. Alright.
11:02 else have a question before we talk skin? Yes. What exactly compared
11:08 ours? Uh It's not that Usually what I see in terms of
11:12 just as a mean is average of first exams here, I guess.
11:16 gotta go this way since you're so one would be here. Exam two
11:20 like this, exam three is kind like this and then exam four is
11:25 of up higher a little bit, there's not that much difference.
11:29 and again, it's really hard with summer class relative to a normal semester
11:34 , Normal semester. My averages are over the last two years have been
11:39 . This would be what we saw what I would expect in a normal
11:45 . And typically in summer semester it's five points higher, but over the
11:49 two years, this is very, specific why summer semesters is where all
11:54 kids are. You're a smart You chose to go to school in
11:59 summer says be lazy around the like my son, I can't be
12:06 at him. He's only 15, still come on anyone else. Any
12:11 questions? All right. Again, you're sitting here and you're like your
12:16 , you feel the tension, stop . Alright, I'm gonna be the
12:21 that's gonna slap you around and say panicking about this type of crap because
12:27 not that big of a deal in grand scheme of things. More important
12:30 is to learn. Do you understand you don't understand, come and see
12:36 ? Let's talk about what you're not and how to get you to understand
12:40 if you understand grades naturally follow There really is no such thing as
12:48 poor test taker. I mean there but there's really we can train you
12:52 of that. Anyone else questions? can I can go back lines skin
13:02 . All right, So today is to break down. This is where
13:07 actually finally getting into the anatomy and way that anatomy normally works is we
13:12 with the epidermis, the skin. basically peel the body away, like
13:17 . All right. But instead of through the muscle right after the
13:21 we go straight to the bones. , it's not really a good
13:24 Alright, When we talk about the , what we're really gonna be talking
13:27 is multiple things. We're going to look at the epidermis, we're gonna
13:31 at hair and nails, which are of the epidermis, and then we're
13:36 jump into the glands alright. Which also derivatives. So really this this
13:41 is about the skin and its derivatives what we say, and then what
13:46 gonna do is when we're done with skin, we're gonna jump to uh
13:50 kind of a brief dip our toes the skeleton, or really into
13:55 What bones are. Okay. And that's what our next class is is
13:58 to be talking about bones. So our starting point here is we're
14:03 to start with the skin because once understand the skin and the other one's
14:06 kind of fall into place. So, skin itself has two main
14:10 . Even though you see three things up here, the two main regions
14:13 skin are the dermis and the If you are in kindergarten and use
14:17 joke, your epidermis is showing you're about this outer layer. Alright.
14:23 you didn't do that joke? You're not a dad joke. That's really
14:26 kindergarten joke you kind of looked No, not that big. All
14:33 . It's the outer layer. All . We've seen this picture before.
14:35 the pink stuff that you're looking up . The dermis is this lower layer
14:39 here and then we have this subcutaneous that we refer to as the
14:44 And so even the names kind of you epi means above. The dermis
14:47 kind of the focus area and then have the hypo which means below.
14:51 , the epidermis is the outermost layer epithelium. It's a vascular.
14:56 there's no blood vessels in it. its job is to serve as a
15:00 between the external environment and everything else your body. All right. The
15:06 , on the other hand is where its its connective tissue. All
15:10 And so what we have is we a whole bunch of blood vessels.
15:12 see nerve fibers in there. There's to be all sorts of different types
15:16 of receptors and stuff to detect changes the shape of that dermis. You'll
15:23 within it as well that there might some muscle. So, for
15:28 there's muscle right there and its job to provide the strength and resilience to
15:35 the upper layers below it so that can be protective and it provides the
15:39 and the other materials for it. lower layer which is not part of
15:44 skin but we included because they draw in the picture and you need to
15:47 what is this hypodermic is both adipose as well as um areola tissue.
15:54 so this is where you kind of those fat layers. All right.
15:58 it's a place where the skin anchors it. How many people here are
16:03 ? You don't have to raise your because people might get mad. All
16:06 , a couple of people. So you go hunting and say you get
16:09 large mammal, you skin it And you basically you cut through that
16:14 upper layer and then you start tearing and you basically finally have this
16:19 This basically this organ is that's basically tissue surrounding meat. So really what
16:23 doing is you're stripping away these two here and you're getting down to this
16:30 . All right. Further. You hunt if you've ever bought a whole
16:35 right? Typically you'll see the skin if you're go underneath and you can
16:40 of pull the skin away. That's that separation point. Alright, So
16:45 this is acting kind of as a absorber where you know in terms of
16:49 the fat is located as well as insulator to the body, but it's
16:53 of the anchor on which these two sit. Now, we can think
16:59 simply. Okay, what does the do? Well, yes,
17:09 Yes. They actually are referred to I've never even no one's ever asked
17:13 question. It's just presumed. This is the cutaneous. Like,
17:17 you ever had a subcutaneous shot Okay. Subcutaneous shot is when they
17:22 that shot and they go just into skin. Like when you've done a
17:27 . B. Test. Yeah. . And what they're doing is they're
17:31 underneath and they're creating that bubble underneath skin and basically waiting to see what
17:37 when your body responds to the TB right back in the day. They
17:41 to do something a little different than they do now. Which was even
17:45 because it was like four needles and went in at the same time.
17:50 , it's like a little rabbit No, it's like being stung by
17:53 wasps. All right. So what want to point out here is that
17:58 not just about protection. There is . So the epidermis plays that role
18:03 protection. So it's a chemical Physical barrier, biological barrier, temperature
18:07 radiation barriers all of those things. if these things don't seem to make
18:12 to you, think about All If I pour something caustic on
18:15 does it just directly eat through my ? Like have you been in a
18:19 lab and you actually spill something on ? Does your body just melt
18:24 No because your your skin is actually resilient. So it doesn't physical
18:30 You know you can think in terms I can scrape or stab myself.
18:33 takes quite a bit of effort to through that through the skin. The
18:37 barrier. You've got bacteria and all of horrible things living on your
18:40 right? You could go swimming in sewer just don't stick your head
18:45 I'm not suggesting to do that. you know if you have to odds
18:51 the way you're gonna get sick is you ingest something. It's not because
18:55 coming through your skin. Alright, barrier. Hot versus cold radiation
19:00 Think of UV light. All It basically protects against all those
19:06 It also serves as a protector of other direction basically. We are basically
19:10 bunch of water inside us. We want that water escape. And so
19:13 is a water resistant barrier. So prevents water loss but also prevents water
19:17 getting in. But that's not all does. It actually has these other
19:23 that we don't quite really think about we think about the skin, it
19:27 metabolically active. Its job is to vitamin D. I used to do
19:33 when I was a post back. you know this is a long time
19:37 . So right out of college I post backing um and would do these
19:41 where I'd have to do something and it sit for a long time and
19:45 didn't have anything else to do. I would go and sit and hang
19:48 outside and I had this really really lab mate, we'll just call him
19:54 dense. And he'd asked me well are you doing? I'm going off
19:57 , I'm going to go synthesize some D. You know because I wanted
20:00 sound smart one and two. I want him to come with me.
20:03 finally I was like dude I wanna you synthesize vitamin D. Was like
20:07 right? So I went outside and sat there and he sat down next
20:12 me, he said when are we go synthesize vitamin D. I said
20:14 doing it right now that's what the does in response to UV life.
20:19 makes vitamin D. What I'm also you you need to go outside
20:24 Alright plays a role in secretion Alright so we get rid of some
20:29 our metabolic waste through our skin. a lot of it. But we
20:32 get rid of some of it. is a selectively permeable so there are
20:36 materials that can be absorbed through that barrier barrier. And lastly it plays
20:43 important role in immunity. Alright. we're gonna see that there are different
20:49 of immune cells that live within the and so they serve as that first
20:55 of defense against microorganisms and other pathogens are trying to break through and trying
21:02 get into our bodies. On top that. We also secrete a whole
21:06 of different types of chemicals that specifically and destroy microorganisms. So we produce
21:14 and DNA as well as things like . G. A. And some
21:18 sorts of chemicals that basically target bacteria break them down. And then what
21:24 is the RNA and the DNA sits and just chops everything up so that
21:28 organisms can't survive. So the epidermis multiple roles. It's not just I'm
21:36 barrier underlying it is the dermis. dermis plays a major role in temperature
21:42 . All right so we have blood . We have sweat glands were at
21:45 post so it allows us to adjust internal body temperatures to meet our needs
21:51 upon the structures that are found in . Furthermore it helps us to understand
21:55 surrounding environment. We're going to see there are a lot of different types
21:59 receptor types that are found within the that allow us to understand what we're
22:05 and what's touching us. So, you're looking at a system, you
22:13 ? So, one of the common I get is how do I know
22:15 important? All right. You things are important when they have different
22:21 . Alright. If if you have a and name be there's a reason
22:25 named differently. Figure out what the is. All right. You're learning
22:29 because we have these two things. here we start off with their cells
22:34 are found in the epidermis. All . And the two cell types,
22:38 two primary cell types are the care sites of the melanocytes. So why
22:43 they different? Why do they get names? Well, the car tennis
22:46 are the most abundant cells. So this side, this is an actual
22:52 of skin. So, this is through a microscope and taking a
22:57 This is the artist's rendition over here the right. All right. So
23:01 car antenna sites are the cells that up the skin for the most
23:06 Right. So, if you're looking if you throw a rock or point
23:10 as a cell, the odds are pointing out of care tennis sites.
23:14 right. So they're the ones that keratin. They're the ones that make
23:18 thing all nice and tough. They to each other by Dismas. Um
23:21 they create this really, really strong barrier hidden within the karate sites every
23:27 and then is a little tiny cell a Millon aside. And so they're
23:31 to show you here again, you need to know the histology to be
23:34 to identify him. You need to what they do. Atlantis sites are
23:40 within the care tennis sites and they of weave their way in between the
23:44 cells. So they have these long like processes that kind of wind their
23:50 through the cells. And that's what artist is trying to show you.
23:52 like here's a cell, here's all sites and you can see that it's
23:56 its body and little bits of its out through between the sites. And
24:01 job is to produce melanin. Melanin a pigment that absorbs UV light.
24:09 this purpose of the melanin is to released by the melon aside to be
24:13 up by the care tennis sites and the care tennis sites from UV
24:18 It's actually kind of cool. so, I think there's a picture
24:22 it a little bit later that I'll you. And so what happens is
24:26 that you're just pumping out melanin The more melanin, there is the
24:31 UV light you're gonna pump out. also some genetic factors that are playing
24:35 role in that. And what you're do is you're gonna release that melon
24:39 the cartoon insights pick that up and the melanin. It's like these little
24:42 Granules that accumulate. And what they is they put them over their nuclei
24:46 the sun facing side of the cell light when it hits D.
24:52 A. It finds those time Odin's basically bust them and and creates these
24:58 . And so they come back and they get repaired they create these really
25:02 die MERS which the machinery can't, molecular machinery can't read. So you
25:09 back and you try to break the urz. And then very often what
25:12 happen is you'll misspell, you'll put wrong nucleotide there. And that's where
25:17 UV damage creates problems because it mutates D. N. A.
25:23 It's not directly mutating the DNA? can see there, It's really making
25:27 and then trying to fix the mistakes causing bigger mistakes. All right.
25:32 so if I can get melanin which UV light and stick it over my
25:36 , I can protect my DNA like umbrella. So it's like you walking
25:40 with an umbrella when it's 98° Like yesterday. It was hot yesterday
25:52 . No, no, no. just kind of like alright bad.
25:57 , really bad imagery. Yeah, like your arms, right? But
26:00 want you to imagine you're in a of people and then taking your arms
26:03 squeezing them through the people. That's like processes. Is that the best
26:11 ? All right. There are five of cells or different types of layers
26:20 should say. It's not just sells ? That are found in the
26:24 All right. From top to Or sorry from bottom to top.
26:27 have stratum easily. Then we have awesome. Then we have granule,
26:33 lucid um and corny um They're named what they look like under the
26:37 right? And they're using latin to it more confusing. But in essence
26:41 we have here are the five different layers that make up this outer layer
26:48 skin. Right? So The three layers. Right. So we have
26:55 bizarrely the Spinoza and the granule These cells are living cells. And
27:02 the last two layers consist of cells are dead. All right. That
27:07 moved too far away from the They've been modified too much that they
27:11 longer are living If we look at , there are some unique features about
27:16 . All right. So stratum basil a single layer of cells. That's
27:21 deepest layer of cells. This is stem cell layer lack of a better
27:25 . Alright, so these are the cells of the epidermis that give rise
27:29 all the other care tennis sites. , it's predominantly made up of the
27:33 team decides that they're multiplying and dividing now and then you'll see a milana
27:37 in there, right. Which has up and into the upper layers.
27:44 can see that we have these up down portions. This down portion right
27:49 is referred to as an epidermal The artist did a poor job of
27:53 . But what would happen is you up with a bump above the epidermal
27:57 . The epidermal ridges appear on the of your skin as those patterns.
28:03 we call fingerprints. Yeah, this the rich. Okay, so that's
28:11 epidermal ridge. And what we're going see this has a different name.
28:16 right. It's called a papillon. dermal papillae. So the ridges.
28:22 portion that's the papillon alright down So what happens is is that this
28:30 the ridge and it gives rise to bump because because of its shape and
28:35 way that the cells multiply. It rise to a bump that appears on
28:38 surface as that that bump. now there is a basement membrane,
28:48 ? We remember what we said. a basement membrane between an epithelium and
28:53 connective tissue. And so they're trying show you here is that basement membrane
28:58 that's what's connecting it to that underlying . So that's a stratum Asali.
29:05 the sally base. Really simple above is a spin awesome. Why do
29:10 think they call it spin awesome. you don't know. Latin spiny right
29:17 the microscope it looks spiny and the for that is there is a whole
29:20 of Desmond's OEMs and what happens is that they're attached and they're pulled by
29:24 dez Mazzone's so it kind of creates more spiky er spiny appearance to them
29:30 this is several layers thick and these are migrating away from the base easily
29:35 they're migrating up towards the cornea and remembers the corny um And so they're
29:41 and dividing along the way and so why you end up with these multiple
29:45 of cells. All right now remember layer up here has no blood.
29:53 blood vessels are gonna be found down . So they're getting their nutrients from
29:57 diffusing through and upward and so that's keeping them alive. All right.
30:04 so they were coming specialized. They're , they're different in appearance and they're
30:10 more and more specialized as they move and further away from this basement membrane
30:15 this basil layer. All right. they travel and divide they get further
30:23 further away from their source of nutrients they're also further differentiating as they move
30:31 away from their source of nutrients. means they're basically moving away to where
30:35 not going to be able to be as a selling more. So at
30:39 point they're starting to starve as part their process of differentiation. They begin
30:46 produce these unique types of keratin. Granules are called Kurata highland.
30:53 It's not quite keratin yet. But starting to produce tons and tons of
30:57 . In fact, the whole purpose a karate insight is to produce
31:01 It says it in the name. so we're not quite there making character
31:05 . We're making a precursor two keratin we're slowly dying and we're not replicating
31:13 . We don't need a nucleus. don't need all our organelles. And
31:17 what happens is those organelles and those that nuclear begins to be destroyed and
31:23 down all right. And as a of its distance from its nutrient source
31:29 well as those changes within the We say that the cell begins to
31:36 . Alright, so it creates this layer that has these spots to
31:40 The Granules, that's why it's called granule, awesome. It's granular.
31:44 you look at it underneath the Now, we haven't gone through the
31:49 process of characterization. This is the of the characterization process by the time
31:55 up here, you will have gone all the stages. Alright, so
32:00 layer is only about uh you a couple of cells thick. And
32:06 they've drawn it here is too but you know, it can be anywhere
32:09 three and five cell layers thick as are pushed along The lucid um is
32:18 weird one. It's only located in the palms of your hands and on
32:24 soles of your feet. Alright. what we have here is a unique
32:29 of keratin that's being produced. It's actually character itself, it's kind of
32:33 intermediate. It's these cells here in particular locations are going from that corado
32:40 protein to this different type of protein um a Leyden. All right.
32:46 so the allied in is there. if you look at these cells,
32:50 kind of clear. Like they don't the Granules that you see in the
32:55 , awesome. But this allied in incredibly immune to UV light. And
33:05 as a result that skin doesn't darken much as your skin does to UV
33:13 . It doesn't take it doesn't need take up the melanin. And you
33:17 see this, I mean the darker the easier it's going to be able
33:20 do this. But look at the of your hands right? Cause that's
33:22 get pretty good sunlight. And then at the palm of your hands and
33:25 should see that they're slightly different in right back your hand is probably darker
33:30 the palm of your hand. This is really clear. We used
33:35 spend a lot of time outside if have darker skin naturally at this
33:39 remember, we've gotten rid of all those uh those organelles. And really
33:44 this point you're kind of a bag of just keratin is a Leyden.
33:50 so what you have here is this protective layer that's kind of flat and
33:56 , but doesn't have a lot of to it now it's thick and so
34:02 helps protect those two places the last of the cornea and this is the
34:07 superficial layer. It can be fairly in terms of the number of cells
34:11 are found there. Um These cells basically been pressed down. So what
34:15 now have, as you can imagine plasma membrane that's been kind of pressed
34:19 close together. All the material inside cell has been removed. There's really
34:23 water in there anymore. There's only proteins, the keratin proteins. So
34:28 basically fat, protein, fat. more than that. But you can
34:32 that's kind of what it's like. you've got layers and layers of
34:35 So it's like like taking a a barrier that's been glued together, that's
34:41 pressed and stuck together. And so you have this protective barrier between here
34:48 then the underlying cells underneath. So is we say it's relatively insensitive to
34:57 different sorts of threats. It's because all those steps that it took through
35:02 characterization process to go from this living cell to this pancake of protein and
35:12 . All right, So there the layers and they're corny um I think
35:19 I think of corn corn, I of like the thing that we
35:23 but really think of something that's more and flaky. That's whenever you see
35:29 , when they're talking about the they're they're talking about that kind of
35:36 . So your body consists of two types of skins. You have thick
35:38 and you have thin skin. Thick is the stuff on the soles of
35:41 feet and on the palms of your , it has all five of the
35:44 that we just looked at. Uh you um you're gonna see lots of
35:48 glands in in those thick layers, you're not gonna see hair follicles or
35:52 glands. Alright, everywhere else? have thin, So this is
35:57 that would be thin. What do have on the back of your
36:00 You have hair follicles, you have sebaceous glands, You have sweat
36:03 but not with the same numbers that see here. If you don't like
36:08 talk, give public talks public do you like classes where you're like
36:13 , there's like maybe one out of people like to do them? Most
36:17 , when they get up in front people, they get really, really
36:19 . And so that's when you get cotton mouth and what's the other
36:21 You get sweaty palms, right? mean you're just sitting there going,
36:26 notice people, people can tell my are sweaty. Yeah. Alright,
36:33 the way, if you get lost tests. Oh, by the
36:35 you have a cheat sheet for your , that's your own body, you
36:39 ? So yeah, I mean I'm you you really A. And
36:42 Is one of those things where you take your own cheat sheet in.
36:46 like oh yeah that's thick. That's what how are those two things different
36:50 you can look at your hand and , oh yeah I've got hair on
36:53 side. So it's wait till you to start doing movement and stuff.
36:58 gonna see people doing this on the . Trust me, it's funny to
37:07 all right. But we all do and it's that's perfectly okay. You
37:10 practice in front of a mirror, know, find a partner whenever you're
37:14 this stuff and use each other as to help you understand what it
37:19 Um And just as an aside and I'll answer the question. So long
37:24 ago before I ever went to graduate I was a ta for a physical
37:28 school. Right? So I did gross anatomy lab and then there's a
37:33 of people that um you know needed and stuff and what in physical
37:38 My wife's physical therapist um didn't meet at the time. This was even
37:42 before then is so basically physical therapy is showing up ladies in a workout
37:49 and basically a pair of shorts and , it's basically a pair of shorts
37:53 you basically manipulate and touch each And so one of the ways they
37:57 anatomy. First off is learning on other as well as the cadaver,
38:02 ? Because physical therapy is literally touching people all the time. You've got
38:06 be comfortable with that, you So you have to be comfortable with
38:09 own body as well. And that's why they're making you do that.
38:12 it's really hard to manipulate somebody when wearing seven layers of clothing.
38:15 So anyway, question. Yeah. I'm not sure if that's necessarily true
38:28 it's the thinnest. It could very be, I don't know that
38:31 I mean, I hear, I so many facts that are probably true
38:38 may not be, I don't But but yes, so the eyelids
38:42 still have sweat glands. They don't the hair as far as I
38:46 I mean maybe if we went looked closely, we could probably do
38:48 But it has a whole bunch of that are embedded within it.
38:53 Mel bony in glands for example, know when you wake up and you
38:57 , there's two different types of you get the crust that's over here
39:00 the car. Uncle, right? probably still have some, cause I
39:03 quite wiped out my yet, but actually glands where your eyelashes come
39:08 right? And I had a student semester, she'd kill me if I
39:13 telling you this, she had a on her eyelid. It was
39:17 It was so, it's just what's a sty basically clogged pore?
39:21 she had a gland right here on front of her eyelid and it was
39:25 the world's biggest zit on her eyelid she was like showing up for our
39:29 exam wearing a hat and she was , can I wear my hat?
39:32 I'm like, why do you need wear that? She like, showed
39:34 . I was like, yeah, can keep the hat on. And
39:38 had email discussion for like three It's finally ruptured. Yeah, I
39:44 all four starts. But yes, you have skin, you're going to
39:48 all these kind of unique features underlying . Now, as I mentioned,
39:54 epidermis plays a role to protect against invasion. First off, characteristically our
40:04 is for the most part dry. . It's we're not moist,
40:08 like frogs and other stuff. We rather dry environment. And and really
40:12 truth is, is microorganisms hate dry . They need to have that moisture
40:16 live, You know? So where we find huge populations of microorganisms that's
40:22 we primarily have warm and sweet That's gonna be your pits and basically
40:27 your Euro or it's really the anal region. So basically your pit between
40:32 legs, right? Where you sweat lot. And so it's like,
40:36 , it's warm. And there's lots water here. So I can multiply
40:39 divide there. All right, But help. So let's pretend for a
40:44 that somehow some sort of organism penetrates those protective barriers and gets down here
40:50 the Spanos. Um Well within the we have another group of cells,
40:53 called the Langerhans cell. And truthfully they are, is there a type
40:58 immune cell called a macrophage? remember many things were just named because
41:03 something different and they're like oh here's different, I don't know what it
41:06 , but I'm just gonna name And the guy who discovered his Langerhans
41:09 so they got to say it's Langerhans , Langerhans cells, the macrophages macrophages
41:15 an immune cell and they're all over body and they travel around very
41:19 But in some places they become residents that's what langer hans is, it's
41:25 resident macrophage and you can see it's of sitting in there and it has
41:29 pseudo podia that are kind of stuck . And what they're doing is they're
41:32 for signals that say I don't belong and once they become activated, then
41:39 they do is they attack the foreign and they send signals to other immune
41:45 to come and localize into that particular . So they serve as that first
41:52 of of immune defense if something actually into the epidermis. So let's deal
42:04 the question of skin color really skin color comes from primarily the presence
42:08 pigments. And so what I want do is the primary pigment in our
42:12 is melanin. It's a primary pigment found in our hair as well.
42:17 what melanin is is as I it's made by these melanocytes and so
42:22 what the little cartoons showing you and melanin is then released out through these
42:27 extensions these processes And out into the between the carotene insights and then the
42:32 antenna sites pick up that melanin and it into the vacuum calls and then
42:36 moved that melanin. And this is it's trying to show you up and
42:41 the nuclei so that it protects the from UV light. All right.
42:47 when you have more UV light you more melanin. Now it doesn't matter
42:55 your skin color is. We all the same number of melanocytes.
43:01 melanocytes produce, produce more or less depending upon the signals that they
43:09 So, some of those might be signals which means if you have darker
43:13 , you're getting a signal that says milana side should produce more than say
43:19 , interestingly blue eyes actually has a and more melanin production than say brown
43:25 . It's a different type of So my blue eyes. Oh I
43:30 my blue eyes get tons and tons mountain my skin. Not so
43:34 All right now there are different types melons. These are the two primary
43:38 that we see in the skin. . So you have this brown black
43:42 that gives you that darker skin. there's also a red yellow pigment that
43:46 you kind of more of that olive . Right? So when I go
43:50 and sit in the sun for a , long time, I don't get
43:54 as in brown. I get more of that beige color. And that's
43:59 I just have a lot of feel in my body. Alright. And
44:03 is genetically determined If you have fio and you have you melanin, which
44:09 the darker pigment. You're gonna have . Right? Which one is going
44:13 dominate in terms of color? Mm gonna be you Melanie. Alright.
44:19 color of skin is simply just a of the melanocytes that we have and
44:23 much melanin they're actually producing. so we all have the same
44:28 It's just What colors are they That's all it is. All
44:33 freckles. If you have pigmented moles things, they're just localized accumulations of
44:41 . Right now, there are other of pigments that can affect skin
44:46 This is where I get to make of snooki you know who snooki
44:49 Okay. Okay. I don't know . I don't know. You can
44:59 ask me questions. I don't know answers to, which is pretty fun
45:03 the stuff that I don't know could books and they do. So I
45:07 know, I'd have to look that curtain carnitine is really has pronounced.
45:13 not keratin is the chemical that carrots . It's what gives carrots the orange
45:19 . Unless you're from A and In which case you guys invented the
45:22 carrot. Did you know that ever the marine care? You're starting to
45:30 about rich why the carrot? so I don't know whether or not
45:38 true. They're related to parsnips, are white and I don't know if
45:41 are in parsnips are directly related or distantly related. Huh? It could
45:49 well be someone may have. that's not something I know the answer
45:53 see again. List of things that don't know. There we go.
45:58 . So perhaps I'm saying perhaps because don't know and I don't and I
46:04 want to if I don't know I don't want to say yes,
46:06 absolutely true. And then go read no carrots are unique things.
46:10 that's why I say I don't All right. Anyway, So,
46:14 a yellow pigment carrot. It's actually one of these chemicals that accumulates in
46:20 . So it's a a fat loving lipid soluble pigment. And so it
46:26 accumulates in the hypodermic and since your uh basically you don't have a lot
46:32 melon or or if you don't have lot of melanin that can actually show
46:36 if you've ever used the rub on ocean. The band is away.
46:45 ? What it's doing is you're basically something that is lipid soluble putting in
46:48 skin. It goes onto the skin absorbed through the skin because lipid soluble
46:53 can be absorbed and it collects in hypodermic. That's what the tanning lotion
46:58 . It's basically putting karate directly into skin in order to get your carrots
47:03 make you look that color. You eat a lot of carrots. There's
47:06 that much Claritin. All right. these aren't the only two pigments,
47:11 these two are the ones that are least worth talking about. All
47:22 To check and make sure of the here. Uh We'll take a break
47:27 the uh Yeah, maybe two So one of the things in the
47:35 , what you're going to see is are cells that are located in the
47:41 basil called tactile discs. All And so they're not they're not doing
47:46 good job in this picture showing So, here is where this where
47:53 going to be looking. But what want you to imagine there's a single
47:56 sitting in the stratum basil that's called tactile disc and coming up right next
48:01 it is a nerve fiber. The disc is what detects touch. And
48:05 communicates with the nerve fiber to send signal forward. But we also have
48:10 nerve endings that penetrate through and into epidermis and can be found within the
48:16 of the epidermis to detect touch as . So, tax, how does
48:20 with things like fine touch, very pressure free nerve endings are primarily responsible
48:28 pain. And if you didn't tickling is a type of pain.
48:33 ? I mean, have you ever that tickling becomes painful after him after
48:36 bit. It's kind of fun to with. But then after a while
48:39 like stop you're hurting me or I pee myself, that sort of
48:43 Itching is another type of noxious It's actually a combination of different
48:51 And so that's what Frene Irving's can . So you can see there's different
48:55 , different types of things that they detect. A noxious. So think
49:00 it like chemical. So it is the presence of a chemical that says
49:05 uncomfortable at this at this position. of a better way to put
49:12 Here's the vitamin D. This is very very long process. You do
49:15 need to know all the steps. goodness. Just understand UV Light results
49:20 the production of vitamin D. Councilor a fancy name for vitamin D.
49:25 you ever noticed that vitamin D. always listed as vitamin D.
49:30 Ever notice that calcium try all. the third step. It's the
49:37 Three. All right. And so what it is is that you have
49:40 in your skin that cholesterol gets converted . Well, there's the vitamin
49:45 Three right there. I'm sorry, am wrong. That's not the vitamin
49:49 . Three. Vitamin D. Three an active form. But what happens
49:52 it goes in the liver, goes the kidney, goes through multiple steps
49:54 become the active form. The active is responsible for the take up of
50:00 and phosphate through the diet. So do we put vitamin D.
50:05 We put it in our milk because have calcium that's in the milk and
50:08 makes it nice and easy to absorb at the same time. That's why
50:12 fortify it. Alright. But the here is just understand UV Results in
50:18 production of Vitamin D. three. get outside make your vitamin d.
50:24 good places. Not not not right . It's yeah. All right.
50:32 don't we go ahead and take like oh, I don't know. Let's
50:37 9 51. Let's try to go 10. I'll give you guys nine
50:43 p. You know, do all fun stuff. Mhm. Not
50:52 But we will. Yes. We a full lecture on the eye.
50:57 talk about that. It has like sizes. Mhm. On the
51:02 Or like like on the edge. . Yeah. And probably aggravated.
51:09 like when you when you open your it pushes the eyelid down which aggravates
51:13 even further blocks the poor scary like . That's what they told her.
51:19 she wanted to see the ophthalmologist I or whatever and they're like we can't
51:23 that one, it's too dangerous if cut it we don't know what's gonna
51:27 . So personally I've seen but they . Mhm. Oh yeah, that's
51:34 . Absolutely awful. Yeah, hers like it was like as if their
51:39 to her and I told her the thing without knowing it was like it's
51:42 put a warm compress on it. actually said heat up a potato and
51:46 the potato against it. Yeah, opens the poor. So really what
51:50 is, if you can think about just a poor we're gonna look here
51:53 pores here in just seconds. So a poor. And then what happens
51:56 that material gets in that poor and become solidified or bacterial kind of keep
52:02 clock. And so what happens is still producing the material and it gets
52:06 and bigger and bigger, Right? all you gotta do is unplug clogged
52:09 pore in theory? Yes, So what happens is like so really
52:21 will happen is is that like, know when we looked at a rough
52:25 plasma particularly there's not just one, there's multiple portions of it. So
52:30 happens is it gets divvied up, ? So mitochondria get divvied up the
52:35 gets divvied up uh the central zone uh basically duplicates itself. So there's
52:43 is called a mother and a And then you duplicate those and then
52:48 get split. And that's when you're to do the cell division. Um
52:52 to think if any others. So er mitochondria. So right. So
53:02 we didn't go into detail because I want to spend like a ridiculous amount
53:06 time on the biology. But so when we replicate the DNA that's taking
53:10 in the nucleus? All right. then that that may topic step,
53:15 we call mitosis has two parts to . It's it's the division of the
53:19 material. So we break down the material, the chromosomes get tied up
53:24 and tight. So they have that of the compact X. Looking thing
53:29 we think, Alright, and then you have is the sentry als basically
53:34 gonna migrate to opposite sides of the . They send out these intermediate
53:38 bind up to these. Now, chromosomes. And then you pull those
53:44 apart. And then once you separate the nuclear retail, then you re
53:48 the nucleus around them. And they unwind them again. So so that's
53:53 first half is the nuclear material breaking the nuclear wall. And then re
53:58 it. Once you've separated the nuclear and then of course the depending on
54:03 the organelles are, they're kind of pulled apart and go their separate
54:08 it's a good question. Okay. . So in theory, yes,
54:17 if you don't let's say there's let's there's a 60 40 split, well
54:21 cells gonna make what it needs. that's part of the instructions like oh
54:24 can't do what all the parts that all the things that I need to
54:27 . So I'm gonna ramp up production make more er I'm gonna make up
54:32 goldy mitochondria. Oh, mitochondria divide then then probably the cell will
54:43 I mean, my suspicion is, know, and again, I don't
54:46 the actual answer to that question. ? My suspicion is because it's part
54:50 this larger this larger system. This membrane system is that it actually builds
54:56 . But I can't say for I don't know if anyone actually knows
55:00 but I'm honestly I'm sure somebody knows because but it's not one of these
55:05 I was like, oh, you , but the idea is that the
55:09 cells typically should mirror each other very closely in terms of the side
55:15 is all the nuclei should be And I, you know, I
55:22 of pause there but there's always gonna a mutation. There's always gonna be
55:25 changes. But in theory you have two clones that look exactly alike.
55:32 right. Even though that's not 100% . Yeah, you're welcome.
56:33 So how the lab test go? , ma'am, sir. Mhm.
56:50 . So so that redness remember the of the very first steps that
56:55 And so what you're doing is you're blood vessels close in there. So
56:58 of the pigments we didn't talk about terms of skin color is the presence
57:02 uh heem in the blood because it's a great idea. But I mean
57:07 terms of an actual pigment that causes color changes but it influences what color
57:14 skin is. All right? So of us who are a little bit
57:16 fair, we can see, for when we Visa dilate, we turn
57:22 , Right? And that's just the of the team and the blood that
57:25 us to do and we're more we're translucent to allow that to happen.
57:29 , for example when you get a right, you've torn away layers of
57:35 , right? So your blood vessels near to and then you're going to
57:38 that vascular ization. That angiogenesis. so you're gonna end up with very
57:43 small capillaries, very small blood vessels are bringing blood near to that surface
57:48 gives it that redness to it. they're open and they're they're close to
57:52 surface of the wound. And then you rebuild the epidermis over it,
57:58 what's gonna happen is you're you're now away. So it becomes less red
58:04 if you get the granule ation on of it. Right? So like
58:09 that harder scar. Now you have tissue in between the blood vessel and
58:14 surface which gives it that whiteness as . So, for example, if
58:18 seen if you've been scarred and you can you notice that it doesn't quite
58:23 the same way? That's that's the . Said you don't have as much
58:28 on that surface and there's less structure . Yeah, like really?
59:05 Right. So so you ve can some pretty amazing things. All
59:12 you can use UV light to train cell where to travel. You can
59:16 use UV light to kill a you know? So it's it's in
59:21 you use it and how that cell to it. So it would be
59:24 to see what their technique was, their protocol was. But you
59:29 like I said, I don't I just kind of nodded my head
59:31 go, okay, that sounds really . Yeah, it sounds really
59:36 Alright. I think we're we've got more winning. Oh no, my
59:41 over here. Alright, so what wanna do is I want to dive
59:45 the dermis and then we'll jump through nails. I mean literally the hair
59:49 things is boom boom boom. and then the glands, So with
59:53 to the dermis, remember now we're here, the dermis actually is very
59:59 from the epidermis in that it has blood vessels, it has the nervous
60:03 , right? It has actual nerve that penetrate through it. Remember I
60:08 free nerve endings can find their way the epidermis. But that's few and
60:12 between. Most of the innovation is to be taking place in the dermal
60:18 . There's lymphatic vessels which you don't need to worry about just now.
60:21 part of of the immune system as as part of the vasculature to move
60:27 around. There are two different And I think the artist in this
60:32 actually does a really good job of of like separating the two. And
60:36 can kind of see the barrier, boundary line between them. If you
60:40 look at a real picture, your mean a real, you know,
60:44 section. You're probably not gonna see like that. But I think he
60:47 trying to uh separate it so that could visualize it. So, the
60:52 layer is the layer nearest the So, when you see people,
60:56 think fingers or hair. All that's that's what the term means.
61:00 you're gonna see I've got these little that are kind of pushing up into
61:04 appears, you know, near to epidermis. And then the lower
61:09 that's a particular layer. And that's because it looks uh kind of like
61:13 a strom a or a network. the papillary layer is aerial or connective
61:22 . Alright, these papillae. remember this is a rich,
61:27 That is a papillon. So they're basically intertwined or interdigital mated with each
61:33 . And so what happens is is can they're not like going in this
61:38 . They're more up and down. so what you can think is that
61:41 interlocking with each other. And this where we get that kind of that
61:46 interlocking interface between the dermis and the . Yes there are molecules holding things
61:51 at the basement membrane. But this you to really kind of lock in
61:56 two tissues with one another. Now artist didn't show it in this picture
62:00 if you go look at that cheaper away view, you'll see that up
62:04 these regions, you'll see these large blood vessels down here. But you're
62:08 see these capillary loops that come deep these uh papillon. And the purpose
62:15 is I'm bringing the blood and the in the blood as close to the
62:19 as I possibly can to provide the for that epidermis. You're gonna see
62:24 whole bunch of different free nerve endings And these are primarily pain receptors in
62:29 types of touch receptors. We're gonna them. Um We're gonna learn them
62:33 . Actually. This is gonna be first time. And then at the
62:36 of the semester we're gonna come back learn them again. Um Which is
62:41 of fun right? Um So when look at this picture, this is
62:44 you can do. Those are where capillary loops are you can see they're
62:47 of up there near the papillary. what we want to focus on now
62:50 down here. So everything kind of this line right there. This would
62:54 the particular layer. So this is denser regular connective tissue. Alright,
63:00 collagen fibers. And they run parallel the skin surface and they create what
63:04 call cleavage lines. And so a line is kind of what you see
63:08 the palm of your hand, So when I bend my hand,
63:13 know, there's these these points uh sure I'm getting that right now.
63:17 a flex line. The cleavage line what what we take advantage of when
63:21 doing surgery. All right. So this is kind of a map of
63:24 your cleavage lines are and what it you is like. This is for
63:28 looking at the the abdomen here. is the direction in which the collagen
63:33 running. So, when I cut a cleavage line, what's going to
63:39 is by cutting the direction of Cleveland , they just kind of separate.
63:43 . So, but if I cut way, then you're gonna kind of
63:46 the things pass or they're going to . Really, really difficultly. It's
63:52 much harder to repair. So, knowing where the cleavage lines is very
63:57 for surgeons to know how to cut the surface create less damage that
64:03 Alright. It's just a function of direction which college collagen is running?
64:08 also some Alaskan that gives elasticity. for example, you can see my
64:12 . Let's do this show. Um see got elastic skin. Yeah,
64:19 you're young. It bounces back. hangs. All right. All
64:25 I already said highly Vasko. lots of nerves. Um The flex
64:31 lines are what you're gonna see on hands. It's not just there.
64:34 got them all over. So, are flex your lines as well.
64:36 so basically these are deep attachments in dermis. And so it allows you
64:42 move your body and move your skin such a way that your skin folds
64:45 exact same way every time so that doesn't do weird things. Right?
64:53 right. I'm sorry about this. just the way that we learn this
64:57 . It's not always easy. So historically they were named after the
65:04 . They discovered them. But now start using different terms and on an
65:09 , I'm not going to separate those things. Alright? So, I
65:14 put like my sinners tactile corpus Alright. Because I want to be
65:22 fair as I possibly can. But know, you're gonna get that little
65:25 lady who hates students, you a couple of years down the line
65:29 they're gonna use like an old term then you're gonna get that young
65:32 New professor who only uses the new . Alright? I'm in between.
65:38 don't have a horse in the All right. So, where are
65:41 located? Meisters? Corpus cell is near the surface of the dermott.
65:49 it's in the papillary layer. All . And what you're gonna see with
65:54 is they're actually these nerve endings that been wrapped around in connective tissue in
66:00 ways and they allow you to detect types of pressure or touch.
66:06 Meisner hours allows us to detect light , light pressure and light vibrations,
66:12 ? It's right there at the I don't need to put a lot
66:14 pressure to be able to detect So, if I am manipulating the
66:18 , I'm probably going to detect it there near the epidermis in the
66:23 So, that's the purpose of mine light touch, light pressure. Light
66:29 , Pacini in core puzzles are laminated puzzles are found deep in the
66:36 Alright, So if they're deep, gonna be dealing with deep pressure and
66:41 vibrations. Alright, so, it's there's kind of hard pressure and actually
66:48 we talk about vibrations here, we're talking about different hurts, which I
66:52 want to go into. It's like frequencies All right. If you look
66:57 the pictures, you can see that kind of have different things in
67:02 I mean, it's hard to see this classroom. But here they're structurally
67:06 . Even the artist draws them structurally , but knowing where those two things
67:12 is kind of like, okay, that's the big goal, then we
67:15 the weird one in between which is Finis Finis is embedded within collagen
67:21 And what it looks for is when collagen gets stretched or gets twisted.
67:27 . And so it's looking primarily at distortions as well as pressures. All
67:34 , so this is our first exposure the different types of touch we
67:38 So for example, if you were close your eyes and you were to
67:42 something, you'd be able to you might be able to text shape
67:46 so on. This is a function the different pressures that you put on
67:51 object that you're touching, right, versus not fuzzy, you're smooth.
67:57 right. And so it's these different of receptors and how they respond to
68:02 you touch them and what sort of they put on the skin gives rise
68:07 that sense of, oh, this what this is okay. Obviously have
68:12 be able to observe it just as example. Um You probably never did
68:16 . Did you guys go to Halloween when you were kids? No,
68:20 did. Okay. Did they ever like turn off all the lights and
68:22 out like bowls of cold food and your hands in and go, oh
68:30 , you're like brains, well, don't know what brains feel like,
68:34 you now imagine they feel like Wet spaghetti, right? But how
68:38 you know it's cold? How do know what I mean? You
68:40 it's like, oh, if it's and I'm touching something, this is
68:44 it feels like. It's cold, wet, it's smooth. And now
68:47 brain is trying to connect it with that you know when you hear the
68:50 brains, you're like, okay, The Easy one, Eyeballs,
68:54 That's when you got the grapes. like I'm touching grapes, but their
69:01 . So this is the first time gonna see them. We'll see them
69:04 with a little bit more detail at end of the semester. Yeah,
69:15 , pain is a weird thing. right. All these things are weird
69:18 and that's really the question you're kind asking here is something more of a
69:22 neuro question, but I'll try to as best I can. All
69:25 So, the understanding of what pain , occurs at multiple levels first.
69:31 being able to experience it, So, if I take, for
69:36 , a lighter and light it on hand, I have nerves that recognize
69:40 in temperature that's going to alert that . But if for some reason that
69:46 goes to the spinal cord and that doesn't get itself up to my brain
69:52 I don't perceive that I'm being I detected it, but my brain
69:57 know that there's something going on, ? So, that's kind of the
70:04 level, then there's regulating pain. so there are things that we can
70:08 to change train ourselves to not detect or to overcome that these natural analgesics
70:15 stuff. And so we even have that turn pain pathways off. So
70:20 you're not feeling pain, it could at any one of those levels.
70:22 don't have the receptor. I'm not the signal up to the brain so
70:26 can't perceive it. Or I'm basically the signal from actually making it.
70:32 there's a lot of different ways that can be affected. So, what's
70:42 here is just a unique type of . Alright, It's basically dead criticized
70:49 that are being produced in this structure a hair follicle. So, where
70:54 we sit? Dead crab and I or skin? Sorry, that was
70:58 answer. With skin. Skin was answer. Where do we see dead
71:02 cells? That's at the very, top in the stratum cornea.
71:07 hair is really the same thing that seeing here. And so the way
71:12 make hair probably, and the answer it does, it's probably very similar
71:18 the way that we make that outer of our skin. Okay, so
71:24 difference is we use the different types keratin. We call it a hard
71:28 . But it's a it's keratin. , it's a little bit more durable
71:32 the way that the cells are range very, very different. It's more
71:35 shingles on a roof. Right? they basically overlap each other instead of
71:40 off. What they do is they sit on top of each other and
71:44 don't move and I'm not going to to split ends. But you
71:48 that's, that's kind of why they flake off. It's just because of
71:52 arrangement. So you'll notice I'll kind go through things the same way.
71:58 kind of look at it, give a big picture, we go through
72:00 . Then we kind of go and through the structure. So this is
72:03 function thing. Alright? So it a role in protection, right?
72:08 can see it on your head. protects against sunburn and injury when I
72:12 young and stupid and I got a of young and stupid stories. Um
72:16 went to see Stevie Ray Vaughan in , like the concert a week before
72:20 man died and it was out in desert near el paso and me and
72:25 buddies, we all got up at o'clock in the morning with several cases
72:28 beer. We parked at the place we were going to go see the
72:31 . It was an outdoor concert. was gonna be taking place at like
72:34 o'clock at night. We started drinking eight o'clock in the morning and we
72:37 all day long. So we're dehydrated the desert sun with no clouds.
72:44 never been sunburned on my scalp I was sunburned on my scalp.
72:51 protects when you see I've got thick right? Normally protects. It doesn't
72:56 you for 24 hours or 12 hours whatever it was. All right.
73:00 anyone know who this guy is? a real person. That's not his
73:06 hair. That was an internet. right. That's still Specter Phil Specter
73:14 was the guy who produced many of Beatles albums. All right. So
73:19 was a music producer. And because heard that word Beatles, you can
73:24 he was a real popular person and was also insane. He threatened to
73:30 a woman and put a gun in mouth. And I think basically went
73:34 court for that and was put in . And so he showed up with
73:38 hair that looked like this. That this tall. It was that
73:43 But it looked insane because he's trying make a case of insanity. So
73:48 made a meme in your nose. got little tiny hairs. They trap
73:55 in your ears. You have little hairs, they trap particles and they
74:00 in directions to prevent things from crawling your nose and into your ears.
74:04 serve as protection eyebrows are all really cool. You'll need to go
74:09 in the mirror and see the shape your own eyebrow. I can see
74:12 your eyebrows. You can look at , you can kind of see they
74:14 this point this way and point that , look right. There's kind of
74:17 arch to it. And they basically natural sweat bands. When sweat comes
74:23 , it hits that um eyebrow and eyebrow pushes the water towards the medial
74:31 of your body. In other over your nose or out laterally and
74:35 from your eyes so that you can Mhm. Plays a role in heat
74:43 . Again, we go back to old Phil specter Plays a role in
74:47 reception. You can detect things because are are nerve endings attached to the
74:52 fibers. This is the time I to tell you the story. I
74:54 over at this girl's house and this back in when we still had shag
74:59 . So, this is like the 80s. So, I mean,
75:01 dawn of time type stuff. We dinosaurs. Alright, so, I'm
75:05 at this girl's house watching a tv and I kept, you know,
75:08 was in a shag carpet and I filling this thing on my arm and
75:11 kept brushing it off shag carpet. ? And finally, after a third
75:14 fourth time I looked down and the that was trying to crawl up my
75:18 was a scorpion light touch. Visual identification. You see somebody and
75:31 get a haircut, you can't identify , right? Because your brain has
75:34 when I see this person with this , that's person, a right hair
75:41 a role in identification, right? also helps us to determine age and
75:47 . All right. So the question why do we have pubic hair?
75:51 do we have to grow hair in where we had no hair when we
75:53 growing up? Part of that is demonstrate this person is now sexually
75:59 Now granted we all were closed So we don't get to look at
76:01 go, oh yeah, I see you're now sexually mature. But you
76:05 imagine in an organism that doesn't wear , that having hair that points to
76:10 areas where reproductive or reproduction takes Kind of the signal says this is
76:16 an eligible person for this sort of . All right, So that's kind
76:21 what it does. It helps us age sex. Those big old beards
76:25 we all get kind of says, know, for a man, that's
76:28 real obvious one. I am now man. And when you're a little
76:33 lady and you have your little mustache . Sorry. So anywhere for any
76:44 for so again, this is a good question and you know again what
76:50 do when you when you have questions that, not you. But when
76:53 do we have to kind of go with an assumption there there's a rational
76:56 for for this. Alright. And I would say is is that this
77:01 probably the reason right? There is pheromone dispersion. Alright. So where
77:08 typically get body odor is primarily in axillary and really the pubic regions.
77:15 . And that's where we get So one of the things is you
77:18 have a substrate on which bacteria can of congregate. And it's also these
77:24 that are in these locations begin function functional at the age of puberty and
77:31 . And so those two things are of congruent. It's like, oh
77:34 , puberty that's when I become sexually functional. Right? So that's that
77:39 sex thing. Alright. Oh. by the way, I want to
77:43 and send out pheromones, humans aren't really big on pheromones. I mean
77:47 produce some you know that some people of smell good. You kind of
77:51 the way that person smells. That's pheromone notice it doesn't make you
77:55 oh gosh, tear off all my . This is the person I'm gonna
78:00 sex with. Right. To the moment that that's not how that
78:04 rats and dogs and other animals do that. But humans do not.
78:09 a little bit more rational I All right. But anyway,
78:14 so the purpose of that hair there probably just to serve that substrate.
78:19 right. Again, that's that's hyper our best guess. You know?
78:26 what does, what is hair? mean this is again this is like
78:30 kindergarten version. I mean we could probably two days talking about hair if
78:34 wanted to. We're not gonna But All right, we have the
78:38 . Alright. The shaft is the of the hair that extends beyond the
78:42 of the skin. The root is portion of the hair that extends below
78:47 surface of the skin. All Now, both the shaft and the
78:52 are all dead cells, just like corny um is a bunch of dead
78:57 . All right. All the living are found down here inside the hair
79:02 , right above the papillon. so here you're going to start seeing
79:08 that's what they're trying to show. like, oh look there's living cells
79:11 here. Alright, so that's deep down inside the dermis. And
79:15 is where hair is already. you can imagine it's kind of like
79:18 producing. I've got cells that are and multiplying and dividing and it's pushing
79:22 hair upward and the further and further . You get from your source of
79:27 right? Which is what the That's where the blood vessels and the
79:30 are found then what happens is those die? And then I get that
79:35 that makes up the hair. All . The matrix down here. This
79:44 that's where the living, That would the equivalent to the stratum,
79:49 Alright, That's the layer where you the cells multiplying and dividing. And
79:55 the papillon right here, that's where blood vessels are located. I'm trying
80:02 keep it real simple. Yes you have to speak rule it
80:08 Right. Yeah. Mhm. I got one right here. It's
80:31 bugging me all day. No no . Yeah. So again when you're
80:35 the hair, what are you You're basically creating a sharp surface and
80:38 you're getting it typically what you're trying do when you cut that hair when
80:41 shave a hair or something like what you do is you're actually pulling
80:44 hair hair upward so that you can it and then it kind of falls
80:48 down below the surface of the Because if you're only taking it to
80:51 surface of the skin, you're going see it within a couple of
80:54 That that hair is up again. is always growing. Well it's not
80:57 growing. We have a we have pattern. Um But that's the idea
81:02 ? So what happens now is you this cut hair and I think I'm
81:05 your question but if I don't just you didn't answer my question. So
81:08 you have this hair and it has sharp edge and if it's not directed
81:13 out through that shaft, what it is it can turn on itself,
81:17 get those ingrown hairs, everyone loves . Right. Right and then that
81:22 a structure that then can be So now you've got the poor that's
81:27 you have bacteria that can actually block up or it can become infected.
81:31 so that's when you get the immune coming in and that's when you get
81:34 parts and all the other fun stuff is basically the immune cells and their
81:39 . So did I answer the Yeah. Okay. Cool.
81:44 So this is a structure here, it's all dead. What we've done
81:47 we've taken a cross section through the . You can see we have the
81:50 whenever you see the word medulla it middle cortex means the outer portion.
81:55 that's here's you see medulla medulla you hear people say majalla as well.
82:00 medulla cortex and then the outer layers cuticles that's just the the portion that's
82:06 the surface. And so we already that these are like shingles. But
82:10 you think of the medulla, this kind of loosely arranged hairs. And
82:14 as a result of that you have that gives hair flexibility, cortex on
82:20 other hand is more flattened and more up against each other. So that
82:25 its its stiffness. So the reason hair kind of can be movable is
82:29 of the innermost portion but the reason hard and capable of not just tearing
82:34 is because of the cortex and the . So the hair follicle actually originates
82:43 the surface from the epidermis. And happens is you get an in vaginal
82:48 . So you can imagine here's the of the skin. It actually pushes
82:51 down so that the hair follicle actually has two parts to it. All
82:56 . It has a portion that comes the epidermis and in our little cartoon
83:00 here, that's the pink portion and surrounding that is connective tissue. So
83:06 refer to that that structure as the sheet. And so there's an epithelial
83:10 sheep which is internal. And then have the connective tissue route sheet which
83:14 external but it's just from the So you can imagine if I'm pushing
83:18 the portion that pushes down with the nearest the hair is going to
83:22 from the epidermis and the portion that's it has to be from the
83:27 Now associated with every hair follicle is to be a muscle called the erector
83:32 muscle. Alright. The erector pili is the really, really cool muscle
83:37 your hair stand up and they act of each other? Have you ever
83:42 like your hair stand up on just one side of your body and you're
83:46 why are you freaking out? And not what's going on over here that
83:50 to be concerned about. Alright. Pili Muscles Act Independent of one
83:56 All right now hair does grow in . Alright. Um Really the key
84:04 here is don't you don't need to all through this, but it's like
84:06 right, the active phase is called antigen phase, That's where the hair
84:09 actively growing. So it's producing new um and it's basically has its blood
84:15 , so you're just, the hair growing and then what happens is we
84:19 giving it blood, we enter into cottage in phase. The contagion phase
84:23 when there's no blood and then now hair just kind of sits there.
84:27 we now have what is called a hair and then intelligent phase. That's
84:32 we basically are sitting there and that is getting ready to fall out.
84:37 at any given time your hair can in an antigen phase, the cabbage
84:40 phase or the telegenic phase. So you've ever washed your hair and you
84:46 hair in the drain, those were that fell out through because they were
84:50 the telegenic phase, That makes Unfortunately, our hair doesn't do it
84:56 at once, not all energetic, that would be awful, right?
85:05 , you're basically killing the blood That's the that's the secret there.
85:11 I'm killing the blood vessel, I provide nutrients to the papillon and hopefully
85:15 damaging the cells of the Papillion as , so that there is no hair
85:20 from that particular location. Now there different types of hair when you are
85:27 fetus. Alright, so you're still sir, go ahead. You know
85:32 good. Sometimes I forget to look alright so again with the tattoo,
85:46 you're not doing your getting below the ? You're you're working into the into
85:52 dermal layers, right? And so idea here is I'm not sure they
85:57 don't know if they're bleaching out the . What's that? Okay, so
86:04 you go. So dispersing the Actually, I had a student once
86:08 had a laser removal company, he former military and he was like that's
86:14 he wanted to do for the So he made people like normal people
86:17 for it. But if you're a he would remove it for free.
86:22 again, so the idea is that can do unique things, you can
86:26 direct the energy to kill the So the idea is that you're killing
86:29 living cells, then your cells can't , you know? But the other
86:34 that you can do is you can or disperse or destroy to to move
86:38 around. Yeah. No, you , I don't know the answer to
86:49 . I do know, so you I know that for example my my
86:54 guy that trained me, my p he had one of those beards that
86:57 know kind of went down the neck became your chest hair, you know
87:00 kind of and he didn't like that when he'd shaved he'd get those horrible
87:05 you know bumps and stuff. So did that laser removal, he had
87:09 do multiple times to kill himself. the purpose there was you're not doing
87:13 cell, you're doing hundreds if not of follicles at a time. If
87:20 was dangerous, would they do Probably. I mean they'll find out
87:24 . But I mean the idea is your only damaging specific types of cells
87:31 the frequency of the light that you're , you know, and and the
87:34 of the light that you're using. , you know, I don't know
87:39 it was U. V. Or it was laser that he did.
87:42 mean that was 25 years ago. , you know, before you all
87:45 born and when you hear those it's like I look back at it
87:50 while ago. So I think I the question, I'm not entirely
87:55 Okay, alright. So types of Linux go hair. This is what
88:00 find on a baby prior to its when it's born. And then um
88:06 it's born it still has some Linux go hair. Um But it starts
88:10 replaced very very quickly by vela's Um vela's hair is that really really
88:16 . Downy hair. So using your as an example is probably not a
88:19 one but it kind of gives you sense of that light hair. It's
88:22 think about the hair that's on your your belly again, women, it's
88:27 . Men would probably have hair on belly, Right? I mean,
88:29 have terminal hair, see, it's shown there, but it's that
88:33 very thin hair as Bella's hair. then terminal hair is the hair that
88:38 see on your head. All But it's also the hair that begins
88:42 through puberty. So, in it would be the facial hair as
88:46 as chest and back hair and belly and pubic hair. And then the
88:51 leg hair that we see in both and females, pubic hair. You
88:54 kind of see they're trying to show on your arm as arms as
88:57 And again, it's more obvious if have dark hair, what terminal hair
89:01 like? It's kind of like, , it's thick and it's scary.
89:03 you know, And then But if like, light like me, I
89:07 , my my terminal hair looks like still like it's valid. It's not
89:11 terminal hair. Yeah. What? . Good reason out with one.
89:25 a good question. I don't know answer to that has to do with
89:28 amount of melanin that they're producing. the rash. The reason for that
89:33 I don't know. You know, that's a fair question. I
89:38 I'm not even gonna try to So, the time of year you
89:44 is depending ponds is dependent upon the of shape it has. All
89:49 So, if you have, say a kinky hair, the shape
89:54 that shaft is like a ribbon. ? So it's kind of flattened and
89:58 that's what causes it to curl on . If you have straight hair,
90:05 what you have is a round So basically just kind of falls like
90:09 and just kind of keeps going. then if you have like wavy
90:15 try to go for the whole, know, Neapolitan look there, Neopolitan
90:21 right chocolate, vanilla, strawberry. wavy hair, that would be where
90:26 have more of an oval shape. it's not round, it's not
90:29 it's kind of in between. Um pigments there's lots of different pigments that
90:35 up the color of hair. There's that are found at the base of
90:39 follicle. And so you've got all different types of colors of hair that
90:43 can be. Uh But if your stop producing melanin, then the hair
90:50 first gray. So that's diminished melanin . See exhibit a alright. And
90:58 when it produces no melanin, that's you go white, you know who
91:02 is? Right? It's a lot . Now, see I get older
91:07 you guys get younger, that's ted . He used to be in cheers
91:10 then he started being in C. . I. Is that the good
91:15 good place. See that's what he's now. See the stuff I don't
91:18 ? But that's that's that's before and . He ain't producing melanin no
91:25 The good place. See All So that's everything you need to know
91:31 hair nails. We've tried to even it even simpler. It used to
91:35 a lot longer basically. These are like modification strategy corny um All
91:41 They job there there there that harder . And their job is to help
91:46 grip things or graphs items and they play a role in protecting the distal
91:51 of your digits. Alright. So you've ever like been doing something and
91:56 jam something at the end of your . C I mean it can make
91:59 cry you like. Yeah, that's the nails for us to help protect
92:02 that. Alright. three parts that want you to understand this part that
92:07 looking at right here. And they're on the that's called the nail
92:12 That's easy. It sits on the bed. All right. So the
92:18 plate over lies the nail bed. nail matrix is down here. So
92:24 what you can't see in your fingers down here, like right in
92:28 And that's where the nail is The nail doesn't grow this way we
92:34 that. I mean your own finger grow this way. It grows that
92:38 . So the matrix is down here and now forward like So this little
92:48 , that little feature I'm just naming because it could be an easy question
92:53 because we want to know the name the things we call it the
92:56 It's the half moon, what's its ? Mhm. Just what it
93:05 Um That cuticle right there. It's the epidemic Ium Alright. Or you
93:12 call it the cuticle. It protects matrix. Doesn't do a very good
93:16 of protecting it but it protects it . And if you're curious the area
93:20 the front of the nail bed or nail plate that's called the Hipaa
93:24 Um That's the one that you jam and it hurts like all get out
93:30 you know these three things. I you're good if you ever want to
93:34 the name of that. That's this why you don't go on the
93:42 I'll catch a picture of you dipping you find a way in my
93:47 Yes sir. Don't know you're asking pathology. Right? I mean you
94:03 so again I'm I'm not a So I don't know many of the
94:10 . I mean I know some of and like if you're asking me why
94:16 couldn't tell you, you just have I would say google it but don't
94:20 anything you read on the internet. . So I don't know. Yes
94:28 man go ahead. I don't know , you know what we're looking at
94:44 is the function of why why it . You know I mean if they're
94:48 it cut off and they continually do . It doesn't seem to be
94:53 Right? So, you know, seems to be okay. Kind of
94:57 circumcision should you do? It doesn't to cause a problem. So why
95:04 ? Or don't you know? That's you know, all I can tell
95:11 is what it was. What we it was was designed for is really
95:14 I'm saying. So don't know the . As if it causes problems.
95:20 it does, I was gonna say the crap out of them. You
95:27 to learn about these glands? Alright. They'll still be on the
95:31 though. Alright, let's deal with glands. Sebaceous is responsible for producing
95:41 . All right. Uh And so is basically the oily substance that your
95:46 is produced everywhere, except for on palms of your hands. The oil
95:51 there contains bacterial sidle elements. And bacteria sidle elements are there to kill
95:58 that are on the surface of your . The other thing that it
96:00 it helps to a smooth out and the skin and hair which helps you
96:07 water loss, kills off stuff. that stuff that you wash off every
96:13 , you know and that you suffered throughout high school. You know,
96:17 that oily skin is there to protect . But it's just kind of
96:21 So that's why we wash it All right. So it's secreted out
96:25 the hair follicles usually. And so is the type of holocron gland.
96:29 you can see sebaceous glands are typically with a hair follicle. So,
96:33 you're doing is you're secretive outward and basically going to the surface or staying
96:37 the hair or on the cell. , on the on the on the
96:41 of the skin or on the shaft . So, the reason I picked
96:44 two people, I just did oily and or oily skin. And these
96:49 the names. These two pictures came and I said, oh good.
96:52 know, suckers. Mhm. different glands are the fancy words we
97:01 for sweat glands. Alright, so is the oil. Sweat is the
97:06 substance that we use to cool our off. All right, these are
97:09 over the body. Only places you not find them on the nipples are
97:12 the general's reason for the nipples is the nipples are the duct work for
97:18 modified sweat glands. So, you're gonna put a sweat gland on a
97:21 gland. I don't know why for . I probably should. All right
97:27 , there are two types that we're in. One is an african
97:30 One is american gland, the one America Quran. We sometimes we'll see
97:34 term at crying. All right. , you can see the Quran glands
97:38 typically going to be associated with hair . Alright, american are typically going
97:43 open straight up to the surface. focusing on the Quran. All
97:49 they're typically located in the actuary in anal genital regions. So again,
97:54 where we're going is we're saying they're their pits and then the groin
97:59 All right. They secrete all the that you're gonna see in a normal
98:04 gland. But they also add in fatty substances as well as some unique
98:08 in their these fatty substances and proteins what served the bacteria as a food
98:15 . Alright. And so bacteria tend locate into these two locations because hot
98:19 moist and so they multiply and divide these actual secretions tend to lack any
98:25 of actual odor to them. There be some but not anything to write
98:30 about. It's the bacteria that when consume the fatty acids and the proteins
98:38 they break those things down, That's the odor comes from. So,
98:42 odor isn't from you, From those things living on your body. So
98:47 you're you're absolved of any sneakiness? blame it on the bacteria. I
98:52 know if that's better. But it's still Okay. All right.
98:56 , why do we have these? do we need them? And
98:58 this goes to that question is like where are they located? And when
99:02 they start working? And they typically function becoming functional purity. Alright.
99:07 so given their locations they may serve an equivalent to a sex gland,
99:13 ? Or sexual scent gland is really word we're looking for here to kind
99:17 say ooh you smell nice to me I'm interested in you, that sort
99:22 thing. I don't know who that . But you know who those two
99:28 are, that one, you should who, who do you think it's
99:38 McConaughey, Who's that? That's master . Okay. He's a he's an
99:46 nutter. One day. He has beard next day. He's wearing on
99:51 yeah, yeah. Actually my so he grew up in New
99:55 My wife grew up in New Valley um they're about four years apart so
100:00 knew him and my brother in law swear sounds exactly like Matthew McConaughey.
100:08 says you valley accent and if you just a listen to people from there
100:12 be like, okay, they're all McConaughey, you just happen to be
100:15 to act sort of All right. that? Menendez, the actress?
100:25 , I don't know my actresses, one of those rom com actresses.
100:30 anyway, I reason I pulled them . Why did I pull them
100:32 Why did I put them on the ? They're sweaty. They're the right
100:36 of sweaty there. The american sweat or cry and sweat glands sweaty.
100:40 basically these are going to be found , palms especially the souls, especially
100:44 forehead especially. So the purpose of is to help thermoregulation basically to prevent
100:50 body from overheating. So we can the blood vessels close that blood contains
100:57 its water. Water holds heat very . We put water on the
101:02 water in the blood. The heat from the blood to the surface,
101:07 the water to evaporate, takes the away. All right. Also,
101:11 how we get rid of some of metabolic waste some salts as well as
101:15 area. It also contains within a bunch of antibacterials that we were
101:19 The fun one is Durmus aydin even you found dermis. So, epidermis
101:26 bacteria on the surface of the Alright. Um This is regulated through
101:31 sympathetic nervous system. And so we this is an example of we we
101:38 because our body tells us either a too hot, there's exertion. So
101:43 know what we need to do Or there might be some emotional aspect
101:46 it. So, it's kind of defense response mechanism. Yes,
101:56 Thanks. Well, so I imagine just has to do with the number
102:00 blood vessels in those locations is really it is. I mean there's blood
102:06 everywhere, but in those particular it's probably just an easy place to
102:10 it to the surface. All we're gonna land the plane here.
102:17 stuff is pretty simple. Any questions the integra mint. So you notice
102:25 he broke it down. We went epidermis dermis. We went hair to
102:31 , right? And from nails to glands. So, you already know
102:34 need to know what you need to about the epidermis. You need to
102:37 about the Dermot. This is just of the way that she studies you
102:40 of break down the class and kind say, how did it go
102:43 We're gonna do the skeleton and we're do some really, really basic stuff
102:47 well because we just had time left and I had to fill it.
102:50 right. So, the skeleton is organ system. It has bones in
102:55 . But it also has a whole of other things, cartilage ligaments and
102:58 tissue, right? The bones are we're gonna be focusing. But just
103:03 we're focusing on the bone doesn't mean there's other stuff there. All right
103:08 . Their primary function is to form framework on which the body is
103:13 All right. If you look at boat itself, the interior cavity contains
103:18 tissue which is red or yellow bone . It is primarily made up of
103:24 tissue so that it's that type of tissue. So, Aussie is tissue
103:28 the outside. Another type of connective . On the inside, there are
103:32 basic types of odysseus tissue. basically the bone is gonna have one
103:37 two types to it. It's going be compact. This is when you
103:40 at a bone, that's what you're looking at your like, okay,
103:43 that makes sense. It's very, thick, very dense. It's white
103:46 and it looks like what you'd expect to be very, very thick because
103:51 its thickness of all the cells and structure or the matrix in which it's
103:56 it's gonna be very, very So the mass of the of the
104:00 comes primarily from this compact bone You're going to see this other type
104:06 bone, it's called spongy bone. looks more like a sponge, hence
104:10 name. Alright. Comes with other . Sometimes you'll see can can sell
104:15 or try vehicular. So this makes the remaining mass about 20%. And
104:20 we look at you can kind of here. So you can see that
104:24 compact bone right? Here's compact bone then here's spongy bone within the spongy
104:35 . That matrix, that's where you'd the marrow is hiding in there.
104:42 all bone and that's why I have these pictures. I'm going to just
104:46 out something whenever you see a picture it's all labeled like this. Don't
104:51 . Figure out what the picture Trying to tell you based on the
104:54 nearby because publishers, what they'll do they want to they have limited
104:59 So they want to get all the in one figure if they possibly
105:03 which scares the crap out of And you get this cognitive overload is
105:07 we refer to as So I just to show you these two things and
105:11 want to be able to point out is called the perry Osti. Um
105:14 industry um is over here, So surrounding on the outside of the
105:22 is a connective tissue layer. fibrous in nature, if you anyone
105:28 like uh pork rib, we can beef rib. But pork rib is
105:32 more common. And when you get pork rib and you take that bite
105:35 that meat and you actually can feel pull away from the from the bone
105:39 . It's actually connected to the There's a layer of tissue that comes
105:44 it. You know what I'm talking ? That is curiosity. Um All
105:48 . And so what it is is it's a denser regular connective tissue,
105:53 ? So that's what you're kind of here. It's being pulled away.
105:56 actually connected by a series of fibers perforating fibers. So that penetrates through
106:01 thicker layers and then underlying that that connective tissue layer. There's a layer
106:08 cells that sit in there. And . And these cells are responsible for
106:13 up that curiosity. Um And actually for building up the bone underneath
106:18 And these are gonna be different types cells that we're gonna learn about.
106:20 progenitor cells. Osteoblasts and osteoclasts. you can kind of see what does
106:25 name telling you. Osteo tells you building bone or part. It's involved
106:29 bones inside the cavity here and you see it is another layer of
106:36 And so it doesn't have all that tissue like we see here. So
106:41 is Perry Osti um Down below. curiosity. Um It's on the outside
106:44 the bone. So inside the bone these cavities, that's in Dostie.
106:48 And so you don't have the tissue you see right here. Instead,
106:52 just a bunch of cells that are of hanging out doing stuff. All
106:58 , so you got compact bone, got spongy bone outside the bone
107:02 You have perry Osti um Perry means to so next to the bone is
107:06 it's called Endo means inside inside the is the endoscopy. Um Looking at
107:13 long bone, we have some parts it. The artist didn't do a
107:18 job here. So, I'm gonna to point out an air.
107:21 so the long shaft is called the thesis. The end of the
107:28 Right? So these regions down here called the epiphany. Asus. So
107:32 step if Asus plural would be epiphany . All right, So the shaft
107:38 the cylindrical portion of the long So what you have is you have
107:43 a thick layer of compact bone internally be a cavity that cavity and adults
107:48 be filled with yellow marrow In It's filled with red marrow because you
107:55 imagine they're growing and they have to tons and tons of cells. But
107:59 you get older, you don't need produce as many cells you get to
108:01 everything with fat. Yay, If Asus on the other hand,
108:09 has a layer of compact bone, then internally it's going to be filled
108:13 spongy bones. The purpose of spongy is because you have all these different
108:17 that are pointing in all different it basically is there to bear stress
108:22 all different directions. The point of between these two things I should point
108:29 also, I see here is there's to be on the surface where it
108:34 into contact with another bone, it's to be covered with cartilage. It's
108:38 an articular cartilage. And this articular allows the two bones to move together
108:43 a joint between the epic Asus and diagnosis is a region which is not
108:49 here. Alright, so it's this right here is called a metamorphosis.
108:55 , so this is the region of bone that contains the growth plate,
108:59 we call the epithelial growth plate. , so at one time where this
109:04 bone is that wasn't bone that was , and so as you were growing
109:09 the bone was growing this direction, was cartilage there that allowed the bone
109:13 grow in both directions. And you see there's this would be the metamorphosis
109:19 here, that's the epithelial line, the other one right there. So
109:23 long bone has a shaft. The has two ends up. If a
109:28 between them metamorphosis, all the other are kind of weird. I mean
109:37 have unique shapes and stuff. There's ones. Alright? They're short,
109:41 can be flat, their regular in . But really what you have is
109:44 have on the surface you have the bone, which is what we saw
109:47 . You're gonna see spongy bone. have a special name for it.
109:51 call it diplomacy. And then there's medullary cavity like we saw here.
109:56 that medullary cavity that's filled with the . Now you can have marrow inside
110:01 spongy bone. And so you'll see inside some of these flat bones as
110:07 . But it's going to be not a cavity, it's going to be
110:10 within the matrix of that spongy So, there are some basic classifications
110:17 flat bone is called a flat bone it's flat and thin. All
110:22 They might have some sort of curve them. So, for example,
110:26 rib is a flat bone. If look at the rib from the
110:29 you'd see Oh yeah, it has flat surface to it. Your
110:35 The bones of the skull are flat . All right, Your sternum.
110:42 one. Their job. Flat bones to protect whatever's underneath them. So
110:46 ribs protect your lungs, Your skull your brain, sternum protects the
110:52 So and so forth. I throw on here because I had six.
110:57 not really a type of bone. just kind of throw these there are
111:01 tiny bits of bones all over the through the body that are too small
111:04 name. So we refer to as . They kind of give their kind
111:08 these small looking sesame seed things. one that stands out though. So
111:12 they classified as a flat bone. textbooks keep it as a sesamoid
111:16 That's your patella. Your patella is kneecap. All right. It's these
111:22 are basically these are bones that on muscles are going to use as
111:28 So they might you might see them of embedded in muscle. The last
111:33 are the long bones. Short bones the regular bones you can imagine.
111:37 bones are longer than they are Hence their name typically. Um They're
111:42 elongated shaft. As we said. the most common bone. You find
111:46 in your upper and lower limbs. only place you don't see them are
111:50 wrists and the ankles which you'll find bones. All right. Short
111:55 Are there not cubed in shape? they have that kind of that appearance
112:01 being about as wide as they are . So they are cute boy
112:05 But they're not necessarily cubes. So the wrist and ankle bones are
112:10 of them. Sometimes the sesamoid bones categorized here. So I just kind
112:16 separated them out. If you're not , you're not short, you're not
112:20 , then you don't know what to with you. So we throw you
112:22 the category of a regular bone. means you have these really weird
112:27 your vertebrae, many of the bones the skull, primarily the face.
112:31 hip bones are fused bones. You at them and it's like,
112:35 I can see you have aspects of iCU aspects of flat. I'm not
112:40 bother trying to figure you out. go in this pile. So those
112:44 the regular bones the last little bit . I want to just kind of
112:49 to before we just get out of . Oh my goodness, it's
112:54 All right, we'll come back to . This is not that important.
112:58 mean literally it's like one minute of . So if I start hitting that
113:03 , you guys should be like
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