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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture08_0923
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00:00 Mhm. All right, Good y'all? Yeah, we're past the
00:07 exam. Some of you may not um All right. So let's let
00:12 just give you a quick recap. , I know you all are excited
00:16 finding out what your score represents. . I know, but I just
00:22 back. I mean literally 9:00 last flew in, you know, terrible
00:28 hits that tarmac and stuff, you ? But anyway, so I haven't
00:32 looked at I haven't even looked at yet. I don't even know who
00:36 tests. I don't know anything literally in this morning reviewed this answer.
00:42 had 100 and 40 something on emails through that down to 68.
00:47 all the student emails I haven't answered . I'll be getting to you
00:51 Um um So that's that's what I right after classes, I'm gonna be
00:55 going through emails so I'll be dealing that. We will probably talk about
00:59 exam on uh Tuesday next week. when I say talk about that's like
01:04 minutes of like, here's great. here's the distribution, blah blah blah
01:09 . I will release the exam for once I'm comfortable. Everyone has taken
01:14 exam is supposed to take the All right, because we don't want
01:17 get them free a's because everyone look my look at my exam. All
01:22 . So that's that's where we And so what that means is is
01:24 gonna have to just go ahead and jumping straight into the Anatomy?
01:29 we're finally talking about Anatomy. All , now just give you a
01:34 Remember we lost the day last right? Because we've had horrible
01:39 Well, all right. It was mediocre hurricane except for some people in
01:42 Northeast part of town. All What's probably gonna happen is we're probably
01:47 to speed up a little bit around skeletal system and around joints. All
01:51 . And the reason for that, mean, we're not going to change
01:54 dates for the reading of science, lecture wise, we might jump ahead
01:57 little bit. The reason is that we're able to do. So,
02:00 not a hard material. Remember? like the knee bone's connected to the
02:05 bone. The thigh bones connect. was kind of like and really joints
02:11 actually pretty straight forward. You'll be a lot of time in front of
02:14 mirror or in front of a partner all sorts of things like stand
02:17 sit down, look at this. know? So, it we'll probably
02:23 a little catch up there. All . So, what we're gonna do
02:27 ? Uh We're gonna pretend like we take an exam. We're not going
02:30 think about it. We're not gonna about it. Do not stress about
02:32 knowing something. I'm looking around because know there's someone out there right now
02:39 , right, don't stress we're not worry about that. And what we're
02:43 do is we're going to focus up . We're gonna talk about the integra
02:46 , our first system and the integrity pretty straightforward. This is your
02:50 your hair, the glands. So other words, the skin and its
02:55 is what we refer to it as right. So, we're just gonna
02:58 of run through all these different We're going to get skin. We're
03:00 look at hair. We're gonna look nails. We're gonna look at the
03:03 and then we'll be done And it's I hope, pretty straightforward. All
03:07 . And so this is our starting . We're going to be should probably
03:13 turn that on. All right. are starting point. And what we're
03:17 at is we're looking at this as skin and we're going to first break
03:21 down in terms of structure. So have a outer layer. We have
03:24 inner layer and then we have another that some people include when they talk
03:29 the skin religion part of the All right. It's a connective tissue
03:33 . And so this out or to epidermis and dermis. Do you guys
03:36 being in kindergarten saying the joke The term is a shot.
03:42 He says I guess when you're like age, that's a huge joke.
03:46 people are looking around what's going It's like no, no, your
03:51 is a skin. Alright. See layer it is an epithelium. All
03:56 . And so because it's an And that means it's a vascular.
03:59 . It has multiple layers to And his job is to protect everything
04:03 it. The derm ist directly underlies epidermis. If you don't know what
04:08 means, epi means above. All . So, you have terms which
04:11 like, okay, there's my frame reference. And then above the dermis
04:14 the above dermis, and then below dermis is the below dermis. See
04:19 hypo dermis, you see, frame reference always makes it easier. The
04:25 is the really kind of the place all the action is going on.
04:29 right. We have a whole bunch layers. Uh There's actually two layers
04:33 there that we're gonna look at. a lot of vascular chair. That's
04:35 vessels. That's gonna be where a of the nerves are gonna be
04:38 Purpose of the dermis is to provide and resilience for the surrounding structures.
04:45 right. So, it's gonna provide for the epidermis. Something to for
04:49 to grab onto this is we have . You did that you're going to
05:00 here is an example of that. going to talk about that erector pili
05:03 in just a moment. But basically that's really about it. It's primarily
05:08 tissue. And then the sub Q . Sub Q. Is subcutaneous.
05:13 an abbreviation. So the sub Q is basically just fat muscle, there
05:17 be some area well connected. Or muscle. Holy, I'm still out
05:21 it. Uh It's adipose tissue. it's fat tissue. Um There's some
05:26 aerial connective tissue. It has other . And really what you're doing is
05:30 attaching the epidermis to underlying structures So this also serves as an area
05:36 shock absorption and insulation. And so , I know not a lot of
05:40 have ever skin an animal, but you skin them, what you're doing
05:44 you're taking off these two layers and see this and then underlying there's a
05:48 bunch of fashion stuff around the more connective tissue that you're connected
05:53 So this is the stuff that protects on the inside. Now, just
05:59 very big picture. What are all different things that the integra mint does
06:04 , broke this down in terms of and dermis. Epidermis protection. It's
06:08 barrier for everything. All right. You are should be amazed at how
06:14 your body protects itself. Alright, you don't hear taking Chemistry lab
06:20 No. Did you ever put anything yourself accidentally? Okay, I poured
06:25 acid on myself. Notice I didn't . I didn't melt. All right
06:30 . The same thing with sulfuric Think about sulfuric acid. It reacts
06:34 strongly with water. So you'll feel on your skin. But you never
06:37 if it's on your clothes until after wash your clothes. How did I
06:40 this out? My favorite shirt in laundry when it came out? It
06:44 like swiss cheese. She's like, , but chemical, you can put
06:49 on your skin and it doesn't dissolve kill you biological physical temperature. It's
06:57 radiation barrier. When we talk we're primarily talking about UBI life.
07:01 there's also different types of radiation that serves as a protective for Alright.
07:07 prevents water loss. So, you actually all that water you put in
07:10 body is basically being kept in your because water doesn't come pouring out of
07:15 body through the skin. Its metabolic right. It's really easy to picture
07:22 . It's hard to picture that it has a metabolic function. The key
07:26 function we think about when we look is vitamin D. Production. When
07:29 was in your shoes. Actually has postdoc or post backing post backs
07:34 I know a couple. All When I was a post back,
07:36 was working in the lab and I'll an experiment and I go and and
07:40 for a little while and go sit sunning myself, right? Because there's
07:45 else to do. And I'm not go wander around the campus. So
07:47 go upstairs and I'd read a book just sit out there and enjoy the
07:52 . There was a guy in the who's not very bright and he asked
07:55 , okay, can I come with ? What are you doing?
07:59 I'm thinking I'm very clever. I , hey I'm making vitamin D.
08:03 know, cool, can I come you? Okay figure at this point
08:08 don't know what I'm gonna do? I go upstairs and I sit
08:11 I'm sitting out there sitting on a , eyes closed. So we're gonna
08:13 make the vitamin D. Said I'm it right now because the skin makes
08:20 D. Through UV light absorption converts , makes the first steps all
08:26 But that's not the other thing. many other metabolic roles that it has
08:29 we're really not going to cover. it's not just a protective barrier.
08:33 It plays a role in some some absorption. So we're talking a
08:36 bit of metabolic waste. It allows absorption of certain materials. If you've
08:40 had some sort of medication given to with some sort of dermal patch,
08:44 , what you're doing is you're absorbing through the epidermis because it's capable of
08:49 so but it's very selective of what of chemicals it will absorb plays a
08:54 in immunity. We're gonna look at a little bit. We're going to
08:57 that there are some immunological cells that living within the context of the epidermis
09:02 so serves as a barrier against So if something can sneak through the
09:09 barrier portion it's going to come across cells that are there to say,
09:14 you're not supposed to be here, get to die? And that's kind
09:17 cool. Alright. The dermis on other hand is a little bit
09:21 It's this is more of that protective . This right here plays a role
09:25 temperature regulation. So this is where blood vessels are. This is where
09:29 tissue. So, those two things be kind of clear when I'm
09:33 I bestow dilate. Have you noticed turn red? You know, a
09:37 when you get hot? Right. so what happens is your opening up
09:41 blood vessels? So that redness is you physically seeing the blood closest closer
09:47 the surface of the skin. And you're doing is you're moving heat through
09:52 water of the blood, bring it to the surface so that it can
09:56 use evaporative cooling to cool you All right. So blood vessels and
10:02 glands play a role in cooling you . Adipose tissue plays a role in
10:06 you warm, right? That extra of insulation. Alright. And then
10:14 we're going to see is there's also tissue there there's different types of receptors
10:18 play a role in sensory perception of external environment. All right.
10:23 have you ever felt that spider crawling your arm? Yeah. And you're
10:28 get it off. So that's because have mechanic receptors. Is this this
10:33 I tell the story about the scorpion on my arm. Often people kind
10:37 stopped and with what? All 19 early eighties Man. That was
10:42 long time ago earlier is over at girl's house. She had shag carpet
10:47 it was just after the 70's shag is it's really little one of the
10:53 mistakes of the seventies. All So, we're sitting there watching tv
10:57 . I'm up on my elbows just of watching, leaning up against the
11:00 and I keep feeling this thing. , I'm just figure it's the shag
11:04 . I keep brushing it off, off. And finally I'm like,
11:07 is this? I looked down the scorpion trying to crawl up my
11:11 . Yeah, I jumped then we it and then we flushed it.
11:17 all right. But there's different types receptors. Pain receptors, some receptors
11:21 poke at me. That was kind a nice thing. I mean,
11:25 . I mean, you live in . You live in the desert,
11:27 just get used to these types of . I remember waking up one morning
11:30 my cousin's house and look up on roof and there's a scorpion hanging out
11:33 . You're like, that would be . Right, wake up.
11:39 you just got to imagine it. right, So what we're gonna do
11:42 we're going to walk through the epidermis we're gonna walk through the dermis.
11:45 right. And this is fairly These are the cells of the epidermis
11:49 major cells that we want to deal . All the correct uh carry Tennessee
11:52 me. In the melanocytes. carotene insights when you look at this
11:57 , you're basically looking at a whole of care tennis sites. All
12:00 They produce keratin. Do you see they get their name from?
12:04 carotene is a fibrous protein. Remember talked about those intermediate filaments. It's
12:09 tough fibrous protein and it provides all protective properties of the skin. So
12:13 is an actual picture. And this a drawing over here to kind of
12:17 you be able to see or allow to see what we're looking at.
12:20 right there tightly connected to one another desmond zones. So that's why again
12:25 skin is a really tough structure because has a tough material in it and
12:28 all connected to each other. So don't separate really easily. The second
12:34 of cells or the melanocytes. And there are few and far
12:37 All right, so here's an example melanocytes. They're saying that little dot
12:40 ? There is a milan A site you can see it has these extensions
12:44 using the cartoon because it's a little easier has these extensions that kind of
12:47 in between the care tennis sites and job are to produce pigment melanin.
12:54 what the melanin does is it actually taken up by the care tennis sites
12:59 there is UV light around. And job is to protect the nuclei of
13:05 of the carry tennis sites. So nucleus remember contains all the D.
13:09 . A. U. V. is incredibly damaging to D.
13:12 A. And so what happens is we get exposed to UV light,
13:16 start pumping out tons and tons of . The melanin gets picked up by
13:20 character or the card genocide. And what it does is it arranges the
13:24 facing the sun or whether UV lights from and protects the nucleus. And
13:29 kind of gives us that darkish tone we spend a lot of time out
13:33 the sun. All right, so that's how it works. It's a
13:39 uh feature of the melanocytes. Now are five layers. And what we're
13:46 do is we're gonna start from the and we're gonna work our way
13:48 They got these in fancy fancy shmancy names. All right. But it's
13:54 it's the basil straight. A So you can just see it,
14:00 , spinal or spiny, granular light corny Alright. And corny. What
14:09 that mean? It means uh like flaky. Alright, so they're the
14:14 layers. So it's you know, gonna hear stratum Asali strategies for no
14:18 stratum granulomas. Some strategy city um Corneille. All right Now if you
14:24 at this. The three outer These three right here are really these
14:31 there's dying that's taking place here in granule, awesome. So the outer
14:34 layers are dead. Really the two plus this one that I have right
14:39 , this granular system are are And so what you're doing is you're
14:43 off with these live cells are dividing then as they migrate, are pushed
14:48 from the basil layer, they die and become these hard thick layers at
14:53 top. All right. So, greater losses, kind of that transitional
14:57 . And we're gonna learn about the city um is kind of a unique
15:01 that's found in very specific areas. , we're gonna start here with the
15:04 Asali, it's the deepest layer. the single layer of cells right down
15:08 at the bottom. All right. , they're attached to the basement
15:13 So you can see here's here's the tissue of the dermis, right?
15:17 . Is that basement membrane that goes the edge. All right.
15:21 you can see it goes up and . And what that does it creates
15:24 are called epidermal ridges. And what does is it basically prevents these two
15:29 from separating them from themselves, If you have to smooth layers,
15:33 can imagine they can slide against each like this, right? But if
15:37 is all intertwined, it's harder to stuff and that's why the epidermal ridges
15:43 . And what happens as a result that you end up with those epidermal
15:46 on the surface, it makes it to grip stuff. Right? And
15:51 if you think of your fingers, you look at those little things that
15:54 call fingerprints, those epidermal ridges are us to grip things fairly well put
16:02 on a table in front of Just slide you can feel the grabs
16:07 right, we're kind of like gecko's . Kind of All right.
16:14 if you look at the cells they're kind of cute boy girl in
16:17 , they might look eliminar. But , we don't care about that in
16:21 it just kind of gives you a of what that lowest layer looks
16:23 Remember when we name this, it's be named based upon that. A
16:27 . Alright, so again, mostly tennis sites, every now and then
16:32 see a Milan a site poke its moving up, we go to the
16:37 . Now, these names come from we were looking at them underneath the
16:42 is like, oh this is the layer, the lowest layer, that's
16:46 the first name came from. Then start looking in there and was
16:48 oh well there's this layer of cells are really spiny looking and the reason
16:53 spiny looking is because they're attached to other by these Desmond zones. And
16:56 when they kind of pull away from other kind of get these spiky
17:00 Now there is no real space in them. But they get this appearance
17:04 they look kind of spiky as a of that. And these are just
17:08 the care tennis sites. So, using the cell as an example if
17:11 cell divides basically once I was going stay behind and once I was going
17:14 move up and so all these cells undergoing division and they're filling up this
17:20 and they're basically becoming that Spinoza And they begin differentiating as they move further
17:27 further away from the basil layer into non dividing specialist care 10 aside.
17:32 right, so it's basically a place it's like okay, I'm going through
17:36 divisions and I'm multiplying and increasing the but then I'm also gonna start specializing
17:41 that's what I stopped dividing is because gonna start specializing. It becomes something
17:45 can be up here so many many thick in terms of the number of
17:51 . But they're just basically if they're first and then differentiating as they get
17:56 the top. The granule, Now is distinguished because you can start
18:01 grand pools under the microscope of the in this layer. They're very distinct
18:07 the underlying layers which lack the Granules the Granules in there. Now what
18:11 Granules are are simply the proteins that being produced by these care tennis
18:17 So as a differentiating they're starting to through this process of producing a whole
18:22 of different types of carotene. So in this particular case it's called
18:27 highland, you don't need it. not gonna ask you which type of
18:29 being produced here, but I want to understand that this is kind of
18:33 distinction why the Granules are there is we're starting to really focus in on
18:38 my function is as a cell, ? It's kind of like the cells
18:41 up and said, this is what do now. And as a
18:45 what it does, it says, know what? There's not enough room
18:47 the amount of character and I want make. So it starts kicking out
18:52 starts removing now. Remember what are purpose of an organized in a general
18:58 , it again, metabolism to do which is really kind of it.
19:03 if I'm starting to kick out what happens to the sell it stops
19:07 able to do stuff. Right. it's becoming very, very focused in
19:11 functionality. It's basically uh starting to a whole bunch of protein and that's
19:17 it's going to be now is basically big bag of protein that has a
19:21 specialized or a unique function now as migrate away from the basil layer,
19:27 moving further and further away from my of nutrients. Remember this is where
19:32 the blood vessels are is where all nerves are located. And so the
19:36 and further away I get from my , the less and less chance I'm
19:40 be able to be fed which means going to die. Right? So
19:44 further I'm away from my refrigerator. me. Right when I was home
19:51 the pandemic, I ate just Now I come to work and I
19:56 how I'm going to survive the That's what these cells are doing.
20:02 right. They're moving and migrating They're kicking out the organized to help
20:07 to stay alive and they're not getting nutrients they need. So the cells
20:11 beginning to die off. All right they won't be this process of
20:19 That's the term won't be complete until up here at this layer right
20:24 That lowest layer or those lowest layers the outermost layer which is the corny
20:30 Okay now we get to the weird . All right. So the easy
20:34 was easily the basal layer. The layer is the spiny layer because that's
20:40 it looks like. And then we the granular layer and then we got
20:44 . Ian. Alright. Or Um All right. What does it
20:48 lucid? Um It means light or and why? Well this layer is
20:55 in some very specific areas. The thick skin of the body.
20:59 where is your thick skin located at bottom of your feet and the palms
21:03 your hands. All right. So not found anywhere else. And then
21:07 gonna show a picture again, thick thin. Alright. But that's where
21:11 thick skin is. And so this the only place where you're gonna find
21:14 lucy there. The lucid um is another type of care 10 for a
21:19 brief period of time. It's an form of that carried. Ohio.
21:24 what it is is it's actually kind clear. But it does this real
21:28 job of both absorbing UV light. right. Now, if you're like
21:33 and you're stuck inside all the we can't really tell the difference.
21:36 . But for the U. Who spend some time outside, you
21:39 look at the palm of your the back of your hand. If
21:41 darker skin. Palm of your back of your hand and you can
21:44 there's a difference in the color that's on your palm versus on the back
21:49 your hand. All right. And because that layer, that loose idiom
21:54 basically absorbs UV light. So you less melanin production on those thick parts
21:59 your skin. That's why that exists that. Now at this point where
22:05 been kicking out organelles and we've been this this carotene and we're being pushed
22:12 against something that's dead and doesn't want move and we're being pushed And so
22:15 happening with the cells that are becoming and more squished. So they're starting
22:19 flatten out even more so than than you saw earlier. So, these
22:24 are for the most part fairly They lack those thick Granules that you
22:29 in the granular layer. All And then, you know, only
22:35 I said, only in the thick where you're going to see that.
22:38 then finally, our last layer is corny um this this flaky later,
22:43 scale layer. All right. And here now the care tennis sites which
22:48 nice and happy growing cells that have , produce all this protein has flattened
22:54 and squished out. And what we here is basically um 15-30 layers of
23:00 cells that are interlocked via these Mazzone's they're packed full of this
23:06 So they're hard and tough. They all their organelles and they flattened
23:11 And remember what is the the the made up of the plasma membrane of
23:16 cell? What's made up of primarily lipids. So, basically what you've
23:20 is you've basically taken this is a example. Please don't write this
23:25 but it's an oreo, right? a it's a layer of fossil lipids
23:30 either sides filled with this creamy carrot . Right? And you squished it
23:36 . And so what you now have you have a waterproof tough structure that
23:42 water from going in either direction. prevents materials from going in either
23:47 and it's several layers thick. So you're even able to scrape across and
23:53 able to flake a couple sells you don't break all the way through
24:00 layers. Stick around for quite some , basically I have up here.
24:04 about four weeks now. What you're is you're losing a little bit of
24:07 time. I think I mentioned or to you previously about the dust in
24:12 air that most of the dust in air is dead skin cells plus other
24:16 stuff. It's horrible to think But it's okay. All right.
24:21 , we're losing flaking a little bit and there and over a course about
24:25 weeks. The stuff on the bottom made its way up to the
24:29 Have you ever gotten horrible sunburn and right now? I know all the
24:34 , the ladies don't do this. do try to get that sheet that's
24:36 big as possible. Yeah. All guys are like, check this
24:43 Right? So when you have damage that, you've actually damaged underlying
24:49 And so what they're doing is you're to replace those damaged cells. And
24:52 there's a little bit more of this that's going on. But it's the
24:56 simple principle, basically. It's these cells are what you're peeling off.
25:01 right. So, what I'm saying is basically that orient. This is
25:05 I'm saying. It's plasma membrane. there's a lot of like there's a
25:10 of foster olympics in there. That's waterproofing part. And then you basically
25:15 all the protein in there that makes tough and rigid so relatively and sent
25:21 to biological chemical and physical assault. right. You guys we've lived here
25:25 Houston long enough to have heard at one story about the flesh eating bacteria
25:28 the gulf. Right? I mean Jackson a couple weeks ago or a
25:32 of months ago had a huge They had to shut down their water
25:36 and stuff. All right. Let's I have a jar of flesh eating
25:40 like as thick as peanut butter. I pour it on the surface of
25:43 skin, are you going to And is it going to eat through
25:45 skin? No. How does it in and cause damage? You have
25:50 have an opening or a scar. it gets underneath that protective barrier.
25:56 ? And then it can go to . The epidermis is tough. It
26:02 that. I've already talked about. acid. If you let it sit
26:05 for a while, it's going to problems. But if you get a
26:07 of hydrochloric acid on you, you're go out and you're gonna wash it
26:11 before it causes any real damage. right. Physical. If I stab
26:17 with a knife, you're going to , Right? But if you get
26:20 like this like the cats playing with , you know? Well, cats
26:25 not a good example, but you the gist, right. I
26:28 you can sit there. I went last weekend. I got 1000 mosquito
26:34 . And just thinking about it makes body itch. Right? I
26:37 you can see Yeah, I so my entire life the last couple
26:42 days, Right? But until I through, I mean, it takes
26:48 lot of effort to break through the . Physical assault. This is just
26:52 example. Just so you can see is thick skin. This thins in
26:55 of the differences. Five layers versus layers, uh thick skin. That's
27:00 of hands, soles, feet. are sweat glands. There ever been
27:03 anyone here not like talking in front classes. You ever had to give
27:07 speech in front of units? See don't want to raise their hands are
27:11 like I'm not here. Please don't on me. All right, Most
27:15 you have this anxiety of getting in of people and communicating. All
27:18 So one of the characteristics features of is that sweaty hands. Right?
27:23 get up there and you get sweaty . All right, well, we
27:26 sweat glands there. There's no hair . There's no sebaceous glands that we
27:31 in the thick skin on thin basically, that's everywhere else. It
27:35 the four layers. So we don't the straddle and see them. They
27:38 all the fun sweat glands. You hair follicles. You have sebaceous glands
27:42 well. So still just kind of here talking about the epidermis. What
27:50 other things we have in here. we said we got the care tennis
27:53 because Atlanta sites but we have these here called Langerhans cells. They're also
27:57 to as epidermal dendritic cells. Anything make it more confusing for you?
28:02 really shoot for. All right. are these? These are a resident
28:08 . Alright, so they're a form immunological sell that hangs out in the
28:13 , doing nothing until something comes That shouldn't be there. And that's
28:17 it activates. It basically sits there destroys. So these are gonna be
28:22 primarily in the Spinoza but they can find their way up to the
28:25 awesome. All right. So I here fig acidic. So it's a
28:30 . All right. Skin color. , well, where did our skin
28:35 comes from? It comes from There's two primary pigments that play a
28:39 in skin color. There's a third less prominent. That's actually the uh
28:45 hemoglobin in the blood basically when it close to service. That can give
28:49 that pink issue or depending how dark skin is. It can change the
28:54 of the skin but basically it's these . So we got melanin melanin.
29:00 different types we have what is called element sorry, you melanin and feet
29:05 melanin. You mehlman is the black pigment. Uh hilo or feel melanin
29:11 a red, yellow pigment. And this is what gives that variety of
29:15 . Not only the skin but also hair. Alright. So everybody in
29:20 world has the same relative number of . It's how much melanin is being
29:26 by those melanocytes. Alright. So basically saying, hey, how much
29:32 I producing? That's what gives rise the skin color. If you have
29:38 or pigmented moles that need to be out every now and then. That
29:42 an accumulation of melanin. So, kind of shows you what's going on
29:46 . All right. So here's our site. It's pumping out this melon
29:50 the mountain gets picked up by the and it gets arranged like So So
29:54 you can see it's arranged above the to protect the underlying nucleus. The
30:00 did a terrible job over here. right. But that's in essence.
30:03 does it to accumulate and sit over nucleus Cara teen is a pigment that's
30:10 in certain plants. What plants do think it's founded carrots? Anyone here
30:17 you don't have to admit it. here ever used the rub on
30:21 Some people like you, do you what the rub on tan is bend
30:28 . You know what you do is go to the grocery store. So
30:30 don't want to get under UV light I don't want to go down to
30:32 mall, but I do want to like. Sookie from I can't remember
30:37 the name of the show is. shore. Thank you. See I
30:40 always catch them. All right. so what I do is I go
30:44 get this stuff and I slather it and it has keratin in it and
30:49 is fat or lipid soluble. And what it does, it gets absorbed
30:53 the skin fairly easily and it remains the hypodermic as And so you can
30:59 that that darkness or the coloring from . You can eat a lot of
31:05 . It's going to take a long for you get that color. So
31:08 just easier Just rub it off. right. It's also when we found
31:11 stratum cranium. So right up there the top. All right. So
31:17 touch, pressure and pain are going be detected in the epidermis. You
31:22 see here this is some of the types of receptors that are found in
31:27 body In the epidermis. We have types. All right. We have
31:31 tactile disc. The tactile disk actually at that stratum easily. Alright,
31:38 you'll see one of these cells sitting in the stratum easily amongst all those
31:42 tennis sites. And then what will is you'll have a fiber that comes
31:47 that's a nerve fiber that is directly with that tactile disk. And so
31:52 is a way for you to detect . It's a very very small receptive
31:57 and some mechanical receptor mechanical means mechanical movement. So, if you touch
32:03 skin, the skin's gonna move. tactile disc basically detects the movement and
32:08 that neuron hey, send a signal the brain that this is where we've
32:11 touched. All right. So, is fine touch and pressure. So
32:17 spider walking across the skin is going be basically detected by the technology is
32:23 is also free nerve endings. And the cartoon up here shows a free
32:26 endings. You can see we have nerve endings also down in the
32:29 But we're just going to focus up for a moment. All right.
32:32 , they're responsible for other things. right. So one is pain.
32:37 is noxious stimuli. And so, can be a variety of different
32:42 So, think of different types of . You can have sharp pain.
32:46 ? So cutting pain. You can a temperature based pain if you ever
32:50 a hot stove or maybe even touched uh, you know, like dry
32:54 or something. It hurts. All . So, that's the type of
32:58 that we're looking at And then you these types of things. The tickling
33:02 ? Have you been tickled so much it's painful? All right.
33:06 what we're dealing with here is we're with a type of mechanical stimulation.
33:11 right. But what can happen is over stimulation can start causing interaction with
33:18 different neurons and it's actually a combination those different types of stimulations that ultimately
33:24 in the perceived stealing. I don't if I mentioned this. I'm pretty
33:29 I didn't. It's probably for the class is so for example, you
33:33 have receptors that detect wet. If you touch something or you get
33:38 in your wet you don't go oh that's the wet receptors on my
33:42 What that is? That's a combination different receptors sending signals simultaneously. And
33:47 brain interprets that to mean uh So it would be like a touch
33:52 , a temperature receptor. Um And couple of others that are involved in
33:56 they do that. All right. so itching is a form of noxious
34:00 . So all of this it's Right? I mean it's frustrating and
34:04 basically there's touch and there's pain and things. Yes sir. Mhm.
34:12 . Typically. Yes. Yes. noxious. Is is is typically just
34:17 that is um unfunded. That's not best scientific definition. There something that
34:25 a irritating irritating stimulation. All And it doesn't just mean touch that
34:30 be chemical. It can be There's there's many many different types of
34:35 stimuli up on the roof. Here we are. Just picture me
34:42 my eyes closed. Tanning. Or picture yourself or someone you're attracted
34:47 . That's probably better. Alright. here it is this is basically what
34:51 is. What we do is we some cholesterol. And what we're gonna
34:54 is with UV light it actually modifies to Kolkata Farrell. All right.
34:58 , all these steps are not important you. The key thing that you
35:01 to walk away from this slide is equals vitamin D. Production.
35:06 All right. So this anyone here vitamin D. Pills? Yeah,
35:12 mean, vitamins Yeah, That's what get. They give you vitamin
35:15 three. Alright, vitamin D. , once it's in the body gets
35:19 around, it gets modified in a bunch of different areas in the liver
35:22 the kidney. And then it becomes active form which has a special name
35:26 trial which you don't need to All right. That's that's vitamin
35:30 That's the active form of vitamin All right. But it all starts
35:34 the kidney. And what is vitamin . To I don't know if I
35:37 this question, but just in case job is to help you to absorb
35:43 . All right. So, when eat food, having vitamin D allows
35:48 to do calcium, which makes your strong, which is why milk is
35:54 for you. Right. And what we do with milk? We fortified
35:56 with fortified with vitamin D. There's in the milk. Give the fortified
36:02 with vitamin D. Causes you absorb better. Uh huh clever down to
36:11 dermis. So all that stuff is epidermis. That's basically that upper
36:16 All right. Now the dermis has layers to it. So,
36:20 you can see up here the pink again. That's the epidermis. All
36:24 oranges stuff is the dermis. And can see the two layers. All
36:28 . There actually. Here's a dividing that separates them out. You can't
36:32 see that. But you can easily it like this. We have a
36:36 layer that's nearest the epidermis. And underlying that papillary layer is everything
36:41 That's the particular layer. All Now, this as I said,
36:45 is just a repeat of what I've before. There's lots of nerves.
36:48 of vasculature. Uh There's also what called lymphatic vessels, which partnered with
36:53 uh the blood vessels helps to move through the body. All right.
36:59 not going to go into detail with lymphatic, but basically it's all
37:03 All right. So, the papillary is this one right up here?
37:07 right. So, just directly underlies papillae. These dermal papillae.
37:12 the dermal papillae are the part of epidermis that hang down. And then
37:16 papillary layer, you have these layers push up and that's where you get
37:20 interlocking layer. And that's what connects epidermis to the dermis. All right
37:25 . This is an area or connective . All right. And there's long
37:31 that come up here. A little capillaries that push up So that when
37:34 blush you can turn red. The you see that red is because those
37:38 are right up there at the They're just not always open. All
37:43 . There's free nerve endings up In that picture that we saw.
37:46 saw those little um nerves that are of going everywhere. We're gonna talk
37:50 those in just a moment, but see them right up in between these
37:54 ations. All right there between the . So in the dermal papillae is
37:59 you can feel not in the epidermal , on the dermal side. All
38:05 , let's see what else. so moving downward. All right.
38:10 if this up here, right up , that's the papillary layer down
38:16 All this stuff is the particular So the papillary layer we said it
38:22 areola connective tissue down below. It's dense, irregular expected tissue. So
38:28 that little dividing line right there. dividing line says up here, That
38:33 a real er down here. That's . In some cases you're gonna see
38:42 are called Cleveland lines. These are uh collagen fibers that are basically coming
38:47 deep in attaching themselves and anchoring themselves deep to the derma. So that
38:53 you bend and move your skin doesn't funky things and bubble up and do
38:58 basically ensures that you get these folds that it allows your skin to move
39:03 way it should, it's probably a and egg thing. So um
39:09 uh there's a last and then there provides elasticity. The older you
39:13 the more obvious it becomes. See you for not laughing my elasticity.
39:23 See right here uh These are these cleavage lines as well and you can
39:29 this is trying to demonstrate the direction which collagen is traveling. So it
39:34 kind of shows you how they're all of moving in the same direction.
39:39 so this also is something that's important surgeons because it tells them in which
39:43 they need to cut. Because when cut with the collagen, um you
39:48 these nice smooth, when you cut the grain, you get these nice
39:53 cuts that are easy to sew back . But if you cut against the
39:58 , then you get this gaping structure much much harder to close. All
40:06 now, as I mentioned, particular , lots of blood vessels, lots
40:10 nerves. You can see the nerves down in here. All right,
40:15 This is these nerves. We're going see here in just a moment
40:17 That's right. These are flex your . Excuse me. Cleavage line,
40:22 your line. Oh, I got back backwards, flex your lines.
40:28 lines, boy, it's bad when Professor gets up and starts screwing stuff
40:32 . Right? She's like mm Crapping . dr 20. Alright,
40:38 again, flex shirt, I remember I close my hand or close my
40:43 , I don't get like this bulging skin going in all these weird directions
40:47 me to flex structure. Cleavage refers the structures when I cut through
40:54 which direction is favorable to cut? , ma'am. Mhm. Horrible things
41:01 we don't want stretch marks are a of producing more and more skin faster
41:09 um faster than the normal rate. that's why it appears because you're basically
41:14 of getting a a fiber structure So the easier one to think
41:20 it's not only women in high out of friends decide to start this
41:23 skinny scrawny kid decided to start start weights and taking some steroids, but
41:30 listening weights. And so he grew , really big very, very
41:33 And he had stretch marks all right? Because his body, his
41:38 had to grow fast to accommodate the growth. And so what it
41:42 is basically it's growing skin. So getting new skin on top of new
41:46 tissue underneath. So it's neither of two things, but it is following
41:51 pattern of like, okay, I've to maintain the college and running the
41:54 way and the skin is growing in a way to accommodate. And so
41:58 you think about a pregnant woman, know that belly grows very, very
42:03 over, really over a six month , right out of the nine
42:06 it's like six months of that is like, right. And so what
42:10 is the skin is growing faster than normally does. So, you get
42:15 new skin growth you can avoid I'm not saying you have to I'm
42:20 saying you can't. One of my she I think you some sort of
42:25 butter, literally like she said, bathed in it. That's how she
42:28 . I bathed and it just all time. She never got stretch marks
42:32 she was big as a house and just recorded that life. No,
42:42 actually very proud that she never got . All right. Anyway, I'm
42:47 . It's a good question. All . So, remember blood vessels play
42:52 temperature, Blood vessel, supply nerves allow us to help us understand
42:58 the things that were touching. All . So, what we're gonna
43:01 And we're gonna come back to these we'll do them again. But you
43:05 to know them now. And then gonna probably try to forget them and
43:08 we're gonna come back at the end the semester and we're gonna go over
43:11 again. All right. It's just of sucks. It's like you get
43:14 double. The only thing in this where you're gonna get the double whammy
43:18 it's like, I got to know once and I got to know him
43:20 . All right. They're hard. partly because the names change. All
43:26 . So, these were the original . And so this is what we're
43:30 to go by. But some textbooks they're more common. I mean,
43:34 more common in, but these new . All right. So, we
43:37 Meisner score puzzles. All right. are all different types of nerves to
43:42 receptors. Meisner core puzzles are easy distinguish because they're right up here in
43:47 papillary layer. Their job is to to detect light touch pressure and
43:53 All right. So, you can about like this. You get your
43:56 and you can rub it across the and you can feel your fingers rub
44:00 across the surface of the structure There is a slight vibration in
44:03 That's the vibration they're talking about. , there's a light pressure if you're
44:09 moving your fingers. So, it of gives you a sense of what's
44:13 near the surface. Pacini in core named after Pacini, Sir, the
44:21 . Of course, baby. Kind like tactile this No, they're they're
44:25 their unique or different what we're gonna a little bit later, which is
44:28 I'm not going in a lot of about them right now. Is that
44:33 They're very, very different. All . You can see how they kind
44:36 look like big giant balls in the here. All right. This is
44:40 part you don't need to know what is. Is It's a free nerve
44:44 that gets wrapped around in a unique tissue structure that gives it a broader
44:49 in which you can detect information or . And so what we're looking at
44:54 is an encapsulated nerve fiber, that's technical term. And so it's a
44:59 a unique type. And what as people were kind of discovering these
45:04 they found that each of these played unique role in helping us distinguish different
45:09 of touch. So, All It's that time of year time for
45:14 parties and and and going to the houses to have people scare the bejesus
45:20 of you. Right. All Did you when you were kids,
45:23 you go to Halloween parties like the with you can you turn off all
45:27 lights and come out with these bowls things and say put your hands in
45:31 , you're touching eyeballs with balls and was like grapes. And then they're
45:36 put your hands here, you're touching like its brains and it was like
45:41 spaghetti. All right. And I say you're touching something. Yes.
45:46 touching a dead cat. That's supposed be the joke. Just 12 and
45:51 joke. All right. But Right. So, that's the reason
45:56 able to detect like why it's like example, if I give you a
46:01 ball, you'll be able to go round and it's fuzzy. It must
46:04 a tennis ball is because these different of receptors allow you to detect unique
46:09 of features. All right. And they're located helps part of that detection
46:15 . So, the ministers are up at the top in the papillary
46:20 deeper in the articulator are the Pechiney And the Ruffini. So here's the
46:24 . Here's the Pechiney in. we're not looking deeply at why they're
46:28 very different. But you can see the Pechiney in which are very,
46:32 deep deep pressure and vibration. What we have up here? Near surface
46:37 . So, I'd be light light vibration. So, you can
46:41 if something is is pressing down into . You'd be able to detect it
46:46 of the Pechiney in. These are down low. The roof finis basically
46:51 looking at distortion of the environment and you can see it kind of It's
46:56 of this elongates you guys remember family is still on remember Stewie's head?
47:04 looks like Stewie's head. All That's it. Elongates. So,
47:09 what it does is you stretch it push on it and it gives you
47:12 sense of pressure and distortion. now, I gave you more detail
47:17 you need to know. Just understand they're located and kind of what they
47:22 . All right. Mhm. Hair moving on. So you see epidermis
47:31 layer in the layers. Dermis slightly functions. Hair, flexible strands of
47:39 correct my cells. So they kind like the outer layer of the skin
47:43 just arranged differently. They use a type of keratin and what we're gonna
47:48 is that we're going to use a called a follicle. And if you
47:51 closely at this picture, remember what the pink? The pink represents
47:56 and the yellow represents dermis. And at what we got here. The
47:59 follicle has that pink all the way the ends. So do you see
48:04 we've done here is we've taken the and we've Imagine a did it.
48:08 this is the structure where hair is produced. So it produces a hard
48:12 10. It's very, very it's very durable. The individual cells
48:16 don't flake off. We're gonna look this picture a little bit more
48:19 you can grab a hair cell and can pull on it and it takes
48:22 a bit of effort to actually cause hair to break, right? I
48:27 it's a hair so it's easy to it, but you actually have to
48:31 a little bit of force into I like this picture because it's again
48:36 alright, plays a role in protection , It's like a helmet. You
48:41 who this is? Some people you know, okay, he died
48:48 this year. That's Phil Specter, was one of the uh music producer
48:52 the Beatle album and why he became famous was that, But then he
48:56 famous again because I think he killed model and that was what he showed
49:01 as his trial. Someone actually this a Photoshop. So his hair wasn't
49:06 this crazy, but it was like and part of his claim was I'm
49:11 , you know? So that's why killed the model. All right.
49:14 Phil specter. All right. I use this as an example of
49:17 . All right. Long time ago I was your age, I went
49:21 a Stevie Ray Vaughan concert In the of the Desert Carter was at like
49:26 . We showed up at 7:00 By the end of the day.
49:31 huh. I had sunburn scalp, ears. It was painful.
49:38 in the nose and in the ear traps particles you're breathing in and breathing
49:44 . So basically that hair serves as way to trap things on the I
49:49 use her as an example basically it's select band. Sweat drips down,
49:54 that and notice your eyebrows push out way downward so sweat rolls out to
50:00 edges and away from the eyes. here serves as a way to move
50:05 and other materials away from the Also, you can talk about your
50:09 . Get close to your eyes. is your idea closes if you touch
50:13 eyelash, your eye closes. So sensitive nerve fibers in their help sweep
50:18 away and when you blink, what doing is you're sweeping air away from
50:21 eyes plays a role in heat Again, we can look at Phil
50:25 there. You can see that would heat very close to your head.
50:30 a role in sensory reception. Here the icky spider crawling along and there
50:35 be nerve fibers associate with those hair or those hair follicles. You'll be
50:39 to feel the spider moving along Visual identification helps determine age, and
50:44 helps to identify individuals. Have you noticed when you get a new
50:47 people kind of look at you kind funny trying to figure out, wait
50:51 second. The hair doesn't match what expecting. It's part of your actual
50:57 . All right. But when we about agent sex, the easy thing
51:00 think about is puberty and pubic hair axillary hair, which is why I'm
51:04 her. And then again, chemical dispersion, The pheromones that our body
51:10 in the actually regions as well as pubic region. Uh those pheromones get
51:15 in hair and helped to serve as signaling um mechanism for those pheromones.
51:24 , in terms of the structure of hair, it's just some very simple
51:27 for us to understand. We've got shaft. The shaft is always the
51:32 that's above the skin. Once you to the skin and move downwards,
51:36 now in the root. All So, everything that you're looking at
51:41 in the shaft and the roots are cells, they're like the outer layer
51:45 the epidermis. Alright. It's only you get down deep is where you're
51:49 find the living cells. All So, here at the base this
51:53 what is called the hair bulb. at the base of the hair bulb
51:56 the papillon. All right. This where you're gonna find the matrix where
52:01 living cells are that are multiplying and kind of like the strategy is ali
52:05 the strategy can assume that are constantly new cells and they're being pushed upward
52:10 that causes the hair to grow And those cells die off because they
52:15 far away from their source of blood nutrients. Um And so that's why
52:21 die off. All right. down here in the papillon. This
52:24 also where you're going to find uh fibers. If you've ever had your
52:28 pulled and it hurt. The reason is because you are pulling and feeling
52:33 from the nerve fibers down at the of the papillon. All right.
52:39 see that. I miss anything here know. I don't think I
52:44 All right. In terms of the of the hair. Two terms If
52:49 think I told you if you see word model, it means middle.
52:51 you see the word cortex, it outside. Maybe that was another the
52:55 class. Alright. You ever see two words medulla, middle cortex.
53:00 layer. Okay. So this is structure of the hair. We have
53:04 inner layer, it's called medulla. are dead cells in there but they've
53:10 or contained within them a flexible That's why your hair can be floppy
53:15 bends and moves. All right. also hair pocket. So it gives
53:19 room for things to move as you out to the cortex. Now you're
53:24 to get denser flatter cells. Kind like what you saw in the
53:28 Um Alright. And they're over laid each other and they have that hard
53:32 in there. That's why the hair hard and stiff. All right.
53:36 then on the outer layer we refer the outer layer as the cuticle.
53:40 here you can see what those flattened look like. They're basically cells that
53:45 each other a lot like shingles do right. But you're not going overlapping
53:50 the body. Your overlapping away from body. Like So All right.
53:55 so these cells do not flake off each other or if they do,
54:00 talking about split ends and that's usually at the end of the step.
54:03 , So they overlap away from the . So away from the body and
54:08 very very densely packed. Like what looking at here, very scale like
54:15 follicle is the structure where the hair growing from. And as I
54:20 we have an epidermal layer and we a dermal layer? The dermal layer
54:25 very, very thin And really what can think about is that during
54:28 what you do is you get these of the epidermis that pushes down deep
54:32 the dermis. So, really you have this epidermis that's still surrounded by
54:36 that's been kind of compressed or All right. So the connective
54:41 the connective tissue park derived from the . All the pink stuff in
54:46 That's the epidermal derived tissue. It's . All right. So connective tissue
54:52 the outside Tinder, chunky epithelium, chunking this structure right here. That's
55:01 erector pili muscle. All right. Pili Muscle has two major roles in
55:09 . The first is when you're cold causes it to stand up.
55:14 You're nervous, You got the chills you get stands up. Now,
55:18 does it do that? Well, at one point our ancestors were a
55:23 bit hairier than we were. And when it got cold, you stand
55:26 and so your hair stands up and pockets of air that traps warm air
55:32 the body. Kind of useless when have thin here, like we have
55:36 . All right. But that's that's job. All right. So think
55:40 a dog or cat or bear when get cold, they puff up.
55:46 right. The second function is to us look scarier and bigger than we
55:51 . Again, this is something that really work for us because we don't
55:55 a lot of hair. But think a cat when you see a cat
55:57 you corner the cat and it's not cat and it doesn't want to be
56:00 or pet what does it do? says, and it gets that look
56:06 and all his hair sticks up on . That's basically saying I am bigger
56:10 nastier and scarier than you can ever . Do not touch, right?
56:16 in essence what it's doing. So you see a cat do that,
56:19 basically saying don't touch me. I a cat just says that generally
56:23 right? Don't touch me. maybe a little bit. All
56:28 Ever noticed that sometimes you can have side of your body stand up on
56:33 other side doesn't it's all regulated through nervous, the autonomic nervous system.
56:40 just thought it was always kind of . It's like look scared on this
56:44 . Doing pretty good over here. growth goes through phases, good
56:55 Not all your hair goes through the same phase of the exact same time
56:59 that would be very disappointed because you go through where you actually shed the
57:04 the air, right? That's what is showing you shedding the hair and
57:07 can imagine how horrible it would One day you wake up and all
57:11 hair is gone. It's a certain of the year. So these are
57:15 phases. Andijan, basically that's the growing phase. So basically you're just
57:21 hair out and it's growing and getting and poufy. Then we have the
57:25 genic phase that's basically the phase where like okay we're not gonna grow
57:28 so we're going to withdraw the blood and basically allow the hair to kind
57:32 just stop and then the telegenic basically the resting phase and then some
57:38 those hairs fall out and then what do is you can start up again
57:42 the energetic phase and you just kind repeat that cycle if you've ever looked
57:45 the bottom of your shower and you've all that clumping hair and you kind
57:49 panic like on going bald or at end of days. No, it's
57:52 part of the cycle that's normal. . Mhm. Yeah it will start
58:06 um not necessarily right away, it just kind of reset itself into that
58:11 phase, right? So how many have ever heard that horrible myth?
58:15 if I pluck my eyebrows and then know, they'll come back and even
58:19 or if I pull out a gray , they'll be replaced by 1000 grey
58:23 and yada yada yada, that's not happening when you when you pull out
58:27 hair unless you're getting it all the down the route, what you're doing
58:30 you're basically chopping it off and so portion that's underlying the skin is now
58:34 and thick and so it doesn't come as a nice pointy thin thing,
58:37 just comes out of the thick That's why it looks thicker and just
58:41 hairs are just evil. So they , once they show up, that's
58:46 letting you know that you're just getting now club hairs when you hear
58:53 that's when the hair fault was in inactive stage right there. So if
58:57 ever hear the word club here, are different types of hair. So
59:02 of cute little babies and how soft how they smell like, I don't
59:06 , fabric softener. Um They have go hair all right. So long
59:12 here will actually have Bella's hair. before they're born, remember where mammals
59:16 producing harry whales have long ago And what they're doing is this is
59:21 hair that covers your body. So new newborn baby has all that
59:24 you know, on their body. long ago hair. Alright. And
59:29 what happens is is the luga hair pushed off and it gets replaced by
59:33 Vallas hair. Now Bella's hair, that fine pale body hair? It's
59:38 to see in kids, you Uh ladies, you're you're very you're
59:44 subject to the androgens that males So you have fine pale body hair
59:49 over you, right, if you of look closely, you know?
59:52 , I see that I'm going to to wax that off. Apparently don't
59:57 wax that off. All right. that's a fail pine. That would
60:01 what you find around the body, midsection and stuff like that. And
60:06 everything else is terminal hair. So stuff to think about this stuff on
60:11 head. Right, guys on her and then pubic hair. Hair on
60:20 chest. Axillary hair. Hair on legs. So, these are the
60:28 , terminal hairs, hair that is upon nutrition and hormones for their
60:33 Okay, so, fellas hair is kind of think pre puberty all even
60:38 we do retain it in some but most of our hairs terminal
60:43 This is terminal here, actually, has different types of shape. All
60:53 . We each have a unique type shape. So, the natural shape
60:57 the natural form of your hair is result of the shape of the
61:02 All right. So, we're just to kind of go through them.
61:04 have ribbon like shafts. So ribbon shaft would be kind of flat and
61:09 . And that forms a kinky type hair. All right. So,
61:14 spins very quickly on itself like a type structure, if your follicle is
61:20 , like almost circular than what you're end up with this straight or course
61:25 hair. And then if you have oval, so not quite round and
61:29 quite flat, somewhere in between that's you get that weightiness. All
61:35 now, hair pigment is just different melanocytes produce different types we saw
61:40 different types of melons and so that's to give rise to the different colors
61:44 hair. I don't know if this like the Clara all numbers or anything
61:49 that, but you know if you and look at all the different hair
61:53 that exist that are natural hair color not talking to pink is in the
61:56 , we don't produce those. but our melons will give us like
62:01 type of range. Now the question used to ask me, I was
62:05 well what's white hair? And I like I don't know. So I
62:08 looked it up. So here it basically the melanocytes when they stop producing
62:13 melanin begins to give that grayish appearance when they have no melon in,
62:18 when you get that white hair, guys know who that is,
62:23 No that's ted danson, he was cheers one of his thing when he
62:30 in cheers, his characters thing was his hair all the time and about
62:35 through the show during the shooting started his hair so he had to wear
62:38 hairpiece and then like the last season pulled it off it looks like and
62:44 he does C. S. So you see my salt and pepper
62:55 , right? Used to be a , beautiful blond hair. It's
63:08 All right. Moving on the Alright, nails are modifications of the
63:14 corny. Um Which one is the um outer layer right out most
63:21 Alright. Their job is to protect distal ends of your fingers. Have
63:26 ever poked yourself at the end of finger? Yeah. Does it feel
63:31 like joy and happiness? No, awful. The purpose of the nails
63:36 to create a barrier so that when jam your fingers against something it catches
63:42 . It also helps us to grip hold on to things. All
63:45 But it's a protective structure. Now are some books that go through this
63:51 and just are like spend way too time talking about nails? We're not
63:55 to do that. All right. part is the nail itself. And
63:58 that the nail plate? All So when you look at your
64:01 that's the nail plate, underline the plate. So the pink thing
64:06 That is the nail bed. All . This is not the nail
64:10 This is the nail bed. So you look at your nail plate underneath
64:14 nail plate, is the nail All right over here, at the
64:18 the distal end is the nail So think about the direction of your
64:23 grow. Do they grow this way grow that way? So the matrix
64:28 on the end from the opposite from direction of what you're growing. So
64:34 the nail matrix over here. We're the nail outward that way. It's
64:39 produces the bed underlying it. And pushes the plate along the way.
64:44 where the cells come from. those are the three structures you need
64:47 know. But because we're always we have this little white thing at
64:54 end, right? We have this white thing right there and then we
64:58 these things that we like to chew on the edges. All right.
65:02 thing we like to chew on is the finicky um technically the Epa Nikki
65:06 or what we call the cuticle is portion right here. That protects that
65:12 . Alright, so right down there then the white part that looks like
65:17 1/2 moon la mula. That's easy remember. Right? It's almost like
65:24 . Yeah, la mula lululemon, moon, love luna, luna,
65:35 almost. I know, I know luna. So, that's what I'm
65:39 to help you remember. So, just a white crescent. All
65:41 So, it's that I used to you what that was and I can't
65:46 now what it is. I think the hype of no ever jam yourself
65:50 there now. Yeah, that's the Nikki um You don't even know that
65:55 all. All right. Never put pictures on the internet. See that's
66:01 I just found. People's pictures on internet and said look at their greasy
66:04 and greasy hair. Mhm Yeah. right. So, what we're doing
66:12 is we're moving to the glands. we said we're going to go skin
66:17 then we went through the hair we nails which was like one question on
66:22 exam is like literally like checkmark type . Okay now we're gonna do through
66:27 glands glands. We have sebaceous The secretion here produces see bum.
66:33 boom is beholden well basically stimulated by . So if you've ever been around
66:40 kids, they don't produce. They're really oily or greasy. They're just
66:45 . Okay. That's because they never . All right. But what sebaceous
66:51 are there primarily found where there's hair and so what they're doing is they're
66:56 out their secretions. The C bomb is an oil and it's there to
67:02 and lubricate the hair and the It actually has all sorts of features
67:05 it. Um It's particularly anti All right. And so what I'm
67:11 suggesting stopped bathing because then you get the stinky part. Right? But
67:16 before we bathe and covered ourselves and and perfumes and stuff. This is
67:22 we kept things from killing us. body has natural protections against things that
67:27 us. And what we do is wipe it off once or maybe even
67:29 daily. So that's what the sebaceous but also because it's an oil prevents
67:36 loss as well. So I was going for the shine here. So
67:39 can see oily skin and oily the second type of gland are what
67:45 called the Sioux difference glands or what would call sweat glands. So remember
67:50 oil, I'm sorry this oiliness is a function of oh, I've been
67:54 . So now I'm oily. It's natural sequence accretions of those ports.
67:59 think about when you get acting, you start getting oily and greasy.
68:03 when your body starts pumping out tons tons of hormones during puberty.
68:08 And then it kind of gets under again and it's not so horrible.
68:13 , so odiferous glands on the other , they are, your sweat glands
68:16 found all of your body, except two different areas which are the nipples
68:21 are an actual type of gland that not going to deal with today.
68:25 going to be dealt with in A P. To write. But nipples
68:29 a different type of sweat gland that been modified for lactation and then we
68:35 the generals which are kind of unique interesting in their own right?
68:38 we're not going to deal with But basically, there's two different
68:41 We have the american glam and the gland mary queen is also sometimes referred
68:46 as the crime sweat gland. All . So, we're gonna distinguish between
68:50 two things we're gonna start with the gland. Because the endocrine gland is
68:55 one that we think of when we of stinky. All right.
68:59 where do we find these are primarily in the actually regions as well as
69:03 anal genital regions. These are structures empty into hair follicles. So they're
69:09 a secretion that is primarily waters plus . Now we're going to focus on
69:14 pits rather than the genital region. right. So when someone sweats and
69:20 shower, what do they become But what's interesting is the secretions of
69:26 april of the african grand in and themselves are not stinky. But this
69:30 a warm environment where bacteria like to and hang out, it's like a
69:37 summer residence for them. They're oh man, I love this warm
69:42 area. And look, the host producing food for me. How sweet
69:47 keeps accreting that stuff. And I'm going to eat this and eat this
69:50 multiply and divide uh the rate at bacteria divided about every 15 minutes.
69:57 , and they're like, oh good . And they eat the proteins and
70:00 produce waste and it's the waste that . So the stickiness from sweating is
70:08 the bacteria that is found on the . All right. So when you
70:14 about the Quran think of that. right. Now, why do we
70:19 these? We don't really know. can make some really good guesses
70:22 All right. These are non functional prep You burnable pre puberty. All
70:29 . All right. Yeah, I've three boys. They all stink to
70:32 heaven. It's because they don't Right. And they don't sweat under
70:37 arms like this. Right. They when they sweat it's like everywhere
70:45 But when we hit puberty then all a sudden those start working. And
70:50 the thought is, is that these actually the glands that we would be
70:55 would be our equivalent of the sexual glands in the body. All
71:00 They are indicators of I'm producing So those are some of the proteins
71:05 the pheromones. And so I am mature. That's what it basically
71:11 Even though you're stinky. All Now, when you think of sweat
71:16 the underarm sweat, you think of full body sweat. And these are
71:19 american glands. Who's that? You need to get out more and start
71:26 some movies and stuff. This is professor at the University of texas.
71:35 . Mhm. You know that? ? You know who that is,
71:39 McConaughey. Oh, can you tell running around in the hill country there
71:44 like a crazy hippie and he's actually a professor in the film department at
71:49 University of texas. Okay. All right. Who's that? I
71:56 remember. Okay, it's jennifer Lopez that here it is. I can't
72:04 . It's an actress. She's It's ready. And why they
72:10 Well, basically now we're doing this gland. So, basically what this
72:13 . It produces water. Plus some . It's primarily water. And what
72:17 doing is we're putting the water on surface so that we have someplace to
72:21 heat. So remember what we did bestow dilate blood goes close to the
72:26 carries with it heat water is a good carry of heat. If we
72:29 water on the surface, then the from the body can heat up the
72:33 on the surface causes to evaporate and the heat away. So, it
72:37 a major role in thermal regulation. also a way to get rid of
72:41 salt and some metabolic waste. All . You don't have to admit
72:45 But have you ever looked your arm like someone else. It's like that's
72:49 kind of salty this this This is right. Well, there you
72:54 You're secreting salts uh through this this also tons and tons of antibodies and
73:01 antibacterials as well as antivirals are on surface of the skin. All
73:06 So, it's just again, part that protective barrier. Alright, this
73:11 sympathetically regulated. So, again, gonna go back to the example of
73:15 getting in front of the class and a lecture. You know what happens
73:19 your hands start sweating, right? you actually start sweating all over
73:24 You get that nervous sweats You heard the nervous sweats. That would be
73:28 it's because of that sympathetic regulation also also plays a role in terms of
73:36 . So there you go. That be regulating for temperature but also to
73:43 the body down while exercising. Got question and then you guys can get
73:48 heck out of here. Land that our tears american spirit. 2nd,
73:57 question is what produces our tears? know the weeping of our No
74:03 That's not it. So, tears different gland. That's the Lakmal
74:06 It's part of the eye. There's multiple glands in the eyes. But
74:10 Lakmal gland is a unique land that above the eye. It's not part
74:13 this system and it produces the Lakmal that then wash over the eyes and
74:19 them clean. It's like it's like windshield wiper fluid of your body,
74:25 . All right, everyone's out of . I'll get to your email
74:32 Mhm.
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