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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture09_0922
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00:07 Alright. So here we are. again, thursday, it's almost the
00:12 . So you don't have friday It is the weekend after this one
00:15 hope. Um Just to give you brief overview of where we're going
00:19 we're gonna talk about the gland, gonna finish up what we talked about
00:22 Tuesday, that should be pretty quick glands are easy. Um Then what
00:26 gonna do is we're gonna talk about osteo genic tissues. Alright, so
00:30 tissue is simply what is bone, it's made of what it looks
00:35 so on and so forth. Um I think this is kind of a
00:39 lecture and then next week Tuesday and think thursday is like easy mode.
00:45 mean for for those who have been at the syllabus you're probably like there's
00:49 chapters and you probably really started reconsidering course right? Like I gotta read
00:56 much but the rest of, I Tuesday is literally the knee bone is
01:00 to the thighbone. Thank you. , you know that sort of
01:04 So it's literally learning the names of bones. And then the next lecture
01:08 that is uh what we call. I'm just going to say it's it's
01:13 but it's basically the different types of and how they work in the
01:18 And these are really easy lectures and you're gonna do and what you're gonna
01:22 about yourself. Is that the best to study this is sitting in front
01:25 a mirror and doing something like It sounds funny but you become your
01:35 cheat sheet on the exam if you your articulations right? It's like oh
01:42 see what this does. Oh yeah can be a cheat sheet in your
01:47 exam alright. But anyway and I encourage you when you do study like
01:53 to someone else so that you can and and and play the bones and
01:58 like that. But anyways that's kind gonna go. Um Like I
02:02 I think these next three lectures are straightforward. Uh So just finishing up
02:07 with the glands, there's three basic that we find in the integra
02:12 Alright is a sebaceous gland and this why I encourage you never to put
02:19 under the internet because I just find pictures. I do like searches for
02:23 greasy face and that's where I got picture. And then I said greasy
02:28 and that's where I got that So I don't know who they
02:31 They're just random people who yeah, just got their sad stuff right on
02:36 internet. All right. So when think of sebum or sebaceous glands secrete
02:40 material CBM that's the oily stuff. so you're probably most familiar with it
02:46 the greasy nous that you get on face or how your hair becomes
02:50 These are secretions that considered primarily There's quite quite fat in it but
02:59 there for a purpose and what it , we can like scrub it
03:03 I mean you guys wash your face night. Yeah, you wash your
03:07 at least once a day. Some you are just gonna know I do
03:09 every other day. But what those this contains a bunch of bacterial seidel
03:15 and your body decreases kind of protective assault thing out environment primarily bacteria.
03:25 we don't see a lot of young like you know, pre people uh
03:30 them produced them, but not not the extent when we hit puberty.
03:35 baby, that's when that's really I mean that first is it,
03:40 know, did you take a picture it and memorialized know anyone who ever
03:46 horrible right before that important day and Yeah, I don't I don't know
03:52 that happens. It just it just these are going to be stimulated primarily
03:56 the hormones. So they can we talked about the different types of
04:01 holocron, these are our type of glands. So this kind of shows
04:07 again where we were. So remember is the epidermis. The dermis hair
04:12 , sebaceous glands are typically associated with follicles. And so they serve there
04:17 protect and soften the hair as it's out also to fight against bacterial loss
04:24 because it's fatty, it basically also as another layer of waterproofing. So
04:29 water doesn't leave the body all that . That's one and then there's last
04:34 fall under this category of what we a sweat gland? All right.
04:39 you and I would refer to the glands, odiferous glands as the other
04:42 for them. These are all over whole body. There's two places you
04:45 find them. One is the genitals. I can explain nipples for
04:49 . Really, really easy nipples are modified sweat glands. Alright, so
04:53 are their own glands. So you're gonna find a gland on top of
04:56 gland genitals? It's a whole another a reason. And I'm I couldn't
05:01 why. Alright, but anyway, we have these secret glands which american
05:07 and we have a broken. So , going back to those definitions that
05:11 looked at, we're gonna divide them these two types. We're gonna look
05:14 african first, which why put it way? It should be probably looking
05:19 first. But again, you can of see here, african glands are
05:22 to typically be associated with hair So there's your sebaceous gland over
05:26 but there's an african american basically open up to the surface of the
05:32 So when we think of these, primarily located the epicurean are primarily located
05:37 your armpit and in your crotch. . Did that wake you up axillary
05:44 or the genital regions. Okay, are the glands that become active after
05:51 or during puberty? All right. so this one I think does a
05:55 job of demonstrating that picture the axillary . So we're again we're dumping into
06:00 hair follicle. The materials that you in this is primarily water, salt
06:05 other waste materials. But what we're do is we're gonna add something
06:09 We're gonna add fat to it. so these fats and some proteins are
06:16 to provide. Um I mean they odor. They provide signals. But
06:22 what they do is they are in warm areas of your body and this
06:27 where bacteria typically live and they typically the fats and the proteins and the
06:32 and the proteins nourish those bacteria and bacteria turn that into waste. And
06:36 you get the stink. So your odor is primarily not yours. Your
06:42 odor is primarily bacteria living on the that your body is producing. So
06:50 do we have them again? You look at pre puberty. All kids
06:54 don't have very active april glands. become active during puberty. So where
07:00 find them kind of suggest maybe that might be scent glands that we use
07:07 a form of sexual attraction or Like people are stinky. Yeah,
07:12 some people smell kind of nice to . You're looking at me like I
07:16 believe that. But it's true. . So basically it could be a
07:22 scent gland Last one. Anyone know that is. Well that one.
07:29 , that's that's not Matthew McConaughey. Matthew McConaughey, you wouldn't know that
07:32 is. I gotta get new All right. Think jennifer Lopez.
07:38 not sure. I'm terrible about I don't remember names. Anyway,
07:43 people, I don't know. It not be J Lo Mendez. I
07:49 remember her first name. Anyway, rom coms there in rom com together
07:54 . So, this is when when think about this wide and this is
07:57 you kind of think about as you about these crime glands. All
08:00 So, they're all over the place on your hands, you're on your
08:03 of your feet. They're all over body there, especially on your
08:07 Their primary job is to cool you . Alright. And so what's happening
08:13 these glands are secreting water plus some stuff. So, there's metabolic waste
08:17 there. There's some salt. There's other things that are there to kill
08:20 bacteria. Do you see what I'm ? When I say your body is
08:24 to fight off infection. Everything on surface is secreted things to kill things
08:29 are going to try to live on . Even your tears do that.
08:33 right. And so what we primarily this for is we put water on
08:37 surface and then as your body heats your blood vessels are gonna dilate.
08:42 you bring that that heat because water heat really well close to the surface
08:47 that heats up the water on the of the skin. Your sweat.
08:51 you heat up water, it boils right molecule by molecule and eventually what
08:57 heat is doing is taking the or sweat is doing as it boils away
09:02 it takes the heat off with That's how you cool yourself down.
09:07 . We can or I should say is completely sympathetically regulated. Now when
09:12 hear that word sympathetic, what we're about here is the autonomic nervous
09:16 You can't control when you sweat, body responds to its environment and causes
09:23 to sweat. All right now, we say sympathetic, we can think
09:27 sometimes sympathetic primarily deals with fight or . So when you're nervous or scared
09:34 when you have to do something that energy. So when you exercise,
09:39 sweat. Okay, When you're do you sweat? Some people have
09:46 , if I got you up here the front of this classroom with 400
09:50 watching and asked you to teach the three slides. how would you feel
09:55 that? She just looked the other . I'm not, I'm not even
09:59 , Right? Would you get a nervous? Would your hands get a
10:02 bit sweaty? Right tongue would dry talking like this. Right. That
10:11 be an example of sympathetic response. That sweat can be alright, easy
10:19 . Since that was not when that you're attracted to comes up and
10:23 Hey, you know your heart starts that and you begin to sweat.
10:32 right. That would be an example an emotional response sympathetic response. Sweat
10:41 . Easy. Okay, let's get the skeleton, Get onto the
10:46 All right. And so what we're do is we're gonna look at what
10:50 the bones look like in general? are some of the characteristics that we
10:53 to be aware of And then what gonna do? We're gonna ask
10:55 How is it structured? Alright, is generically what is the tissue
11:00 So today is tissue day Tuesday is the bone day. Okay, I
11:06 to make that distinction here. when you think of the skeleton,
11:12 , this is a new system. really the musculoskeletal system. But we're
11:17 out just a skeleton portion. The is not just bones. The skeleton
11:22 of all sorts of different things, cartilage as well as bone, its
11:26 and there's other connective tissues involved in . All right. So when we're
11:31 about here is only a portion of entire skeleton. We're just focusing primarily
11:35 that osteo genic tissue. Alright, the bones are the primary organs.
11:40 why we think about it. Um serves as a framework for your
11:46 And what that means is is that shape is dictated by the shape of
11:50 bones that underlie the external structures. ? So you look the way you
11:56 because your bones are the way that they are. Okay. Now these
12:01 play multiple roles right? They play role in protection and they play a
12:07 in locomotion. So they're there to things inside you. But they're also
12:14 to help you move around. If look at the bones, the interior
12:19 of them there's a lot of them it said C. T. Means
12:22 tissue. So there's lots of T. And what you'll find in
12:26 connective tissue is marrow and american exists one of two types of red
12:31 Yellow marrow. We'll talk about that just a moment when you look at
12:36 you'll see as you take a cross through it there are two different characteristics
12:40 different types of bones or structural uh . We have what is called compact
12:46 and once that's called spongy bone they have other names that are associated with
12:50 . But we're going to focus here compact and and spongy. So when
12:54 look at a bone you pick up bone doesn't matter. Chicken bone,
12:57 bone whatever on the outside you're gonna it's a hard Hard white material that's
13:02 compact bone alright. It makes up 80% of the total mass of the
13:07 . So when you look at a and it's like okay it has this
13:10 80% of it is a function of presence of that compact bone. But
13:14 you're to break that bone in half look on the inside, what you
13:17 is you start seeing the spongy bone the spongy bone is named that because
13:22 looks kind of spongy, it looks what you'd see in a sponge.
13:25 so it's very very porous and it about 20% of the bone mass.
13:30 so when we look at these things can kind of see here. So
13:34 looking at two different bones and their . So we have like long bones
13:40 we're gonna have flat bones and there's couple other ones are short bones and
13:44 so on. But these two kind represent what we see here. So
13:47 can see in this picture right Alright, that would be compact
13:53 And then up here you can see spongy bone going back, sorry here
13:58 can see the compact bone and inside the spongy bone. Alright, so
14:05 bones have both kinds in them in in terms of their arrangements.
14:10 compact bone is on the outside. bone is on the inside. If
14:16 look at a bone out on the and on the internal side. So
14:21 be here in these little tiny spaces the spongy bone is we have living
14:27 bone is living tissue itself. But is the connective tissue that's associated with
14:31 bone. The part on the outside called perry austin. Perry means outside
14:37 or next to. So it's outside bone. The end Osti um is
14:41 the inside and it says the name the bone Indo osmium. All
14:46 And so with regard to the perry which you can see clearly here,
14:50 it would be on the outside here well. What we have is we
14:53 two layers on the outer layers. is this dense irregular connective tissue.
14:58 closely adhered to the bone. And reason it's adhered is because it has
15:02 fibers that penetrate into that compact bone hold it tight. We call these
15:08 fibers. Again, the names are generic. They'll tell you kind of
15:12 they do now if you've ever had , you guys eaten ribs, Good
15:17 , you get down and you get those pieces and you're actually pulling off
15:20 that that last little bit of meat it has that connective tissue attached to
15:25 . That is Perry Osti. Um it's there on the surface serving to
15:31 you know, kind of serving as cover to the bone. So the
15:35 layer of that is that that dense tissue and underlying it are series of
15:41 it like a layer of cells that living. It's whose job it is
15:46 to make and to break the outer bone. Alright, so that's that
15:51 layer that's the cellular layer. And we have there we have different types
15:55 osteogenesis cells which we're going to talk a little bit later. So when
16:01 think of the outside, I have protective layer of connective tissue called the
16:06 Osti um Outer layer is dense connective , the inner layer nearest the
16:10 Living cells responsible for building and breaking bone. The endoscopy um doesn't have
16:20 same outer fibers layer. Alright. if you go into this cavity or
16:24 look in this uh into the spongy or hear what you'll see is there's
16:29 layer that's very similar to that inner . Alright. It's not complete layer
16:34 . But what you have is you the osteogenesis cells, cells that will
16:39 make and break down the bone. . So on both surfaces inside and
16:46 we have living cells responsible for constructing breaking down bone and looking at a
16:54 bone. Long bone is when we about bones that's typically what we think
16:58 right, we have lots of long in our body. Long bones are
17:02 simple. They're basically longer than they . And so these are examples of
17:06 bones here. They have nomenclature that with them. All right, so
17:11 long portion, this portion right here you're looking at is called the dia
17:16 it's the shaft of the bone. the thing that makes it long
17:20 Typically within the shaft, what you're see is you'll see a empty
17:26 Alright. It's an open cavity. called the medullary cavity. Now this
17:30 is not simply just open their stuff . They're typically what it's going to
17:34 filled with some sort of marrow. Children. That marrow is gonna be
17:37 marrow on the in the adults, gonna be yellow marrow and if you
17:42 at this cavity it's not just smooth the inside, it's actually spongy
17:47 So what you have on the outside you have the compact bone and as
17:51 move inward it turns into spongy And then you have that cavity filled
17:55 marrow. And so that's the diagnosis the ends of the bones. We
18:02 the epic Assisi's. That's plural epiphany is singular. So the epic Asus
18:07 filled. It's again it's covered with compact bone but then it's filled completely
18:12 spongy bone. And if you're some , if you're part of an
18:17 what you're going to see is you see cartilage at the end of that
18:22 . The name of this type of whenever you have a joint is called
18:27 cartilage. Why articular because a joint called an articulation. So it's a
18:34 of cartilage you find in a joint cartilage. So you can see it
18:39 down here, you see it, don't see well actually this head right
18:42 would be covered. Okay. And lastly in this picture doesn't show it
18:48 it's poorly described in the text. you have something called the metamorphosis metamorphosis
18:54 simply the point where the diagnosis becomes epic Asus. So it kind of
18:59 as that generic region between the All right. And so this is
19:04 bone. And so you can see this particular case, you see this
19:08 here. Alright, the band up . Those are called the epiphany zeal
19:14 . We see them in long bones they become I mean while you're
19:18 they're made up of cartilage. But you grow eventually, what they'll do
19:22 they'll classify and they become solid That's when you finished your growth
19:29 Alright, so very young, you still grow tall because your bones haven't
19:35 matured. But when that region becomes , then you have stopped growing that
19:42 where this little little region. Is epithelial growth plate? Alright. That
19:47 line, that is the metamorphosis. , so diagnosis shaft epiphany Asus or
19:57 ends metamorphosis. Is that transition point the two where the epithelial line is
20:06 so far? Not too too Right, Okay. All right.
20:12 the rest of the bones look like . Alright, now. Not in
20:17 of their shape, but in terms their organization. So, we saw
20:21 diagnosis. Was it hollow on the or was it filled on the
20:26 Hollow emphasis. What do they have the inside? Spongy bone.
20:31 all the bones in your body that not long bones that don't have those
20:35 features are basically a layer of compact and a layer of compact bone on
20:40 side or surrounding the entire outside. then the entire inside is filled with
20:45 bone. When we see that type spongy bone, we give it a
20:49 name, we call it diplomacy. still spongy bone, but you
20:54 scientists having to name stuff make it . Have another question on the exam
20:59 of thing. All right, so is deployed. All right, so
21:03 external surface is always going to be bone. The internal surface is gonna
21:07 the spongy bone and there is no cavity. Alright, now that doesn't
21:13 that there isn't stuff in those Right? We still have those cells
21:17 are living there and we will find see that there is marrow actually in
21:22 place is Alright, so every other is not like the long bone.
21:31 bones are unique, that's why it down slide, everything else falls under
21:35 type of organization. So there are four types of categories for bones.
21:45 you look at a bone, if had a bunch of boxes, you'd
21:48 going, okay, what do I this bone in? Which box do
21:52 put it in? Alright, so have the long bones and if you
21:56 a long bone there must be a bone and then we have a flat
22:02 and then we're gonna have the one just doesn't fall in any of those
22:04 categories we call it the irregular bone it's neither short nor flat nor
22:10 Alright. It's a weird shape. , so long bones have these features
22:15 them, right? Flat bones. guess I had long but I thought
22:20 was because I guess we're starting the bones. Flat bones are flat.
22:25 that hard? Okay. No, hard by definition. But when you
22:30 some of these flat bones you can a second. Why don't that a
22:32 bone? All right. It has do with the shape and remember the
22:37 bone has within it. It has medullary cavity. And so these longer
22:42 that don't have medullary cavities. If look at them from the right angle
22:45 like oh I see now it's a bone. An example of a flat
22:49 . That doesn't seem like it would a flat bone would be a
22:52 All right. When you think about rib it kind of long because right
22:58 my body kind of long. but when we look at ribs you'll
23:01 okay. Yeah, I see what mean. Alright, so they're
23:05 they're thin some of them are The bones of the cranium are
23:14 All right, but look at your , your skull flat, curves
23:20 Okay. The scapula scapula shoulder All right. Great shoulder blades,
23:29 or less flat called the flat All right. And then the
23:33 You guys know what your sternum is your heart and then the ribs.
23:39 right. Now, there's a class of bones that we call Sesamoid.
23:45 fall into all sorts of different And I'm just gonna put them aside
23:49 because sometimes they fall into the flat category. Most often they look like
23:54 tiny peas. All right. And we you have hundreds of these through
23:58 bodies and they don't have names with exception of one. Alright, the
24:03 is one that is a sesamoid but sometimes it's called a flat bone
24:10 , you know, your Patel is . All right. That is a
24:15 bone. But it's not actually a bone because it falls into the definition
24:20 what a sesamoid bone is. these are typically found within your
24:24 They develop independent. They're small. flat, usually oval shaped. They
24:29 a role in muscle leverage. You them all over the place. All
24:35 . But they don't fall into the one of the special categories that
24:39 So, we have flat bones. bones, short bones, irregular
24:43 and then sesamoid are just kind of , well, they're over on the
24:51 . Long bones. We've already seen easier there. Long right. When
24:57 think of bones, this is what think about their primarily shafts with two
25:03 . So, they are the diagnosis two epiphanies most common bone shape.
25:08 is why we think about them. ones you can think about. Where
25:11 we find them? We find them in the upper and the lower
25:15 All right. So, what are upper limbs where your lower limbs
25:24 What are your feet in your That's a good Well, that would
25:29 close. That would be your But your hands All right. Think
25:34 a skeleton. We're getting close to . We got a couple of
25:37 Alright, y'all picked up your costumes . It's gonna be like a trash
25:42 with a sign on it and said blank. Yeah, Yeah. You've
25:48 that before. I'm in debt. you go. Oh yeah. So
25:56 you guys. Yeah. No, just thinking about all the dead stuff
26:01 you guys are gonna have to put with for the rest of your life
26:03 just sad anyway. Yeah, quit money anyway. So, think about
26:14 hands of when you look at a , right? You'll see the wrist
26:18 . But the wrist is up right? That's where that flexes.
26:23 you have a long bone here, long bone there, a long bone
26:27 , a long bone there and then fingers are long bones. So your
26:35 and your fingers are long bones, your wrists. But you have two
26:40 bones in your forearms. And you a long bone up here. You
26:45 a long bone here, two down and in your feet and in your
26:50 . All long bones. So, kind of easy to identify,
26:54 I mean they are in your upper your lower limbs. And there's an
26:58 because we have the short bones. short bones, as we said,
27:03 sorry, are going to be the pulls in the tar cells and they're
27:07 the same length as they are the . Now, if you actually look
27:10 them and measure them out, are exactly are perfect squares? No,
27:14 if you look at them, you , okay, they're definitely not long
27:18 they're roughly the same length as they the width. So, if you
27:22 know what carpools and the tar cells . The carpools. Easy to remember
27:26 your wrist bones if you're on your too long and typing, what do
27:29 get? Carpal tunnel syndrome? it's just telling you where it's
27:33 Right. And then your tar sal's ankle bones. All right. They're
27:39 ones that make up your ankles. , wrists and ankles. And then
27:45 I said in the last group and sometimes sesamoid bones fall into this
27:50 Again, it's depending on the author who who's doing what? So that's
27:56 we just kind of say sesamoid bones there. And lastly we have a
28:00 bones, irregular bones. These are that have these really strange shapes to
28:04 . All right. They're not just . They're not just short, they
28:07 all sorts of things, literally, don't know where to put this.
28:11 I'm gonna create my own category. your vertebrae, for example, bones
28:15 the face are gonna be in that hip bones are basically you look at
28:22 way, aren't they flat? but they have this irregularity to them
28:28 puts them into this unique category. , so those are the irregular
28:32 Yes ma'am. The which region No. So the only one that
28:47 the medullary cavity is the lung So let me just say with
28:53 so that's how I pronounce it, can be uh Well, I don't
28:57 I've never even heard it said medal or anything like that, but you
29:03 refer to it as the medulla, you might hear some people say
29:08 Alright, so medullary cavity, medulla. Alright, but no long
29:15 are the only ones that have the cavity. Alright, let's get back
29:20 fun pictures, pictures, pictures, things easier. How many guys are
29:24 the lab couple of you. All , this is so whenever you are
29:30 bones, the easiest way to learn bone is to hold it in your
29:34 , touch it, feel it, the bumps, feel the holes,
29:38 all that stuff. The hardest part learning this is staring at a flat
29:42 in the classroom going okay, I'm to memorize this. Alright, so
29:47 tried to help you guys out a bit by adding a little bit more
29:51 the ask and answer the questions with digital software that we have. But
29:56 real way to learn bones is to hold them in your hand, play
30:02 them. All right? So what want to look at is what are
30:07 of the features of bones? Anonymous spent a lot of time trying to
30:11 how bones and muscles work together. so they created or noted different sorts
30:16 features that are helped them identify functionality those bones. Alright, so these
30:24 what we refer to as the bone . We have three different types.
30:27 have depressions, openings and projections. not gonna have you memorize these,
30:32 as we come along them, you be able to you know what they
30:37 they refer to. I think on test, I think if I'm asking
30:41 I'll ask you like, you know of the following is a depression and
30:45 might have like, like that, ? But I'm not gonna ask you
30:49 is a fossa as as it That kind of makes sense.
30:53 so depressions are simply cliffs where either meets another bone or a blood vessel
31:00 nerve moves along the bones or where bones articulate. Alright. And so
31:05 upon what you're looking at, you're to see different types of these types
31:08 cliffs. So for example, this right here a facet is where another
31:14 comes into contact with another bone. a groove for example would be where
31:19 have a blood vessel or nerve traveling the length of the bone.
31:24 So basically serves as a site of indentation where that can actually occur.
31:32 see fosse's here's femur, for the phobia and the femur. Alright
31:38 we have openings. Alright. There's think two easy ones here.
31:45 we have the foramen the framing is a hole at literally what that's what
31:51 word means, framing means whole. right. And so for example,
31:55 the skull we have the magnus or me the frame and magnus. What
32:00 you think? Freeman magnus means the hole. See this is not like
32:06 science. Right? This is biology . All right. And then we
32:13 this a me a tous say that . It's not notice me a
32:19 Yeah, I'm just gonna let you you're gonna pronounce these things wrong all
32:25 time. It's okay. I go a member of the human anatomy and
32:30 society. There's a professor who is considered like one of the world experts
32:36 all this all the all the right? And he offers a session
32:40 time at our conference to see It's how do we pronounce the words
32:45 And he'll throw up a word and how do you pronounce it? And
32:48 you like four different pronunciations and you quarter the class will be one quarter
32:52 the you know, these are faculty , right? These are people who
32:56 the course and invariably, you it's like, nope, you're all
33:00 it wrong. It's this one. okay. All right. But I'm
33:05 try to help you me a It's not me this Alright, so
33:10 framing you're gonna see those all the fishers kind of the same sort of
33:13 holes in bones. This is going tell you where something travels through.
33:17 these holes are gonna be for blood or nerves, but like the frame
33:21 magnus, that's actually for the spinal . So the big hole through which
33:26 spinal cord goes down. Then we projections. And there's lots of different
33:33 of projections. Uh So here are some examples, projections are these extensions
33:40 have all these different shapes is where muscle tendon or ligament is gonna
33:44 Alright, so condos, you'll see lot epic condo means above the con
33:49 . So that's just a projection as . You'll see two vehicles and two
33:53 as you'll see heads. Here's an of the crest spines process,
34:01 trot, canter. That's a weird . And lines again, simply think
34:06 I see something sticking up on a , something has to be attaching to
34:10 and then what we do is we whether it's a muscle, whether it's
34:14 ligament or a tendon. All So that's the purpose of a
34:24 So far you with me. We're memorizing that list just yet. We're
34:28 kind of saying which things fall into kind of categories. All right,
34:36 move inside the bone. Red Yellow marrow. All right. Red
34:43 is hematopoietic. That's a scary What do you think I'm out of
34:51 ? It has to it. But kind of what do you think it
34:55 stay up there? It doesn't What do you think? What do
34:58 think it has to do with Makes blood? There you go.
35:03 . That's a good answer. when you see poetic at the end
35:05 a word, it has to refer the origins of. So this is
35:10 your body makes blood cells. So marrow is where blood cells come
35:15 It's not just red blood cells, all The blood cells. You're the
35:20 of red blood cells to the white cells is like 98-2. I
35:24 it's just the ratios are heavily skewed original pieces and original sites. So
35:32 why red marrow looks like red, know, because there's um sites there
35:40 in adults and your adult. This gonna be found within that spongy bone
35:46 the long bones and or the dip of the flat bones. So,
35:51 , you think about where my flat are, I have to go if
35:55 am becoming a blood donor or a bone marrow donor, I have
35:59 go into some of the hardest and difficult places to reach to in order
36:03 get bone marrow. Alright, so would be your sternum. You don't
36:08 to go digging into a sternum, too close to the heart. We're
36:11 gonna do that. All right, where's another flat bone? I can
36:14 after I go after my scapula. don't know if I want to do
36:18 . So, typically what I do I go drilling into the top end
36:23 the long bones, primarily into the is right there. That's not a
36:29 of fun. Okay, now, I'm a kid instead, every medullary
36:35 have is filled up with red bone and that's because you're just constantly producing
36:39 cells as you're growing. So your is just like let's just keep pumping
36:44 , pumping out, pumping out cells much easier to go find bone marrow
36:49 a child than it is to find in an adult. So, moving
36:53 a child to an adult, what is is that that red marrow gets
36:57 with yellow marrow, Alright. And we have here in yellow is primarily
37:02 . So just another thing to make feel good about yourself is that you
37:07 fat in the middle of your bones you get older. Yeah. All
37:15 now, should the need arise and become anemic? Alright. In other
37:21 , your body needs red blood It will multiply up those retro sites
37:26 it will start taking over the medullary again and start filling up that those
37:32 cavities with the red bone marrow. it's only under anemic conditions, Moving
37:42 to the cellular level. four different of cells that we're interested in in
37:50 . We have a group of cells are related. We call those the
37:55 cells and then we have the OsteO . So this picture just kind of
37:59 um So these three are related to other. This one is not guys
38:05 watch Sesame Street. Yeah, one these things is not like the
38:11 Okay, so the other three are . The one that's not like the
38:16 is the one we kind of focus making it easier to understand this
38:19 All right. We're gonna start with three that are related and really what
38:23 looking at here is different stages of in these cells. So all three
38:29 them exist. All of them are right now, sitting on your
38:32 we have the Osteogenesis or the Osteo cells. This serves as a stem
38:37 to this population of cells. So basically they're multiplying themselves to make sure
38:43 you have enough of these cells to what they need to be done.
38:47 other words to build up bone. osteo progenitor cells or the stem cells
38:51 give rise to the cells that build bones. All right, Where do
38:57 find them? We find them in peri Osti um We find them in
39:00 end Osti. Um Alright. So we're looking at here this right down
39:06 , it's probably easier to look at right here. Alright, so let's
39:10 focus here. So here you can the bone up here, that's that
39:14 tissue of the perry osteo. And these right here would be the cells
39:19 were giving rise to those osteoblasts They're trying to show you that they're
39:24 up but they would be on the level. Alright. The idea is
39:29 you have Osteo progenitor cells a divide give rise to osteoblasts. And one
39:34 behind as an Osteopath Senator. The is the cell that is responsible for
39:42 bone. All right. You're constantly bone, you're constantly breaking down
39:47 It's a very active tissue. And so what they're doing is they're
39:52 matrix out and they're building up the and as the bone gets built
39:57 their secreted in all different directions. so what ends up happening is that
40:01 osteoblasts surrounds itself with a bone matrix so you can see that's what's happened
40:06 is that we've had a cell that itself with the bone matrix and when
40:10 gets trapped inside that its own What happens is that cell differentiates one
40:16 time. So whenever you remember what said, whenever you see blast at
40:19 end of a word that means it's immature cell. When you see site
40:24 in its mature form. So that after it's secreted matrix matrix entrapped
40:30 it matures and becomes this osteo The Osteo site is responsible for maintaining
40:38 structure and the arrangement of that So you can see in this little
40:43 right here it has these extensions that around it. So it's actually living
40:50 the bone itself. It's surrounded by . It's actually in contact with other
40:55 sites. This picture doesn't show that it's through these little tiny branches that
40:59 be in contact. So it's receiving from other cells. It's very much
41:04 . And what it's doing is it's the stress or detecting the amount of
41:09 that's being applied to that bone matrix it. And so if the stress
41:16 inappropriate, what it will do is will help to rebuild the bone in
41:21 for it to deal with the And really that's where the osteoblasts come
41:25 in. So build the bone, the bone is how we think about
41:32 . This gives rise to the Osteoclasts matures into the Osteo site.
41:37 building matrix, I'm maintaining matrix so so good, the Osteoclasts osteoclasts is
41:49 cell that breaks down the bone. you can imagine if all I'm ever
41:53 is building bone and building bone, just keep growing and growing and
41:56 But you don't, there's a point you stop growing but your bone is
42:00 being remodeled. Alright. And so osteoclasts is it is a different type
42:06 cell, it has a different type of origin and what it does is
42:11 is responsible for looking at bone that's being used and it breaks that bone
42:18 and destroys it. And that's what is trying to show you. I'm
42:21 it down and so I'm creating this . So this is a process called
42:27 . So osteoblasts make bone osteo sites the bone osteoclasts, a different type
42:33 cell is responsible for breaking down the . And so we go through this
42:40 of basically resumption and rebuilding over and again. And so this is kind
42:45 , we're gonna start here with formation we're just gonna kind of work our
42:48 around. Alright, I love this because it looks like inky blinky and
42:55 . Thank you for recognizing that. But what you have here is so
43:00 can see here here are my three , they're coming along, they're coming
43:04 and they say, oh there's a that's here in this bone and this
43:08 not good because if the stress is here, the bone is gonna break
43:13 it's no longer doing what it needs do, remember this at the microscopic
43:16 . Alright. So every time you , every time you lift something,
43:21 time you use your musculoskeletal system, creating stressors on the bones. And
43:28 as you create those stressors, those are detecting and say how do we
43:33 this stuff up? How do we it stronger? So that's its job
43:38 to make the bones stronger where you're it. So the Oscar blast come
43:43 , they find that point stress. what they do is they remodel the
43:47 and rebuild bone so that it can with that particular stress that would be
43:54 . And then let's just pretend this point is not dealing with stress.
44:00 it's basically it's overcompensated. You don't bone in this particular location, This
44:04 where the osteoclasts comes in. And it's doing is it's sitting there going
44:09 right, let me break this And the whole purpose is not just
44:13 the rebuilding and the breaking down of . It's also you can think of
44:18 as a place where I store up for later use. So when I'm
44:22 bone, I'm actually putting calcium into calcium bank. And when I'm breaking
44:27 bone I'm releasing calcium from the calcium . And so that's what the osteoclasts
44:32 , it's looking for places where it break down bone so it can release
44:35 out into the environment. So you see here's the osteoclasts come along and
44:39 basically uh dug a hole. And let's say it's it's dug too far
44:46 that part of the bone now is overstressed and then we have osteoblasts that
44:51 in, rebuild the bone and you see the process just recycles itself over
44:55 over again. Now, to put in perspective, I think this is
44:59 really interesting number. Our bone mass recycled roughly. 5% of our bone
45:06 is recycled every week. That means 20 weeks we've recycled the equivalent of
45:14 skeletal mass. So, I think entire skeleton has been recycled now,
45:20 it your entire skeleton? No, the quantity, the the volume that's
45:27 . All right, So is this dead tissue? What do you
45:31 Dead now? Very much alive, determining what you're doing? This is
45:36 importance of exercise, right? When move around. Alright. I'm not
45:40 make fun of your grandma's because you grandma, I think your great grandma's
45:45 , they're a little older, a frailer, right? They have a
45:49 time moving around, Is that My grandmother is 96 years old,
45:54 she was like two years ago, like shoveling sidewalks, so she's like
46:00 crazy woman. Alright, but she's , right? You push her
46:05 She's gonna snap into right? You're gonna push her over. She won't
46:11 you. I tried. No, I'm just teasing just trying to see
46:16 you're awake. Alright. Right? part of that is is that grandma
46:21 move around quite as well as she to 40 years ago she played tennis
46:26 , right? You know, 10 ago she was you know, still
46:32 around and getting her friends places. bowled. My grandmother bold up into
46:37 late eighties, you know Now not much and that lack of activity results
46:43 weaker bones. Weaker bones means less which leads to weaker bones, which
46:49 to less activity to put in your , sitting at home watching youtube in
46:54 chair and not moving results in weaker , which means more youtube or weaker
47:01 , more youtube, yada yada. see that? So exercising, getting
47:06 , just walking and moving around, stress on your bones that causes your
47:12 to naturally want to counter that Okay. All through this process
47:23 So how many spells 4? Which the Weird 1? Still class.
47:34 , now let's get down dirty and inside. What is bone made
47:42 Alright, there's two parts Alright, . It's very similar to cartilage.
47:48 lot of collagen in it. All . But the difference between cartilage and
47:55 is that we have added in an material to it. Alright, so
48:01 organic portion is called the osteo is collagen. There's some glycoprotein in there
48:07 well. There's the cells that we've talked about. All right. And
48:13 we do is we arranged it in a way. So we end up
48:15 these columns of collagen and this resists stretching and twisting. All right.
48:24 cartilage doesn't twist all that much. just it just kind of fights it
48:29 this arrangement but to make it this is when we add in the
48:34 salts, mineral salts is primarily calcium . All right. And so what
48:39 do is we're gonna take these It's called hydroxy appetite. And what
48:43 do is you line it up on on the cartilage or sorry, on
48:47 on the collagen. And then that's to make these nice tough bone
48:53 Alright? So basically it's just hardened is the way to kind of think
48:58 it. So this makes it very rigid and very inflexible. And also
49:04 it compression strength. Um I like use my kids as an example.
49:09 one of things I like about collagen cartilage in general is that it's it's
49:14 malleable. So you don't break collagen cartilage all that much. One of
49:19 kids when he was like four or fell out of a tree. Um
49:24 that far is like six ft. he comes in he said daddy,
49:30 wrists hurt. You know, my physical therapist, I look at
49:33 I said I I don't feel anything . My wife. Yeah, I
49:36 feel anything broken. Okay, go and play, you know, three
49:40 later he's still kind of protecting his . It's like I bet I bet
49:45 broke something. So we took him there and it was a compression fracture
49:49 cartilage can squish, right, you squeeze it. And that's where that
49:53 came from. My other son was school and they're running in circles right
49:59 around the gym because that was what coach thought was exercise. And then
50:05 kid, you know, you remember games where you like knocked the feet
50:08 from somebody, you know, remember . So, if someone did that
50:12 him while he was running around and landed on his arm and broke both
50:16 old and the radius. Yeah. know, and then you go to
50:20 in his arms, like you and like all right. So what happened
50:25 is like, you know that that of his body and landing on his
50:30 basically caused it to snap, Because it doesn't compress and it doesn't
50:36 or twist all that. Well, right. So, it had no
50:39 based on the forces applied to it break it. All right,
50:45 structurally tough stuff, right? It's there to prevent that kind of movement
50:54 cartilage allows. So, I want to focus up here at this
50:59 Alright, this picture is a long . You see the medullary cavity right
51:04 ? I see that you see this all compact bone Yes or no.
51:10 , okay. Alright. So, we're doing now is we're going to
51:14 in. You can see So right here this would be the spongy
51:19 That's the medullary cavity. This right would be the compact bone.
51:24 so you can look at the compact , you can see the arrangement of
51:28 fibers. So this structure right if you look at it from the
51:31 looks kind of like a bull's That's called an austin and this is
51:36 structural unit of of of bone. right. So you can imagine these
51:40 fibers that are all traveling in the direction. Well not all in the
51:44 direction. You can kind of see range kind of in these unique
51:47 But there are these pillars that are in kind of in close proximity to
51:52 other, that gives the bone its . And because of the arrangement of
51:56 fibers within the Asean, you can here each of those different rings is
52:01 movement of fibers in one direction and fibers in the next ring go the
52:06 direction and so on. So you're the strength of the fibers in these
52:11 and then together they are what creates that resistance to twisting and spinning Or
52:20 or stretching. Now I like to a lot of movie references. So
52:25 you don't watch movies you're gonna have start making a list. All
52:29 Um actually, I did this another . There are students out in the
52:33 row and she had had before and she started writing down I think at
52:36 end of the semester had like 50 odd movies that I've mentioned. But
52:40 you all seen the blind sides? know the blind side? Alright.
52:44 the blind side, the opening scene the blind side is a football game
52:47 the new york giants and the Washington who are no longer the Redskins.
52:52 . And so the quarterback for the was joe Theismann, his real name
52:57 these men. But because when he in college he was hopeful for
52:59 he's gonna get a Heisman, they him, you know, so the
53:03 , I know he makes a he gets the ball and he's going
53:08 throw a pass and he makes an round run and chasing after him as
53:12 of the strongest most dangerous linebackers in game. Lawrence Taylor, Lawrence Taylor
53:18 along, jumps at joe. Theismann his foot on the ground and then
53:23 to make him fall to the But because his foot was planted when
53:27 rolled, what did the bone It? Had a twist your bone
53:35 do that because of this. And the opening of that movie talks about
53:39 happens when the blinds, you know you don't aren't guarding your blind
53:43 And of course L t who is this? Like I said he was
53:47 monster of a blind backer. He the bone snap and he felt
53:52 I was I was watching the game . It was I mean just watching
53:55 movie. I cringe every time I it because he gets up and the
53:59 is like this right? And he's at the side at the sideline coming
54:04 coming out. I know what happened . You know it was just a
54:08 thing. But that structure those austrians there to prevent that from happening.
54:14 it just shows you the kind of that he did. Alright now this
54:18 picture right here is showing you what Austrian looks like under a microscope.
54:23 so you can see that there is open area on the inside and then
54:26 can see the rings as you kind move outward. And so we're going
54:30 focus here on the rings for a . And what's in one of those
54:34 in the Austrian? So the central is called the central canal in that
54:40 . That's where you're gonna find blood and nerves. If it's dead
54:43 you wouldn't need blood vessels and you need nerves. Have you ever been
54:47 in the shin? Does it Yes. Why? Because there's
54:53 Right so the blood vessels are there provide nutrients for the cells that are
55:02 inside. That Austin each. Excuse . Each of those rings are called
55:07 mela. Alright so you have them concentric arrangement. So you have
55:14 bigger, bigger, bigger. And the boundary of these concentric lamelo.
55:18 where So you can imagine I'm laying matrix this way I was laying out
55:23 that way. And so that's how cell got trapped. So that osteo
55:27 is trapped in a structure called the . Which is just a fancy word
55:31 saying little tiny lake or a little lagoon. And so it's sitting in
55:34 watery environment trapped on either side by of these concentric lamelo with the fibers
55:41 in opposite directions. So here you see here's our Osteo site, there's
55:46 osteo site sitting up in there and can see that they have these little
55:50 extensions and those extensions are going off the next little osteo site. So
55:54 communicating with each other. And so are being delivered by these blood vessels
55:59 those cells. And those cells are nutrients between each other and telling the
56:03 osteo sites what's going on around The little tiny canals between each of
56:09 Osco sites. So this little structure here, that would be a
56:14 So it means a little tiny Alright, so again, here is
56:19 micro microscopic view, you can see little black dots represent where the Osteo
56:25 are located within their lacuna. And in this electron micro graph you can
56:29 the central canal and you can see pits, that would be the
56:34 So that's where those Osco sites would residing. Now if you took a
56:44 bunch of round things and put them , there would be space in between
56:49 . Cynthia osteo sites are around. can see the little tiny spaces here
56:53 between them, right? And this just been pulled out. So you
56:56 see the the concentric arrangement. All . The blood vessels that are going
57:03 and down are connected to each other canals that are called perforating canals.
57:08 , so a blood vessel has to in there somehow. And that's what
57:11 way that they do. So this space is filled in between are going
57:16 be called interstitial. Lomeli. Interstitial in between. So whenever you see
57:22 word interstitial in between. So what's is is one of two things.
57:27 I, the the osteoblasts and osteoclasts built this stuff or they've torn down
57:34 osteo site and rebuilt or an Austrian rebuilt an Austrian. And in doing
57:39 , the remaining bone that was there was left behind is interstitial. So
57:47 basically they're one of two ways. either building it by filling in between
57:52 it's a remnant of one that was and rebuilt. And then finally we
57:57 on the outside of the bone being by those osteoblasts on the outside in
58:05 perry Osti um is you're gonna have that are called circumferential. So they
58:10 up the circumference circumference. So we that on the inside. So that
58:15 be internal circumferential. And on the that's external circumferential. And it also
58:20 to resist that torsion. That twisting that easy or you know? So
58:33 just kind of identifying where these things built from. Spongy bones a lot
58:38 because it doesn't have all those different to it. Alright, what we
58:44 is this lattice work, I saw hand now. So we have lattice
58:49 . So you can see the spongy , you can see the space in
58:51 there and what these lattices are referred as is traditionally alright. And these
58:58 looks like Austin's, they aren't austrians they're kind of a range like
59:02 There is no central canal because you marrow and other stuff out here in
59:06 environment. So material can actually pass the curriculum to the osteo sites but
59:12 still have these uh these layers, ? These different types of Lomeli.
59:18 refer to them as parallel mellie because referring to them in this direction,
59:23 ? So they grow along that length it's still structurally very similar. You
59:30 rings of them with Osteo sites stuck between. It looks haphazard but it's
59:38 true particularly are built on stress So the strength of your bone is
59:45 on the stressors it detects. And that spongy bone is there to
59:49 oh I feel there's a stress line , I'm gonna build up a bone
59:54 and support it. It's kind of when you were building tents in your
59:57 , you remember doing that as a , right? And what you do
60:01 you'd like to take a poll and put up your blanket and then other
60:05 falling over here. So you go a pillow and put it here and
60:09 the tent was kind of falling you kind of restructured. That's kind
60:12 what bone is doing. Except it's using pillows and your mom's broom.
60:24 , we're getting ready to land the . Questions about this so far arrangement
60:34 ? No, I said on the and I'll start thinking he's gonna be
60:37 here quickly. I was like, , if we just get him to
60:40 talk through this, we're out of now, that's gonna be Tuesday,
60:44 . It's like me bone, thigh out of here, how does your
60:49 actually form? Alright. There's one two ways. It's through a process
60:54 ossification or what we can do. , there's the whole process is
61:01 but it's one of two ways either be through a process that's intra member
61:04 or indo control. All right, I even go into it, what
61:10 you think? Intra membrane? This inside membranes. Alright, Indo contra
61:15 do you think it means? Indo what Kandra cartilage. Alright,
61:23 Alright. So immediately when you look a word that you're sitting there
61:27 I don't know what this you know you get confused, look at the
61:30 and ask yourself what does it Okay, so those are the two
61:35 that we're gonna do it. There's gonna be some sort of membrane or
61:39 gonna use some sort of template made of cartilage to do this. Now
61:43 inter membrane, this is the way we make flat bones in the control
61:46 how we deal with the rest of bones. So, basically long bones
61:49 well as some of these strange shaped . All right now, this begins
61:54 embryo genesis and this will continue on your childhood through adolescence and even up
62:00 about the age of 25 for some Alright, some of you have stopped
62:05 and actually even in adulthood, so gonna look at a bone a little
62:09 later part of the sternum, That's void process. That's that little bone
62:13 sits at the bottom of your If you've been punched their, you
62:16 , like you lose your you horrible feeling right right now for you
62:22 , it's all cartilage for me Is to turn the bone so about the
62:27 of 40-50 is when it starts turning bone. So the process of ossification
62:34 an ongoing thing throughout your entire life most of it takes place very early
62:41 . So we're gonna look at intra nous. So what do we say
62:44 remembering this was inside membranes? All . So the way this works is
62:51 early on development. You your body divided into different regions as a result
62:57 I'm trying to stay away from the too much. But there's a region
63:01 called Mesen keen. Alright. The gives rise to all sorts of different
63:06 . But the mesen kind, what happen is that there are cells that
63:10 going to differentiate within this material and gonna become osteogenesis. Alright. Give
63:16 to the cartilage. So that would Condra genic and then we have a
63:20 that gives rise to the bone. so what will happen is these cells
63:26 differentiate. And what they'll do is start laying down matrix. And as
63:31 doing that they're gonna be dividing along well. So remember we have different
63:36 of, we have the osteo We have the osteoblasts and then we
63:39 the Osteo site. Right? So osteo progenitors are dividing and becoming
63:45 Osteoblasts are laying down matrix. And here you can see I'm laying down
63:49 matrix that's that Osteo Oid. And what will happen is that then that
63:54 becomes calcified. Right? We're adding the calcium phosphate crystals. And so
64:00 trapping cells within that and as I'm cells those cells are becoming osteo
64:07 But notice where the osteoblasts are on the outside, right? And they're
64:11 matrix. And what they're doing is pushing that mesen kind into a tighter
64:16 tighter and tighter structure. In other , what I'm doing is I'm compressing
64:21 tissue. So you can see look how loose the mezzanine is in
64:26 area. But look here that mezzanine is being compressed downward and becoming that
64:35 connective tissue that we refer to as osteo. And then those cells that
64:39 on the outside laying um laying they become that inside layer of cells
64:47 that perry Osti. Um Here, can see the the compact bone
64:53 Or I'm sorry, this is this called woven bone. But you can
64:56 here here's compact bone, there's that bone. And what's happening is is
65:01 as I'm laying down, the compact is being laid by this layer
65:07 the spongy bone is what is left from what we started with? So
65:11 get this woven material that looks kind like sponge, but it doesn't have
65:16 sort of strength. When is it to build up its strength when I
65:20 using it? Right. And so the time we get to this point
65:25 actually now in that place where we're test and try the bone. And
65:31 the woven bone becomes the spongy We have cells that are trapped inside
65:37 have cells that got trapped in the . So what would that be called
65:43 this is perry asking what are the that are trapped in here called?
65:48 austin, correct? So that's how inside of membrane gets formed. There's
65:55 template. We're just messing team. what we're doing is we're growing in
66:00 and we're pressing them as in kind create those flat bones and that's what
66:05 looks like. It looks like a bone spongy on the inside, compact
66:10 the outside, parry Osti um cells on the inside. That would be
66:14 Dostie. Um And then here's our tissue. That one seemed hard.
66:23 finally this one very early on in , this is you very early on
66:29 . You can see we have a skeleton. Alright. That cartilage skeleton
66:35 gonna serve as the structure on which gonna build bone. So the first
66:41 this is about 8-12 weeks of First step after that we're gonna have
66:45 vessels penetrate in. And what they're do is they're penetrating through this calcified
66:52 . So on the outside, what doing is we're laying calcium on this
66:57 . Alright and when I put if I put this calcium, what
67:00 doing is I'm depriving the material on inside of nutrients. In other
67:07 what I'm doing is remember with cartilage have this matrix that has water in
67:11 so nutrients can travel anywhere it wants , it just moved down their concentration
67:16 . But if I put a seal bone around it then those cells on
67:20 inside no longer can receive their So they begin to die. Blood
67:24 penetrate in there and bring in our progenitor cells. And so we start
67:30 this ossification center. All right. then the inside has basically died
67:35 And so we end up with this space and then what we're gonna do
67:38 we're gonna start building bone so that that dia thesis actually starts creating that
67:44 . So we end up with a that now has blood vessels in
67:47 So you can imagine why would I red marrow there? Because I have
67:51 source to hide these cells and so can multiply and divide and now join
67:56 with down here at the bottom of epiphany sees and at the top of
68:01 epiphanies again, blood vessels go in ossification centers. The cartilage basically dies
68:08 and it gets replaced with these osteo cells and it gets replaced so that
68:12 inside becomes like that spongy bone and where this is. You know where
68:18 trying to demonstrate this. This is very early on. You're already out
68:22 the world testing your body around right up and down stairs downstairs a little
68:30 more dynamic here you can see we have cartilage, see that car lives
68:42 . So that would be in that , that region where you still have
68:46 , you're still able to grow the is in this because we can still
68:53 down bone where there's cartilage and the is still multiplying and dividing. So
68:57 actually laying down new cartilage that's slowly replaced by that bone. By the
69:03 you reach the end of what we puberty, maybe a little bit
69:07 Is that the cartilage or the bone has is growing faster than the cartilage
69:12 and it replaces it and eventually catches and it removes all the cartilage at
69:17 point, your bone can't grow lengthwise you've reached your height, your maximum
69:24 . So I have the ages It can happen between the age of
69:27 . Anyone here basically stopped growing around age of 10. No one,
69:31 one's gonna admit that. Huh? , but it wasn't that much
69:35 right? I mean, some of grow, stop our growth spurt very
69:40 on. Some of us keep I worked for the basketball program at
69:44 when I was about, y'all's age little bit after college and I was
69:49 an elevator with four freshman players and shouldn't sound anything. Two of them
69:55 over seven ft one was just under or just under seven ft and they
70:00 still growing, right? They were , I mean, look at
70:05 I'm like 5-10 if I'm if I on my tiptoes, maybe, you
70:09 , it was like this in an . It felt like I was in
70:11 forest, right? But you those type of players, you
70:17 are sought after because they know they're stopping at seven, they're gonna keep
70:21 right because their official place haven't closed . All right. I think I
70:29 a picture now. Yeah, I have a couple of pictures that show
70:32 . Alright, so when you're growing length, this is what's happening is
70:38 can imagine this portion here is living that's trying to grow in this
70:46 So what I'm doing is I'm laying here in the light blue so that
70:49 pushing the dark blue further away, you can see the cartilage is moving
70:54 direction. The bone, on the hand is growing that way too.
70:59 basically saying uh that area just above is being deprived materials, those cells
71:04 dying and so I'm replacing those dying with bone tissue. So the cartilage
71:10 growing that way, the bone is after it and the rate of cartilage
71:15 versus bone growth. Bone is so it eventually catches up.
71:20 so this is what is referred to , sorry, interstitial bone growth,
71:27 is kind of what it looks So you can see up here,
71:30 is the stuff that is laying down cartilage and so it's basically pushing this
71:36 up by laying cartilage down here. that's moving this direction and down
71:41 you can see the bone, it's up as these areas are dying
71:46 So this would be the living This would be the dying area.
71:49 I'm pushing the dying area away from living area or where I'm pushing the
71:53 area up away and the dying areas behind it. And this is slowly
71:58 up. I'm not going to ask what these different sections I never
72:01 I just want you to see the . But if all your bones did
72:06 grow this direction, you'd be this , tiny thing with little tiny pencil
72:11 . Think about how big you were you're two years old. How big
72:14 your mounts? Right, Maybe that ? How big are you now?
72:21 that big? How big are your inside you now? About like this
72:25 right, So, we also have outward and that's called oppositional growth.
72:31 growth is where that curiosity. Um laying more layers on that compact bone
72:37 , right? So I'm growing outward direction and on the inside in the
72:43 um I'm breaking down bone because I want it to be too thick because
72:48 my bones are really, really they become very heavy and then I
72:50 to work harder and we're all against hard. Right? So oppositional growth
72:56 I'm growing fast out this way and breaking out that way, but the
73:01 is slower. So as I grow my bones get thicker but relatively
73:08 I'm not as thick as when I . So you can kind of see
73:12 this is done the way you can about this. The rate of adding
73:16 on the outside is faster than the of which I reabsorb bone. So
73:21 end up with a thicker, stronger to support my structure as I am
73:25 relative to when I was younger but not relatively the same thickness. Are
73:34 done? What do you think? we done? You sure? Are
73:40 Are you really sure is the Yeah. Okay, we're done.
73:46 . I will see you on Tuesday we'll go through the bones, The
73:49 bone's connected to the thigh bone, yada
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