Description

This video is about the Connective Tissue

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🔹 Development of Connective Tissue (Mesenchyme)

• Embryonic Development: Zygote → Blastula → Gastrula
• Germ Layers:
  • Ectoderm → Skin and Nervous System
  • Endoderm → GI Tract, Glands, Respiratory Tract
  • Mesoderm → Connective Tissue (CT), Bones, Cartilage, Hematopoietic Cells
• Mesenchyme is an embryonic tissue, found near the neural tube during development.

🔹 Classification of Connective Tissue

• Common Origin: Mesenchyme
• Connective Tissue Proper: Loose CT, Dense CT
• CT with Special Properties: Adipose Tissue, Hematopoietic Cells, Elastin, Mucous Tissue
• Supportive CT: Cartilage, Bone

🔹 Composition of Connective Tissue

• Located under the basement membrane
• Consists of:
  • Cells (Fibroblasts, Reticulocytes, Myofibroblasts)
  • Extracellular Matrix:
    • Fibers: Collagen, Elastin, Reticular
    • Ground Substance: Glycosaminoglycans, Proteoglycans, Multi-Adhesive Glycoproteins
    • Extracellular Fluid

🔹 Dense Connective Tissue

• Regular Dense CT: Found in tendons, collagen fibers aligned.
• Irregular Dense CT: Found in deep dermis, collagen fibers arranged randomly.

🔹 Collagen Fiber Types

• Type 1: Resistant to tension.
• Type 2: Resistant to pressure.
• Type 3: Maintenance in organs.
• Type 4: Supports basal lamina.
• Type 5: Resistant to tension (works with Type 1).
• Type 7: Connects basal lamina with reticular lamina.
• Type 9 & 10: Found in cartilage and bone.

🔹 Types of Connective Tissue Fibers

• Elastic Fibers:
  • Oxytalan (Strong fibrillin fibers)
  • Elaunin Fibers (Elastin + Fibrillin)
  • Proper Elastic Fibers (Elastin + Fibrillin)
• Reticular Fibers:
  • Consist of Type 3 Collagen.
  • Produced by Reticulocytes.
  • Histology: Found in lymph nodes.

🔹 Ground Substance

• Located between cells and fibers.
• Acts as a lubricant and barrier against invaders.
• Contains Glycosaminoglycans, Proteoglycans, Multi-adhesive Glycoproteins.

🔹 Histology of Connective Tissue Cells

• Macrophage: From bone marrow, bean-shaped nucleus.
• Mast Cell: Large, contains granules with histamine and heparin.
• Plasma Cell: Derived from B-Lymphocytes, “cartwheel” nucleus.
• White Adipocyte: Energy storage, nucleus at the periphery.
• Brown Adipocyte: Found in newborns, rich in mitochondria.

🔹 Challenge at the End of the Video!

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Transcript

Introduction 0:00 hello and welcome to another video in 0:02 this video I’m gonna cover the basics of 0:04 connected tissue in terms of histology 0:06 so as you probably know we have four 0:08 main types of tissue in the body we have 0:11 epithelial tissue we have nervous tissue 0:13 we have muscle tissue and connective 0:15 tissue so in this video I’m going to 0:17 mainly focus on the connective tissue 0:19 all right so the first thing we start 0:21 with is the development of connective 0:23 tissue CT stand for connective tissue 0:25 what I’m gonna mention the mesenchyme 0:27 and I’m also going to talk about the 0:29 classification of connective tissue and 0:31 then I’m going to talk about the 0:32 extracellular matrix which include the 0:35 fibroblast types of dense connective 0:36 tissue reticular tissue and ground 0:39 substance and I’m also going to talk 0:40 about the cells in connective tissue 0:42 which include the macrophage must cell 0:45 plasma cell and the two different types 0:48 of adipocyte we have or a so let’s start Development of Connective Tissue 0:51 with the development of connective 0:52 tissue so it all starts when sperm 0:55 fertilizes an egg and becomes what is 0:57 called a zygote and then the zygote is 1:00 going to divide a lot and become a ball 1:02 of cells called a blastula and then the 1:05 blaster is going to keep dividing and 1:07 become what is called a gastrula and 1:10 already here you can see that the cells 1:12 are starting to differentiate you can 1:14 see that you can have an outer layer in 1:16 blue and inner layer in orange and then 1:19 a middle layer in green all right so the 1:22 outer layer in blue right here we call 1:24 this one the ectoderm 1:25 and the ectoderm is eventually going to 1:28 form things like the skin and nervous 1:30 system alright and the inner layer in 1:33 orange we call this one the endoderm and 1:36 from the endoderm you can have things 1:39 like the GI tract envelope the 1:40 gastrointestinal tract that’s gonna be 1:42 the gastric system and the dorms also 1:45 gonna form different glands in the body 1:47 and also respiratory tracts like the 1:49 Trangia bronchi and the alveoli of the 1:53 lungs but here in the middle of the 1:55 green one we call this one in the 1:57 mesoderm and the mesoderm can form 1:59 things like the mesenchyme 2:01 and the mesothelium the mesothelium is 2:03 gonna be a membrane of simple squamous 2:05 epithelium which develops into several 2:08 body cavities but what I wanted to get 2:11 to eventually is the missing 2:13 because that’s what’s going to form the 2:15 connected issue so the connective tissue 2:18 comes from the middle germ layer the 2:20 mesoderm alright and from the mesenchyme 2:22 is going to develop things like bone 2:26 cartilage tendons ligaments and capsules 2:30 for joints and even some hematopoietic 2:33 cells like the blood all right so if we 2:36 zoom in into that picture you’re gonna 2:38 see different nuclei right here you can 2:41 see nuclei here and here and all those 2:42 dark spots are gonna be nuclei and all 2:46 those cells are gonna be what we call 2:47 mesenchymal cells another thing you can 2:50 see when you look at them in the 2:52 microscope is that mesenchyme is gonna 2:54 have cell processes which forms and 2:57 network with each other and that network 2:59 that mesenchymal cells form is called B 3:02 as in qiyam alright and nothing gonna 3:05 see right here I’m gonna talk more about 3:06 it later but you can also see what we 3:09 call a ground substance between the 3:11 cells see it’s not gonna be an empty 3:13 space you’re gonna have what is called a 3:14 ground substance all right so these 3:17 mesenchymal cells form mesenchyme which 3:20 is an embryonic tissue because the 3:23 mesenchymal cells are gonna find them in 3:26 the embryonic development and if you 3:28 look at this picture right here and this 3:30 is what you literally see in the 3:32 microscope in the middle here is the 3:34 neural tube highlighted in blue but in 3:37 order to find these cells in order to 3:39 find the mesenchymal cells you need to 3:41 look at the sides of the neural tube 3:43 I’ll for you in green so if you ever 3:45 look at it in the microscope look at 3:47 this area right here you will find B 3:49 mesenchymal cells alright so now that we Classification of Connective Tissue 3:52 got the development sort out let’s look 3:54 at the different classification of 3:56 connective tissue as mentioned earlier 3:58 the different types of connective tissue 4:00 are gonna have a common origin that’s 4:03 going to be the mesenchyme right and we 4:05 classify connective tissue into 4:07 connective tissue proper and connective 4:10 tissue with special properties and 4:11 supporting connective tissue so if you 4:14 look a little in-depth in each of these 4:15 categories we’ll start with the 4:17 connective tissue proper and connective 4:19 tissue proper we can have loose and 4:22 dense going to do consisting mainly of 4:24 elastin and collagen 4:25 fibers loose is just loose and it’s 4:29 gonna be very easy to look at because 4:31 you’re gonna have different fibers 4:33 running in all different directions and 4:35 easy to find the ground substance and 4:38 the different nuclei in it and we’re 4:41 going to show you a picture of this 4:42 later but dense connective tissue can be 4:44 classified into a regular and irregular 4:47 dense connective tissue going further 4:49 with the connective tissue with special 4:51 properties also going to be the 4:52 superheroes of connective tissue because 4:53 those are gonna have different abilities 4:55 we can have adipose tissue out here 4:58 which stores energy in form of lipids I 5:01 will find both brown and white adipose 5:03 cells which I’ll mention later we’re 5:06 also gonna have a hematopoietic cells we 5:09 call this a fluid connective tissue from 5:11 which some blood cells are gonna come 5:13 from also connected tissues special 5:16 properties are the Elliston flexible 5:18 type of connective tissue I will find a 5:20 lot of these in lungs and and our tuft 5:23 and the skin I will also have the mucous 5:26 tissue composed of ground substance 5:28 alright I’m also going to have 5:30 supportive connective tissue consisting 5:32 mainly of cartilage and bones and only 5:36 by looking at all of this you can 5:37 already get a picture that a connective 5:40 tissue is not only going to be simple 5:42 connective cells it’s gonna be very 5:45 important because connected to strong 5:46 gun responsible for providing and 5:49 maintaining the form of the body it’s 5:51 gonna bind together and provide 5:53 mechanical support I also gonna support 5:56 metabolic defense transport and even 6:00 storage processes and it’s also gonna 6:02 support a boundary / actually an 6:05 inflammatory response I’ll get to that 6:07 later 6:08 so now let’s draw a little picture of Extracellular Matrix 6:10 what we’ll expect to see so up here you 6:14 can have apathy oh yeah with a basement 6:16 membrane and now let’s look at the 6:18 composition of connective tissue under 6:20 the basement membrane a connective 6:22 tissue is made up of cells as you see 6:25 here and also XSL your matrix the XSL 6:29 matrix is made up of fibers organic 6:32 ground substance found between cells and 6:34 fibers and also a fluid in which cells 6:37 and fibers are 6:38 suspended in all right so I want to 6:41 start by talking about the XSL error 6:42 matrix first and then go over to the 6:44 cells of connective tissue so as 6:46 mentioned earlier the XSL ER matrix 6:49 consists of fibers ground substance and 6:52 excess Ellery fluid and I want to start 6:54 with the fibers first so I mainly have 6:57 three types of fibers we have a collagen 7:00 and elastin fibers here we see a typical 7:02 picture of loose connective tissue as I 7:05 said it literally looks loose you can 7:07 see that both a collagen fibers and 7:09 elastin fibers gonna run all directions 7:11 all right you gonna have collagen right 7:14 here and Edison right here you can 7:16 already tell that these two are really 7:17 easy to tell apart because collagen will 7:19 be thicker than 7:21 Elliston are the third type of fibers we 7:24 have in the body are reticular fibers 7:26 I’m gonna talk more about this later but 7:28 one thing to notice here is that you’re 7:30 gonna always find these lose nuclei 7:33 looking at fibers the fibroblasts these 7:37 are actually what synthesizes the fibers 7:40 produces the fibers but in reticular 7:43 fibers in other hand you will have a 7:44 special type of fibroblast synthesizing 7:47 the reticular fibers called the 7:49 reticular sites so before I go into 7:52 these fibers I want to talk a little bit 7:54 more about the fibroblasts because it’s 7:56 really important to have a background 7:57 knowledge about fibroblasts before going 7:59 into the fibers alright so fiberglass as Fibroblasts 8:03 mentioned earlier is the predominant 8:05 self-type looking and connective tissue 8:07 fibers fibroblasts are going to 8:09 synthesize a proteins for ground 8:11 substance and fibers you can already see 8:13 them in this picture here you see the 8:15 fibroblasts and here you see the 8:16 different fibers and behind it you can 8:19 see ground substance or a so fibroblast 8:22 gonna have a lot of function is gonna be 8:23 important in different processes and 8:26 also unbound healing where they become 8:28 what is called Maya fart blast which 8:30 contracts the bound helping closing it 8:33 also important to mention is that 8:36 they’re gonna have many forms according 8:38 to where they are but you can’t really 8:41 see it here but they’re also gonna have 8:43 cell processes just like be missing I’m 8:45 I might add a picture up here showing 8:47 the cell processes of the fibroblast – 8:49 Illustrated Dense Connective Tissue 8:51 so if we go over and talk about the 8:53 dense connective tissue you will 8:54 immediately see that the fibroblasts 8:57 here are elongated they’re going to be 8:59 pressed against the adjacent fibers so 9:02 when we look at dense connective tissue 9:04 as I mentioned earlier we have regular 9:06 and irregular connective tissue 9:08 now you might already sense the 9:10 differences between these two in regular 9:13 dense connective tissue you can have 9:14 their fibrous run alongside each other 9:17 I’m gonna look nicer and you find these 9:19 in attendance for example but irregular 9:23 in the other hand they’re gonna run in 9:25 all directions and will mostly find 9:27 these in deep layer of the dermis or Dense Regular Connective Tissue 9:30 also let’s look at the dense regular 9:34 connective tissue a little bit to get 9:35 our broader picture of that in tendons 9:39 is a picture of a tendon right here 9:41 attendance consists of both collagen 9:43 fibers both dense and loose and there’s 9:46 actually a way to distinguish those two 9:49 looking at this picture and that’s by 9:52 looking at the nuclei of the fibroblasts 9:54 you know that collagen fibers are going 9:57 to be pressed together and that’s also 9:59 gonna press the fibroblasts making it 10:01 really thin and elongated and here in 10:04 the sides you can see that the nuclei 10:06 looks different it’s round so here must 10:09 be the loose connective tissue because 10:11 there’s no fibers that presses the 10:14 nuclei so this rod up here is a loose 10:16 connective tissue and in tendons and 10:19 they’re the same cell but in tendons the 10:21 fibroblasts that lies in collagen fibers 10:24 gets the name tender blasts and in Lewis 10:28 connected to sure they keep their name 10:29 fibroblasts so we also categorize the 10:33 thickness of the tendons by orders a 10:36 tendon can be up to ten orders I think 10:39 around there but just give you a little 10:42 picture of it the first order would be 10:44 between two tender blasts in collagen 10:47 and the second order would be between 10:50 two loose connective tissue across the 10:53 collagen fiber all right so if you go 10:55 ahead and cut the tendon right about 10:57 here and look at it in a transverse 11:00 section you’ll see that it looks like 11:02 this you will see the bundles of 11:05 collagen with their tender blasts 11:06 clearly with loose connective tissue in 11:09 between each bungling all right so now What are Collagen Fibers Made Up Of? 11:12 let’s look a little bit of what collagen 11:14 fibers are made up of so let’s say this 11:17 is a collagen right here and if you look 11:19 inside it if you continue this picture 11:22 right here you will see that the 11:25 collagen fiber consists of a lot of 11:27 small things those small things are 11:30 called the fibrils so every circle right 11:33 here is one febrile and fibrin is made 11:36 out of what is called microfibril and 11:40 microfibril is made out of through poor 11:43 quality and helix that make up the 11:45 collagen fibers so only by looking at 11:48 this picture can already tell that 11:50 collagen fibers are really really strong 11:52 and it’s really important to have them 11:54 strong in the our body because we need 11:56 to keep our different structures in the 11:58 body in place all right and we classify 12:01 collagen fibers in two different types 12:04 but before I talk about the different Suffixes of Cells -Blast, -Cyte, -Clast 12:07 colors and types I want to mention these 12:09 suffixes we use because looking at the 12:11 different types of collagen you’re gonna 12:13 see that different cells are gonna make 12:16 different collagen types so when you see 12:19 a cell and they meet blast blast is 12:20 gonna be a suffix they’re gonna mean 12:22 that this cells gonna produce a protein 12:25 for the matrix the remember matrix gonna 12:27 be a proteins for a fibers n and ground 12:29 substance and when you see the ending 12:32 site sight means that this cells gonna 12:34 maintain the matrix and clast is gonna 12:37 destroy the matrix so if we look at some 12:39 examples of these as I mentioned earlier 12:42 we have a fibroblast but you can also 12:44 see fibrous site and fiberglass those 12:47 are going to be the type of cell that 12:49 produces a fibers I’m going to have 12:52 osteoblasts or suicide and osteoclast 12:54 which are going to be the type of cell 12:56 that produces maintains and destroys 12:59 bone and you’re also gonna have a 13:02 chondroblasts chondrocyte and con 13:04 request those are gonna be the type of 13:06 cells that produces maintains and 13:09 destroys cartilage 13:10 all right so try to keep that in mind 13:12 during this video when you look at the 13:14 car players you’re gonna mainly see 13:16 a chondroblasts in the slide when you 13:18 look at fibers you can also find 13:20 fibroblasts and osteoblasts when you 13:22 look at bones alright so now let’s look Table for Collagen Fiber Types 13:26 at the different type of collagen fibers 13:28 we have if I recall correctly about 29 13:32 types of collagen fibers has been found 13:35 but here are some of the most important 13:38 collagen type fibers we have most of the 13:41 collagen fibers we have in the body are 13:43 going to be type 1 collagen and type 1 13:46 collagen the main function of this one 13:48 is that it’s resistant to tension and if 13:51 you try to imagine all the places that 13:53 all the time exposed to tension is going 13:55 to be the bones skin tendons ligaments 13:59 and internal organs and the cells that 14:02 produces the type 1 collagen will be 14:04 fibroblasts and osteoblasts and the next 14:08 type of collagen fibers I’ll talk about 14:09 is the type 2 collagen which is 14:11 resistant to pressure and if you imagine 14:14 what in the body are all the time 14:16 exposed to pressure that’s going to be 14:18 cartilage right the joints between bones 14:20 and here we have the chondroblasts 14:23 making the cartilage and the next type 14:26 is the type 3 collagen which is mainly 14:29 going to be found in internal organs 14:31 type 3 collagen is important in 14:34 maintaining the structure in organs and 14:38 the cells that produce type Theory 14:40 collagen are going to be fibroblasts and 14:42 reticular cells and as I talked about 14:45 the reticular cells I’m going to talk 14:47 about this later but reticular cells or 14:50 reticular fibers I’m gonna mainly be 14:52 type 3 collagen all right so the next 14:55 type of collagen we have is in the type 14:58 4 collagen and if you if you remember 15:01 from a particular tissue when you look 15:02 at the basal membrane at the basal 15:05 membrane consists of basal lamina and 15:07 reticular lamina the basal lamina 15:09 consists of type 4 collagen and here are 15:13 the epithelial cells muscle cells and 15:15 schwann cells are going to be are gonna 15:17 synthesize the attack for collagen and 15:20 the main function of the type 4 collagen 15:22 is support it supports the basal lamina 15:25 alright so the next type is the type 5 15:28 collagen 15:29 whenever you think of type five collagen 15:31 you can think of type one collagen 15:33 because you always find type five with 15:35 type one and the next one is type seven 15:38 and so a Type four makes the basal 15:41 lamina and type seven is what connects 15:44 the basal lamina with the reticular 15:47 lamina and here you can have an 15:49 epithelial cells they’re gonna produce 15:51 the type 7 collagen and a type seven 15:54 collagen as I said is what connects the 15:56 basal lamina with a reticular lamina so 15:59 this one’s going to be an anchor for the 16:01 basal lamina to underlying tissue 16:04 alright so the next one is the type 9 16:06 collagen whatever you think of type 9 16:09 think of type 2 because type 2 and type 16:12 9 will be together and type one and a 16:15 five are gonna be together 16:16 a’right so two and nine are important 16:19 numbers and one and five are important 16:22 number numbers and four and seven are 16:26 important numbers because these are 16:27 always gonna be together alright so the 16:30 next is the type 10 collagen fiber which 16:33 forms bones or supports bones a type 10 16:37 collagen fiber is synthesized by 16:39 chondrocytes and this one forms a 16:41 network inside the bone alright so Elastic Fibers 16:44 that’s what I wanted to talk about in 16:45 collagen fibers now let’s go ahead and 16:47 talk about the elastic fibers 16:49 elastic fibers has three types as you 16:52 see right here we have oxy Talon can be 16:55 found in the eye and also 16:57 stratified squamous epithelium of the 17:01 skin connects with the basal lamina 17:04 occipital and fibers are not elastic 17:06 because they don’t have any Alice teen 17:08 but they are highly resistant to pulling 17:11 forces because they contain strong fit 17:13 Berlin at twines so the next is the 17:17 Elenin consisting of a mixture between 17:19 elastin and the female in these are 17:22 mainly found in ligaments of the teeth 17:24 and also the connective tissue of the 17:27 dermis so the next is the proper elastic 17:31 fibers which also a consists of filling 17:33 and elastin but this one has a higher 17:35 amount of Ellison and this one’s 17:37 typically found in the water for example Reticular Fibers 17:40 alright so that is elastic fibers next 17:43 one is the reticular fibers and as I 17:46 mentioned earlier the reticular fibers 17:48 are mainly going to be a type 3 collagen 17:50 and the reticular fibers are made from 17:53 the reticular sites and the reticular 17:56 sighs I’m going to make a network and 17:58 support soft tissue such as the liver 18:01 the bone marrow and the lymphatic system 18:03 so if we look at this picture right here 18:06 this is gonna be a cross-section of the 18:07 lymph nodes in order to find the 18:11 reticular fibers we need to or it’s 18:13 easier to look at the reticular fibers 18:15 if you zoom into the lighter areas so if 18:19 we go ahead and look at the one of the 18:21 lighter areas this one for example you 18:23 will see that it looks like this and 18:25 just on only by looking at this picture 18:27 it’s really messy let’s try to organize 18:31 a little bit so if you remember what 18:33 cells do you find most in the ferric 18:36 system that’s gonna be a lymphocytes 18:39 right so a lymphocytes are gonna be you 18:42 know you see those dark nuclei dark dark 18:45 rounded nuclei right here with a small 18:47 cytoplasm all those all those cells are 18:51 going to be lymphocytes but in order to 18:53 find the reticular sites you need to 18:55 look really closely because 18:56 reticulocytes I can have self processes 18:59 so their cytoplasm are gonna be more 19:02 than the lymphocytes and their nuclei 19:05 are gonna be lighter so if you look 19:07 closely you can have this one for 19:09 example you can see that the 19:11 clea of this one is lighter and you can 19:13 also see the cell process right here so 19:15 this is our reticulocyte and I also find 19:18 one here for example these processes in 19:21 this light nuclei and this one’s also a 19:23 reticular site and and this one’s also a 19:27 reticle site and here we see one as well 19:29 and here you see one as well alright so 19:32 you really have to sharpen your eyes to 19:34 see the reticular sites so if we zoom in 19:36 to another place in the same slide 19:38 you’ll see this one can you pause the 19:41 video and try to differentiate the 19:44 reticulocytes from the lymphocytes and 19:46 then I will try to look for some and 19:50 myself all right so here you can see one 19:54 a reticle side because you can see there 19:56 what the light nuclei and the cell 19:58 process isn’t here is he one as well and 20:00 see if I can find some others here is 20:03 see one as well and here you see one as 20:05 well and you can also see you one right 20:08 here you can see the nuclear lighter and 20:10 you also see the self processes right 20:11 here now right so that’s how you 20:14 differentiate the reticulocytes from the 20:16 lymphocytes and the reticulocytes I’m 20:18 gonna synthesize and form the reticular 20:20 fibers alright so the next thing I want Ground Substance 20:23 to talk about is a ground substance and 20:25 the ground substance if you’re if you 20:27 remember from which I mentioned earlier 20:29 lies between the fibers and the cells or 20:31 it fills the space between them and the 20:34 good thing in having the ground 20:35 substance is that it acts as a lubricant 20:38 for fibers in cells and also acts as a 20:40 barrier for invaders 20:41 so in grant’s substance you can have a 20:44 fluid from which cells and fibers are 20:46 suspended in together with minerals 20:50 you’re also going to have different 20:51 proteins you can have three different 20:53 proteins I wanna mention the first one 20:55 is AG liqui I mean nuclear cons 20:57 the glucosamine equal cons are gonna be 20:59 long and unbranched of repeating 21:03 disaccharides and then the next one is 21:05 the proteoglycans this is a protein 21:08 course to which glycosaminoglycans are a 21:11 link to and also the third one is the 21:14 adhesive glue Co protein which are large 21:17 macromolecules responsible for fastening 21:21 different components of the 21:23 extracellular matrix together 21:25 so if when whenever you think of milky 21:27 adhesive glue copper teen just think of 21:29 glue because that’s what you can do is 21:31 gonna connect different parts of the 21:33 matrix together and one more thing I 21:37 wanted to mention I want to talk about 21:38 the ground substance is that you’re 21:40 gonna have an enzyme in the ground 21:42 substance called the mate matrix 21:44 metalloproteinase ER this one is a type 21:47 of peptidase are degrading different 21:49 types of excess cellular matrix proteins 21:52 so this one is really important when it 21:55 comes to regulating at the different 21:57 proteins in the ground substance alright Cells in Connective Tissue 21:59 so that is the ground substance and the 22:01 next thing I want to talk about is the 22:03 cells in in connective tissue and the 22:07 cells in connective tissue and wanted to 22:09 talk about is the macrophage must cell 22:11 plasma cell adipocytes so let’s start 22:14 with the macrophage the macrophage comes Macrophage 22:17 from the bone marrow and this one when 22:20 is in the blood it circulates as what is 22:22 called the monocyte and then when it 22:25 enters the tissue it becomes a 22:28 macrophage so whenever you think of 22:31 macrophage just think of pac-man because 22:33 that’s what they can do is gonna go 22:34 around the tissue end and if phagocyte 22:37 or eat different stuff that’s not 22:39 supposed to be there and and then 22:41 present it to other white blood cells to 22:44 include them in the battle and so when 22:47 you look at them in the microscope 22:48 macrophage are characterized by the 22:50 nuclei you can see that this nuclei is 22:53 is being shaped right and if you look at 22:57 from a from another picture now again it 22:59 looks really messy but if you try to 23:02 sharpen your eyes again you can see this 23:05 cell for example this one has our bean 23:06 shape so this is a micro phage and this 23:10 one right here is micro fiche as well 23:12 this is a bean shape and this one right 23:14 here and and you have one right here 23:16 also so that’s how you differentiate the 23:18 macrophage alright so the next thing Mast Cell 23:21 I’ll talk about is a mast cell a mast 23:23 cell are really easy to differentiate 23:25 also these are large cells and have many 23:28 granules in the cytoplasm containing 23:30 histamine heparin when a mast cell is 23:33 triggered by an antigen histamine is 23:36 secreted and when histamine is 23:38 created increases the capillary 23:40 permeability so that sales can arrive 23:44 and enter the inflammation area easily 23:47 and also when mass cell is triggered is 23:50 gonna contract the bronchioles 23:52 histamines our major reason for 23:54 allergies because they cause 23:57 inflammation where they are exposed to 23:59 antigens of something you’re allergic to 24:02 so the pills you take against allergic 24:05 the allergic pills are usually of 24:08 antihistamine alright so that’s how they 24:11 look like in the microscope and if you 24:13 look at it another picture you can see 24:14 they can also be really dark right here 24:17 because they contain a lot of granules 24:20 so a Dallas must sell the next thing is Plasma Cells 24:23 the plasma cell and the plasma cell 24:25 arrives from Bethel emphasize and what 24:27 does that mean that means that remember 24:29 when I talk about the macrophage 24:31 presenting the antigen to different 24:33 cells and it’s kind of a cascade 24:36 reaction so you can have better 24:38 lymphocytes that are presented to the 24:40 antigen and then the beta lymphocyte is 24:42 gonna make the plasma cell and the 24:45 plasma cell is gonna synthesize 24:46 antibodies against that antigen the beta 24:49 lymphocyte was presented to and if you 24:53 look at it in the microscope you can see 24:55 the plasma cell looks like this you can 24:57 see that they would call this a 24:59 cartwheel nucleus because the nucleus 25:01 literally looks like a cartwheel you’re 25:04 gonna have the nucleolus right here and 25:06 the arrow chromatin in the middle and 25:08 then I’m a big cytoplasm right here 25:11 alright so here’s another picture as 25:13 well here you can see the plasma cell 25:15 you can see the cytoplasm right here and 25:17 the nuclei is is big and it’s dark 25:19 around the edges and the middle is is 25:21 kind of light so that’s another way to 25:23 to differentiate look for in the center 25:26 should be light and around it should be 25:29 darker alright so the next thing I White Adipocytes 25:32 wanted to talk about is the white 25:34 adipocytes and adipocytes are really 25:38 easy to see because they have a big 25:41 lipid droplet inside them you see right 25:43 here those those spaces right here are 25:46 the lipid droplet inside the cell these 25:50 type of cells are going to be the fats 25:52 or the energy storage which are a burned 25:54 later when we need them and at the sides 25:57 of the and at the sides of each cell 26:00 you’re gonna see that the lipid droplets 26:02 store right here in cytoplasm and 26:03 because the lipid droplet is big it’s 26:06 gonna push the nucleus of the atom aside 26:09 to the side so that you can seem on each 26:11 a cell you can see the nucleus of the 26:14 Oedipus ID at the at the corner right 26:16 here you can see it right here you can 26:17 see in here you can see it here and here 26:20 all right and the other besides is what 26:23 we call subcutaneous tissue because they 26:25 lie under the skin and this is what we 26:28 call white fat because it looks white 26:31 and it’s it’s a primary fat we have in 26:33 the body and this is another picture to 26:34 kind of show you how they look like in 26:37 the microscope you can have the lipid 26:38 droplet here and there in the in the 26:41 cytoplasm and the nucleus is pushed to 26:44 the side right here alright and another 26:47 type of episode we have is a brown ad Brown Adipocyte 26:49 beside so we are first when we are first 26:51 born we do have a decent amount of brown 26:54 fat within us but as adults we more or 26:58 less get rid of that brown fat and we 27:01 call the brown fat Brown because they 27:03 literally look Brown underneath the 27:05 microscope it looks like that because 27:07 they have a lot of mitochondria within 27:10 the cytoplasm you can see the lipid 27:13 droplet here and you can see the the 27:15 cytoplasm of the adipocytes 27:18 is brown and not only in the lipid 27:21 droplet is also going to be a little 27:22 darker than the white adipocyte and 27:24 here’s also another picture to show you 27:26 you see the brown cytoplasm in the 27:30 adipocytes alright so that was all the Quiz Yourself 27:32 structures I wanted to talk about in the 27:34 connected issue now just to challenge 27:36 you a little bit here we see a pic three 27:38 pictures of a different types of 27:39 Canadians you could you post a video and 27:42 tell me all the cells you see in these 27:46 pictures and I’m going to reveal the 27:49 answer in three two one 27:51 there you go so that is the answer here 27:54 you see the lose connected tissue with 27:56 elastic fibers right here the thin ones 27:59 that run all directions and the behind 28:01 here the thick ones you can see the 28:03 collagen fibers and the fiberglass 28:05 are they gonna see fibroblasts between 28:08 the fibers and the background here you 28:11 can see ground substance and here is a 28:14 dense regular connective tissue bundles 28:17 in at the tendon these are tender sites 28:19 and here in white you can see loose 28:22 connective tissue between them with the 28:24 fibroblasts and this right here is a 28:26 reticulocytes and lymphocytes here see 28:28 here we see the lymphocytes and the 28:31 reticulocytes are here for example and 28:33 here we see one and here we see one as 28:36 well alright so that was a video about 28:39 the connective tissue and I hope this 28:40 was helpful