Biology GIFT (GOSALITES INTERMEDIATE FOUNDATION TUNING PROGRAMME) | Dr.SIDDHARTH YADAV Sir - DAY - 5

Ajouté : 2026-05-07

[00:00:00]All the students on Zoom and YouTube.

[00:00:03]Good evening to all of you. I hope you are having a very fantastic day today.

[00:00:08]After your results, I think now your anxiety level will be little less. Your cortisol, your adrenaline will be little settled down right now. Your heart rates would be around in the normal rate.

[00:00:22]Yeah.

[00:00:26]Good evening. Good evening. Good evening, people. Good evening. Good evening. Good evening.

[00:00:32]Shall we start? Okay, everyone audible, visible, perfectly, all fine?

[00:00:39]Audible and visible, guys? Good evening.

[00:00:41]Good evening. Good evening. I hope I am audible and visible. So, let us quickly start. You can see on the screen.

[00:00:49]We will [snorts] be starting with little bit of question-answer session.

[00:00:53]I will be asking you some basic MCQs. Whatever we have studied yesterday.

[00:01:00]So, I like to have a habit of revising little bit of the last class so that to check every student is revising, not revising. Even though it has to be habituated for all the other classes as well and the other subjects.

[00:01:18]So, let us start without wasting the time.

[00:01:21]We will have the first question. So, I hope that everyone has revised yesterday's topic. You have gone through it. You have made certain notes about it.

[00:01:31]Okay? Chalo.

[00:01:33]Uh sir, can you give MCQ in this class also, sir? Yeah. Every Sunday then there will be exam. Few MCQs we can do in the classes as well. Okay? Sometimes we do, sometimes we don't do.

[00:01:46]So, it's on and off practice, but it's a very healthy practice to check suddenly if you are studying or not. Okay, so let's see the first question on your screen.

[00:01:58]Which of the following is an example of unicellular gland found in the elementary canal? Come on.

[00:02:07]Everyone, let's start. I think 5 seconds you will require for this.

[00:02:13]Which of the following is an example of unicellular gland found in the elementary canal? Option A, salivary gland. Option B, goblet cells. C, pancreas. And D, the sweat gland. Okay?

[00:02:28]So, shall we lock? Many people are commenting tremendously here. Option B.

[00:02:34]So, right answer is option B, goblet cells. So, you might be thinking, "Sir, what are you asking, sir? Very easy question you are asking, sir."

[00:02:44]It's a very easy one. So, let me tell you a small fact.

[00:02:49]In the NEET UG examination out of the total 90 MCQs which are asked throughout the botany and zoology some 60 to 70 questions, at least 60 to 70 questions can be solved in 30 to 45 seconds.

[00:03:09]30 to 45 seconds.

[00:03:11]Some questions will be little tricky. That may take second, third reading, reading carefully, again analyzing your thoughts. But the maximum questions will be easy pickings, easy scoring the marks.

[00:03:27]Okay? So, that you have to keep in mind.

[00:03:30]This will be also applicable to the students who are going to appear day after tomorrow. I think everyone knows the NEET examination is there, right? Now, they are nervous. They are very anxious. Now, their heartbeat is racing. Cortisol, adrenaline level, and yes, the teachers also are little worried about them, but more than worried, I am confident they are going to do very well. Okay?

[00:03:55]Now, moving ahead.

[00:03:57]Next question about the duct system.

[00:04:01]Glands that pour their secretion through ducts are known as which glands? Option A, endocrine glands. Option B, heterocrine glands. Option C, exocrine glands. Or option D, that is compound glands. What will be your answer, guys? Come on, quickly.

[00:04:23]In the ducts, in the ducts.

[00:04:27]So, here the secretion is not poured in blood. It is poured inside the duct.

[00:04:34]So, but obvious, it is not going in the blood. So, answer will be what, guys?

[00:04:39]Tell me. Here the answer will be quickly. Come on. Let's see the answer.

[00:04:42]Quick answer. Here it is poured in ducts.

[00:04:46]In ducts, who are pouring? Exocrine glands. Which glands, guys? Exocrine gland. Now, if I change this question to blood at the place of duct, if I write blood here, what you will answer?

[00:05:01]If I change the question and I write there as blood, that which glands are going to pour in blood, then what you will answer? Then the answer changes into endocrine. If I change the question to blood and duct both blood and duct both if I write blood and duct both if I write, then what you will say?

[00:05:26]Then it will be heterocrine gland. Then it will be heterocrine gland. So, see, guys, whenever you are solving the MCQs, as you start your journey of the NEET preparation, remember out of the four options, one is the answer for the particular question which is being asked. But think about the other three question options also when the possibility it can also become answer.

[00:05:50]So, if you start doing that by solving one question, you are actually probably solving two or three more extra questions. So, that habit also we have to be applied.

[00:06:02]Okay? Are we clear? Moving ahead, guys.

[00:06:04]Next question. Come on, let's see the next question quickly.

[00:06:08]The pancrea is classified as heterocrine gland. Why it is classified as heterocrine gland? Is it only endocrine?

[00:06:18]Is it only exocrine? Is it performing both the functions? Or is it made of compound epithelium? Come on.

[00:06:27]Just now gave the answer. In the before previous question we just discussed that the answer will be here both exocrine and endocrine.

[00:06:37]At the place of pancreas, at the place of pancreas if I write testes, at the place of pancreas if I write ovaries, then also answer will be C only. So, here it can be pancreas, it can be testes, it can be ovaries as well, because all three glands are becoming the heterocrine glands. Are we clear with this?

[00:07:05]Yes, everyone? Shall we go to the next question? Come on. Let's go to the next question. Two more questions, let's see.

[00:07:12]Compound epithelium consist of two or more layer of cell.

[00:07:16]What is its primary function? Why it is two or more layer of cells? Why it is two or more layer of cells?

[00:07:35]>> [laughter] >> Why there are two or more layer of cells? So, very simple.

[00:07:47]Two or more layer of cells, they are not going to do a lot of secretion, absorption function we studied. They are not also going to help in filtration, diffusion also a lot. So, mostly they are for protection against the mechanical and the chemical stress.

[00:08:06]Protecting against wear and tear. Okay?

[00:08:08]So, what is the right answer? B. Option B, protection against chemical and mechanical stresses. Are we clear?

[00:08:17]Yes, guys?

[00:08:19]Moving ahead. Last question of the day.

[00:08:23]Which type of glandular epithelium is formed by cluster of cells? The cell word is little hidden there. I have to rewrite that. Okay, some alignment problem has occurred. Cluster of cells.

[00:08:40]>> [clears throat] >> Easy question.

[00:08:42]Easy peasy lemon squeezy. Come on. Is it a unicellular gland? Is it a simple squamous epithelium? Is it a multicellular gland? Or is it simple columnar epithelium? What is the answer, guys? The answer is multicellular gland. The answer is multicellular gland. Option three is the answer. Or option C is the answer. Are we clear with this, guys? So, yeah, many students are giving correct answer.

[00:09:10]So, thank you. I think you are revising.

[00:09:13]Okay? Now, let's move on to our next topic. Come on. So, a lot of quiz quiz is done now. Now, we will move move to our topic.

[00:09:24]We have to go and start learning about the connective tissue. Shall we start, guys? Come on.

[00:09:32]Okay, everyone ready?

[00:09:34]Now, let us start with the connective tissue. So, yesterday before ending the class, I showed you this picture, right?

[00:09:43]This is a histological image. Study of tissue is histology. So, this is a histological image of connective tissue.

[00:09:53]And we guessed it that it is a connective tissue slide. It is a slide of connective tissue.

[00:10:01]And I said the dark colored cells what you are observing here, what are these dark colored structures I told you? Tell me guys.

[00:10:10]What are these dark colored structures?

[00:10:12]What are these?

[00:10:13]What are these? Tell me.

[00:10:16]These will be nothing but your cells.

[00:10:21]This will be nothing but your cells.

[00:10:23]Okay? Now surrounding the cells, surrounding the cells on the background if you see the light colored background, the light pink colored background which you see.

[00:10:35]Sir, it means that our cells are dark pink and pink color. No, no, no, no, no.

[00:10:40]It's not pink color. It is the stain which has been used to color the cell or to color the ground substance behind it. So basically the hema- hematoxylin stain which we are using to stain the tissue, that is giving the color. So remove that in your mind that your connective tissue is pink in color and other tissues are different color. It's not a rainbow inside. Okay?

[00:11:08]So moving ahead, these are the cells and in the background what you see, in the background what you see, it is the matrix.

[00:11:19]Background what you see is the matrix.

[00:11:24]Okay?

[00:11:26]Actual color it is colorless, beta.

[00:11:28]Actual color it is colorless. You'll not be able to see. That's why we are staining. Okay?

[00:11:33]So there is outside matrix. Now you only tell me what is a tissue made up of.

[00:11:41]How we define tissue? Tissue is made up of group of similar kind of cells doing a common function and along with what is present in between the cells, what is present?

[00:11:54]In between the cell there is presence of intercellular substance. What substance?

[00:12:01]Intercellular. These are some cells.

[00:12:03]These are some cells. In between them the space is called as intercellular space. The space between two cells is intercellular space. In that space what is there? In that space matrix is there. What is the another name of matrix? Matrix can be also called as intercellular substance.

[00:12:27]Matrix can be also called as intercellular substance or it can be also called as ground substance. It can be also called as ground substance or you can use one more word, extracellular substance.

[00:12:43]You can also use one more word, extracellular substance because other than cell it is extra. So extracellular, outside cell extracellular substance. Are we clear with this? So these terminologies little bit little when you revise again and again, this will get fixed in your mind. Okay? Are we clear?

[00:13:06]So any tissue is made up of cells. Okay, there are cells.

[00:13:11]Then there is matrix being formed. Sir, where did this matrix came from?

[00:13:17]The cells are there. Okay.

[00:13:20]But where did the matrix came from?

[00:13:23]Who produced the matrix? Now the question mark. Who produced the matrix, sir? Who made this intercellular substance? Who made this? The cells made them. Who made them? Cells made them. So cells are actually producing the matrix.

[00:13:39]They are synthesizing and secreting the matrix or you can say the ground substance or intercellular substance.

[00:13:48]Are we clear?

[00:13:50]Now while going yesterday's at the ending of the class, what did I say here?

[00:13:57]Are there many cells in connective tissue or are there few cells in connective tissue? Tell me. In a connective tissue there are many cells or there are few cells? What you will say?

[00:14:12]Are there are many cells or there are few cells? Come on. Yes, there are few cells.

[00:14:21]Number of cells are lesser as compared to epithelial.

[00:14:25]It is not a barrier by the way.

[00:14:27]Epithelial made the barrier you need to add a lot of cells. But this is not making a barrier. So here there are few cells.

[00:14:35]If cells are less then the space is more.

[00:14:41]More space is there.

[00:14:43]So we will say intercellular space.

[00:14:47]The space surrounding the cell is more.

[00:14:50]If space is more then inside that space ground substance or matrix will be also more.

[00:14:59]Do you agree? Cells are lesser in number. Matrix is more in number.

[00:15:06]Okay? This is a feature. What is this?

[00:15:08]This is a feature of connective tissue.

[00:15:11]Are we clear?

[00:15:12]Are we clear? Achha, tell me what about the vascularity? Tell me what about the blood supply? We studied that epithelial tissue has a lesser has a lesser no blood supply. What I'm speaking?

[00:15:26]Epithelial tissue is avascular. No blood supply. That was a important characteristic feature.

[00:15:34]Whereas in connective tissue blood supply is tremendous. Highly vascular word I will use. What I will use? I will use highly vascular word. Okay? So let us go on the slide and see one by one what are the features. Okay? So let us go ahead.

[00:15:54]Okay?

[00:15:56]So come on, read the point. Are you able to read? Connective tissue possesses relatively few cells.

[00:16:04]Relatively few cells and widely separated from each other.

[00:16:10]Cell number are less and everyone everyone is living in you know, two two BHK room or everyone is living in a villa. They have a full space of a villa for themselves. So lot of space is there.

[00:16:25]And in that space what is filled? In that space what is filled? In that space lot of intercellular substance matrix is present. Okay? What is present? These living cells are responsible. These living cells are responsible. All these cells are responsible for secreting large amount of intercellular substance.

[00:16:51]That is also called as ground substance.

[00:16:53]That is also called as matrix. Are we clear with this, guys? Very easy.

[00:17:00]Sir, blood is a connective tissue? Yes, beta. It is a connective tissue. We are going to discuss the classification also of the connective tissue. So hold your horses. Okay? We will talk about that as well. Okay? Moving ahead.

[00:17:15]What is matrix?

[00:17:17]Let's see what is matrix made up of.

[00:17:20]Basically matrix is a non-living material.

[00:17:24]Matrix is a non-living material. Tissue is living.

[00:17:28]Tissue is made up of cells but the cells are secreting the matrix.

[00:17:33]Okay? The cells are secreting matrix which may be liquidy.

[00:17:41]The matrix might be liquidy like in blood plasma.

[00:17:46]In blood there is blood cell and blood plasma. But plasma is very watery.

[00:17:51]And you have to keep it like that then only the blood will flow. Then only the blood will flow. So the matrix of the blood is liquid in nature or fluid in nature so that it can flow.

[00:18:04]Whereas talking about connective tissue, areolar connective tissue, adipose tissue, how they will be? Will they be very liquidy? No, they are not liquidy or fluid. Basically they are semi-solid.

[00:18:20]They are semi-solid.

[00:18:22]Talking about cartilage, cartilage your ear pinna, your nose tip, that is little solid. Not semi-solid, solid.

[00:18:34]Your cartilages. But talking about your bone, your bone is solid and hard. It is quite solid and hard. So what do we understand here, sir? We understand that changing the matrix nature, changing the nature of matrix, you can get different different types of connective tissues. You can get different different types of connective tissue. Bone is a connective tissue.

[00:19:03]Cartilage is a connective tissue. Blood is a connective tissue. Tendon is a connective tissue. Ligament is a connective tissue. And everyone's matrix if you see, everyone's consistency if you see, it is different.

[00:19:17]Why it is different? Because it depends upon the matrix. It depends upon the ground substance what the ground substance is made up of.

[00:19:27]And very very important, very very important component in connective tissue, we are going to speak about fibers. What we are going to speak about? Fibers. So now there is entry of fibers. So connective tissue is basically made up of three things.

[00:19:46]Cells. All tissues are made up of cells.

[00:19:50]Second, matrix ground substance. And the third part will be fibers. The third part will be the protein fibers. Are we clear with this, guys? Yes? See what I have written?

[00:20:06]Embedded in the matrix. Inside the matrix only. Inside the matrix, there are varieties of connecting and supporting fibers. These fibers are proteinaceous in nature. They are made up of proteins. Which are the two main types of fibers we have to focus on? We have to focus on two main fibers, collagen fibers and elastic fibers.

[00:20:32]Collagen fibers and elastic fibers. Are we clear with these points, guys? These are the important characteristic features. Okay, to summarize, how we can summarize this thing, guys? Tell me quickly. How we can summarize this?

[00:20:49]Okay? So, we have the connective tissue.

[00:20:53]ठीक है?

[00:20:55]And we are saying it is made up of three components. We are saying it is made up of three components. The first component is the cells. The second component is the matrix.

[00:21:08]Yo.

[00:21:09]And the third component which we are saying is the fibers.

[00:21:15]The third component what we are saying are the fibers.

[00:21:18]ठीक है? There is cells, there is matrix, and there is fiber.

[00:21:23]Who secreted matrix?

[00:21:25]Who secreted matrix? Who secretes matrix? Cells only.

[00:21:29]Who secretes fibers?

[00:21:31]Who secretes the fiber? The fiber is also secreted by the cells only.

[00:21:36]So, the matrix and the fibers both are secreted by the cells of the connective tissue. Sir, but will one cell will do everything?

[00:21:49]No. There are different different cells.

[00:21:52]So, different cells we have to study.

[00:21:54]What are the different cells in the connective tissue? And if you change the connective tissue, in bone the cells will be osteocytes. In cartilage, the cell will be called as chondrocytes.

[00:22:04]Yes? Everywhere commonly you can observe fibroblast cells because they are making the collagen and elastin fibers, except the blood because in blood you don't want the fibers. So, like this we are changing the different cells. Okay? But, remember always the connective tissue is made up of cells, matrix, and fibers.

[00:22:27]Only one exception is there. Only one connective tissue is there where there will be no fibers. What did I tell you?

[00:22:35]What is the exception? The exception will be blood. The exception will be your blood. The exception will be your blood. In blood, we will not be having fibers. Otherwise, all the connective tissue we can have the fibers. Are we clear with this, guys? Shall we go ahead? Okay, understood this point? ठीक है? Moving ahead.

[00:23:04]>> [cough] >> Okay.

[00:23:08]So, let us start.

[00:23:10]Connective tissue.

[00:23:13]In [snorts] all connective tissue, not from this slide, I think we came we jumped a little bit. Yeah.

[00:23:19]Connective tissue. Okay? Why we are calling them as connective tissue?

[00:23:25]Why we call connective tissue as connective tissue? Why? Because their name connect.

[00:23:32]To connect different tissues.

[00:23:35]So, you will never find connective tissue on the surface.

[00:23:39]Do you find ever connective tissue on the surface? Will you find them on the skin? Will you find on your elementary canal, digestive tract, reproductive tract lining? No. So, can I say connective tissue ever makes the lining of the organs?

[00:23:55]Or the external layer of your body?

[00:24:00]Is it making any lining? No. It will be always sandwiched between two tissues.

[00:24:08]Like you are going not going to put the tomato outside the sandwich. You the tomato or the cucumber will be always in the bread only, you know, between the breads.

[00:24:18]Yeah? So, here also the connective tissue is a binder kind of a tissue which binds and holds the two different tissues together. Like simple example, what is this tissue here?

[00:24:34]On your body surface, what is the tissue here?

[00:24:37]What is the body tissue here? Skin, epithelial tissue. Skin is epithelial tissue, correct? Now, below the skin, do you have muscles? Do you Do you have muscles? Yes or no? So, who will connect the epithelial tissue to the muscles?

[00:24:55]Who will connect the epithelial tissue to the muscles? Epithelial tissue is your skin. Beneath your skin, you have muscles also. But, in between that, between skin and between muscle, there is a tissue which you call as the loose connective tissue. Which you call it as what? Loose connective tissue. And one of the types of loose connective tissue is areolar connective tissue which is going to be there.

[00:25:23]But, obvious, little bit fatty tissue also going to be there. Okay? So, if you are very much healthy, there will be a little bit more of adipose tissue, the fat cells. And if you are lean enough, then you might be having a little bit lesser adipocytes. Are you getting me, guys?

[00:25:42]So, connective tissue always connects.

[00:25:45]Like if I ask you, who connects? Like this is the biceps muscle, okay? The biceps muscle is attached to the humerus bone here. It is attached to my arm bone. So, who is connecting the muscle to the bone?

[00:25:59]What tissue you use the word? Come on.

[00:26:01]Have you read that in your lower standards? Tendon you might have heard.

[00:26:05]Tendon, tendon, tendon. When you are eating your chicken and all, ठीक है?

[00:26:10]Then the last part you are tearing it little bit, little difficult. Okay, sorry for the vegetarian people. Okay?

[00:26:18]So, basically you are tearing the tendon. So, tendon is also a connective tissue which is connecting the muscle to your bone. Or I can say ligaments which connect the joints together. Okay, your elbow joint, your knee joint, so many joints in your body, they are protected.

[00:26:38]They are connected, reinforced by what?

[00:26:41]The ligaments which are holding your joints and securing your joints so that you don't slip your joint. Dislocation should not occur.

[00:26:50]And similarly, one beautiful tissue which is roaming everywhere in your body. Roaming everywhere in your body, constantly it is roaming in your body, delivering one substance to other part, other substance to other part. Yes? Can you tell me which substance I am telling? Which tissue I am telling which is continuously roaming here and there?

[00:27:11]That is your blood. So, see, connective tissue, what what does it do? The name has the function, to connect. To connect the different tissues. So, connective tissues are named so because of their special function of linking and supporting other tissue or organs of your body. Are we clear with this? ठीक है?

[00:27:34]They range from different different types. There are certain soft connective tissue. Like areolar, adipose. They are soft.

[00:27:46]But, some are specialized.

[00:27:49]Which are the specialized one?

[00:27:51]Cartilage, bone, adipose, and blood will become the specialized type. Okay, so let's try to classify here. Let's try to classify the connective tissue. Like how you classified epithelial into simple and compound. Then in simple, you studied based on the structure, squamous, cuboidal, and columnar. Now, what we will do is now we will see the classification of connective tissue.

[00:28:16]Okay? So, let's see that quickly.

[00:28:19]The classification of connective tissue.

[00:28:22]Here it is.

[00:28:24]You can see here.

[00:28:26]Okay, everyone? Clearly visible?

[00:28:29]Clearly visible? Connective tissue can be classified into three types.

[00:28:35]So, whenever you do any classification, like like you classified the epithelial tissue, what was the basis? On which basis you classified epithelial? Single layer, multiple layer.

[00:28:47]Later, you classified simple epithelium based on structure and shape of the cell. Flat, cuboidal, columnar, ciliated, brush bordered. Here, on which basis you will classify? So, I will just write down here. The basis of classification is What is the basis of classification?

[00:29:09]The basis of classification is basically the nature of matrix.

[00:29:18]What, guys? The nature of matrix.

[00:29:23]We will say the nature of matrix.

[00:29:27]The nature of matrix means is the matrix soft?

[00:29:32]Okay, or jelly like? Or is it semi-solid? Or is it solid? Or is it hard? Or it is liquidy, fluid like?

[00:29:42]So, nature of the matrix changes depending upon the tissue. Then, it can be also classified on the basis of cells, yeah, and the amount of fibers.

[00:29:55]And the amount of fibers.

[00:29:58]And the amount of fibers. Like when I say the muscle is connected to the bone via tendon, tendon has to be very strong.

[00:30:10]Similarly, when ligaments are securing your joints, bone to bone is connected by ligaments, they have to be very strong.

[00:30:19]Amount of fibers will be more. So, some tissues have a lot of fibers.

[00:30:26]Some tissues are having sparse amount of fiber. Sparse meaning sparsely means very less quantum fibers.

[00:30:34]Because that will be enough.

[00:30:36]But some tissues like blood, you don't need any fiber at all. Fiberless. Fiber not required there. Okay? So, generally you see the fiber, but the orientation of the fiber, the concentration of the fiber, the amount of fiber, and the orientation, and its presence or absence will change the tissue. So, based on this we are classifying them into loose connective tissue, dense connective tissue, and specialized. As you can see, now apply your common sense and tell me. Apply your little bit common sense and tell me. In loose you will have less fibers or more fibers? Or in dense you will have less or more fibers?

[00:31:23]Come on, tell me. Loose will have more fibers or dense will have more fibers?

[00:31:28]First tell me who has more fibers, dense or loose?

[00:31:32]Sir, we don't know, sir. You tell us.

[00:31:33]Just apply. What is the meaning of dense?

[00:31:36]What is the meaning of dense? Dense means too much packed. Like India is a densely populated country.

[00:31:45]Per square kilometer everyone is living tightly. We are like epithelial tissue.

[00:31:50]Tightly packed.

[00:31:52]So, densely means more amount of fibers.

[00:31:58]Loose connective tissue is having sparse amount of fibers, less amount of fibers.

[00:32:04]Are we clear with this? In specialized, specialized they change. Like blood is specialized, no fibers.

[00:32:12]Bone, the matrix is very hard, mineralized, calcified, too much strength is there, strong collagen fibers are there. Ligaments, little bit elasticity is there. Okay?

[00:32:26]So, what I will do, I will write down the names. You also write down. Loose connective tissue, you are going to study areolar connective tissue here.

[00:32:36]What you're going to study? Areolar connective tissue. In loose connective tissue, the first tissue you're going to study areolar connective tissue. And areolar connective tissue is the most important connective tissue in our body.

[00:32:51]Areolar connective tissue is the most important connective tissue in the body.

[00:32:55]Everywhere it is working like a glue. It is working like a glue. So, wherever your skin is there, your skin is attached to the inner parts, the lower tissues inside, via the areolar connective tissue. Inside you are having lining mucous membrane lining, that is also epithelial. That is also connected to the internal tissues via areolar.

[00:33:23]And one thing I can also say, areolar is the widely widely means present everywhere.

[00:33:31]And the most abundant connective tissue in your body.

[00:33:36]Okay? Most widely and abundant connective tissue in your body. Okay, moving ahead. Dense. In dense what we are going to study?

[00:33:45]In dense connective tissue we are going to study regular dense and irregular dense.

[00:33:52]Regular dense and irregular dense.

[00:33:57]Regular dense and irregular dense.

[00:34:00]Regular, irregular. So, what is the meaning of regular, irregular? It is depending upon the orientation of the fibers.

[00:34:08]Fibers are properly parallelly arranged, then it will be called as a regular dense connective tissue.

[00:34:17]And the fibers are not having a orientation, they are randomly arranged, then we will call them as irregular connective tissue. Now, tell me, tendon and ligament where you will place them?

[00:34:28]Tendon and ligament, will you place place them in regular dense or you will place them in irregular dense?

[00:34:35]Where you will place the tendon and ligament?

[00:34:40]They are very thick fibers. They are very thick tissues. They are regular.

[00:34:45]They are regular. In regular you will study two, that is tendon and ligaments.

[00:34:56]Tendon and ligaments we will study in regular dense connective tissue.

[00:35:01]And in the last we are having the specialized connective tissue. Okay?

[00:35:07]Which are the specialized connective tissue, guys? Come on, tell me. There will be adipose tissue.

[00:35:14]Okay? The fatty tissue, adipose tissue.

[00:35:17]There will be bone.

[00:35:20]There will be cartilage.

[00:35:24]There will be cartilage. And what we are missing? We are missing blood.

[00:35:29]We are missing what, guys? We are missing blood.

[00:35:32]Are we clear, everyone? So, adipose tissue, bone, cartilage, blood goes into specialized.

[00:35:40]In dense we are having irregular regular. In regular there are tendon and ligaments. Irregular, irregular is kind of a connective tissue where certain collagen fibers are there, but they are irregularly arranged.

[00:35:58]At certain places of your body you have irregular dense connective tissue. Okay?

[00:36:04]Mostly beneath your skin. The best common example is just below your skin.

[00:36:09]Okay? They are not further classified.

[00:36:11]Like dense is further classified into tendon and ligaments. Sir, is areolar the only loose? Yes, beta. We can say areolar is loose. Okay? Previously we used to classify adipose also as loose.

[00:36:26]Now, here comes the concept.

[00:36:28]The thing is that adipose is kind of specialized loose.

[00:36:35]Adipose, your adipose tissue, the fat tissue, is kind of a modified loose connective tissue.

[00:36:43]So, that's why I'm not writing in the loose. Technically it is a loose one, but now it is specialized just to store fats.

[00:36:51]Okay? So, certain places you might find you might find that adipose is present in the loose connective tissue, that is also correct. But if it it is asked as specialized, you have to consider adipose as a specialized connective tissue.

[00:37:07]Because it is derived from loose, but now it is specialized just to store your fats in the body.

[00:37:15]Are we clear? Someone are asking, "Sir, what about lymph, lymph, lymph?" Lymph will be coming under blood only. Blood and lymph are together. Actually lymph is a byproduct of the lymph.

[00:37:25]Lymph is a byproduct of blood.

[00:37:28]So, when the blood goes in your organ, blood goes in your organ via artery.

[00:37:32]Artery divides into capillaries.

[00:37:34]Capillary when they leak out the fluid, okay? Technically then we can say it is the tissue fluid or the lymph when it goes into the lymphatic capillaries. So, lymph is kind of derived from blood only. However, there are certain differences, but blood and lymph are also coming under specialized connective tissue. Are we clear, guys?

[00:37:56]Are we clear with the classification?

[00:37:57]Yes or no? Tell me quickly.

[00:38:01]Come on, Zoom people, students. Yes?

[00:38:03]Shall we go ahead? I hope you had made some quick notes here.

[00:38:09]What's happening on online? YouTube people, what are they doing? Enjoying?

[00:38:13]Enjoying chatting? Yes?

[00:38:17]>> [gasps] >> Some people are studying.

[00:38:21]RCB lost last match.

[00:38:24]>> [laughter] [snorts] [laughter] >> RCB lost the last my last match. I was actually planning to watch the match, but See, I'm from Mumbai, so when I whenever I try to watch Mumbai, I have given up on Mumbai. Actually they always find a way to lose.

[00:38:53]Now, suddenly I saw RCB's playing very well next my last match. I thought, "Okay, we will I will watch RCB."

[00:38:59]Okay, but then I started watching RCB, then they lost.

[00:39:03]Now, I'm planning a not to watch again. Okay? Because whatever I'm picking up, those guys are losing.

[00:39:11]Okay?

[00:39:13]So, okay. Jokes apart, yeah, we are going to discuss about macrophages also.

[00:39:21]We are going to discuss about uh macrophages also. Yeah, come on. Let's go ahead. Now, what we want to start with first? First we are going to start with loose connective tissue.

[00:39:33]First we are going to start with loose connective tissue.

[00:39:37]That is the most important one. Because in in body the most abundant and widely present is the areolar connective tissue in the loose connective tissue. Okay?

[00:39:48]Come on. Let's go ahead now.

[00:39:50]One by one. Okay, before going to that, let us read about little bit about the points of connective tissue. This point has left here. Already you have understood this point. Come on.

[00:40:02]We can read together. In all connective tissue except blood.

[00:40:07]In all connective tissue except blood.

[00:40:10]Okay, these are NCERT lines.

[00:40:13]These are NCERT lines, so please focus.

[00:40:15]Okay? So, yeah, but except blood.

[00:40:20]So, in the all connective tissue except blood, these cells secrete fibers.

[00:40:26]What are fibers made up of? The cells secrete fibers. They are structural proteins. They might be collagen or they might be elastin.

[00:40:36]They might be collagen or they might be elastin. Two different types of protein.

[00:40:40]Collagen and elastin. Okay? I want you to do to do something. Okay? Repeat like this. Can you pinch your skin like this?

[00:40:49]Can you pinch your skin like this? Just hold your skin like this. Can you pinch your skin?

[00:40:54]Little bit it comes. Yes?

[00:40:55]Little bit it is coming. Can you pinch more and pull it out?

[00:40:59]Can you become fantastic four leg person, that Mr. Stretchable guy? Can you stretch it out further? No.

[00:41:07]At certain point I cannot stretch. There is a limited stretch here. You can see only little bit stretch is there.

[00:41:14]Why?

[00:41:15]Why? Because the loose connective tissue beneath your skin, the areolar connective tissue beneath your skin, it is there providing rigidity also.

[00:41:28]That is strength.

[00:41:30]Plus it is also providing elasticity.

[00:41:34]So, collagen and elastin, collagen and elastin in your loose connective tissue, they kind of give both strength, rigidity also.

[00:41:45]And they also provide elasticity. So, little bit you can pull out your skin.

[00:41:50]Along with the skin you are also pulling out the loose connective tissue.

[00:41:55]Why you cannot pull out more? Because the collagen fibers, they are not allowing.

[00:42:03]Collagen fibers, they provide rigidity.

[00:42:06]Okay? Their tensile strength is very high.

[00:42:10]So, they will again pull back the skin back to the position. Whereas the quantum elasticity what we have, the quantum elasticity is there. Okay?

[00:42:21]That is due to your elastin fibers. And as you leave your skin again, the elastic fibers recoil and your skin goes back.

[00:42:32]So, both these fibers are very important. So, what is written in the NCERT? What is the NCERT saying here?

[00:42:38]These fibers provide strength. Strength is for rigidity purpose, collagen.

[00:42:45]Elasticity by elastin. Flexibility again by elastin. Okay? To the tissue. So, it provides strength, elasticity, and flexibility. Then, these cells also secrete. We have already discussed. The cells secrete fibers also and the cells secrete matrix also.

[00:43:04]These cells also secrete modified polysaccharides.

[00:43:10]What saccharides? Modified polysaccharides.

[00:43:13]What are the modified polysaccharides here? Which part we are saying? We are talking about the matrix part. We are talking about which part, guys? We are talking about the matrix part.

[00:43:25]The ground substance.

[00:43:28]The matrix part or ground substance.

[00:43:31]Are we clear? So, a question might be asked. What is the matrix of the connective tissue made up of? The matrix of the connective tissue is made up of modified polysaccharides.

[00:43:44]Have you heard hyaluronic acid? Have you ever heard hyaluronic acid? Lot of shampoo ads and facial creams, anti-aging cream. They are saying hyaluronic acid is there.

[00:43:56]Apply hyaluronic acid. Collagen containing creams and all. These all are naturally secreted by your connective tissue.

[00:44:08]These all are naturally secreted by your connective tissue.

[00:44:12]Okay? The hyaluronic acid is nothing but a modified polysaccharides.

[00:44:17]These are called as glycaso glycosoaminoglycans.

[00:44:22]Glycosoaminoglycans, GAG, or proteoglycans.

[00:44:26]These are specialized modified polysaccharide. Specialized modified polysaccharides which are negatively charged, which can hold water.

[00:44:38]Which can hold water. So, please understand. Forget what I said the glycosoaminoglycans and proteoglycans.

[00:44:45]That was little too much. Okay? The main purpose was that this modified polysaccharides are negatively charged and they can hold the water molecules.

[00:44:55]What they can do? They can hold water molecules.

[00:45:00]Okay? So, the loose connective tissue which is beneath your skin, it is holding a lot of water. Why it is holding a lot of water? Because these modified polysaccharides, they are holding water and they are becoming gel like substance. What they are becoming?

[00:45:16]Gel like substance.

[00:45:19]Okay? That is acting like a lubricant. I can say that is giving some space to the tissue. Are we clear with this? So, when I said connective tissue has lot of intercellular space. Lot of space is there. In that space these proteins are present. So, the matrix is made up of these proteins.

[00:45:41]And they are holding water and they are making the matrix a gel like substance.

[00:45:48]Are we clear? But the same connective tissue if you talk about bone, there is a deposition of lot of calcium and other minerals which is making them hard. Are we clear? Yes? Yeah, that's why we say that keep the skin hydrated.

[00:46:04]If you keep your skin hydrated, you will glow. Basically, why how to keep the skin hydrated? You pour water on your face? No. Basically, you drink water.

[00:46:14]That will reach your areolar connective tissue. Okay? Now I'm sounding like some Instagram influencer on skin uh therapy and all. Sorry. Let's go back. So, secrete modified polysaccharides.

[00:46:28]Which is accumulating between cells and fibers. So, there is cell. There is fiber. There is matrix. Matrix is made up of modified polysaccharide. Are we clear, guys?

[00:46:39]Yeah, everyone. Are we clear? Shall we go ahead now? Come on.

[00:46:44]Come on. Come on. Come on.

[00:46:46]Okay. So, what is this here, guys? What is in your front of the screen? Come on.

[00:46:51]Look at the picture.

[00:46:53]Again, I have taken an NCERT diagram.

[00:46:56]I have taken an NCERT diagram. Okay? No, Vaishnavi, there are other cells also which secrete the polysaccharides. Okay?

[00:47:07]What is this, guys? Come on. Tell me.

[00:47:09]This is a picture of what? Do you see cells? Cell number one, cell number two, cell number three, cell number four, cell number five. Do you see cells?

[00:47:19]Do you see cells?

[00:47:21]Achcha. Do you see fibers?

[00:47:23]Do you see fibers? This blue color bundle of fibers. Blue color bundle of fibers. Some Y shape orangeish fibers are there here. In the background some purple color fiber is there.

[00:47:36]I have I am showing you cells. I am showing you fibers.

[00:47:42]So, what I am showing you? And in the background, the light pink color background. What is the light pink color background here? That is matrix.

[00:47:49]What is that? Matrix. So, I am showing you here all the three components of loose connective tissue. I am showing you all the three components of loose connective tissue.

[00:48:04]Okay? Are you getting me, guys? Are you yes or no? Are you getting me? Look here.

[00:48:11]So, what if >> [clears throat and cough] >> So, let us basically draw now. Let's draw again and again.

[00:48:20]Okay? Let us try to draw.

[00:48:23]So, what is this I am going to show you?

[00:48:26]The loose connective tissue.

[00:48:33]Okay?

[00:48:34]So, in the loose connective tissue, first of all, you are going to have the fibroblast cells.

[00:48:41]Which cells you are going to have? The fibroblast cells. They are mostly star shape. What are they mostly? Star shape.

[00:48:49]What are these cells? I will say these cells are fibroblast cells. What are these cells? Fibroblast. Basically, they are going to produce the fiber and matrix. So, this is our the fibroblast cells. Most important cell of your loose connective tissue is fibroblast. The most important cell is the fibroblast. Fibroblast is going to secrete fibers. Which kind of fibers it is going to secrete? First, it is going to secrete bundles of fibers like this.

[00:49:19]It is going to secrete bundles of fiber like a Spider-Man.

[00:49:23]Okay? Secreting fibers. Okay?

[00:49:28]Lot of bundles of fibers are coming out.

[00:49:31]So, white colored bundle fibers. White colored bundled fibers wavy in nature.

[00:49:39]What in nature? White colored bundled fibers, wavy in nature. These are collagen fibers. What are these?

[00:49:48]Collagen fibers. So, when I talk about loose connective tissue When I talk about loose connective tissue here, and specifically I am talking about areolar. Specifically, I am talking about areolar. What is the location? Tell me, guys. Location will be below skin.

[00:50:12]Location will be what, guys? Location will be below skin. Are we clear? So, we are talking about loose connective tissue, that is areolar connective tissue. Location is below the skin.

[00:50:24]There are other locations also.

[00:50:26]I am talking about the most commonly observed location, below the skin.

[00:50:31]How many components are there, guys?

[00:50:33]Tell me how many components are there?

[00:50:35]There are total three components here.

[00:50:38]There are how many components? Total there are three components. There will be cells.

[00:50:44]There will be matrix.

[00:50:47]And there will be fibers. There will be what, guys? Fibers. Okay, which cell we discussed? Tell me first.

[00:50:56]Which cell right now I discussed? I discussed the fibroblast cells. Which cells I said? Fibroblast cells. Who produces matrix? Fibroblast produces the matrix. Who produces the fibers?

[00:51:10]Fibroblast produces the fiber. Are they The name has the function itself, fibroblast. I am a cell who makes fiber.

[00:51:17]So, my name is fibroblast. I also make the matrix. And the matrix is nothing but modified polysaccharides.

[00:51:25]The matrix is nothing but the modified polysaccharides.

[00:51:30]Achha, which fiber I said first? I said the collagen fiber. Which fiber I said first? Collagen fibers. How collagen fiber appear? Collagen fiber appear bundled wavy. Branched or unbranched? Tell me.

[00:51:48]Do you think it is branched or unbranched? Any branches coming out of the fiber? There is no branch coming out of the fiber. They are unbranched. What are they? They are unbranched. Okay.

[00:52:01]Sir, what is the next fiber? The next fiber is the linear fibers. The next fiber are the linear fibers, which are branched. The next fibers are the linear fiber, which are branched. So, you can see this fiber is not bundled.

[00:52:21]This fiber is like linear, straight. And it is showing branching. So, which is this fiber which is unbranched, linear?

[00:52:30]What I will say? This is elastin fiber.

[00:52:33]What is this fiber, guys? Elastin fiber.

[00:52:37]The next fiber is elastin fiber. Sir, who secreted the elastin fiber, sir?

[00:52:44]Who secretes the elastin fiber? Again, elastin fiber is also secreted by fibroblast cells. It is also secreted by fibroblast cell. Are we clear?

[00:52:56]Yes or no, guys?

[00:52:58]Then, sir, what are the other cells?

[00:53:01]What are the other cells? Okay, I will tell you about the other cells also.

[00:53:07]There will be some large cells.

[00:53:10]Okay, having kidney shape nucleus. There will be some large cells having kidney shape nucleus.

[00:53:19]They are a type of WBC.

[00:53:22]It means if any dead fiber is there, some fiber is damaged, certain cells are damaged, little part of the tissue is damaged, or some foreign body has entered.

[00:53:35]So, it is basically a phagocytic cell.

[00:53:38]It is a phagocytic cell. It will do phagocytosis. It will consume the dead tissue, the damaged tissue, or the foreign bodies, and it will digest it.

[00:53:48]So, basically, I will say it is like cleaning the house.

[00:53:52]It is cleaning the tissue. So, this cell will be called as what, guys? This cell will be called as a macrophage. So, another cell which is present in yours loose connective tissue will be your macrophage.

[00:54:07]Will be your what? Macrophage.

[00:54:10]And what does the macrophage do? The macrophage what what does it do? The macrophage does the phagocytosis process. What it does? It does the phagocytosis process. Do you know the lysosomes, guys?

[00:54:24]Have you studied lysosomes little bit?

[00:54:27]Cell chapter, lysosomes. Lysosome contains so many enzymes, lytic enzymes, hydrolytic enzymes, which can digest a lot of stuff. Yes or no? So, macrophage also a type of a WBC, a specialized cell. Okay? And which is able to digest the foreign bodies. Why? Because macrophage inside has a lot of lysosomes. That is going to help them to digest it. Okay. Which is the other cell?

[00:55:00]The other cell, little bit you can also see the fat storing cells.

[00:55:06]Which storing cells, guys? The fat storing cells.

[00:55:10]These cells here are storing fats. So, these cells are which cells? These cells will be called as the adipocyte cells.

[00:55:18]Which cells?

[00:55:19]Adipocytes.

[00:55:21]Adipo means fats, and site means cells.

[00:55:25]These are adipocytes. What will adipocytes do, guys? Adipocytes will store the fat. So, there is a fat storing cell also. There is fibroblast which is making the fiber. There is macrophage which is clearing the debris, dead tissue, and other cellular debris which is there inside in the tissues.

[00:55:43]That will be cleared by the macrophage.

[00:55:46]Sometime you may also observe uh another cell. Okay?

[00:55:53]You may also observe a very special cell here.

[00:55:57]Okay? Like this. Okay? Which has a lot of granules inside them. Nucleus probably S shape. Nucleus probably S shape. And this cells will be called as what? They will be called as the mast cells. What they will be called as? Mast cells.

[00:56:16]Have you ever heard mast cells, guys?

[00:56:19]Are you aware of mast cells?

[00:56:22]Are you aware of mast cells?

[00:56:26]Are you aware of mast cells, guys?

[00:56:28]Must cell nehi hai. Must nehi hai. In Hindi, don't you read must. It is mast cells. Okay? Now.

[00:56:37]Mast cells are very important cells.

[00:56:40]Thik hai?

[00:56:41]Whenever you get injured, a mosquito bit you, you got injured, some cut, some bruise happened. What happens after some time? That area becomes very red.

[00:56:53]That area becomes very red. What is the word you use? Inflammation.

[00:56:58]What is the word you use? Inflammation.

[00:57:01]Have you heard of inflammation? So, mast cells are responsible for inflammation of the tissue.

[00:57:09]What it is responsible for? Inflammation of the tissue. Where your underneath the skin.

[00:57:17]It becomes red. It becomes swollen. It becomes painful. So, redness, swelling with pain is called as inflammation of the tissue. Where flame means fire. Your tissue is on fire. So, any insect bite, any injury, any harmful harsh chemical is there on your body, or you are having any allergy and all. That makes your skin red, swollen, painful, itching and all. That is called as inflammation. So, who is responsible for that inflammation?

[00:57:48]That guy is mast cell. Because mast cell it stores different chemical granules.

[00:57:57]It stores different chemical granules.

[00:58:00]Like one of the important chemical is histamine.

[00:58:05]One of the important chemical is histamine. One of the important chemical is histamine. That causes the inflammation. What it exactly causes, we are going to study in the higher classes. Okay? So, histamine that is stored by the mast cell, that causes the main inflammation.

[00:58:24]Are we clear? So, mast cells, remember, very important for inflammation. It may also secrete other chemicals like heparin, which is an anticoagulant.

[00:58:37]What it is? It is an anticoagulant.

[00:58:39]Histamine is a vasodilator.

[00:58:42]Histamine is a vasodilator.

[00:58:46]Vaso means blood vessel. Dilator means to dilate. Vaso means blood vessel.

[00:58:52]Dilator means to dilate. So, whenever you get injured cut, wound, bruise any insect bite, mosquito bite sting of the honeybee Suddenly, the redness increases. Why?

[00:59:07]Because the blood flow has increased.

[00:59:09]Why? Because your mast cells have ruptured. Your mast cells have ruptured and released all these chemicals, which leads to inflammation.

[00:59:19]Are we clear with this? So, again going back Again going back. What is this cell here, guys? This is the mast cell. So, let's quickly do the labeling. Let's quickly do the labeling. What is there in the background we say? In the background we say there is matrix.

[00:59:36]In the background we say there is matrix. What is this cell here tell me?

[00:59:41]This cell will be your fibroblast.

[00:59:44]What is this fiber? This fiber are collagen fibers.

[00:59:49]Wavy, bundled, unbranched.

[00:59:55]Wavy, bundled, and unbranched. Whereas these fibers, these are elastin fibers.

[01:00:04]Collagen fiber provides rigidity, strength. Elastin fiber provides elasticity. What it provides?

[01:00:11]Elasticity. It is a linear and it is branched. It is linear and it is branched. Are we clear and the other cells?

[01:00:21]Fibroblast, cell number one. Cell number two we said macrophage.

[01:00:29]Okay?

[01:00:30]Macrophage, the scavenger, which removes the debris and the other unuseful parts in your tissues. Then we will say adipocytes. Adipocytes which are storing the fats.

[01:00:44]And this cell here, we can call this guy as the mast cell. As which cell? The mast cells. Are we clear with this? So which is this tissue we studied? Tell me. We studied the loose connective tissue. Which one? We studied the areolar connective tissue. We studied which one? Areolar connective tissue. It is the widely and the abundant tissue of your body. Basically binding two different tissues together.

[01:01:15]Okay? Binding two different tissues together. So that's all for this class.

[01:01:21]Tomorrow we will continue with the remaining connective tissue.

[01:01:26]Okay? So better revise and come. Few questions we can have certain MCQ round.

[01:01:32]So that's all for this class, guys.

[01:01:34]Thank you so much. See you all tomorrow.

[01:01:36]Bye-bye, guys. Bye-bye. Bye-bye.

[01:01:37]Bye-bye, everyone.