Histology of the Nervous System

today we are going to discuss about the histology of nervous system right what is nervous system by the way yes I think you are going to tell me what is the nervous system a system which is all that I'm nervous there's nervous system okay I will make it simple nervous system is basically made of lot of neurons and their supporting cells which is mainly concerned with the collection of information from external and internal environment what nervous system is doing it is collecting the information from external and internal environment and within the nervous system lot of information is stored and scenes are made about the responses and then through its motor system nervous system generates responses right so what is nervous system nervous system is a special system present in our body made of neurons and their sporting cells right main function of the nervous system is that it should collect the sensory information from external environment as well as from internal environment right and it should integrate the information coordinate the information in its central part and then generate responses through the motor system right so nervous system is anatomically divided into two parts central nervous system and peripheral nervous system so let's suppose here I draw central nervous system of course you must be recognizing the part of the central nervous system up to this what is this all this part hurry up please spinal cord right and right so this is spinal cord and what is from here to here yes Matala and what is this pons yes very good what is this midbrain midbrain what is this cerebellum sorry the alum and what is this cerebrum sorry Brahm there are two cerebral hemispheres right and left of course so this is a diagram of central nervous system central nervous system consists of its upper part all that part of the central nervous system above the spinal part is called yes what is it called brain is it right and here is spinal cord so we can say central nervous system consists of spinal cord and the brain is the right in the brain there is brainstem right and brainstem consists of with which structures and the brain there is brainstem brainstem consists of which structures brainstem consists of midbrain pons medulla these three structures are called brain stem right midbrain pons and medulla are called brain stem and on the back of the brain stem you have cerebellum and above the brain stem you have cerebrum or cerebral hemispheres those are right now this is your central nervous system now how really nervous system work let me make a very simple diagram that again I repeat the diagram of here central yes plays in our system and there is peripheral nervous system now what is the duty of peripheral nervous system peripheral nervous system peripheral nervous system peripheral nervous system has one part which is collecting the information from the periphery this part which is taking the information to the central nervous system right this part of the neurons which is taking information to the central nervous system this is called which part of the nervous system this is sensory sensory system right there are a lot of neurons in the body which are collecting the sensations from external and internal environment and taking those sensations to the central of a system this is it right so this part of the peripheral nervous system which takes the information to the central nervous system is called sensory system then from the central nervous system once information goes to the central nervous system right information is recognized it is compared with the present information with the past information and appropriate responses are generated and these are the neurons which are bringing information and response outside the central nervous system and this group of neurons right which bring the information from central nervous system to the periphery and generate the response this is called motor system so we can say that anatomically nervous system is divided into central nervous system and peripheral nervous system standard level system has brain and spinal cord very firm nervous system has sensory part and motor part right now all these part of the nervous system has lot of cells which conduct the electrical impulses or which conduct ah yes action potentials is there right now basically we say central nervous system and peripheral nervous system consists of two types of cells when you talk about astrology you talk about the types of the cells there are cells and nervous system there are two types of cells which are present in the nervous system right of course everyone knows that there are neurons and there are what is the other group of cells yes glial cells or we should call them sporting cells because glial cells are the supporting cells and central nervous system and their Schwann cells and other cells which squirt the peripheral nervous system but when we talk specially about the nervous system we can send our system has neurons neurons are very special type of cells right and each neuron is one special type of cell how many neurons you have Ahmad you never counted you're busy in of them says until you have for a few thousands oh my god he has a few thousand I think frog as in millions yeah there are how many ten millions or billions billions yes you must remember you have billions of the neurons your billionaire as far as neurons are concerned right as far as neurons are concerned you are billionaire yes Sean what you are saying how many two hundred billion neurons I never counted them but that is why you're wrong look actually neurons and supporting cells are different right neurons are about their billions of neurons and sporting cells are many times more than the neurons right but this don't sit and count your neurons all the time just remember that you are billionaire as far as neurons are concerned is that right now the billions of the neurons and squirting cells to the neuron the far more than the neuron itself right but there is one question what is the difference in the neuron and the squirting cells or in center system what is the difference in neuron and that glial cells the answer is coming from yes man what is the real difference between the neuron and the glial cells for example you removed my central nervous system I hope not and you separate neurons or one side and you put all the Goliath ID cells on the other side what is the real and basic difference in the neurons and non-neuronal cells because these are not neuronal tell all the cells in central nervous system and peripheral nervous system other than the neurons are archived non-glare they are called squirting cells and squirting cells in the central nervous system are called goliath cells what is the real difference in neuron and glial cell yes I'm about to be impressed by someone okay he has come up with an idea that neurons cannot be regenerated once they are destroyed and glial cell may be I think that there's some more important difference between the neurons and glial cells yes please oh my god you yeah what is the difference between Iran and the glial cells there is some very basic difference the main thing is neurons are conducting cells they conduct the current they conduct the action potentials they are excitable cells right and glial cells are non conducting cells that is so simple when you start the astrology of central nervous system you simply say central nervous system has basically two types of cells or the whole nervous system has two type of cells it has one type of cells which are conducting the electrical impulses right cells which can generate and propagate action potentials those are called conducting cells is the right so in the nervous system all those cells which can generate and can be excited and generate action potential and conduct action potential all those cells as a group are called neurons and all other cells in central nervous system which cannot generate that potential and which cannot conduct action potential which are a group as a group functionally they are non conducting cells they are called glial cells and central nervous system am i clear right now today we will discuss into detail only neurons and in next lectures we'll talk about glial cells so first of all we talked about the neurons what our neurons now from this discussion we have already an idea that neuron the very special type of cells which are capable of conducting signals in the form of action potentials this is a right in the central nervous system and peripheral nervous system right in the central nervous system and the peripheral nervous system those cells which can generate and conduct the electrical impulses action potentials they're called neurons right neurons very special type of cells now there are many types of neurons again first I will make a typical neuron a typical neuron is having a cell body of course every cell has a cell body isn't it so neurons also have cell body because they are cell so let's suppose this is a simple cell with the nucleus and what is this cytoplasm and from here from its membrane you bring many extensions out you are bringing many its extensions out now from this cell we are bringing the extensions out and these membranous extension of course having some cytoplasm these small extensions right they usually receive the information from other neurons or from the receptors they receive the information right so these are called what are this part of that this type of extensions they are called dendrites what are they called dendrites right and neurons have a typical neuron has one very long process here right and this long process is called yes this is called please tell me exam right so what and what is this this is the cell body of the neuron and cell body of the neuron is also called soma so we can say that every neuron consists of a typical neuron consists of cell body and extensions from the cell body right some extensions are called dendrite and one special extension which is very long as God called eggs on these are right now my question is what is the real difference between dendrites and axon just please yeah what is the real difference between the dendrite and as long you have studied this topic you told me yeah say it loudly so that yes what is the gender ID that's very good actually look what is this what is the neuron neuron is the fundamental basic unit cell of nervous system and it should be able to receive the information and pass the information forward actually dendrites are those extensions of the neuronal cell body these are those extension from the neuronal cell body which receive the information right for example there's one neuron here it is giving message here there's another neuron which brings the information here some other neurons bring information here so actually dendrites are extensions from the cell body just to increase the surface area of the cell body on which information can be received from other neurons so you can say this is the sensory part of the neuron itself that is there right the action potential in the dendrite move from the periphery to the cell body the electrical impulses in dendrite moves from the periphery to the yes please cell body so what are dendrites dendrites are the receptor component of the neuron because it receives the information so dendrites are the Septor components of the neuronal neuron Archaean remember basically one neuron may be receiving information from how many other neurons you can say neuron is listening to other neurons if neuron is listening to other neurons androids are like their ears Sam you know that many years to one neuron how many neurons are maybe simultaneously talking like if we talk about in math how many girls simultaneously talk to you but you are not lucky to have always two girls okay he is confused anyway what I'm saying that how many girls can talk to a man usually you have two years you're two receiving points even though many can talk here and here but still neurons simultaneously can receive information from one neuron can simultaneously receive information from how many neurons more than 10,000 neuron can you imagine you're billions of the neurons and every neuron on averages talking to to 10,000 neurons you can say how many social circuits are going on in your central nervous system you are getting it how many processing units and conducting units are there how many circuits are there one neuron on average the sieves information from about 10,000 neuron now look if 10,000 neuron need to bring information to this neuron that its cell surface area is very less so there will be extension for the cell membrane making the dendrites and the many many dendrites so every dendrite hundreds of the neurons are giving their information am i clear so what are dendrites the androids are the receptor component of the neurons and they are receiving the information and information electrical information moves from the ends of the dendrite towards the cell body and what is the difference between the axon and dendrites and axon yes plays classically speaking typically speaking as long as that that process of the neuronal cell which takes the information away from the cell body right for example many neurons stimulating these generates and cell body then action potential will move through the axon to the next neuron so it means that in the eggs on impulses are traveling away from the electrical impulses or action potentials are moving away from the cell body and in case of dendrite information is moving yes towards the cell body so what did we learn up to now that are typical what is neuron neuron is a cell present in the central nervous system our peripheral nervous system this is basically a cell which is specialized in generation and conduction of action potentials is that right and we have billions of the neurons and these billions of the neurons made lot of connections with each other on average one neuron in the central of a system simultaneously receiving information maybe from about 10,000 neurons right because a neuron has to receive information from many many other neurons so it's cell body has many many extension so surface area is increased to receive the messages from other neurons so dendrites and the cell body are in a way the separate component of the neuron and with all the information which come to the neuron through the dendrite or direct you know one neuron will be bringing information to the dendrite or some neuron may bring information directly to the cell body right whatever information comes here eventually this information will determine the production of action potentials in the axons and from the exams action potential we move away from the cell body so don't write take the action potential towards the cell body as one's take information away from the cell body dendrites are receptor component of the neuronal cell axons are effector opponent they produce effect on the next cell so example called effector component of the cell you Ronal cell body right there is another term which is very commonly used as you know there are dendrites and there are exams right remember usually one neuron may have many dendrite but one neuron has only one exon is that right now in such neurons which are many many dendrite and one axon we call them multipolar neurons we'll go to that in detail later now there is another term used which is called new right what is new right now you heard of the term new writes you writes yes please what are new rights any one new rights are all the extension coming from the neuronal cell so all the dendrite and exons together are called new rights why I say this term because you should not be confused by this what is new right new rights are all extensions from the neuronal cell body there are two types of new rights there are dendrites and there are yes please axons I might left any problem up to this No now we come to morphological classification of neurons

Channel: Dr. Najeeb Lectures

Views: 284,682

Keywords: nervous tissue histology, nervous system, nervous tissue, histology of the nervous system, nervous tissue definition, nervous system definition, nervous system histology, histology of nervous system, nervous system lecture, nervous system organs, nervous system function, connective tissue, central nervous system lecture, peripheral nervous system, central nervous system histology, central nervous system, pathology of nervous system, pathology of nervous system histology

Id: 29NxjKdQbd0

Length: 22min 33sec (1353 seconds)

Published: Fri Nov 23 2018