Blood Supply to Brain - Circle of Willis - Neuroanatomy

today we are going to talk about the blood blood supply to the brain central nervous system now let's supply to the brain before we really start about the anatomical aspect I want to know that how much percentage of the cardiac output goes to your central nervous system everyone knows that heart is normally producing about five liters of blood per minute is the right left ventricle cardiac output per minute is about five liters so out of that five litre blood which is Purdue cards which is the cardiac output normally in a resting person how much is really going to the central nervous system 15% that's very good so about 15% 15% of the cardiac output is devoted to the central nervous system is there right now we have to see how it really goes there fine let's pause here is your from where we should start the study from the arteries going to the central of a system or we should start directly from the heart let's start from the heart from the left heart let's suppose this is your left atrium and this is your what is it yours all right Yoda karch and here is just place brachiocephalic trunk that's good and here is your very good left common carotid artery and here it is yes left subclavian right now blood which children to the central of the system that is going through two systems right one is called carotid system and second is vertical there is a system now when we talk about carotid systems you know common carotid arteries as they are going upward right they go into what is the sky rotate finest and found there there are external carotid and internal Croton right so these are your internal carotid arteries which are headed to central nervous system right so one source of blood supplier to the sent one of the major source of blood supply to the central nervous system especially to the brain is internal yes carotid arteries this is the right and second source is that there are vertebral arteries which are taking origin form yes subclavian system right vertebral arteries let me make them green but they are not green in fact right so these are vertebral arteries and vertebral artery initially move upward their posterior with posterior to the filtered system and eventually they turn medially and yes they will move from here also from the left side move upward this is which artery yes please vertebral artery - good and vertebral artery of the left side also moves medially right and eventually behind behind the throated cistern their sense of word and eventually move meet together and then yes now this is vertebral artery system right and of course this is right vertical artery and this is left vertebral artery and this is also supplying to the central nervous system now when we talk about the blood flow to the brain now we have seen that there are two systems one is your carotid system which is also called anterior system which is also called anterior systems other is vertebra regular system which is also called posterior system right so we can see the interior system which is chaotic system and posterior system which is vertigrow basilar system right now first we will discuss into detail vertebra business systems and after that we'll discuss in to detail the carotid system supplying the brain now let us go to the vertebral vertebral system now when we talk about vertical system these are the cervical vertebra I'm making a very simple diagram of cervical vertebra they're right what are these transfers processes a very important thing is that in the transverse processes there are four Amina cervical vertebra and the transfer processes there are four Amina and through these phenomena yes which arteries are going up vertebral arteries that is the important point that when vertebral arteries ecoregion from subclavian system they move upward and medially they reach to the transverse processes of cervical vertebra and through the inlet within the transverse processes of cervical vertebra there are foramina they go through those from foramina upward is the right and then through the foramen magnum they enter into cranial cavity now through the foramen magnum when they enter into cranial cavity you know they will keep on moving upward and eventually move medially and through the foramen magnum they will go into cranial cavity right now when they enter through the foramen magnum into cranial cavity right exactly at which space they are these arteries are located again listen to the question you know their central nervous system around that this Pia mater outside that there is subarachnoid space then outside that there is recognized matter and then there is dura mater okay let me tell you know where is a very very simple diagram central nervous system yes you will tell me what is it just adjacent to it are you have SP emitter outside that what is here yes recognized matter and what are the subarachnoid space full of CSS - good very good and then of course all of you must be doing outside there is dorama this is a very simple diagram right now the question is that when crota system enters in the cranial cavity and vertebral system enters in cranial cavity the major arteries which are supplying the central nervous system those major arteries including the circle of villas they are present exactly in which area area number one area number two area number three area number four look area number one is that space space between the d'haran recognized or area number two is subarachnoid space or location between the pi and the central nervous system but Julie there is no space there because pi is very faithfully applied with that and then within central nervous system I want to know that when arteries enter into cranial cavities as carotid artery internal carotid arteries enter as vertebral arteries enter and in the end we'll discuss the Circle of Willis form all these major arteries are located in which area yeah you think that all of them are present in subarachnoid space you mean that Circle of Willis is floating into CSF yes you have any different idea you think it is subdue those spaces we have number one okay you can who believe it's Pierce number one raise your hand okay this is and people who believe it space number two people who believe it space number three and people who believe it space number four okay but for people's powers you're wrong absolutely because these are the small branches which enter here okay listen the right answer is that all the are three major arteries it's circle of the left they are really floating into CSF is the right you have to remember right it means you do not know exactly where the circle of the less is there where the major vertebral arteries vislar arteries and and internal carotid artery and their major branches where they are present they are present outside the central nervous system and of course outside the TR mater these major vessels are present into which space subarachnoid space position number two why it is so important to know because you may be knowing that there are special type of aneurysm called Varian or isms right these are far these are specially present very commonly in the Circle of Willis the rupture and when they rupture berry aneurysm they produce a hemorrhage in subarachnoid space that's the clinical importance this is the minimum of students should know about the blood supply to the central nervous system that major vessels going to the central of the system which are carotid system and vertebra business system and eventually making Circle of Willis all this major arterial system is present and sub recognized space all the time floating in see yourself exactly right so whatever why I asked this question because I was selling vertebral arteries are going upward through the foramina present in transverse processes as cervical not thoracic cervical vertebrae and eventually they go medially right of course there should be something called skull over here with foramen well this is the skull again very simple diagram this is foramen magnum right so naturally this vertebral arteries through the foramen magnum will enter into cranial cavity now I told you where the major vessels should be in which space of record space so it means there must pierce dura mater you must go through dura mater right the major artery should feel a recognized mater and then appear into subarachnoid space there the major vessels are there and from there the final small branches are going on and to brain substance am i clear to everyone okay let's go into detail of vertebrobasilar system right first we'll study posterior system and then we will talk about interior systems why it is so important to know the blood supply to different parts of the brain because one of the very common cause of neurological admissions in USA or spittle neurological dysfunction produced due to vascular problem the Communist cause communist causes of neurological dysfunction are vascular events right and you must know which part of the brain is supplied which are tray and which artery will be disturbed and what type of clinical problems and the logical dysfunction will appear in patient system let's come back we are going to talk about vertebrobasilar system and let's draw a simple diagram you know brain stem how many of you know Princeton very well Linstrom comprises off yeah what is it midbrain right you can recognize it good and then what is that yeah formed I think this is bitten stomach you symmetric in my case and then what is indirect and here it is spinal cord right what is this Ponta middle a junction and of course pyramids here and olives here here is bonds midbrain right okay this is the integer aspect brain stem is looking to you right so that you really understand it is look into you essentially after the brain stem and we have to explain the arterial system and reference to that okay before we really do what is the structure here sherry bellum and this is the undersurface of sorry done is it clear now already you know the vertebral arteries have been moving like this on the sides right through those foramina no fun in explaining those though we have discussed it already right and you know from where they are coming from subclavian arteries as will reach the lateral side of that lower part of metal ah the start moving to the medial side right so what we see vertebral arteries here they have gone to the media yes now and these vertebral arteries meet each other at the port or middle rail junctions right and left again what we see whatever all trees are going up through the transverse foramina not foramen and the transverse processes we're also cervical then the move medially the path through foramen magnum we're smarter Mattern recognize metal appear into sub lag net space then the move forward upward and medially over madala right and both vertebral arteries meet each other at what point what is this point font or metal a junction and there they move upward as ones United trunk which is called basilar artery right which is called dizzle ER already right so and then what really happens at this point this basilar artery divides into terminal branches right and these terminal branches yes what are they called these are going posteriorly you know the hooded edit backward so they are going posteriorly and we call them posterior cerebral arteries posterior cerebral arteries now this is the basic structure of vertebral bezler system right the vertebra business system has its origin in subclavian arteries ascending two major branches as right and left vertebral arteries they meet together at Ponto middle D Junction and then this united trunk becomes basilar artery right and visible artery just above that what are these don't tell me I know is this is third cranial nerve regions in oculomotor now that comes out from this point outwards you just see these these are third up suggest above the third nerve exit from the brain stem from the midbrain right there bezler artery divided into terminal branches two terminal branches which are right and left posterior cerebral artery okay posterior cerebral artery supply which part of the brain posterior part of the cerebral Hemisphere please mention at least midbrain they are moving how near the midbrain isn't it then of course they go to the back of the syllable hemisphere we'll talk about that later now this is the basic structure right now bring the branches important branches number one yes from here branches come from vertebral artery from lower part of vertebral artery in front or middle left branches comes right and left they unite together and then they descend and the anterior median fissure of finals called what is this branch coming down anterior spinal artery tear spinal artery right so we have anterior spinal artery originate it originated in front of the middle ah from the country view pre branches of vertebral arteries we move medially and in front of the the part of it Allah they make anterior spinal artery which defends downward yes descend downward in the anterior spinal yes which is your media interior spinal fissure is the right now this is this first batch after that other important branch is yes from here another branch yes who will tell me the name of this branch posterior inferior cerebral artery you know so much that's good but don't forget it supplies the middle also because this is the important point if people forget the supplies the natural part of metal art so and this is called posterior inferior yes the reburial artery by car what is the meaning of no bikers are by keyser term jews and psychological eating disorder there's a special type of eating disorder which is of psychological disturbance called pica yeah some people start eating the clay or soil or pika okay you know pika so pica is actually defined as an interest in special interest eating the non-nutritive thing you cannot understand that because some times you have to get pregnant to understand a pregnancy males sometimes get the struggles that they suddenly develop an urge to eat the thing which are not new creative right that is a psychological disorder which is called pica is all right and one of my friend who was always afraid of his wife when he wife got pregnant his ran away from home I said why you say my wife as well of pika I said but why you run away you say she made them might be interested in eating my brain right so that is not a right situation pika mean posterior inferior cerebellar artery now first I will talk about into your spinal artery and its territory of supply and then about this I will make the spinal cord section here yes I hope you recognize the component am i clear and this diagram this is to post a root into your root okay now anterior spinal artery is basically law it over here and defending here this diagram is very important that how much part of the spinal cord is supplied by the anterior spinal artery actually this is interior yes interior 2/3 of the spinal cord interior 2/3 of the spinal cord is supplied with the blurred form and TPO spinal arteries it means if anterior spinal artery is blocked that then anterior 2/3 of the spinal cord at that level of the blockage will undergo infarction necrosis is the right undergoes Kimia and if ischemia elsewhere that will lead to the depth of necrosis of that part of spinal cord so what really happens that anterior spinal artery supplies about interior 2/3 otha what spinal cord right another important thing of course they look so much blood coming from here that it will supply all the down rather there are special branches which are called segmental arteries which are coming at multiple levels to reinforce the blood flow to the deer spinal artery do you know that the segmental arteries because in the spinal cord if in tears fell are to start from here and goes down right it does not have enough blood to supply all the spinal cord into your 2/3 so it is reinforced right from certain branches which are coming from our fries which are outside the vertebral column and they are giving branches to the anterior spinal connects special supply to the interior Spaniel artery so that added blood should come there and spinal cord should be properly nourished right so let's suppose this is one artery what is this now already caused segmental artery so segmental arteries are entering into from the some arteries which are on the side right and these segmental arteries as the move medially they divide into interior and the divided into posterior divisions right anterior division which will reinforce and tear spinal artery and a posterior division and Tyrael VN is called yes please interior radicular artery and post shared VN is called yes posterior radical radicular artery and imperial viens right they are reinforcing the blood flow in what is the anterior spinal artery and for still dreams are reinforcing the blood flow in posterior spinal arteries remember there is one anterior spinal artery but there are two posterior spinal arteries this is the right we know about the region of anterior spinal artery that anterior spinal artery originated from vertebral artery right who knows the region of posterior spinal arteries from where the posterior spinal arteries originate raise your hand who knows what is the origin of posterior spinal arteries yes please you are just moving fingers okay I thought maybe raising hands from where that posterior spinal arteries come everyone knows into your spinal arteries are coming from right vertebral arteries what about posea spinal arteries they are j/o depends on what depends on that you will answer or not of what you just your who knows posterior spinal arteries they are coming from where don't tell me that they are coming from some artery which is posterior yes posterior spinal arteries are also coming from vertebral artery or either they come directly from the vertebral artery or the comes in directly from spica posterior inferior cerebral artery let me tell you okay listen either you know these are coming in front posterior spinal artery must go on the back is a right in some people's posterior spinal arteries coming directly from vertebral artery or in some people it is coming found what is this yes Nikita is there right now let me make it more clear to you I am going to make a section of spinal cord at this level this is your busy learn arteries and here it is your vertebral arteries right and here was your what was here until your spinal right these are right and posterior spinal okay I should make Woodward's here who Stephen Pierce Eddie barrel this area and lied just to scissor right actually post in spinal artery take region from pica or from vertebral artery and then they descend on the back off yes spinal cord right just behind the posterior root is that laughs no problem up to this before we really go to vertical better system let me tell you another important fact as I told you there are many arteries which are present here here here and found there the segmental arteries are going and supplying it at least you must know three important arteries which are giving segmental branches to reinforce the blood flow into spinal arteries right at least you must know three arterial systems which are given what are these segmental arteries to reinforce the blood in spinal arterial system right yes who knows what is this first group of Hartman yes deep cervical arteries so why have you straight Anatomy and then the second group is intercostal arteries enter yes custom arteries in the thorax and a number region to that lumbar arteries so what I'm saying that basically outside the vertebral column there are some arteries which are giving branches to the would write as segmental branches these are and the next either deep cervical artery then you go down it is intercostal arteries then mole down Jesus lumbar arteries from all these artery segmental branches are coming to the vertebral column entering into intervertebral foramina and then as segmental arteries then dividing into anterior and posterior vertical radicular arteries and then reinforce in the interior and posterior spinal arteries am i clear now what's the fun to know all this thing okay before really and leave this what is the most important reinforcer to the anterior spinal artery which is if I say you must know only one most important artery which really brings lot of blood to the interior spinal arteries because if that feeder is blocked if that outer is block big part of spinal cord may undergo infarction yes who is going to tell me first listen my question again all there is an artery which is supplying this a very important powerful strong high blood flow segmental artery which is coming to the spinal arteries and reinforces the blood flow what is the most important there was some name from there Adam or Eve Adam okay right what is the full name of that artery do you know spelling of that and from where that artery comes there are drinking salt of course that the big artery must be coming from aorta from the aorta is a direct supply right usually either it is there is only one artery so it comes from the left side or right side most of the human being this is coming from the left side entering into vertical column from the aorta a very big fielder coming to the spinal arterial tree really flush it with high blood flow right and that artery name okay that is coming from where from yota directly in most cases that is that is called great medullary artery of Adam okay it's really worth remembering because the most important feature great medullary are free of Adam Adam and I think of this very long name so you can write it like this right like a doctor right so you're in if you want to know then I can tell you kie right we'll have to consult it again and again W is easy now it's up to you how you pronounce it right but you have to remember that there is an atom size artery coming from your top to reinforce the blood flow of the spinal artery why it is so important to know because out of all these feeders especially if this major feeder is blocked a big part of spinal cord may undergo infarction is that right now before we really leave the blood supply to spinal cord there are two important clinical points one point is that what is the weakest area of blood supply which level of spinal cord is the weakest area of blood supply in the territory of anterior spinal artery yes what is the weakest area of the cause look for example if I say this is the weakest area here the blood flow is very very last let's pose if I say the blood flow here is less then even if there's partial block and artery here that depth of infarction spinal tissue will be at this point because this is normally under perfused actually there are two points which are under profused and you must know that supply area of and Teeter spinal arteries there are two points which are very very delicate point because they are normally in a healthy person even blood supply a blood flow through the entire spinal artery is very very little right at this point it is very little because major enforcer is just under it and then it just point it is very little and major reinforcer our major feeder is under ed what are these two points yes who knows that one is at the level of P 4 P 4 should be somewhere here and other is at the level of L 1 what does it mean it is a clinical meaning clinical meaning is that if blood flow through interior spinal artery is reduced infarction most probable area where infarction will occur and spinal cord is at the level of P 4 or at the level of L 1 I hope you will remember that right these two areas are very very vulnerable to infarction when they reduce blood supply to the into your spinal artery am i clear another thing this was about the territory of anterior spinal artery what about the territory of posterior spinal arteries and posture spinal arteries going down which single-most area is very very vulnerable to reduced blood flow yes who will tell me that is at the level of T one two and three it means posterior spinal arteries are posterior spinal arteries are having minimum black minimum blood flow at thoracic segments one two and three after that they get a powerful reinforcement and blood flow become good is that right and then into your spinal arteries the area which has least blood supply is t4 and l1 am i clear to everyone now we move upward so we were talking about yes vertebra bezler system let me base here again yes please tell me what is it mid grain and here is your friend what is it palms in here is Road Allah and yes cerebellum and under surface right now you will tell me rapidly what is the third ribbon Bob vertebral and what is still going up silver to Braille right so these are vertebral arteries and after the union the move upward as yes basilar and eventually the divided into terminal branches as yes posterior cerebral of cerebral cerebral not cerebral cerebral posterior cerebral emmaclaire important branches now you will tell me not me yes contributory branches to anterior spinal then a very important branch what is it posterior inferior cerebellar artery the most important point you have to remember that we especially supply the lateral part of medulla right which student for that I don't know why we only remember the cerebellum position serious a part of cerebellum and what is this artery going down yeah posterior spinal arteries may be originating from vertebral system or may be coming in directly from for student fear sorry we're not to the fight and of course this out we may give little branches here these are middle v medullary ultimate you have very small venture now as is going upward right it gives another set of arteries now this artery may originate from vertebral or may originate from vessel it depends person-to-person I put a question mark next order which I'm telling and some people will take arisen from the beginning of visitor and in some other people the same architects vision from the vertebral right and this artery right this artery supplying yes this is going again to cerebellum inferior surface but more interior look this also spline then inferior surface under suffer for cerebellum this is also supplying the under surface of cerebellum but this is going posteriorly and this is supplying anteriorly this is the right so this is posteriorly vas for CNCs cerebral artery then interior should be five interior inferior cerebral artery so this is PI K and that is I cracking they're like sisters pi Chi and Aika right so both of supplying the under surface of cerebellum is the right so you can say that from the voltage log regular system first there are two smaller drink arterial system and to your spinal artery and phosphates Maillard reservation then two sisterly branches come out which are by kind i car any question up to this now an important point which we have to remember about I Chi is that it supplies your lateral part of bones also not only supplies under the cerebellum but also supply the forms also while stressing is listen everyone by due to the name of the arteries remember that Phi Phi and I car supply under surface of cerebellum but a special point is fika is also supplying the lateral area of medulla and I Christ supplying special lateral area of Palms right that is specially supplying the lateral area of the palm am i clear up to this after that we move upward our trip start which is a very very long travel and again this altar which is going for very long distance artery right this long distance service may be originating from bid ler or in some people it is originating from a car right this artery is going forward laterally and then it moves with the semeth now and a eighth cranial of facial nerve and rest you look cochlear nerve and this artery goes along with the facial love and vestibular cochlear nerve into internally caustic v8 us and go to inner ear and the supply the inner ear inner ear has a blood flow you know inner ear cochlea and vestibular area and there are semicircular canals and labyrinthine system you know that energy of structure right you don't know that you have some idea okay let me tell you more clearly you know you have a head and neck isn't it this is your nose and here is your ear external ear actually is everyone knows right and here is proudly sitting who is sitting here which will rewrite and what is this foramen magnum right now look here this is external ear external ear here it is yeah what is it middle ear and here is your cochlear system and vestibular Leben thin system this all system of canals is present within this bone this is pit rest let us bone right which was part of temporal bone right now look here there the special foramen please tell me there is what is this foramen called what is this area internally caustic Nieto's and this is connected from here up to inner ear is the right emmaclaire now here was okay will keep a foramen magnum from where the artery came what the Sartre coming out today bruh and what did it mate bezler there is no fun in Tallinn what was rapidly rapido what is this branch aterial final and what is this branch for sales final you are really good and this is Micah right and what is this I car and then from your long disregard recovering from here going from here up to let length of the year these are called labyrinthine artists why I makes a diagram and everything to go from how do to some idiopathic reason shouldn't forget this ranch right so you have to remember it as good student good doctor that from here this is an artery which is going long long way right and with the 7th and 8th love which are going to internally costing me it does this level ensign artery also goes and goes to the inner ear and supplies over there is that clear color now so actually I'm learning Spanish you know ok so what is here come here there was this for FICA in this branch we can add here what was this here Aika and what was this long-distance business going Levantine right I think you have learned a lot now let's relax there are some small branches now from here what are these your Pantanal train am i clear good now you are going into Brazil adultery you go up and you come in front off what was this oculomotor comes out through this point is a right oculomotor is coming out to this point basilar artery gives five more branches just under the third cranial nerve exit and that are to the word what is this spear a spear your surface of cerebellum slang little bit midbrain and also to the cerebellum this is called superior cerebellar artery please don't confuse these two branches this is superior cerebral artery this is posterior cerebral artery this is for cerebellum that is for posterior part of Surrey Brown right spirits heavy barrel originate right it is moving under the third nerve and superior posterior cerebral is above the third nerve emmaclaire no problem up to this right okay now I will draw it rapidly and you will tell me what I am drawing so that I become sure so you really understood it or not I will see you can speak more rapidly you have to speak loudly or I can draw more rapidly right let's have a computation here as I will draw the structures you have to name them just right yes yes yes yes yes yes yes yes please what happened vertebral artery please you think this is vertebral artery okay okay let's come here yes we're different yes yes posterior posterior cerebral okay now your test will come yes interior and yeah posterior final okay and you can write that word and like liberal fine and now I cocky and one time that's good and failure and what of this okay now one more way I want to see your imagination I know your medicine is very good in some specific thing let's talk about your imagination about the arteries right first of all I will draw the brainstem here yeah first I will tell what are these structures this is the midbrain pons medulla spinal cord is the right class now your two-tailed arteries vertebral fusion posterior cerebral good now and their final from the vertebra Spica and from vislar I car and from physical long distance level and time then small branches from gorillas I am then from the Bigler branches going to the cerebellum again just to find a lot let's have a computation of speed right listen okay okay that's good I think this topic is so easy should not be taught isn't it it should not be taught anymore all right okay I'm so happy that you know about vertebrobasilar system now let's talk about garroted system and then we'll connect the system to make a circle right let's have a break first now we will be discussing about the carotid system which supplies the brain the de block supplier ID or the college interior blood supply system now carotid system as we discussed in the beginning of the lecture that this is the internal carotid arteries which are going to supply the cerebral Hemisphere right so let's see that how the internal carotid arteries and turn into cranial cavity and what are the important branches they are given right so let me make of you do you recognize the structure okay so from here with can you tell me what is this big foramen thank you what passes through it yeah please tell me spinal cord first of course vertebral arch it path to that what spinal cord is the first thing and of course don't mention SFA does it does not pass it from here now no it is important to tell through sometimes from second choose the thing there is a very big foramen there must be a positive there right so it is for spinal cord and vertebral artery and another very important structure from down going up through this spinal part of portion of 11 cranial nerve anyway leave it it's behind now we are going to concentrate on some other area and this area is in th no fossa what are this middle kind of fossa and what is it was taking office all right and we have to develop that how the internal carotid artery comes there already you know that it's a very small branch yeah this is from subclavian system to milk rotation what is this doing on internal carotid internal carotid add moves upward it enters to a canal here and this canal yeah someone is going to tell me all these structures right there back in all here right at the undersurface of stab these of the cranial cavity cranial cranium right from here what is this artery internal carotid artery it enters through the skin all which is called which can all get out it can all and then through the carotid canal and enter and it comes out through so oh my god okay listen this is carotid canal through which it enter and this is form unless serum don't you look it is initiated a Mariette like Jade edges now you should remember this is less irritated foramen foramen less serum actually there is a funny thing it enters through the carotid canal but carotid canal is opening on the undersurface but does not have opening into into middle kind of fossa actually carotid canal moves upward and then moves forward and goes into formal less room and from there this artery turns up what is this artery and then it will exert from foramen lacerum that's great when it will exert from foramen lacerum now read it as read middle cranial fossa and in the middle fossa here there the dural venous sinuses what does the CV even a final the vermis sinus that's great in the cavernous sinus it moves forward and then from here returns upward now the point which I want to highlight is that listen carefully it is very important to understand it that internal carotid artery start from the common carotid artery where common carotid artery divides into sternal gloated and internal carotid Julie there is a dilation dilation here which is called zero straight sinus not governess finest dilation here is K rotates and carotid sinus right now internal carotid artery moves upward it comes just under the medio-cam fossa it enters into carotid canal force upward then moves forward and interior part of carotid canal open in the foramen lacerum through the foramen lacerum this moves upward and as it pierces the dura mater it finds itself in two they were not finest in the government sinuses move upward and here the interior clean head process right just medial to that it moves upward and pierces the dura mater again and now it is present where in subarachnoid dura mater and recognized matter are placed and now it has come into subarachnoid space this is the right am i clear now exactly the strength I will show in another way so that the position of internal carotid artery should be very very clear let's pause here is the yes now you will identify the structures I think it should be little posterior this is sella turcica are you understanding position on force of course foramen magnum video for the force and interior force or moves should be here fine now where is foramen lacerum foramen lacerum is here and here where here is anterior glenoid processes and here our posterior glenoid processes right actually common carotid arteries from here comes like this moves within cavernous sinus and then medial to the interior cleaner process it goes upward and versus director right and now it comes into Kriya subarachnoid space at this point is there right is it clear right and here what was the structure in which it was present there were no sign of push spread it on both sides is it clear so you have to remember internal carotid artery enter into governor final through the foramen lacerum passes through the governor's finest and medial to the interior cleaner process it turns up for sharply and paces the dura mater and erect net matter to appear in subarachnoid space and of course you should not forget your friend is here who is this visually right so you must know that these arteries are on the sides of which were pregnant and you know what is at the top of the pituitary hypothalamus right anyway we'll talk about that now what are the important branches which are coming out of this okay just a minute I think I should make this little bit if you like a bigger node isn't it now here is your what is it can you tell me what is it with your luck 10 mm this is orbital cavity this is orbital cavity this is a little habit in which there is orbit such a big cavity and you call it Fischer it means you have not seen the Fischer this is a big cavity orbital cavity right here is orbital posterior orbital speed orbital fissure and what it is opteka not right now why I've drawn it the call the washer shoot some branches okay what should be the color of branches green okay what is this branch going of tell me Carter right I will not tell that of tell me Carter give posterior ethmoidal branches even I will not tell it gives into your tomato branches and I do not want to mention that it is making fart rock layer and supraorbital want to know I am really concerned with a very important branch which is going to you will recognize it now someone blond having blue eyes and branch of soft al McHale tree going into this yeah what is it retinal artery central retinal artery you never heard of it right now have this arterial supply and it is very important to know that this is internal carotid artery which is giving the ophthalmic artery of selma currently enters into into what is this orbital cavity through optic canal of selmak re-enters there and it gives one of extremely important branch which is going to the yes what is this retina right this is called central retinal artery moreover it gives posture vital artery anterior spinal artery mrs. Sylvia are tree there are interior what is this coming from here and here so part of the supraorbital artery right now you do not need to remember that but you have to remember there is of kalmyk artery and there is a branch of ophthalmic artery central retina rocks you may be thinking why I'm so fussy about it there's a reason for that because look here many times there are some fun buys from the valve from the valve of the heart from from become into circulatory system are some tome by our President Clark's our president left atrium or there is some claw as some throne by present on a or take valve listen some thrown by from the left atrium or from mitral valve or from aortic valve they may come into carotid circulation or if there is a through the chlorotic plaque here some thrown by from here come so all these some time ago here here here here there is a yes and produce blindness and one of the features of anterior circulation failure carotid circulation failure is you develop blindness in one eye due to occlusion ask closure of central retinal artery this is one of the clinical feature of problems with the crew trade system that carotid system is getting some thrown by the source may be hard for source may be from it of lien in the carotid system so the right so I want my source to remember that found the internal culture are very important branches are of selmak artery and its most important batches central retinal artery am i clear okay thank you for knowing it then another important branch which is coming from here and it is going backwards this is called yes there are two branches which are going backward right one branch is very very both are very very important yeah who will tell me these two branches which are going backward from the internal one is both are going backward guess what is this posterior communicating artery I will gating artery what is it communicating it is communicating between the carotid and vertebrobasilar system this branches communicating between carotid and yes please vertebra basil system we'll discuss in detail about it posterior communicating artery is one branch then there is another branch here what is this this is doing backward so what is this branch car it is the carotid artery which carotid artery anterior or posterior this is anterior choroidal arteries which is going posteriorly yeah this is very funny thing but actually carotid arteries are arteries which are going to the caride plexus of third twenty fourth and lateral ventricles right these are carotid arteries now carotid artery this cradle artery is coming from anterior circulation so it is called interior creditor artery but it's is going backward and as we move backwards it will supply the choroid plexus of lateral ventricle so this is anterior choroidal arteries later on we will learn that from posterior cerebral artery there are posterior cried aloud so what is this blood until here cried an ultra-light now thus knowledge is you haven't F thermic artery you push your communicating artery you have until your carotid artery and now after giving these three important branches it will divide into its terminal branches what will move laterally and one will move anteriorly this is called interior cerebral artery and let which is moving laterally it is called middle cerebral artery again listen carefully what is happening when internal carotid artery comes out through out through the roof of governor sinus of thermacore interiorly and posteriorly there is posterior communicating artery and other name is a anterior choroidal arteries budget is also going posteriorly to supply the choroid plexus of lateral ventricle then after that after giving these three branches and terminal carotid artery will divide into two mineral branches - final branches and these branches are one branch will move forward and other will move one branch will move until early and other will move laterally until your moving is anterior cerebral laterally moving is middle cerebral is that right now let me develop some interesting situation you remember that there was okay I think this thing should be out and let's start developing a relationship there I will remove this kreidel artery for a while and what is this here and who is sitting here way shorter you understand it I hope what is this cavernous sinus mi clip this is the chaudhary system then there must be - enough - another find out or not they should be isn't it and of course there should be an eye also on the other side but I will not talk about that now another and this is Richard from here another artery should come out for yes what is this internal carotid artery from the left side and there is no fun in telling that this will also have all other branches but I will make it two terminal branches what are there splash anterior cerebral artery this is on the right side and that is on the left side and what is this middle cerebral artery on the left side a mic left any question up to this are you very sure okay I'll make just this was and you can see on up to this anyone who is confused no one is confused okay now right system wants to talk to the left system so they should dwell up what are their anterior communicating artery switch from any case between the yes right and the left anterior cerebral vessels is the right any problem up to this interior and as it is giving posterior communicating it should also give what should it give it should also give posterior communicated no problem up to this okay that's great now we should not forget our friends what were these two arteries coming here and what was this alright what was this basilar okay let me make it more romantic type of artery how would the complement is now do you feel now it's romantic or not these are what vertebral arteries vislar artery post your circulation and here it is until your circulation and here it is posterior circulation and after posterior circulation reaches here posterior cerebral artery and posterior cerebral artery now this was your whatever business system just for a ravie and rapidly what is this part okay what is this branch okay what are these branches PyCon and what are these branches what is this long-distance calls what are these what is this right what do you know this okay these are going to talk to that yes right now you see a beautiful ring is made right and what is the frame now let me tell you exactly you will look here this is one side of internal carotid and what is this other side of internal carotid right here is what is this anterior cerebral and here it is middle cerebral right and here was rapidly vislar no problem and and what is it and what is this and what else this communicating and this is the ring this is called Circle of Willis it connects the right carotid system with the left carotid system and also connect up rotate until your circulation to the what's your circulation and zero rate circulation with the vertebral vizla system any question up to this now there is cerebral hemisphere here anterior cerebral artery should supply them middle cerebral artery should supply them and posterior cerebral artery should supply the we'll see the detail of that supply let me erase it now you know exactly where is the circle of the less it is present in subarachnoid space yes under the base of the brain find in front of the of course midbrain and under the cerebral hemispheres okay now I will draw the structure that you were tell me the name right what are these internal carotid and okay now this will divide into what is this branch until you and what are these made of and now what okay what is this very special communication and what is this is no problem you'll make an another way just to see now we have to see into posteriorly and troposphere only mean to decide exactly where in the central nervous system it is present I hope you recognize this structure fine of course no vendor here fine we have to see on this view where exactly Circle of Willis is present you must be doing this here right but anyway it will really make it what is coming out from here and what is yeah okay my triangular change becoming funny now they're becoming a symmetric which type of lis and produce this type of brain and this is now posterity look here what was that internal carotid and what were these yeah anterior cerebral what are these middle cerebral and and and what is it yeah and this is the ring that this is what you see in the diagram that the Circle of Willis now I'll draw it and you have to rapidly say it loudly what are these what are these what are these what are these what are pusher and what are these this where no problem now what is the advantage of this ring the advantage of this ring is of course these are metal circles big advantage of this ring is that first of all posterior communicating artery is a connection between the interior circulation and posterior circulation right for example if you to some reason for sheer circulation is blocked normally blood frumenty posterior circulation is up to here and blood form into your circulation is coming up to here so blood in meeting really in de which artery Soccio communicating but let's suppose if this artery is blocked then work from this side will come and feed in this area right in the same way blood from the left carotid system and right carotid system the meet over here but if blood supply here is less positive heart red somewhat under profuse less the blood can move from here and then Google so advantage of the circle of the left it is a very unique type of collateral supply system that if one point has less less supply than other from other five blood will come and meet the demand of the body or compensate is that fairly clear and one thing which is worth mentioning that interior cerebral anterior communicating artery is the most common site for the Burien or isms you know what Ino isms abnormal dilatation of some part of arteries they are called aneurysms right actually above route sixty percent of and rhythms most of the aneurysms in the center of the system vessel is in the circle of villas and within the circle of villas very and rhythms are most common in that interior communicating artery or its junction with anterior cerebral here are extension with the anterior why because aneurysm which is present here it may compress the optic chiasma right or for example if another term is present here right or here it will compress the third cranial love you are understanding so you should know exactly where these ranges present and what are the structures there now I will make ring in the air and let's see what you can recognize it what are these two arteries commend internal carotid is the right and what are these branches interior middle and these interior connected with until you're communicating right and found this water backward also communicating and what are these vertebral regular cell villagers and procedure communicating of meeting that that is awesome this is their right okay percolo fella now it's on to that what are the areas in cerebral hemispheres which are supplied by anterior cerebral artery and then middle cerebral artery and social circle arteries first I will show you the support lateral surface of hemisphere right cerebral hemisphere I mean okay this is your cerebral I hope you recognize the structure something like that there is central sulcus and the precentral code central and guide I was no fun in telling these things right now we have to see the blood supply over here right that how the blood supply reach to this cerebral Hemisphere so we have to talk about super lateral area plus we have to talk about Jess medial area of course here is your friend what is it Karpov sellers right now Circle of Willis is somewhere here okay we'll move your friend here what was this internal carotids is the right internal carotid these are interior cerebral and clear communicating yes posterior cerebral you know exactly where the situation is now anterior cerebral moving tearily upward and then backward over this over what over corpus Keller and anterior cerebral local I'll make it a color different I will make it blue anterior cerebral moves forward then upward and then moves backward and arches over the what are the structure purposes right now here it is given branches of course or under surface of frontal lobe it is giving cortical branches to the frontal lobe now these branches go upward it is the medial surface of the frontal video surface of the parietal lobe alright these branches are long and offset at the top they turn on the other side they turn like this what does it mean there on the medial side of cerebral hemisphere within the cerebral inter circle longitudinal fissure you find the anterior cerebral artery is running forward then upwards and backward is the right and giving cortical branches right to the medial surface of the frontal lobe and parietal lobe as well as branches are long enough to supply the upper part of what is the frontal lobe and right away it means if you can look here then this branches are coming here like this am i clear you have to move these structures in detail so that it becomes more clear what are these are the branches form anterior cerebral artery is there right now when we talk about middle cerebral artery you know middle cerebral artery is moving from here laterally and from there also left early we want to see rectly where it is now I will take this structure here and look this is frontal lobe and this is temporal lobe I will separate them you may be thinking why do you understand this diagram that what I have shown here look this was frontal lobe and this was temporal lobe actually they have folded on it is downward and it is upward together I opened it like this is that rare actually if you really want to move your circle of the left this is suppose like this this hemisphere right we have opened taken the frontal lobe upward temporal lobe downward and where we look circle of the list it is here internal carotid artery internal carotid artery yeah what was doing here interior this will cheer communicating and this will ring so straight from here this is middle what is this middle cerebral and for other loop other side so middle cerebral artery we can say middle cerebral artery moves laterally and what is this area this is a stem of stem of the lateral sulcus you know level Sal Cassano concept this is the stem of lateral filter okay let me show you this is lateral sulcus it has 180 RMS speed RMS and posterior Rimmer's right and actually you open it stem is inside is just like this that lateral sulcus is here and over that frontal and from blue to brush and from lateral circus this is the medial side of the lateral sulcus and in the narrow side of lateral circus from here push we RMS speed of Emma's interior mo but anyway what is happening that in this diagram this is your lateral surface which is this is the medial side of lateral circus this is the lateral side of the lateral surface on the medial side of the ladder of success is the internal carotid artery dividing into its terminal branches which is interior cerebral and middle cerebral Whipple cerebral moves laterally through the lateral sulcus right until it appears on the surface of this surface of course on the super lateral surface of the cerebral Hemisphere it appears here it means that you may still stand Ram more easy and digestible so this is the point where which artery will come middle therapy everyone is clear from where it came when you open this another side there a circle of pillars from here it will coming laterally so I'm showing here it is come so right now from here important branches of the way number one it will give deep branches here penetrating branches here and here these are called central branches from the middle cerebral artery they are going into deep part of cerebral Hemisphere it will go deep inside and supply the deeper structure like basal ganglia they will supply the corpus striatum or lenticular nucleus internal capsule you get it these are very important branches because these are called lenticular striatal arteries you are know heard of them you heard of them right because they are going into deep structures right in the corpus striatum carpet striatum is what corpus striatum is what caudate nucleus and lenticular nucleus why it is called striatum because many arteries are going like a style through that corpus striatum that part of the basal ganglia through which many many branches are of arteries are going when you make a section it looks like there is a corpus through which multiple striae are going so that part of the basal ganglia is called corpus striatum so these are plenty go straight or branches or simply central branches these are very important because these are very thin walled and these are very long and very commonly they get occluded or blocked and then this blood supply going to the basal ganglia and internal capsule right may lead to then function of the dependent area right and may produce hemiplegia on the opposite side of the body now as soon as this artery come here or from here it will give branches like this in super lateral area this is a you can say territory of middle cerebral artery and there is a small just strip this is territory of anterior cerebral artery my class now so we can say in this diagram what I what will show these are the branches our middle cerebral artery and of course goodsoon will not forget what were these branches yes anterior cerebral arteries now what is so important to learn let me tell you what you know here is central sulcus is their central sulcus here or not central sulcus here is the motor area this is the motor area isn't it please central gyrus this is the present here in one class this is the motor area for the face do you know and then here is your beautiful trunk and our ments what are those finger important thing there is an medial side what is it here foot area do you know this thing I mean if electrically if you stimulate this area hi danette muscles will move if you stimulate here fingers an arm will move if you stimulate at the top of the medial side foot will move to the right by this diagram the important thing is that that foot area is supplied by which artery interior server and we a foot and leg area supplied by anterior cerebral but arm and trunk and the head and neck is applied by middle sorry versus middle cerebral is blocked then this area of the body will be weak paralysis of this area of the body will occur as you can say if middle cerebral artery of left side is block then paralysis on the right side of the body will be there but foot and leg will despaired it will not be read but if someone will elapse left anterior cerebral artery occlusion right then it's less than right foot and let will be weak or paralyzed but rest of the body will not be a mic less the importance of this right if someone has glorified well of hemiparesis and I develop arm and Punk problem the right side right which cerebral cortex is affected left and the right and which are three areas do this top middle cerebral but if I develop weakness only in the lower leg and forth on the right side then it is left on the interior server and if I develop problem in the arm trunk and leg all of them may be virtual it means both territory but you will is such extensively and kill the person actually it is internal capsule because fiber from this area and this area all of them go together down and internal capsule they are back together and these lenticular artery which are going there that is blocked so that is still Julie branches from middle circle are you understand me what I'm saying you are not understanding so not understanding I will make a diagram a small diagram just for you this is Mossad on their side clear lower motor neuron what really happens look here now carefully this area was supplied by anterior cerebral artery and this area was supplied by middle cerebral is the right now look fiber which are coming from this part and also coming from this part we are converging to corner radiator through the internal capsule they will be passing like this and from here their cross you know parameter crossing and then supply heads right actually at this point there is an internal capsule because not going to get you love until as you study the internal capsule yet or not okay then you should be knowing yet that all of these fibers converge into internal castles and through the internal capsule they are going down now if middle cerebral is blocked then soup connections from that super medial side of cerebral cortex they are intact so foot will move and if Imperial cerebral is affected supplies you'd use below circle is working then foot will be affected and that's what the body will be okay let me repeat it again rather I will ask you a question if someone has middle cerebral problem right then foots will not be paralyzed but that's so the body will be but if someone has into your cerebral problems yes then photos will paralyze the rest of the body will be okay so this is about the middle syllable and into your cerebral article branches but if the deep branch is penetrating branches which are coming to you have lenticels fatal bunches because if you really want to know the structure here is your which nucleus if you recognize it put ax men below the sliders and here is your internal capsule now this this structure put oven is here now you see this tray little bunches of passing through that and coming to the telegraph so this visa block then all these fibers either from middle cerebral cortex context or from the anterior cerebral artery cortex all of them are put together and they are dead here then contralateral side of the body big areas hemiplegic am i clear no problem anyway now we come to the posterior cerebral artery right that what is its supply area I will draw another new diagram here was your circle is the right dealer interior to your communicating and yes yeah from here this is posterior cerebral this is going backward and other is going for us now this will supply so she'll sell you what is this midbrain also it will supply the temporal lobe from under temporal log inferior area and from menial area and free area and occipital loop what is this posterior cerebral now this is from a medial side the medial side if I draw the posterior cerebral this is the supply from the posterior cerebral right now on this diagram if I'm a posterior cerebral green then this is the area supplied by posterior surface is that right you are not clear about it are you player you are not understanding no you should understand Claire look these are two hemispheres right what is this frontal lobe frontal lobe parietal lobe occipital lobes temporal lobe are you clear about it okay this is one hemisphere this is RM is fear here is internal charge internal probe directly now first you imagine until your server this is the medial side and this is superlattice now anterior cerebral moves like this over the corpus callosum now interior will supply the medial side of the frontal lobe VGO Toyota parietal lobe and it will also supply it to the over the edge you are understanding is supply of Interior settler middle cerebral will move through this like this as my finger is going through that middle syllable will come here from this side it will supply that structure my class this is anterior cerebral area this is medial cerebral area and here we go cerebral is giving you deep branches radiator is their height now we are left with post you set up a social circle from here you going on the backward when you going backward it will supply temporal lobe from the strip of the temple is to slide by the middle circle as it is going on that side and posterior part of temple load is applied by posterior cerebral and then occipital lobe by posterior cerebral am a class now when you see from the medial side this all is the territory of anterior cerebral this is the territory of social survival and the strictest middle circular from where it is all going a lot now we turn take care it should not fall what is this super lateral surface frontal what is this right Oh what is this it is my wrist not occipital and what is this not thumb here it is temporal right now look middle now super lateral surface how we see the structures because here was what interior so it was supplying this area at the top right indeed server here what was this branch but it comes from the side gives lot of coverage to super lattices from here or going back so on this side little bit it gives is that really clear no problem I'm surprised you learn it now I will draw it again and you will tell me the territories I think that there's about something life she should be little bit prestigious okay it is which surface video some part of the pro lateral support lateral right of course I should make it something like this here so you should know what it is exactly right now supply I will draw and you will tell me what is the supply yes anterior cerebral what is this supply for sale cerebral and the rest of all this is that you make it like this so even kids can make it like this you ask any baby this is right no problem Claro okay now we come to the medial side Claire should come more and terribly basically I think you understand this structure right and of course up now you have to tell me what is this branch going yeah anterior cerebral and from here what's available and middle cerebral from here was going through all the structure deep isn't it here we are giving some tip to the temple right okay I will draw another diagram I'll see how good you are you'll see the view from the top top of the head but not my head in practice there are me otherwise I have to get the hair transplant now look here what is that scores it is brain the frontal lobe from the top is a temporal lobe and either occipital lobe right now which was the artery here interior so they are giving branches like this both interior right I will draw the circle hypothetically to somewhere what is this internal road is maybe someone brain substance is transparent some people do have music who don't think so through that we are looking at the Circle of Willis and here was your and Syria server here what was moving here metal cetera and they meet here and I hope you understand it article branches of Buddha's cerebro what is this posterior cerebral and of course you will not forget what is this interconnection do communicating what are this is there right no problem any question Plus business thank you [Applause]

Channel: Dr. Najeeb Lectures

Views: 524,448

Rating: 4.8918648 out of 5

Keywords: blood, supply, brain, cerebral, circulation, dr najeeb, usmle step 1, neuroscience, neuroanatomy, anatomy, medical education, neuroanatomy (anatomical structure), medical lectures, medical videos, circle of willis, lecturio, dr najeeb lectures, blood brain barrier, neuroanatomy lectures, armando hasudungan, neuroanatomy made easy, blood supply to brain, blood supply to cns, anatomy lectures, neurophysiology, blood supply of brain, central nervous system, ninja nerd, ninja nerd science

Id: GCev2n15ONM

Length: 99min 36sec (5976 seconds)

Published: Sat Apr 22 2017