Meninges | Dura mater | Arachnoid mater | Pia mater

today we are going to talk about the coverings of the membranous coverings of the central nervous system right there are three types of membranes which are enveloping around the brain in the spinal cord right let me show you that by a simple diagram first of all suppose here is your central nervous system of course you'd recognize these structures right now the first covering which is very very intimately covering the central nervous system is Piatt met by a metal is the connective tissue layer which is highly vascular it is highly vascular very delicate very thin very closely covering all the surfaces of brain and spinal cord right and this paya meta this moves throughout with the central nervous system right so we can say that this black layer is pyometra what is meant by the paya matter what is meant by the word paya and mater just who'll tell me anyone yes very good paya means soft and mater means mother so it's a soft mother taking care of the central nervous system why a matter is the most close the layer of the connective tissue covering the central nervous system this layer is highly vascular and it is very very soft right that is why it is called paya netter paya mean yes soft matter mean mother a very soft mother taking care of a central nervous system right outside the pile matter there is next covering and this covering is called a recognized matter this is the outer covering outside the PI emitter and this covers the central nervous system and this is called reckon I'd I reckon I'd matter what is the meaning of arachnoid what is the meaning of spider right so we can say this is another mother taking care of the central nervous system protecting the central our system but when you look at a recognised matter it look like a spider why it looks like a spider because it has multiple connective tissue ridicul I right and these trabeculae are connecting the recognized matter with the Piatt matter right these are connective tissue arabic you lie is that clear now outside this there is dura mater what is the layer outside dura mater and dura mater is a very very tough and strong membranous structure it's made of connective tissue of course but it is very tough it is very strong right and that is why it is called dura dura mean strong tough hard right so dura mater right in this way there are three coverings of the turtle of a system there is Pia mater then there is reckon I'd better and then there is dura mater I will draw them again and now you have to tell me the names of these coverings let's suppose here is central nervous system right now this is the first layer coming I'm changing the colors so that you have to really think what is the first layer yes please Pia mater is it vast floor of nonvascular highly vascular then what is the second layer yes please I reckon I'd and it is relatively nonvascular and outside that a very strong layer what is that layer yes dura is that clear right and I recognized has a big line now before we really go into detail I would like to talk about some very important clinical relevance with these coverings have you heard of the terms called epidural hemorrhage epidural hemorrhage then there is another term which is called yes subdural hemorrhage then there is another term which is used for yes another hemorrhage we have to talk about these all hemorrhages epidural subdural then there is some recognized hemorrhage arachnoid hemorrhage and then there is intracerebral hemorrhage delta cerebral hemorrhage before I really go into detail I would like my stroll should be very very crystal clear about these different type of hemorrhages because these different four types of hemorrhages are at different locations in different spaces and different places and clinically they have different causes and different consequences right first of all we will talk about epidural hemorrhage where the epidural hemorrhage occur every epidural hemorrhages or epidural hematoma or epidural bleeding is in epidural space now we have to see what is the epidural space where is the epidural space so who will tell me where is epidural space yes we are talking about epidural hemorrhage er then epidural space so who knows where is exactly in this diagram at funerals face anyone yeah [Music] excellent very good let me tell you what he is saying let's make a more simple diagram that this is your skull bone right this is skull bone it's a very simple diagram and here is your what is this dura mater right dura mater basically has two layers when we talk about in relation to the skull you know mater has two layers one layer is very much attached with the bone right this is the layer of the dura mater which is very much I must draw that it is sticky with the bone and this layer which is sticking with the bone this is called periosteal layer of the dura mater this is Perry Bastian layer of the dura mater then dura mater has one more layer which is called meningeal layer the second is called this is meningeal layer and this is Perry Australia now this is the meningeal layer of dura mater right at some places it becomes separated from the periosteal layer and make a space there the space here at some places naturally physiologically these two layers separate and they make a space and in this space this space is lined by and o3 yes what is it endothelial cells and this endothelial cells line space is meant for a very special purpose through the space venous blood is running right again let me repeat this is meningeal layer this is periosteum and at some places Magellan and Padilla still separate and the channel is made and through this channel blood is running physiologically this space is called this through which the blood is running this is called dual sinus there within the dura mater there is a sinus through which the blood is running so we call it venous dural sinuses what we call them venous dural sinuses these are natural I will teach you those things later in tomorrow's lecture Venus dural sinuses but usually at other places these two layers are very close to each other this layer and the other layer when in your lair and periosteal layer very very close to each other they are almost attacked sticking to each other but battle by some pathological process we can separate it and create a space again listen these two layers are very very close accepted what is this Venus Bureau thanasis right they are very close right but sometimes they can be separated because normally physiologically space is not there we say that there is no actual space there is potential space when there are two layers in the body there are any two layers in the body they are sticking with each other right but with some pathological process we can create a space but normally there is no space we say there is no actual space there is only four tential space so between these two layers of the doer metal actually normally there is potential space when we talk about the sky and relationship or Bureau matter am i clear now but a very important vessels run through this area very important blood vessels run through this area who will tell me the blood vessels which run at this point okay let me make a more clear diagram so that you remember those vessels that there are some blood vessels which run at this area course is artery and there is a wane along with it the meningeal arteries and veins excellent who said it good good I read good so meningeal all trees and meningeal veins which supply the blood to the skull bone as well as mainly to meninges meningeal arteries and veins run between the skull bone and what is this layer meningeal layer or you can say meningeal artery and meningeal veins run between the what is this periosteal and meningeal dura mater some people assume periosteal layer should be taken as skull part right so this is the manager layer of the matter now these meningeal vessels exactly where they run let me explain let's see who recognizes these landmarks first of all here is your nose I hope you understand what are these and like me a little bit here now don't laugh at your teacher right I have do have some here now listen now what is happening anterior cranial fossa and middle game of cosine first we are going to force of course you must be doing at least this foramen what is this - magnum thanks for knowing it okay this is of course what is that Solara schita which would be Lancet over here like this yeah now this is middle cranial fossa from here through foramen spinosum meningeal middle meningeal artery comes out and it gives an interior branch which runs like this and posture branches now this artery is running in a groove between this is the bone and this is the durometer or to be very accurate this artery is running between two layers of the dura mater it is very accurate and this space this is the artery running a mcclure now this artery is exactly running at this space this is a branch of anterior branch of middle meningeal artery this is very important branch why because if you hit someone at temple if you hit somewhere at temple the bones here are very weak there is sequoias part of temporal bone and there is squamous part of vital bone and these bones here are very very weak and under this area there are meningeal artery is vessels and if you get an injury here if this bone the fractured right and within the bony groove these vessels are running these vessels are ruptured or lacerated and a bleeding start and this bleeding or blood which leaks out which accumulates between the skull and the dura mater right so what really happens if this vessels rupture yes what will happen hematoma will go like this all this blood is what is this hemorrhage blood is accumulating here right now this is out of meningeal layer right so we call it hemorrhages within the epidural space please don't confuse this hemorrhage with the hemorrhage later on I will explain which I can at this point hemorrhage at this point number 1 this is epidural hemorrhage right later on I will explain that here is what what is this I reckon I'd right and hemorrhage can occur between do dura and recognized at this point that is the different hand rage entirely with different causes with different consequences right so right now we are concentrating only in epidural hemorrhage some authors call epidural hemorrhage as extradural hemorrhage also because they say the truly durometer is a membranous layer right so this hemorrhage right this one this is epidural as well as it can be considered yes extra bureau hemorrhage now someone asked you now what are the causes of this type of hemorrhage you can say ROM or to the skull injury to the skull most commonly on the temple right especially when it involves the ruptures or bleeding from the which are trees anterior branch of middle meningeal artery and waning emmaclaire really now very special point about this epidural hemorrhages you know the cause right you know the vessel which is involved now a little bit clinical so what is the very special thing about this which really if you as a doctor you know that you can save lives the special thing is something called lucid interval in the clinical picture let me tell you what is the lucid interval usually what happens person gets the injury is that right he gets the injury if he becomes unconscious if a person gets injury and injury and he gets unconscious if there is no bleeding he should recover rapidly this is the right listen now carefully if someone get a head injury here number one he should not be unconscious number two if he become unconscious and there is no hemorrhage within the brain if he is unconscious due to contusion all injury to the brain substance he should recover very rapidly but a person who has hemorrhage like this his clinical picture is different either he becomes unconscious due to initial injury and then recovers after the recovery he again Garage gradually start falling into deeper level of lower conscious level you have to remember this that initial injury if it produces unconsciousness normally should recover rapidly or it may not produce unconsciousness right but if there is epidural hemorrhage then gradually over the hours or days or even weeks patient progressively goes into deeper and deeper level of fall in level of conscious unconsciousness right so we can say this interval between the initial event and later on development of the drowsiness and unconsciousness this time interval is called lucid interval what is it called lucid interval it is very very typical of epidural hemorrhage it's very very typical of epidural hemorrhage that for example person is brought to the hospital and he is progressively going into deeper levels of coma and there is some history of head injury right and people who bring him they may nurit that after the head injury in initial did not last the consciousness and after a few hours or days he started or they say initially he lost the conscious level he recovered and then later on he started losing it am i clear to everyone no problem here another important point about this type of hemorrhage is of course I'm teaching doctors that point is important all of you are going to be doctor am i right right and it's a very important point is when you suspect some problem like this immediately do the CT scan right from CT scan if this hemorrhage is they are there will be you know hematoma visible the blood is very very dense it makes dense image darker image than the brain substance right but this image is very special configuration of this image of the streamer Toma which helps you to differentiate this hematoma from other hematomas what is special thing about this hematoma image the special thing is that dura mater is attaching with the skull tightly because dura mater is normally attaching with the skull tightly when once bleeding the curve between the skull and the dura mater do you think blood will easily separate or it has to produce pen tension it will produce tension right so it will start producing tension and making a very important hematoma which forcefully separates the dura mater from the skull but as you know metal is stripped away a point will come where dura mater is attached with the suture of the suppose these are the skull bones and you know in between the skull bones there are what is there suturing ligaments sutural ligaments at the suture of ligaments mean dura mater is tightly held at the sutural ligaments dura mater is tightly sticking with the skull so blood cannot escape into that direction then as blood is trackin down here maybe this is another suture on another bone and in between the bone that is suture and this is another suture or ligament so again this is very tightly held here so what really happens that dura mater will be stripped like this right but dura mater cannot lift it from this suture point attachment point and durometer cannot be lifted away from this point so what really happens that the shape of this hematoma is now you see like that it is like a lens this shape is like a lens on one side there's go on other side there are doodle attachment so this is very very diagnostic point that if you suspect hemorrhage in the cranial cavity and you take MRI or you do the CT scan and on that you find the hematoma is making lens shape lens shape or by convex arrangement right or hematoma especially abruptly blocked by sutural points you must think this is what kind of hematoma or what cut what type of hemorrhage Rohan I hope you'll remember that and treatment is not that difficult if you diagnose it right transfer it to the neurosurgeons and usually they produce a burr hole here and evacuate the clock any question up to this No so this is epidural hemorrhage again epidural space in the cranial cavity is it a real space or potential space potential space is the right and which are trees bleed there meningeal arteries and veins is that clear right now we come to the next subdural hemorrhage right we have to differentiate this with the subdural hemorrhage okay I will draw subdural here so that you can compare and contrast the both this is what was this epidural is that right now we will come to the concept of subdural hemorrhage few minutes spent on this console may help you to save lives suppose this is the bone skull bone and what was this layer very austere layer and what is this layer please meningeal layer right and after that yeah what was here in please what is this here I reckon I'd better I reckon I'd better isn't it and there's no fun in telling that there must be of course cerebral hemisphere here central nervous system and there's no fun in telling that here is Pia mater am i clear now you have to develop a very clear concept what is the cause of hemorrhage and subdural area for that you have to understand anatomy of certain vessels there are veins we drain the blood from the cerebral Hemisphere those veins as a group are called cerebral veins what are those veins cerebral veins now let's now where the circular waves drain this is cerebral way in which is draining from multiple point and taking the blood out of the brain and then it will pass through Piatt matter several veins will pass for piyah matter then it will pass through I recognize that's very good after passing through Pia mater it has to pass through yes recognized mater and through the recognized matter then it passes perforates what is this point dura mater and eventually it drain into venous sinus I'll make this vein more clear what does this mean this is an example of cerebral wayne right and cerebral wins again they are from cerebral hemisphere going out Pierce a parameter pairs the recognized matter pacer dura mater and drain into different dural venous sinuses is that clear now first I tell you the space we were not going to talk about which hemorrhage yes subdural hemorrhage subdural hemorrhage should be between which two areas

Channel: Dr. Najeeb Lectures

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Keywords: meninges, pia mater, anatomy, dura mater, arachnoid mater, brain, neuroanatomy, brain anatomy, human anatomy, dura, arachnoid, central nervous system, neuroscience, cerebrum, spinal cord, usmle step 1, midbrain, cerebrospinal fluid, human anatomy and physiology, nervous system, brainstem, meninges function, pia mater brain, meninges layers, pia mater function, brain dura mater pia mater, meninges of brain, 3 layers of meninges, dura mater spinal cord, meninges lecture

Id: 2OwxdqjM4-g

Length: 27min 0sec (1620 seconds)

Published: Sat Sep 09 2017