hello everybody and welcome today we're going to be looking at the anatomy of the cerebellum cerebellum meaning little brain now despite its size there's actually a lot of anatomy to go through so I've chaptered this video if you want to jump to a specific topic now we're going to start by looking at the shape and the location of the cerebellum before diving into some more detailed Anatomy so let's have a look at this MRI scan here we have a sagittal coronal and axial slices the coronal and sagittal slices have got contrast the axial is uncontr it scan here let's start with our sag image and we can see the cerebellum here it lies in the posterior cranial fosser which is made up predominantly by the occipital bone and the anterior part of this posterior cranial fosser is made up by the petus part of the temporal bone it's sitting in that posterior fosser if we scroll to the midline we can see that the cerebellum lies posterior to the brain stem here's the midbrain the ponds and the medalo blata it also lies inferior to the cerebrum here now the cerebellum is separated from the cerebrum by this double fold of Jura known as the torum cerebell and you can see how the torum cerebell curves upwards as we head medially here and it follows the shape of the cerebellum we can see the superior margin of the cerebellum curves with that torum cerebell above the midline of the cerebellum we can see this structure here which is filled with contrast it's filled with Venus blood if we go to our sagittal plane again we can see that's the structure we're talking about here which is known as the straight sinus the straight sinus drains blood towards the tular herophili or the Confluence of the sinuses it's receiving blood both from the inferior sagittal sinus as well as the vein of galin here which is getting blood from the internal cerebral veins as well as a superior cerebella vein here that Confluence of the sinus then drains blood into two separate transverse sinuses that flank the lateral parts of the cerebellum we can see the transverse sinuses here on our coronal plane they start at the Confluence of the sinuses and then they Traverse the lateral margins of the cerebellum here they then become the sigmoid sinuses that drain blood into the dular veins okay so there's where the cerebellum is sitting we can see how the superior surface has this shape the inferior surface of the cerebellum is these large pendulous loes that we're going to look at and name later on we can also see the cerebelum has a midline structure here which is known as the fourth ventricle it houses CSF the fourth ventricle receives CSF from the third ventricle superiorly via this channel here which is known as the cerebral Aqueduct or the aqueduct of sylvus it then drains out CSF CSF leaves the fourth ventricle via a midline opening here known as the median aperture or the framan of mendi we can see that on our axial slices here if we scroll inferiorly this opening here this midline opening is the frame and mendi if we stay on these axial slices we also know that there are two lateral openings here the lateral apertures or the parameter of lushka anteriorly here this is alala of blata and as we head up superiorly the pwns and the midbrain here we know that the midbrain is separated into an anterior portion the tegmentum and a posterior portion the tectum by the cerebral aqueduct that's draining CSF from the third ventricle to the fourth ventricle and the tectum have the calculi the superior and inferior calculi here you see the superior and inferior culi that's what's known as a quadral plate the CSF syst behind the quadral plate is called the quadral syst and that lies superior to the cerebellum here inferior to the cerebellum we also have a large SST that's lying within the fan Magnum this is what's known as the sna magnets the largest s of the if we were to go to the sna Magna let's scroll down on our axial slices here's a sna Magna we can see there's also a system that's running around the medala of lataa and the ponds that's what's known as a cerebella pontine or cerebella medary syst here okay let's get into the actual cerebellum itself if we go to the midline we look at our coronal plane here we can see at the midline we've got these large lateral structures these are what's known as a cerebella hemisphere the left and right cerebell hemisphere at the midline we can see this bulge here that extends all the way around the cerebellum that's what's known as a cerebella vermis a small midline bulge before the cerebellum extends out to the cerebella hemispheres now the vermis we can see on our axial slice here we can see the vermis as this midline structure here and as we scroll down the vermis continues down in the inferior aspect of the cerebellum here again if we look at our sagittal plane notice how the cerebellum extends superiorly and actually the Superior part of the cerebellum here is much higher than these occipital lobes here and you can see if we were looking at an axial slice how we would see both occipital loes and cerebellum let's scroll superiorly on our axial slices and I'll show you what I mean we're in the cerebrum here and as we scroll down we start to get the cerebellum coming into view whilst we've still got a lot of the cerebral hemispheres in view here this can be confused using to people as to why we're seeing so much cerebellum whilst we're still within the cranial Vault within the cerebrum here here you can appreciate that midline vermis and those lateral cerebella hemispheres and we can see how those cerebella hemispheres are attached to the brain stem now the cerebella hemispheres are attached to the brain stem by three panles the largest of which being the middle cerebella ped dunal here we can see the pedal on our coronal slice here as we scroll into the fourth ventricle we can see how the brain stem is attached to the cerebral hemispheres by this large middle cerebella peduncle inferiorly we can see these bulges here this is what's known as the inferior cerebella peduncle we look at our axial slice and scroll inferiorly the inferior cerebell ped unles are here now when we look at our contrasted scan later there's a Michelin man sign here and the legs of the Michelin Man what make up those inferior cerebella ped unles superiorly we've got these Superior cerebella ped unles or Superior cerebella ped unles depending on how you want to describe it that attaches to just below the quadr geminal plate that we were talking about of the midbrain earlier if we look at our sagittal images and scroll across an Al coronal to that cerebella peduncle you can see there the superior cerebella peduncle as we scroll out laterally there's the middle and here are our inferior cereb pedal here okay so that's how the cerebellum attaches to the midbrain now let's go back to the midline if we're on our sagittal images what we're at here is we're cutting through that vermis we're not cutting through the cerebella hemispheres now the vermis is separated into nine different lobules these lobules will also extend out towards the hemispheres and they will become different names but essentially they're extensions of the vermos into the cerebella hemispheres let's go about naming those different lobules so the cerebellum is separated in into three different loes primarily we have an anterior lobe which is smaller than the larger inferior posterior lob so an anterior lobe and a posterior lobe and then we've got a focular nodular lobe which we're going to look at later a small lobe on the anterior and inferior surface of the cerebellum the anterior lobe has is bound posteriorly by the primary cerebella fure here that's this fure here that we can see a vessel running into this is what's known as the anterior lobe and that has three lobules within the anterior lobe now the first lob is the most anterior lobal and it's a small lobal extending out here you can see it here this small region Here is known as the lingular lob of the cerebellum lingular meaning tongue if you can remember the lingular lobe in the left lung a tongue likee projection of that lingular lobe the same here the way I like to remember it if you think of the cerebellum as a shoe here and we were putting our foot into the fourth ventricle our toes then extending out this way you think at the tongue of a shoe that you pull up before you tie your laces that's the lingular lobe a very small thin lobe heading up here behind the lingular Lobel is this lob here this is what's known as the central Lobel if we were looking at the brain as a whole this Lobel would probably be the most Central of the lobules within the cerebellum behind the central lob is one of the larger lobules of the cerebellum this is what's known as the colan it extends up superiorly here if we were scrolling on our axial slices remember when we scrolled into the cerebellum here this is the tip of the cman that we see first here now colan if anyone's into bird watching they will know that the colan of a bird's beak is that peak of the superior Ridge of a bird's beak Colman meaning Peak we can think of culminate when we reach the peak that's why this lul is called the cman now that is the anterior lobe of the cerebellum we know that this is called the primary cerebella Fisher below the primary cerebella Fisher is our next lobal here known as the declive lobal decl meaning to lower or to fall we can think of the word decline and that makes sense we're coming from the Coman here and then we're descending or falling down to the decline Lobel then we've got a very small lob here it looks like a branch extending out that's what's known as the folium so we got the deive the folium and we then reach another Fisher here so we've got the primary cerebella Fisher the next Fisher the second largest Fisher of the cerebellum is what's known as the horizontal Fisher it runs along the whole edge of the cerebellum the horizontal fish I like to think of as Horizon and that helps us to name the next lob down here that we can see known as the tuba if we think of uh tuba of a plant it's a swelling of the roots of a plant a potato is known as a tuba if we were to bury a potato it would be below the Horizon it would be underneath the horizontal Fisher that's why this is the tuba Lobel of the vermis of the cerebellum then we have this large triangular-shaped Lobel here that's separated from the tuba by this fure this fure is what's known as a pre parimal fure and this large triangular lob with this large base here is called the pyramid lob for obvious reasons because of its shape here so the pre pyramidal fissure and the pyramid lobu here then we have a Lobel that hangs down towards the fan magn this is what's known as the uila you know the uila at the back of your throat also hangs down like that and it's a good way to remember and it's why this is called the UIL here then just like the lingular above we've got a small lobu here known as the nodule and when we look later at our cerebella hemispheres we're going to look at that nodule again but that's the last lob of the cerebellum now difficult to name all of these but they are important as those lobules then extend out into the hemispheres and become different names so I'm going to go through those lobules again and tell you what the hemisphere counterparts are called we start with the lingular and the central lobules when we head out into the cerebella hemispheres those are just known as The Wing of the lingula and the wing of the central lobu those are easy to remember the wings of the lingular and the central Lobel then we have this large lobal here which we know is the cman that becomes the quadrangular lob of the cerebella hemispheres you can see the primary Fisher here again again we can go to our axial slices here and scroll down to that primary Fisher see the primary Fisher here this is the Coleman essentially and as we follow that primary fish around these bodies of the cerebella hemispheres are what's known as the quadrangular lobules below the colan we have the deive the deive heads out laterally becomes the simple lobules of the cerebella hemispheres now the folium and the tuba lie on either side of the horiz Al Fisher like I said they become the superior semi lunar lobal and the inferior semi lunar Lobel so the folium becomes the superior semi lunar lobal and the tuba becomes the inferior semi lunar lobal semi lunar meaning Half Moon shaped you can imagine them running as a half moon around into the cerebella hemispheres here we can see on our coronal plane how these hemispheres extend out and you can see where if I scroll down more inferiorly on our still here we can see where the folium and the deive will be heading out into these lobules here then we have the pyramid Lobel of the vermis that pyramid Lobel becomes the bental Lobel those are quite large lobules on the inferior surface of the cerebellum here now the uula we talked about the uula hanging on the back of the throat it's cerebella hemisphere counterparts so what's known as the tonsils you would have heard of the tonsils when we're looking at herniation of the cerebellum through the F and Magnum if we scroll down inferiorly on our axial slice here we can see the cerebella tonsils that shouldn't extend through the fan Magnum we know that the last structure we were talking about at the vermal plane here at the midline plane was the nodule here now the nodule as it extends out to the cerebella hemispheres becomes what's known as the fulus and the combination of the nodule as well as the fulus becomes a focular nodular lobe remember we had the anterior lobe and the post lobe the focular nodular lobe is a separate lobe in itself and you can actually see it on our axial slices as we head up here you can see how it's actually separate to the rest of the cerebellum so our nodule is here and we get this tissue heading out of the cerebellum making up these little wings here that's what's known as a focular nodular lobe see it extending out here now you mustn't get this confused with an acoustic Sanoma this is a at the cerebellopontine angle this is where acoustic schomas occur and they occur at this opening here known as a porous acusticus internis here this is where we're going to see a vestibular Sanoma or an acoustic schwannoma the focular nodular lobe can often be confused with that especially when we get contrast added here because this can often light up much more than the rest of the cerebella hemispheres and really look like a vula chanoma but we don't get widening of that porous acoustic internis where a vestibular chanoma would occur Okay so we've named the lobules we can see the organizational structure of the cerebellum here is similar to the cerebrum we've got gray matter on the surface of the cerebrum the same with the cerebellum we've got gray matter on the surface and internally we've got white matter the axons heading out of the cerebellum through those cerebella ped unles towards the brain stem unlike the brain where the suai are seemingly random in their orientation the cerebellum has these almost parallel folds on the surface here known as Folia almost like pages in a book you can see these F got a highly organized structure of the cerebellum and then we've got this white matter this is a T1 weighted scans so gray matter is darker gray matter is less intense than white matter now within this white matter just like within the re we've got basil nuclei we also have cerebella nuclei within the white matter here it's difficult to see those cerebella nuclei on a T1 weighted scan and we often need heavily T2 weighted scans or T2 star weighted scans we can actually appreciate it best on anwi image remember when we look at a susceptibility weighted image we know that we can see the red nuclei much better the substantial much better and as we scroll down inferiorly into the cerebellum we're actually going to see the largest deep cerebellum nuclei here this hypointense relatively speaking to the surrounding cerebellum this hypointense structure almost a jagged edge rounded like this it's a lateral structure this is the largest cerebella nuclei known as a dentate nuclei now these are lateral nuclei as we had medially and just behind the fourth ventricle we've got much smaller nuclei and going from lateral to medial those nuclei can be named we're not going to actually see them very well on this swi image and those nuclei are called the emboli form the globos nuclei and the fial nuclei we're not going to see them on the scan but you may be asked to name the four Cabella nuclei the dentate nucleus the emboli formform nucleus the globos nucleus and the f nucleus Okay so we've named The Deep nuclei we've seen the structure of the cerebellum and the shape of the cerebellum the last thing I want to touch on is the blood supply to the cerebellum let me get a contrasted axial image here load it up now the cerebellum as we saw in the sagittal it kind of extends from inferior to Superior it runs from posterior to anterior much like the midbrain is angled forward like that and our blood supply follows that and we can see the vertebral arteries here that left and the right vertebral artery they've gone through the transverse feramin of the cervical spine they've entered the framan Magnum and they're going to give off the first Branch to the inferior surface of the cerebellum here and we know that inferior is more posterior so this is what's known as the posterior inferior cerebella arteries those vertebral arteries combined to form the basil artery and it's going to give off a second Branch we can see the branch here follow it round heading towards the basil artery that that branch is what's known as the anterior inferior cerebella artery we're still supplying the inferior surface of the cerebellum here but we're much more anterior now you see how those vertebral arteries go from posterior to anterior as we head up through the basil artery we're going to see our last Branch as we had more and more superiorly our last Branch here this is what's known as the superior cerebella arteries those branch off the distal basil artery before our posterior cerebral arteries that contribute to the Circle of Willis here okay so we've now looked at the location the structure the organization of the cerebellum the loes and the lobules of both the vermis and the cerebella hemispheres the Deep cerebella nuclei and the blood supply to the cerebellum it's a lot to cover as I've said again a reminder I've chaptered this video if you want to come back and revise a specific part of the cerebellum jump to that chapter save this video into a playlist on your YouTube and you can come back to this video for reference I really hope that you found this video useful at least for me learning cerebella Anatomy took a long time so I hope videos like this help expedite that process help you learn this Anatomy quicker that's all for me today I'll see you all in the next video goodbye everybody