hey everyone welcome to professor long's lectures in anatomy and physiology i'm professor bob long in this video we're going to be going over some of the internal anatomy of the brain some of the internal brain structures at least the limited number that we can see on our models we'll be bouncing between page 32 and 33 on the list of things to know if you're watching these videos you know they're intended for my students the students that are enrolled in my course but if anyone out there in youtube land finds them helpful by all means please hit like and subscribe or at least like so that i know that my videos are helpful and i can keep making them and i'm going to try to pretty them up in the future now i have two brains here one is upside down one is not we call this the puzzle brain it's the 3d one this is the brain on half shell because it comes in half i'm going to start with this model and start showing you some of the anatomy of the internal structures of the brain so i'm only going to use half the brain when we break it open if you just slice through the brain the knife would actually run through the longitudinal fissure a certain distance and then it would hit the corpus callosum from on top so i'm going to open this one up for a second and you can see if i tilt it just a little bit the two hemispheres are separated by a big gap called the longitudinal fissure and you could literally stick something down there and touch the corpus callosum okay now if i slice through the corpus callosum i'm going to get a lot of these other structures so what i'm going to try to do is i'm going to i'm going to try to zoom in on this so that you guys can see exactly what i'm talking about so you're not gonna see me or my face but i'm gonna zoom in a little bit okay so give me just a second let me get my camera going so that you guys are all nice and zoomed in and you can see all the structures again you're not gonna see me in this video mostly you're gonna you're gonna hear my voice but i got a face made for radios so um now obviously all of this up here would be cerebrum this would be the medulla this would be the pons this little structure here this is our cerebellum you can see the white tree-like structure inside the cerebellum called the arbor vt now the first thing we hit is this large arching structure here which is called the corpus callosum now the corpus callosum as i said before is a bridge from the front of the brain to the back and side to side now the corpus callosum is sitting above an empty space so look if i took my two hands like this and made an empty chamber if i was looking from the front of the brain and we sliced the front off then i would see this empty chamber in the middle of the brain if i put a piece of paper across there they would be separated by a little membrane i would still have all of this empty space and all of this empty space those are called the lateral ventricles the membrane that separates them is called the septum pellucidum pel means almost in latin and lucid means clear this little membrane right here is so thin you can almost see through it so they call it the septum pellucidum septum meaning a divider so this is the corpus callosum this is the septum pelucidum and then this little white arching structure just below it is called the fornix so corpus callosum septum pollution and fornix corpus callosum septum pellucidum and fornix and the way to learn this stuff is to repeat it three or four things at a time then i have medulla pons and the cerebellum with the arbor vt now if you look carefully if i sliced right above the ponds across here and right above the rest of this stuff some people refer to this as a duck's head because this would be the the nice uh crown of feathers on the top of the duck this would be the the main part of the head with an eyeball this would be the duck's beak and it's biting onto a little stick with this hanging off this would be the neck of the duck okay well this little neck area is called the midbrain it's one of our major brain regions medulla pons and then just this section is called the now if i go above this all of this up here from the midbrain to the fornix including all of this is called the diencephalon now the corpus callosum the septum pellucidum and the fornix are sitting kind of on top of the diencephalon the major structure in the middle of the diencephalon is this thing right here which is called the thalamus this little almond-shaped structure is called the thalamus now it's a little bit hard to see but once again if i took my two hands like this and i made a mass on either side and i stuck them together and joined them at this knuckle then you can see some space kind of in front of my fingers underneath and even up here above it would go all the way around in three dimensions if i break it in half and turn it you don't really see this space you're seeing the rest of my fist but this knuckle sticks out well this thalamus would be the fist and that little dot that little gold dot in the middle would be my knuckle where the two halves are joined our thalamus is mostly separated and they touch each other at a structure called the interthalamic adhesion and then some people call it the intermediate mass and then some books call it the masa intermedia which is latin for intermediate mass so you can call that little gold dot if i ask for it the interthalamic adhesion the mousa intermedia or the intermediate mass i will accept any of the three names that's where the two halves of the thalamus meet and join this area below that is called the hypothalamus hypothalamus because it's below the thalamus got it so let's run through real quick up here we have cerebrum we have the cerebellum we have the pons and the medulla this little area that looks like the head of a duck is the diencephalon between the top edge of the pons and the diencephalon this area is the midbrain above the diencephalon we have the corpus callosum the septum pellucidum and the fornix the middle part of the diencephalon the major structure here is the thalamus and the little gold dot would be called the intermediate mass and then this little flesh colored area coming down here which would be sort of the bill of the duct it's called the hypothalamus now it's biting on this little white dot when you learn the 12 pairs of cranial nerves one of the things you're going to learn is this if you look at my fingers this nerve is going to go to one eyeball this nerve is going to go to another eyeball and they crisscross those nerves since they go to the eyeball are going to be called the optic nerves where the optic nerves form a little x it's called the optic chiasm and it's really right where they meet if i can slice right down the middle of this and turn it what i would be seeing is that little white dot right there that little white spot is called the optic chiasm it's on your list and it looks like the word optic chiasm but it's pronounced optic chiasm chi is the greek letter x there's a little tiny stem hanging from the optic chiasm to this little meatball that stem is called the infundibulum it connects this structure called the pituitary gland the pituitary or also called the hypothesis so pituitary gland pituitary or hypothesis they're all the same thing the hypothesis or pituitary is connected to the optic chiasm and the rest of the brain by that little tiny stem there called the infundibulum now if this is the pituitary gland then way back here this little pink stripe ends in a little tiny meatball back here and that is going to be called the um oh my gosh i'm drawing a blank uh where the superior colliculus is the pineal gland i'm sorry the pituitary gland and then the pineal gland is this little red mass right here and i know it's kind of hard to see but just below the pineal gland there are two bumps right here the top bump is called a superior colliculus the bottom bump is called an inferior colliculus again these words are on your list so have it handy so i have the pineal gland superior colliculus inferior colliculus now the superior and the inferior colliculus are the back part of the midbrain now one of the things we're going to learn on another model but i'm going to cover it here is what we call the ventricles of the brain the empty chambers i got a ventricle here on this side of the septum pollution if i could poke through the septum pellucidum there would be a ventricle on the other side since there's two ventricles on the side they're called lateral ventricles we tend not to ask it on this model they're going to drain through a little tiny opening here into this area that surrounds the middle of the thalamus and runs through the hypothalamus which would be where we find what we call the third ventricle and then the third ventricle is going to drain through this little groove right here called the cerebral aqueduct also called the mesencephalic aqueduct also called the aqueduct of silvius from the guy who first described it now prosencephalon would be forebrain hindencephalon would be the the back of the brain the brainstem the diencephalons in here the midbrain is sometimes called the mesencephalon meso means middle and so that's the mesencephalic aqueduct that little groove also called the cerebral aqueduct also called the aqueduct of silvius i don't care which name you choose the fluid in the lateral ventricles will drain through the third ventricle then run through the cerebral aqueduct into this chamber this little space at the base of the medulla i'm sorry of the cerebellum is called the fourth ventricle so on this model we tend to like to ask what is the groove here that would be your cerebral aqueduct and that would be the fourth ventricle the other two ventricles are better seen on another model so now that's quite a bit of stuff let's run through it one more time i have the cerebrum up here i have the cerebellum with its arbor arborvitae and i can even see the folia in it i have the medulla and the pons and the midbrain all of this duck head looking thing would be the diencephalon this arch is the corpus callosum the membrane connecting the arches is called the septum pellucidum and then this little arch would be called the fornix this round or oval mass right here is called the thalamus the little dot in the center is called the intermediate mass down here would be called the hypothalamus now the white spot is called the optic chiasm the little stem is called the infundibulum and the red meatball is called the pituitary gland optic chiasm infantry victim pituitary gland now if i go to the back over here this little red spot at the end is called the pineal gland and then i have two bumps a superior and an inferior colliculus the cerebral aqueduct and the fourth ventricle now we have the other half of the brain the only difference is it's facing the opposite direction and they miss the infundibulum and pituitary but all of the structures would be the same corpus callosum septum pelucidum fornix thalamus intermediate mass hypothalamus i get a very good view of the optic chiasm the infundibulum would be there the pituitary is missing there's a little mass right here called the mammillary body it's very hard to see i'll show you on another model i have the thalamus the optic chiasm the hypothalamus i'm sorry i have the thalamus the intermediate mass the hypothalamus optic chiasm infundibulum we're missing the pituitary here but there's the pineal gland that little red meatball and there's a superior and inferior colliculus and the cerebral aqueduct the fourth ventricle pons medulla midbrain cerebellum with the arbor vt finally i'm going to go to our puzzle brain we're going to take the cerebellum and remove it you can see again the vermis and the folia and the two cerebellar hemispheres the vermis is also visible on the bottom i'm gonna get rid of that if i break the two top parts of the brain of the cerebrum off i can look underneath and see some white matter and some gray matter the gray matter of that layer is called the cerebral cortex i also see it from this view and i'm going to face this to where he's facing up at the ceiling you can see the cerebral cortex on the edge the type of tissue there would be called gray matter type of tissue here would be called white matter this is our corpus callosum going from front to back if i pop the corpus callosum off this little light yellow arch right here coming back is called the fornix we don't see the septum pollution on this model but that would be the fornix since the corpus callosum would be above this there would be a membrane right down the middle here separating it called the septum pelucidum that would give me this big empty space in this big empty space that goes from here all the way here those empty spaces are called the lateral ventricles so you can see a good view of the fornix there now i'm going to remove part of the frontal lobe i'm going to pull this out of the temporal and occipital lobes and i'm going to get down to what we call the brain stem and diencephalon i have the medulla here i have the pons here this white area up here would be called the midbrain and then all of this was called the diencephalon they called it that because die means two encephal means head or inside the head and i have this mass and this mass most of this mass across here is the thalamus and it's massive up here it runs across and connects to this one and makes another thalamus now on the outer edge here i see this series of folds that looks like cerebral cortex it has gyra and sulci this little piece right here on either side is called the insula or the insula of rail so this this series of folds is called the insula now when i point to this people think i'm pointing to the whole thing and i'm not i'm just pointing to this outer edge the beauty of our puzzle brain is on one side they have it to where i can remove the insula underneath it is this red bean shaped structure a lentil is a type of bean so this is called the lentiform nucleus or it's also called the putamen or some people pronounce it puttamin so this is the putamen or lentiform nucleus this white area that surrounds it is called the internal capsule because it encapsulates all that and then what covers it is this thin layer called the insula if i peel the insula off underneath would be the putamen and then i have the internal capsule on the other side if i peeled the insula off there would be a putamen in the internal capsule now if i look down on top of it this way i can see the putamen i can see the top edge of the internal capsule this red structure that wraps all the way underneath is called the caudate nucleus that's your caudate nucleus all the way around cauda means tail it has a tail that tucks underneath i can see the caudate nucleus over here as well everything in the middle including these two big lobes hanging off is all part of our thalamus and i can see it from the front connecting right here now on the back side of the thalamus this little meatball in the middle would be called the pineal gland this model is missing a pituitary gland but it does have the pineal gland this top bump is called a superior colliculus this bottom bump is called an inferior colliculus and i have oops i have two superior and two inferior collectively all four are called the corpora quadrigemina quadra means four gemini means twins and corpora means bodies and plural so that's your corpora quadrigemina two superior chelliculi two inferior colliculi and of course this big gap back here would be where the fourth ventricle is so i have the insula if i peel it off i get to the putamen the internal capsule and the caudate nucleus everything across the middle here is all thalamus that's the pineal gland superior colliculi inferior colliculi collectively the corporate quadrigemina if i flip it around to the front i see the medulla i see the pons and all of this is the midbrain and those two little green dots would be called the mamillary bodies this is your two optic nerves they make this x here called the optic chiasm that little white spot where the hole is is called the infundibulum that's where the pituitary was connected and there's the two mammillary bodies one of the things we remembered as students is o optic chiasm i infundibulum am a mammal there's two mammillary bodies the two little green dots now if i break this open this is this the only difference is one is missing this infundibulum in the pituitary and it's missing the corpus callosum the fornix the septum pollution so here you see the corpus callosum and the fornix here i only see the fornix this little red stripe is where the fornix would be this would be the thalamus that would be the intermediate mass this would be the hypothalamus there's an optic nerve so that's the optic chiasm the infundibulum and the mammillary body here i see the pons and the medulla oblongata and here i see the superior and inferior colliculus that groove is the cerebral aqueduct this is where the fourth ventricle would be now that's quite a bit of anatomy and the only way you're going to get it is if you do it so you have to print all of these pictures and you have to start practicing labeling them until you can label them from memory but you should be able to grab a brain model or grab a picture and say this is all cortex corpus callosum septum pellucidum fornix thalamus intermediate mass hypothalamus optic chiasm infundibulum pituitary pineal gland super superior colliculus inferior colliculus here i have the medulla the pons and the midbrain i have the cerebellum with the beautiful arborvitae there's the cerebral aquaduct and the fourth ventricle on this model you should be able to pick it up and say this is the medulla this is the pons this is the midbrain there's the two mammillary bodies this is the optic nerves and the optic chiasm where they meet and that's the infundibulum i have the insula putamen internal capsule and the red on the other side is the caudate nucleus all of this in the middle would be thalamus i hope you had as much fun as i did i hope you learned something this stuff is really hard to to teach and learn sort of in an online setting usually what happens when i'm teaching in a classroom is i have every student with the model in their hands and we go over it they can see it and touch it and feel it so print print the pictures download the images of the of the brain models the brain pictures print them put them in a clear sheet practice labeling them if you have if you can't get them all that's okay do just four and do them in the same order so you can't stand it erase it do it again erase it use a dry erase marker do it again erase it do it again erase it until you can do it from memory the first time you're going to cheat and look at your list second time you do a little less cheating until you don't have to cheat anymore okay it's the only way to learn all this stuff we have quite a few more brain structures and spinal cord structures going so i hope this was helpful i hope you learned something hope you had as much fun as i did and i'll see you in the next video thanks for watching