This exercise is going to cover the parts of the brain and we are going to go over the brain folds, the duramator folds. These folds help protect the brain in the skull and the cranium. So when we look at the brain, you'll notice that the brain is two hemispheres.
We have a right and a left cerebral hemisphere. So this is your right cerebral hemisphere, this is your left cerebral hemisphere, and down the middle you have the longitudinal fissure. Now to ensure that the brain is protected, think about glass. If you're moving, you wrap glass in paper or bubble wrap, the duramator folds go into spaces in the brain for extra protection.
So the first duramator fold is going to be what I call the rainbow. It's this whole region here. So this is representing duramator. You can see that it is stuck to the bone here, the cranium.
And this fold is called the falx cerebri and it separates the brain into right and left halves. and it goes into the longitudinal fissure all the way up to the corpus callosum. The corpus callosum is what holds the two halves together. Okay. Now when we look at this picture of the brain, we are going to see that here is our cerebrum, here is our cerebellum.
Between the two, we're going to be able to have a fold about right there. This fold is known as the tentorium cerebellum. So this fold to me kind of looks like flares or fins, and it goes out in both directions.
And this is known as the tentorium cerebelli, and it's going to separate the cerebrum from the cerebellum. It's not a total separation, it's just those folds go in there to help fill in the gaps for protection. Now, when we look at the back of the brain, we're also going to have small separations that occur between the two cerebellum halves.
This separation is going to be found at the base of the skull, and you can see this little bridge here that I'm covering right now. That little bridge is known as the falx cerebelli. The falx cerebelli helps protect the cerebellar hemispheres.
So we have three of these. duramater folds. The rainbow is the falx cerebri.
This one separates the right and left cerebellum. Sorry, not the cerebellum, cerebrum. Right and left cerebrum. We have the tentorium cerebelli, and this separates the cerebrum from the cerebellum.
And then we have the falx. cerebelli, which helps protect and separates the two cerebellar halves. Now, again, this is not full separation.
It's just kind of getting into those cracks and crevices for protection. Next, I'm going to go over the outer anatomy of the brain, the outer anatomy of the brain. First, we're going to have what we call these little noodles. So all of this is a noodle.
These little noodles are called gyri. Some people call them gyri. You might hear it called gyrus, which is singular.
And then in between the noodles, you are going to have the sulci. These are the grooves. Some people call them mountain and valleys. Either one's fine. Sulci is plural.
Sulcus is singular. Now, the sulci and the gyri are going to cover the whole cerebrum. And then there's going to be more distinct ones that help us with marking areas.
So the first one I'm going to go over is going to be this one. This is your lateral sulcus. And it's basically going to separate your...
Temporal lobe from the frontal and the parietal lobes. And then we have your occipital lobe back here. Now another major one is going to be your central sulcus.
And in front of the central sulcus, remember, front is pre. You have your precentral gyrus or gyri. You go for both sides.
And in back of that sulcus, you are going to have your postcentral gyri or gyrus. We also have the longitudinal fissure. You cannot see it from this particular view, but when I go to this view, you can easily see the longitudinal fissure separates your right and left cerebral hemispheres, just different views.
Again, you can see the central sulcus really nicely. And then in front and behind, so seven, I'm sorry, not seven. So we would have the precentral sulci and the postcentral sulci. Same thing here, pre and post.
Now, when you cut in to the cerebrum, You are going to see that your cerebrum is going to be made up of tracts and cortex. So we call those the cerebral tracts and the cerebral cortex. Cerebral tracts are always going to be white matter, so it's going to be myelinated axons.
Cerebral cortex is going to be gray matter, and gray matter is going to be unmyelinated axons, dendrites, and somas. So it's really cool when you see this, because it's really not white and gray, it's more like beige and brown. But the cerebral cortex is going to cover the outside of the brain. So all of this brown kind of color, that is your cerebral cortex all the way around. Okay.
And then your cerebral tracts are all this kind of beige matter. That's white matter, myelinated axons. And you can see the tracts really nicely in this picture. You cannot see cerebral cortex and tracts unless the brain is sliced through the cerebrum. So you won't see it naturally through the longitudinal fissure, because remember, the longitudinal fissure is going to be the area between the right and left cerebral hemispheres that goes into the corpus callosum, which we have not gone over yet, and it's going to be filled with that duramator fold, which is the falx cerebri.
Okay, now we are going to go over the internal parts of the brain. So what we have here is the left hemisphere. You can see that all we're seeing is the noodles, which are the gyri, and then these grooves, which are the sulci. We can't see the cortex or the tracts because the brain is not cut in through the cerebrum. Okay, the first part we're going to go over is going to be the diencephalon.
That basically just means the middle part of the brain. The diencephalon is... going to be what I call kind of the duck region. If you don't see it, don't stress about it.
Okay, so the first thing I'm going to go over is your circular region right here, which is the thalamus. Inside the thalamus, we have this little dot that is known as the intermediate mass. So thalamus and inside of it is the intermediate mass.
So to me, that is the head and the eye of the duck. Now, below the thalamus and the intermediate mass, you are going to have the hypothalamus, which is the beak of the duck. Okay. And then we can see that right beneath the thalamus, we have your pituitary gland. Okay.
all of this together and the epithalamus, which you do not have to identify as the diencephalon. Now on the head of the duck, we're going to have kind of like the little flare coming off of the head to give the duck some characteristics for mating. And this little flare is going to be the penile glands or the penile body. Either name is fine. And this is part, again, of the epithalamus, and it produces melatonin, which helps you with sleep.
Now, above the epithalamus, or above the diencephalon, we are going to have your corpus callosum. That's this big slug, and this is what... connects your right and left cerebral hemispheres.
And then right beneath the corpus callosum, you're going to have this kind of small area and that is known as the fornix. Okay, now the next area we're going to go over is going to be the brainstem. The brainstem is going to be basically from here down, maybe not that far down because I included the spinal cord, but about right here.
And the brainstem consists of three major regions. The first region of the brainstem we're going to color green, that's going to be the midbrain. The second region of the brainstem is the pons. And the third region of the brainstem is the medulla oblongata. Okay, then these three parts together are what we consider the brainstem.
Now, each of them are individual. areas, but all together they make up the brain stem. Okay, now from the brain stem, we would have the continuation of your spinal cord right here. So that is your spinal cord that connects directly with your brain stem.
Okay, now let's go over some parts. In the midbrain, you are going to have your tectum. If you look really closely, you can see one big bump, two big bumps.
two bumps. The tectum, also known as the capora quadrigemina, tectum is much easier to write and say, but the capora quadrigemina tells you four. So you're going to have four bumps, two on each half.
We're only looking at a left cerebral hemisphere, so we're only seeing two of the four bumps. The bumps are known as the superior and the inferior colliculi. colliculus is singular and this tectum is really just the back half of your midbrain it's the back half of your midbrain so even though we're learning that separately just remember that all of this is your midbrain okay next is going to be the cerebellum the cerebellum is the little brain right here the cerebellum has Three main parts that we're going to learn.
The first part of the cerebellum is this white area. This is going to be like branches. We know that as arbor vitae, tree of life. It is also known as the cerebellar tracts. Do not get that confused with cerebral tracts.
So arbor vitae, tree of life is the white matter, also known as cerebellar tracts. Now the brown around it, the brown around it is going to be known as the folia. Folia basically means foliage, leaves. So all the brown around it is going to be gray matter, and that is going to be cerebellar cortex. Not cerebellar.
Yeah, cerebellar, sorry. and we can tell that my spelling is just not great today. Okay, so the cerebellar cortex is the same thing as folia.
Arborvitae is the same thing as cerebellar tracts. Most of the time people like to use the term arborvitae and folia so they don't confuse cerebral tracts and cortex with cerebellar tracts and cortex. The next part of the cerebellum is the vermis. This is not a good angle to see the vermis at. But the vermis is going to be this kind of ridge area that connects the right and left cerebellar halves.
So let me get a quick Google picture since I did not provide one in this PowerPoint. if we can find one quickly yep right here so this is looking at the posterior view of the brain these are your cerebellar halves right cerebellar half left cerebellar half we can't see on the inside of it so we're not seeing the arbor vitae but all the gray matter is the folia and then each of these little ridges so you can see my finger pointer each of these little ridges is the vermis together. It looks like a worm connecting the two.
So the vermis connects the two cerebellar halves. And again, if we looked at this picture, you can see that they kind of circled it and wrote vermis right there. So it's this little part connecting them.
So this is, again, the posterior view of the brain. Here's your occipital lobe. Here is the cerebellar halves.
Here's your vermis. And then here's the tip of your spinal cord. I will do a separate video on cranial nerves.