Okay, so we're going to start with an external view of the sheep brain. As you can see, the meninges have been removed except for the pia matter, which is kind of the shiny sheen that you see. But the arachnoid and dura matter are completely removed. We'll see a small part of it later when I show you the inferior aspect. But as far as the parts that I'm going to mention, I would like you to go back eventually and look for functions for these individual parts.
Now from this superior view, as far as what we can see here, we have the cerebrum, which is the large region here. You have a longitudinal fissure. separating that cerebrum into left and right hemispheres.
As you go posterior to that, we see the cerebellum here. And notice on the sheep brain, the cerebellum is directly posterior to the cerebrum. In human anatomy, the cerebellum would be more inferior to the cerebrum.
Now as I flip this over to the inferior view, here we then see the brain stem. So you have the midbrain, the pons, and the medulla here. Once you go beyond that, you see the spinal cord.
This is the region where we removed the remaining dura matter. You see a little bit of dura there. We also removed the optic nerve, the pituitary gland, and the trigeminal nerves.
I'm going to remove those so you can get a better view of that brainstem again. Now again, for the regions of the brainstem, please make sure you go back and find the function. So midbrain, pons, medulla.
If we go back to the cerebrum, back to this view. I would like you guys to consider the lobes. We have the frontal lobes here, the parietal lobes.
If we get our lateral view here, we see the temporal lobe. And then as we go to the posterior aspect there, you see the occipital lobes. So please make sure you go back and find functions for the lobes.
There is a fifth lobe that's not visible here, but that is the insula. Again, take a look at pictures of the brain. that were sent out and you will get a view of the insula there.
So make sure you guys find that. Otherwise from here we're going to make a mid-sagittal section of the brain. As we section the brain, we can now see the internal anatomy of the brain as far as the features that we're concerned with. Please remember that as we look at the cerebrum here, once you begin to go deep, this is now white matter.
And deep within the cerebrum we see this large region of white matter known as the corpus callosum. Here's our corpus callosum. Within the corpus callosum is where you find the lateral ventricles.
And notice at the tip of the pointer there, that region where you see tissue, it looks like there's a little bit of film covering the tip of the pointer. That is the septum pellucidum. So lateral ventricle, corpus callosum, septum pellucidum. As you go inferior to that, you do see the fornix here. And once you go posterior to the fornix, we now get a good view of the thalamus.
or the central commissure of the thalamus. Inferior to that you have the hypothalamus, this region here. And notice the optic chiasma here just in front of that hypothalamus. If we go back to the thalamus, notice the space here.
This space now is then our third ventricle. Going posterior to that we now see the pineal gland and the corpora quadra gemini. So if you notice kind of from a side view here on the corpora quadra gemini, You do see the superior and inferior collicula.
And then here is the midbrain. Well, this is part of the midbrain. Here is the cerebral aqueduct now draining into the fourth ventricle. So the space that you see here is that fourth ventricle. Otherwise, you see the pons and the medulla.
And you also see the arborvitae, which is the white matter within the cerebellum. Those are the major parts of the internal anatomy that we're concerned with. Again, please make sure you find functions for those. That's it.