 In this video we are going to compare MRI images of the brain to this schematic 3D model. By doing so we will get a better intuition for how the parts of the brain fit together. So the three sets of images you see here are taken in three different planes. The coronal, sagittal and transverse planes. And this corresponds to these planes on our 3D model, coronal, sagittal and transverse. Throughout the video I will be moving through all three planes. Notice how if I click and drag on this image we move through the slices on the other planes. Take a look at the coronal plane as I drag the cursor through the sagittal from right to left. I will bring that back to the center. Take a look at the transverse plane images as I drag the cursor from the top of the brain downward. Fantastic. Occasionally I will bring up or enlarge one plane like so. This is a sagittal plane image right in the midline. So we are looking at the very middle of the brain here. Let's move over to our 3D model for a moment. To really ground ourselves let's recreate the image you can still see on the left there. So in order to do that we will take away half of all the models. And then we can line up our sagittal image. Okay so now that you have a bit of a sense of perspective let's begin talking about the anatomy. The first thing we see is the cortex, the gray matter on the outside of the brain. In our eye now we see the darker gray cortex. It's all bumpy and knobbly which is why it goes by the name cortex. It means bark in Latin because anatomists from back in the day thought it felt like the bark of a tree. The cortex is divided into lobes which we will just go through briefly. That's the frontal, parietal, occipital and temporal lobes. Beneath the gray matter moving over to look at our MRI again is all this white matter. The white matter is the axons or the electrical wires of the neurons that make up the brain. The cell body, the part of the neuron that generates or manipulates information is in the cortex. Let's put this in context with an example. So in order to move our muscles a message has to be generated in the brain and sent down the spinal cord. Let's think about the passage of that information in the brain. The cell body in the motor cortex which sits in the back part of the frontal lobe generates the message. It sends it down the axon part of the white matter here and the axon passes through this area called the internal capsule. That's just a name to describe this particular chunk of white matter in the brain which is oriented like so. If you look at our MRIs it's kind of hard to make out the internal capsule but we can see it best on our transverse plane. See that part there? That's the internal capsule and we'll return to it later on. Our axon then heads for the brain stem, this part here. It runs through the front part of the midbrain first, then through the pond, then through the front part of the medulla oblongata. Let's go through that in our MRIs now. So there's the midbrain, there's the ponds, and there's the medulla leading to the spinal cord. In our coronal plane there's the midbrain, there's the ponds, and there's the medulla. The brain stem plugs straight into the spinal cord. On from there our axon heads towards its muscle. Now what about a message carrying sensory information? It would go the other way, right? It would come from the spinal cord up through the brain stem again but instead of running straight out to the cortex it would drop its message off at another neuron which has its cell body in this area called the thalamus. On our MRI here's the thalamus here. Now follow this part as I move through the sagittal section. So we're in the very centre of the brain now. Moving over there's the thalamus and if we keep on moving laterally we see it gets bigger and moves posteriorly. Now let's go back to the centre and look for it in the axial plane. It's hard to distinguish but here's a good marker. See this shape here, that's the midbrain. Let's go down from the bottom again. Spinal cord there, medulla, ponds, and midbrain with its funny little legs sticking out. So we know that's what the midbrain looks like and we know the thalamus attaches directly to the midbrain. So if we move slightly up from there, that's the thalamus. And hopefully you'll remember that's the internal capsule just lateral to it. So our neuron started off in the thalamus, right? Its axon then heads through the internal capsule and drops it off, drops its message off in the sensory cortex which is in the front part of the parietal lobe. That's a lot to take in for one video but I hope you take away from it a better appreciation for the foundation of neural pathways in the brain as well as the importance of these structures that we've talked about. The cortex, the underlying white matter, the internal capsule, the thalamus and the brainstem. Hit like and subscribe if you found this video useful. Thank you for watching and we will see you next time.