 Please have a few really at your respective stations with your specimens. Sonya has done a wonderful job of introducing the camera for us. Now is I'm going to walk you through each and every structure on this specimen here. And as I walk you through, please look at the same structure in the specimen at your station. Some of you will have wide arms at the brain, some of you will have a left arm. It doesn't matter, both arms are symmetrical. So let's start with the lateral surface of the brain. I'm holding the right hemisphere in my hand. I'm holding the right hemisphere. This is the central surface. Central surface of Rolando. As you can see it's slightly downwards. Can you tell the audio is down? You know how to work this thing to make it better? Yes. So this is the lateral surface of Rolando. Which goes all the way down but does not touch the lateral surface. This is the lateral surface. So please identify the two most important sulky on the lateral surface. I presume all of you have identified it. So anything that is below that is the temporal lobe and anything which is above is the frontal and the parietal lobe. Are we good with that? So you can see the lateral central surface very clearly here. This is the central surface. This is the central surface. Now let's see just posterior to that. You can see another sulcus. This is the post-central sulcus and you can see a gyrus. This is the post-central gyrus. This is area 312, the primary somatosensory cortex. Just in front you see another sulcus which may not be complete but it is there. This one. This is the pre-central sulcus. And this gyrus in front is the pre-central gyrus. The primary motor. This is area 4. In front of this you can see this triangular area here. This triangular area. This area. This is the pre-motor cortex. Area 6. Which extends to the medial side as the medial frontal gyrus. This we have said was the supplementary motor area. The rest is the pre-frontal cortex. The rest is pre-frontal. So on the lateral surface this is called the DL-PFC. Dorsal lateral PFC. On the medial surface is the medial PFC. The medial PFC includes part of the cigarette sulcus also. Cigarette gyrus and the rest. And this is the orbital frontal PFC. The orbital frontal PFC. This is the orbital frontal. Because this is in contact with the orbital blade of frontal bone. So three parts of the PFC. So we have seen only one more important functional area remains in the frontal lobe. Let's look at that. The most important one from our perspective. This happens to be the right hemisphere. So it will not be present in this. But those of you who have the left hemisphere it will be present. And what is that? The Broca's area. So I am going to show you the location. The Broca's area at least see the location in the left hemisphere. This is going to be just anterior to the central sulcus. It is located here and here. These two. This and this is Broca's area. Just above the lateral fissure and this region. This is Broca's area. On your left hemisphere this is where the Broca's area is. So in your description, in your exams what you get is as you can see it is quite far from the anterior part of the frontal lobe. So it is actually the posterior part of the frontal lobe just in front of the central sulcus is situated in the Broca's area. This is the Broca's area. Not on the right side but on the left side. So a typical question that I gave you yesterday was a patient after an attack of stroke developed a foreign language tone. Where is the site of lesion? So you have to mention this site. Similarly after an attack of stroke a patient developed inability to speak where is the site of lesion? Left, inferior frontal gyrus or whatever. So this is how you must look. So we have seen all the important functionalities in the frontal lobe. We recap primary motor cortex, premotor cortex, Broca's area, media frontal gyrus, prefrontal cortex. Yes, one gradient remains. This line, this one that you see here. This is the superior frontal sulcus, and this is the inferior frontal sulcus. None of these sulcus will be continues as shown in the books. So this is the superior frontal gyrus, this is the middle frontal gyrus, and this is the inferior frontal gyrus. So the frontal ideal will be situated here. This is what the frontal ideal will be situated here. This is concerned with to the opposite side. Are we good? Still now, has everybody followed the functional areas in the frontal lobe? Okay. Now, let's come to the parietal lobe. Again, we'll start with the central cell this year. Those central gyrus, primary sensory cortex, 3, 1, 2, stereognosis, graphistesia, endosthesia, all sensations. Look at this. This cell just here. This one. This is the intra parietal cell this. So, the portion about that is the superior parietal lobe. And the entire portion below that is the inferior parietal lobe. SPL, IVL. I am on the non-dominant side. Remember, non-dominant ideal is even more important. And you have a whole syndrome or the syndrome of non-dominant ideal. What was the feature of that? Two most important features. What were they? Contralateral heavy neglect and construction apraxia. That means if the region is on the right side, the person will neglect his or her left side of the body, left visual image, left tactile extension, left auditory extension, left half of the body, no dressing, no washing, no brushing, whatever. Everything left side gone, not recognizing. Construction apraxia safely, not drawing anything on the left side of the image. Your clock, you will not draw the left side of the image. You will draw them in the right side, and so on and so forth. So, this is the syndrome of non-dominant ideal, non-dominant. I have the non-dominant side on me. So, those of you who are the dominant side, you have another syndrome. Can anybody name that syndrome for me? These are the ones we have to know. We call it Burschman syndrome. And what was that Burschman syndrome? Finger egnosia. Especially, egnosia on the right hand, because it's on the left side. Egg alcoolia, alexia, agrafia, right left right hand side. These are all features of the left dominant mysterious ideal. Those of you who have it with you. STL, what are the functions? Again, stereognosis, somatognosis, stereognosis, somatognosis, and statognosis. Stereognosis, somatognosis, statognosis. These are the things which need to know. Superior parietal lobobu, inferior parietal lobobu, dominant, non-dominant. That's parietal lobobus. Now, let's come to the occipital lobe. Now, it becomes the media side. We cannot describe the occipital lobe on the left hand side. How do we differentiate the occipital lobe? You can see the surface here. This is the parietal occipital sulcus. Why is it called parietal occipital? Because it separates the parietal lobe in front from the occipital lobe behind. That's why it's called the parietal occipital sulcus. This is the one which we have forcibly made it on the left hand side, but actually it is not there on the left hand side. Actually it extends only on the media side. So that's why we can see only on the media surface. This whole portion behind the parietal occipital is the occipital lobe. We will further subdivide it into a lower and an upper part by this sulcus here. This is called the calcarine sulcus. That is the reason why this whole occipital cortex is also referred to as calcarine cortex. When we divide it into a superior and an inferior bank, they are referred to as superior inferior banks. The superior bank is roughly triangular in shape. It is called the cuneous gyrus. The inferior bank is roughly tongue shaped. It is called the lingual gyrus. I told you I am holding the right hemisphere. The right occipital cortex serves the left visual field and vice versa. The superior bank serves the inferior visual field and vice versa. So only this cuneous gyrus will serve which visual field. Left lower visual field. This particular lingual gyrus will serve which visual field. Left upper. Keep this point in mind because this is where you will be asked questions. This is what we need to know. Further details about the visual pathways we have seen in block 3. Cuneous gyrus lingual gyrus. Just around it is V1. You cannot see the V1, V2, V3, V4, V5 here. That is all that we need to see in this. But the few details which we have mentioned in the glass is all described. Everything is described around this area. Now let's come to temporal lobe.