 No specific ablution, but we'll have the test so I'm going to do can I do graphys thesia on you and stereo noses on you so I'm going to call you over and I will ask you to demonstrate How to do stereo noses? I'll ask you to show how to do stereo noses and how to do graphys thesia Okay, and I think that will be the only one stereo noses graphys thesia Okay So good morning, anyway So we are going to demonstrate the functional areas in the bridal low Again as usual, let's pick up where we had left off with just adding the frontal low Let's put a few solca in place and then we'll put the functional areas as I told you earlier The entire portion of the brain most of it behind the central sulcus of Rolando is the bridal low So let's put the first sulcus in place as again Like the previous we saw that there is a sulcus which is roughly parallel to the central sulcus That is the post-central sulcus Once we put the post-central sulcus in place we have again a gyrus which is demarcated between the two and that gyrus is known as the post-central gyrus Which contains the primary somatose sensory cortex broadmen area 3 1 2 This receives all the sensations from the entire body If you were to look right at the bottom of this primary sensory cortex, there is yet one more area This is called the second reason why the sensory cortex or s2 if there's a lesion of the primary sensory cortex Let me go for that. Let me tell you the function of the primary sensory cortex The primary sensory cortex is responsible for not only receiving all the primary sensations But it's also responsible for appreciating some of the higher integrative cortical sensations And what are some examples of the integrative cortical sensations? One of them is graphysthesia Other is stereognosis. May I ask Is it to come over here and demonstrate to us How to do the test for stereognosis? She's going to pick up an object with her eyes closed and she'll be able to describe it so please pick up an object with your eyes closed and Tell us what this is So this is stereognosis the ability to move an object in your hand Without seeing it. It's important that you first move the object in your hand and then be able to describe it I'm going to use I'm going to do another test on her Which is also testing of the same area and that is I'm going to keep your eyes closed. I'm going to write something on your palm and I'll ask her to identify what I've written What did I write? Okay So that is graphysthesia. Thank you very much This area is the integrative cortical sensations which we which are perceived by the primary sensory cortex somatosensory cortex So if there's a lesion of this area the person has got contralateral a graphysthesia Contralateral a stereognosis opposite side. What about the lesion S2? Here we get a unique situation It is a lesion of the area S2 the person has got what is known as Cereothalamic pain syndrome Dissociation between pain and its meaning So these are the primary and the secondary sensory somatosensory areas. Let's continue with other areas of the parietal Let's put another sulcus in place We can see that the sulcus runs right through the remaining part of the parietal lobe This sulcus is known as the intra parietal sulcus Once they put ventral parietal sulcus in place again We can see that the rest of the parietal lobe gets divided into an upper and lower part The upper part is known as the superior parietal lobeule SPL and the lower part is known as the inferior parietal lobeule IPL Let's take them one by one The superior parietal lobeule Has got two areas five and seven what function does this this is a higher order of sensory than the S1 and S2 This is a game responsible for stereoclosis Statognosis and somatognosis body image So therefore if there's a lesion of this area the person has got again A-stereognosis A-statognosis A-Somatognosis and also the patient will have bilateral A-praxia So this is the superior brand this area functionally is referred by the somesthetic association area It is a higher order than S1 and S2 Let's come to the remaining part They fear parietal lobeule We have demarcated one important area in the dominant side There's a gyrus which is at the end of the sulcus here This gyrus Which we have labeled as 39 Is a very important gyrus which is seen only on the dominant side and this is known as angular gyrus It is also referred to as Einstein's area because it performs a higher order of mathematical calculations Finkler recognition and not only that we will see in our subsequent slides that this area is also part of other functional areas like wordy case Visual association area oxymony field and so on and so forth So therefore this area is very important on the dominant side and therefore this area has been called the Einstein's area If there's a lesion of the Einstein area angular gyrus on the dominant side We get a unique situation called Gerstmann syndrome where the question had person has got inability to perform calculations a calculia Cannot write a graph here Cannot recognize his right fingers because this on the left side that is called finger agnosia He has got right left disorientation And so these are the features of Gerstmann syndrome which is seen only of lesion of angular gyrus Let's put one more place Gyrus in place on the dominant side in the inferior branch of the movie That is known as the supramarginal gyrus area 40 This is again seen on the dominant side and this lesion of this area produces Conduction aphasia because it contains the superior longitudinal fasciculus running inside it Apart from this lesion of this area will also produce Orofacial apraxia. That's also an important manifestation in general if there's a lesion of the Infine parietal low view on the dominant side apart from all these manifestations the other manifestations will be ideomotor apraxia Ideational apraxia These are all various types of apraxia which is seen lesions of the dominant side However, what is not shown in this picture, but the same inferior parietal low view is present on the non-convenient side also Which you cannot see here, but in some other side That has got a totally different set of functions and it does not have the separate angular gyrus or supramarginal gyrus But it is considered as the IPL as a whole and that IPL as a whole is called the multimodal association cortex What does that it is concerned with body image And if that area is destroyed of the non-dominant side It is called syndrome of non-dominant IPL and the two cardinal manifestations of syndrome of non-dominant IPL are one Person has got construction apraxia They're not make a simple diagram or cannot construct a simple object and The person also has got Sensory heminegalect of the opposite side So since the divisions on the non-dominant side, that's the right side the person tends to neglect Not only the left side of his body, but every sensation on the left side of the world That is called left sensory heminegalect that happens only on the non-dominant side So we have seen the functional areas on the lateral surface of the brain the parietal lobe What about the media surface? So again, let's come back to the picture the media surface which we had left off let's put a Functional area on the media surface and that is this area This whole area is pre-cunious. This pre-cunious is nothing but the continuation of The superior parietal lobe which we saw on the lateral surface That's why the color coding is the same and the functional area is also same if you notice here the pre-cunious on the media side is The continuation of the superior parietal lobe and it's called the same function Only thing is the pre-cunious is on the media side. So that finishes with the parietal lobe