[Music] welcome back to the easy med channel where medical topics are made easy in this video we're going to be talking about the brain specifically the different lobes of the brain that make up the cerebral cortex and what their different functions are you can see we have a side lateral view of the brain remember that the main components will be the cerebrum which is that colored portion this makes up the majority of the brain and the other components include the cerebellum and brain stem we're going to focus on the cerebrum today and there will be future easy med videos that go in more detail about the cerebellum and brain stem the cerebrum is the largest part of the brain and it's divided into the right and left hemisphere the deep groove that divides the two hemispheres is known as the longitudinal fissure and the two hemispheres are connected by what's called the corpus callosum and this is how the two hemispheres can interact and communicate with each other we'll see some more pictures of the corpus callosum later on in this video the cerebrum has many different functions and we're going to be talking about these functions as we go through each lobe so you don't have to memorize them right now but the overall concept is that the cerebrum will be involved with executive functioning such as problem solving and judgment it's also going to have motor and sensory components again we're going to go in more detail about all these functions as we walk through each lobe but first there's a couple more anatomical features to point out when looking at the overall structure of the cerebrum as you can tell the cerebrum has a lot of different functions and in order to execute all of these different functions it needs to increase its surface area within the cranium or skull and it does this by having a folded structure well this folded structure creates peaks that are called gyri and grooves that are called sulci the singular is gyrus and sulcus this becomes important because there's specific gyri and sockeye that matter when we talk about the anatomy and different functions of these lobes so what are the different lobes of the cerebrum and what exactly is the cerebral cortex the cerebrum is made up of an outer layer of gray matter known as the cerebral cortex and this surrounds the inner layer of white matter the cerebral cortex can be divided into four main lobes the lobe in the front of the brain that you can see in blue is called the frontal lobe the lobe and yellow which is posterior to the frontal lobe is the parietal lobe the lobe in the back of the brain is known as the occipital lobe and the one in green is known as the temporal lobe these different lobes are named after the cranial bones that overly them if you want more information on the anatomy of the cranial bones make sure to check out the easy med video that goes over the anatomy of the skull including the cranial bones sutures and facial bones it's in the anatomy playlist each lobe has one or two primary functions and within each lobe there are specific cortical areas that help to execute these functions there's a simple trick to remember what all these functions are so make sure to stay tuned until the end of the video so you don't miss out we're now going to walk through the anatomy and functions of each lobe starting with the frontal lobe as the name suggests the frontal lobe is located in the front of the brain the frontal lobe is the largest lobe in the cerebral cortex there are a couple boundaries that separate the frontal lobe from the parietal lobe in yellow and the temporal lobe in green the first one is the central sulcus this is the sulcus or groove that will separate the frontal lobe from the parietal lobe the second one is the lateral sulcus also known as the sylvian fissure and this will separate the frontal lobe from the temporal lobe the frontal lobe has many different functions the easiest way to remember the overall function of the frontal lobe is to think of the word action this will include both mental and physical actions so what exactly does this mean well starting with the mental actions this is going to include executive functioning this is primarily mediated by the neurotransmitter dopamine and these executive functions will include things like planning problem solving motivation judgment decision making impulse control social behavior personality memory learning reward and attention so as you can see the frontal lobe plays a major role in determining our personality behavior and decisions and we're going to talk about those specific cortical areas within the frontal lobe that help with this but first we got to talk about the physical actions the physical action of the frontal lobe involves motor control and this includes the planning control and execution of voluntary muscle movements of skeletal muscles muscles that help us move the eyes muscles that help us produce speech and control speech and muscles of the face so again the overall function of the frontal lobe is action this could be mental actions that are involved with executive functioning or physical actions that are involved with motor control and just like we said with executive functioning how there's specific cortical areas within the frontal lobe that help with that there are also specific cortical areas that help with motor control let's talk about what those areas are now as we said before the central sulcus divides the frontal lobe and parietal lobe will just anterior to the central sulcus is a specific gyrus known as the pre-central gyrus this is the anatomical name the functional name is the primary motor cortex and the job of the primary motor cortex is to initiate and execute voluntary muscle movements so the brain will send information from the primary motor cortex of the frontal lobe through the spinal cord out to the skeletal muscles to tell them to move and the body can be mapped out on the primary motor cortex like you see on the image what this does is it shows which specific area of the brain controls movement of which specific body part and if you notice as you move from the medial aspect of the primary motor cortex to the lateral aspect you're moving from the lower body to the upper body so the medial part of the primary motor cortex is going to be involved with movements of the lower extremity whereas the lateral part of the primary motor cortex is going to be involved with movements of the upper extremity and face this becomes important when we talk about strokes if somebody has facial droop or they can't move their arm this involves a different part of the brain and blood supply than if somebody can't move their leg as we move anterior to the primary motor cortex we hit another functional area this is known as the motor association cortex and it's made up of two areas the pre-motor cortex and the supplementary motor cortex the common theme you're going to see among all of the lobes is that every primary cortex has an association cortex and what the motor association cortex does and again it's made up of the pre-motor cortex and supplementary motor cortex is it's involved with planning and coordination of movement whereas the primary motor cortex was more involved with the actual execution of the movement itself the next functional area is just anterior to the motor association cortex it's known as the frontal eye field and its job is fairly simple it's involved with voluntary eye movements specifically rapid eye movements so far we've talked mostly about those physical motor actions but like we said earlier the frontal lobe is also involved with mental actions like executive functioning this is where the prefrontal cortex comes into play the prefrontal cortex is the functional area that sits at the front of the frontal lobe and it's involved in all of those executive functions that we talked about earlier as well as behavior personality memory and learning the final location to talk about with the frontal lobe is broca's area broca's area is usually located in the dominant hemisphere so in most people it's going to be in the left hemisphere because they're right-handed and what broca's area does is it stimulates the muscles that help us produce speech so that covers the main functional areas of the frontal lobe again you can see the overall function of the frontal lobe is action both mental action with executive functioning and physical action with motor movement the other three lobes are going to be more involved with sensory functions rather than motor and we're going to start off with the parietal lobe the parietal lobe sits right behind the frontal lobe and there's a few boundaries to know two of them we've already talked about so that makes it easier the first one is the central sulcus remember this is going to separate the parietal lobe from the frontal lobe the second one is the lateral sulcus or sylvian fissure and this is going to separate the parietal lobe from the temporal lobe and the last one we need to learn is the parietal occipital sulcus this is going to separate the parietal lobe from the occipital lobe as the name suggests whenever you think of the overall function of the parietal lobe think of the word somatosensory so what exactly does this mean well the parietal lobe is going to be involved in awareness of somatic sensation this will include touch pain temperature pressure and vibration it's also going to be involved in processing and analyzing this information as well as storing it as memory so we can recognize it in the future lastly we're going to talk about proprioception with the parietal lobe this is the coordination of all the sensory stimuli so we can develop spatial and body awareness just like what we saw with the frontal lobe there are specific cortical areas within the parietal lobe that correlate with these functions and we're going to talk about those now let's use the central sulcus as our starting point again well if we move just posterior to the central sulcus we hit an important gyrus called the postcentral gyrus this is the anatomical name and the functional name is the primary somatosensory cortex this is similar to what we saw with the frontal lobe remember just anterior to the central sulcus we had the precentral gyrus and this is where the primary motor cortex was well now we have the primary somatosensory cortex and it's going to be involved in conscious awareness of somatic sensations this will include things like touch pain temperature pressure or vibrations so whenever we feel something this somatic stimulus will travel from our periphery up through our spinal cord into the primary somatosensory cortex of the parietal lobe and just like what we did with the primary motor cortex we can map out the body on the primary somatosensory cortex the map is going to look the same the medial part of the primary somatosensory cortex will be the lower extremities and as we move laterally through the cortex we're going to move up the body so for example if we feel some kind of somatic stimulus to our toe that information will travel to the medial aspect of the primary somatosensory cortex versus if we feel something on the face that information will travel to the lateral aspect once that somatic stimulus reaches the primary somatosensory cortex we become consciously aware of that stimulus well now we have to process and analyze that stimulus and how do we do that well that takes us to the next functional area just posterior to the primary somatosensory cortex we have the somatosensory association cortex as we said before you're going to see a common pattern here with every primary cortex there's an association cortex we saw it before with the primary motor cortex and motor association cortex and now we're seeing it again with the primary somatosensory cortex and somatosensory association cortex the job of the somatosensory association cortex is to take these somatic stimuli and process and analyze them store them as memory or compare them to old memories so that way we can recognize what this stimulus is so for example if we close our eyes so there is no visual stimulus and we're handed an object let's say an apple we can feel the shape the firmness the texture of that apple maybe we'll feel that stem and as we process and analyze that information we're going to compare it to old memories from when we've held an apple before and through pattern recognition we're going to know that we're holding an apple without actually seeing it and it's the somatosensory association cortex that allows us to do this there's also a component of proprioception with the somatosensory association cortex and the reason for this is as we process all that somatic stimuli it allows us to gauge our body position in space but we're going to talk more about proprioception in this next area which is the posterior association area you can see that this area is not only in the parietal lobe but it also dips into the occipital lobe and temporal lobe and there's a reason for this the somatosensory stimuli from the parietal lobe the visual stimuli from the occipital lobe and the auditory stimuli from the temporal lobe all meet at the posterior association area and we process and analyze all this information which helps us with proprioception and to develop spatial awareness of our body position and everything around us so these are the main functional areas of the parietal lobe again when you think of the overall function of the parietal lobe think of somatosensory now we're going to talk about the occipital lobe the occipital lobe is located in the back of the brain and there's a couple boundaries to know here the first one we already talked about which is the parietal occipital sulcus and this is going to separate the occipital lobe from the parietal lobe the second boundary is not an actual sulcus it's more of an imaginary line there's a small notch where the temporal lobe and occipital lobe meet it's known as the preoccipital notch and if you can imagine drawing a line from the preoccipital notch up to the prior occipital sulcus that's going to be the boundary between the occipital and temporal lobes whenever you think of the overall function of the occipital lobe think of vision because it's involved with visual stimuli it's going to make us aware of visual stimuli when we see an object and it's also going to play an important role of processing and analyzing these visual stimuli and comparing them to old memories or forming new memories so we can recognize what this stimulus is again there's specific cortical areas within the occipital lobe that correlate with these functions and we're going to talk about those now similar to how there was a primary cortex in both the frontal and parietal lobes we're going to see another primary cortex in the occipital lobe this time it's going to be the primary visual cortex remember it was the primary motor cortex in the frontal lobe and the primary somatosensory cortex in the parietal lobe the primary visual cortex is located in the back of the occipital lobe and its job is to provide us with conscious awareness of visual stimuli so the eyes will send visual information to the primary visual cortex which will make us aware of that stimulus well now we have to process and analyze this information and how are we going to do that you're probably catching on to the pattern here it's another association cortex rightfully so it's called the visual association cortex so again we saw the primary motor cortex and motor association cortex and the frontal lobe we saw the primary somatosensory cortex and somatosensory association cortex in the parietal lobe and now we're seeing the primary visual cortex and visual association cortex in the occipital lobe so once we receive visual information to the primary visual cortex and we become consciously aware of this visual stimulus we send most of that information to the visual association cortex so we can process and analyze it we take a look at the color and shape we also compare to old visual memories we form new visual memories and this helps provide meaning understanding and recognition of what we're looking at so that covers the main functional areas of the occipital lobe again when you think of the overall function of the occipital lobe think of vision the final main lobe is the temporal lobe it's located on the side of the brain and there's a couple boundaries and we've already talked about both of them the first one is the lateral sulcus or the sylvian fissure this separates the temporal lobe from the frontal and parietal lobes the second one is the preoccipital notch remember this is the imaginary line from the notch up to the parietal occipital sulcus and it separates the temporal lobe from the occipital lobe when you think of the overall function of the temporal lobe think of auditory the temporal lobe helps to make us consciously aware of auditory stimuli this is the actual hearing of different pitches and frequencies of sounds it also helps us process and analyze these auditory stimuli so we can understand what it is we're hearing again there's specific cortical areas within the temporal lobe that correlate with these functions so let's talk about those the temporal lobe is going to be similar to the other lobes in which we're going to see that same pattern of a primary cortex with an association cortex so first we have the primary auditory cortex and the job of this area is to provide us with conscious awareness of auditory stimuli so various frequencies and pitches will enter our ears and then enter into the primary auditory cortex which will then make us aware of this stimulus well now we have to process and analyze that information so again there's going to be an association cortex this time it's the auditory association cortex and this will help us process and analyze auditory stimuli it's also going to allow us to form new memories of auditory stimuli compare them to old memories and again this will help provide meaning and understanding to the stimulus the next functional area is wernicke's area it's similar to broca's area that we talked about with the frontal lobe and that it's usually in the dominant hemisphere so again in most people this is going to be the left hemisphere because they're most likely right-handed wernicke's area is involved with comprehension and understanding of written and spoken language so again broca's area was the actual production of speech now the wernicke's area has to do more with comprehension and understanding of that language so up to this point we've gone over a few different senses we've talked about touch we've talked about vision and hearing the only two we haven't talked about are smell and taste so starting with smell this is going to be located on the medial aspect deep inside the temporal lobe it's shown in orange on the picture but just know that it's deep inside on the medial aspect of the temporal lobe so just like every other cortex there's going to be a primary and an association cortex the primary olfactory cortex will be involved in making us consciously aware of smells the olfactory association cortex just like all the other association cortices will help us process analyze and understand that stimulus so these are the main functional areas of the temporal lobe again when you think of the overall function of the temporal lobe think of auditory but don't forget about smell or wernicke's area the final sense we haven't talked about is a sense of taste in order to find the functional area involved in taste we have to pry open the lateral sulcus we have to pull apart the temporal lobe and the frontal lobe and when we look deep inside that lateral sulcus we're going to see the insular cortex or the insula and the insular cortex is involved in taste visceral sensation autonomic control and possibly vestibular information in equilibrium the last thing we're going to talk about and then we'll go over a simple trick to remember the main functions of each lobe is the limbic lobe now there's going to be a separate easy med video that goes in more detail about the limbic system the limbic lobe is just one structure within the limbic system some textbooks lump together the limbic lobe as one of the lobes of the cerebral cortex so that's why i'm pointing that out now so first on the image i want to point out the corpus callosum we talked about that at the beginning of the video the corpus callosum is what connects the right and left hemispheres of the cerebrum and then surrounding the corpus callosum deep inside the cerebrum because we're looking at a sagittal side view of the inside of the brain we've got the limbic lobe and the main components of the limbic lobe include the cingulate and para hippocampal gyrus again the limbic lobe is just one structure of many that make up the limbic system that we'll talk about in a different video and these include the limbic lobe amygdala hippocampal formation thalamus and hypothalamus the primary functions of the limbic system include learning and memory emotions behavior and smell let's wrap this up with some easy tricks to remember the main functions of each of the lobes so starting with the frontal lobe think of the motor of a car the engine sits in the front and this is what drives everything else this is what allows the car to move and is the executive that allows the car to function so think of the frontal lobe as being the driving force in the front of the brain it controls motor movement and it also controls executive functioning for the parietal lobe think of all the p's proprioception pressure pain position this will help you remember the somatosensory stimuli for the occipital lobe think of binoculars this will help you remember vision for the temporal lobe think of tempo of songs and music and this will help you remember hearing and lastly for the limbic system think of love and learning and this will help you remember emotions and memory hopefully this gave you a good overview of the cerebral cortex and the anatomy and functions of each lobe if you found the video useful please give it a quick like before you go or drop a comment if you're new to the channel please subscribe so you don't miss out on future content that makes medicine easy videos are constantly being uploaded and you don't want to miss out i'm also going to link down below in the description the easy med blog that correlates with this video so feel free to check that out as well thanks for watching and hope to see you again