right now let's look at some deep cerebral structures and we'll start with the basal nuclei and the basal nuclei are shown here in red and we're going to have three nuclei that comprise these nuclei a caudate which needs tail and that is this sort of curved nucleus that arches around and it has both a head portion and a tail so we have the caudate of the caudate so to speak the tail of the tail and then inside of that we're going to see two nuclei that together will form what's called the lid to four nuclei and linda form means lens shaped and we'll look at those in just a second in coronal view but notice the relationship of the basal nuclei to the thalamus so they really sit just outside of it so if we were to look at our brain model and we take up through the inner part here we remember our thalamus here and we've got the thalamus shown here as well in orange we then have the basal nuclei here so this would be the caudate nucleus right here and we'll see in just a little bit what it looks like in coronal view so here's our coronal view and here we have our caudate nucleus that curves around here are all in two form nuclei that are consisting of the putamen and the Globus pallidus so named because it is a pale round structure so it looks sort of like a pale globe in coronal section now we also have some white matter tracts that are some good landmarks here here we have what's called the corpus callosum which we've been over before it's one of our white matter commoners that are linking hemispheres of the right the two hemispheres of the cerebrum then we have something called the corona radiata which is basically just white matter tracts that are traveling through they're going to travel through the basal nuclei through this little highway so to speak called the internal capsule so the corona radiata is just going to be white matter tracts that are going to be connecting the cerebral cortex with lower structures and we're going to have to have this white matter trap to be able to run some way through the basal nuclei to get to the lower structure so they run through in total chasm so all of this is the internal capsule we'll also notice this other structure called the amygdala body and we can see it here as well sort of at the anterior portion at the tail of the caudate and it is typically grouped with limbic structures and this is going to be very important for assessing fear and threat situations so it's going to assess the threats that's going to modulate your reaction to them so it's a very important iblis and what it's damaged sometimes people will start to show ever aberrant behaviors - - noxious or foreign threat causing stimuli now let's look a little bit again at this brain model because this is the caudate this here would be some representation of some of our white matter fibers that we'll be running from the corona radiata through this internal capsule here now the function of the basal nuclei is subconscious adjustment of ongoing motor movements so it's basically I'm going to put the brakes on so to speak some of the commands issued by the motor cortices and it's going to adjust the force and velocity of these movements so that they're not just some perky jerky movement out there and we don't have uncontrolled muscle movements so a lot of times people who have damage to these areas will not be able to coordinator control their muscle function very well and they're also very important for initiating and we will see that the basal nuclei are connected as you recall with the substantia from the midbrain so some researchers group the substantial right along with the basal nuclei because they're working together to adjust the motor tone these ongoing motor movements these conscious motor movements but the basal nuclei are constantly adjusting and fine-tuning these movements here once again as your amygdala and there again that's important for threat assessment and basically modulating fear responses now let's look at some other structures called the limbic system which we've already touched on and the amygdala which is shown right here is actually considered part of the limbic system so we're going to have some cortical structures that you can really only see in sagittal section so we're going to have the cingulate gyrus so called the casita it means belt and the cingulum runs right over top of the corpus callosum here we also have something called the parahippocampal gyrus which is on the interior surface of the temporal lobe so that would be on the interior surface which we really can't see on our brain model but we can see it here and the parahippocampal gyrus is going to contain this red structure called the dentate gyrus and the dentate gyrus contains a structure called the hippocampus and the hippocampus is so called because it looks like ec worse at least anatomist thought it looked like a seahorse so they gave it the Latin name for seahorse which is campus now the hippocampus is very important for two major functions one of which is the consolidation of short-term memory into long-term memory so that is if you're trying to take a fact that you've just learned and turn it into something that you'll remember two weeks from now two months from now two years from now then you're going to have to consolidate that from short-term memory to long-term memory so when you think of short-term memory you think of things like memorizing telephone number long enough to dial it and then once you reach the connection you forget it you don't need it again but other things other bits of information like what you're studying through your anatomy and physiology course you want to remember it for long duration so hopefully you'll be able to remember it for the rest of your life you ideally it would hope so so in order to get that information out of your short-term memory and put it into long-term memory which is a process called consolidation we need to hippocampus in order to do that without the hippocampus you can't accomplish that task there was a very famous patient who went by his initials HM and he had a bilateral hippocampus to me so other words they took it out completely he had a situation where before they back to me remember all the events of his life up to that point after that point you could remember anything new he could learn any new fact and he couldn't lay down any new episodic memories about his own life so he could have a conversation with a doctor you might come in and interview him for some time she could introduce herself from they could play games together and they could do all kinds of things and spend several hours together then she could leave but because he couldn't put any information from short-term memory into long-term memory she could come back in the room three seconds later and he would have no idea who she was however his procedural memory that is being able to do physical tasks was unaffected he could still learn to do new things physical things that didn't require any factor episodic memory but he couldn't lay down any new ideas or information about the episodes in his own life or new facts that human learned the hippocampus is going to be strongly interconnected with regions of the hypothalamus so we have a white matter tracked here called the fornix which links structures of the limbic system with structures of the hypothalamus and one of these structures that are strongly connected or the hippocampus to the mammillary bodies and while we already have learned of the mammillary bodies role in mediating reflex eating movements they also have a role in consolidation of learning and memory and work with the hippocampus we also have another function of hippocampus that's not really talked about book and that's facial navigation so both in humans and and other animals if we're able to record activity from cells within the hippocampus we will find that if you put animals say a rat in a maze and you put electrodes all along the hippocampus and record from individual neurons what researchers have found is those individual neurons will start to become active when the animal enters a certain area of the maze so the certain area certain cells within the hippocampus will come to represent certain areas within the maze and there have been quite a bunch of interesting research studies done both on animals and on here examining the role of the hippocampus in spatial navigation so the limbic system has a lot more function than just you know mediating emotional states as we've thought of it before and we've talked of it before but it also is going to be important for consolidation of short-term memory to long-term memory and also spatial navigation what's interesting about the hippocampus is that whenever you have a very strong emotional reaction to something you're much more likely to remember it so the hippocampus is going to be much more active laying down bits of information if there's a strong emotional valence that's tied with it another interesting fact is that we're going to have so our olfactory cortex very close alongside parts of the limbic system and the hippocampus and so smell as another really potent thing that can evoke memories so smells can evoke very very strong memories