Intracranial Regulation (Neuro AP)
Articles

Intracranial Regulation (Neuro AP)


Alright guys, this is going to be part 1 of Intracranial Regulation. So if you have your outline, just pull that out because what this piece is going to be is going to over the basics of the neurological system which is basically a review of your anatomy & physiology. Before we get into the nervous system itself, I want to talk about the concept of intracranial regulation I put the definition on your outline, but if you really break the word down, when you think “intra” you think inside, “cranial” being the head, the brain area, so we’re inside the brain and we’re going to try and regulate the processes that go on in there. There is so much you’re going to learn as you move through the program about different disease processes that can affect the brain but we’re going to give you just the basic overview of the neurological system and the basics of intracranial regulation. So, you know your neurological system overall helps to regulate the majority of your bodily functions. It controls your muscle movements. It controls your senses. It controls your ability to think, to process things as well as your emotions. So, you collect different sensory input. Next week we’ll talk about part of the sensory lab. We’ll look at some different sensory stimulations that you may experience and then it collect all of that it processes it and interprets and then it causes responses throughout the body based on what it has taken in. So, I like to think of it as a switchboard and I have a picture of that a little later on because if you think back, which some of you may have to Google this to know what it is, but there was a point and time when we made phone calls. It all went through a switchboard and you would just pick up the phone and you would tell the operator the number of the person you wanted to talk to and then she would move wires and lines to get you connected to that person and that is basically what our brain and our nervous system does. So as far as just the average regular presentation of the nervous system, you have two principle parts, one being the central nervous system and one being the peripheral nervous system. The central nervous system consists of your brain and your spinal and the peripheral nervous system deals more with your cranial nerves and your spinal nerves and then you also have the piece called the neuron which is the basic cell within the nervous system. This is covered by a myelin sheath which is just kind of a longer and larger-type of nerve and it helps with the speed of conduction of the impulses that we receive. So you will learn about disease processes where there is damage to that myelin sheath. If that sheath becomes damaged and the rate of the input being able to travel to the brain or from the brain back to the back, slows significantly. Then you also have the white matter of the nervous system which is the material within the brain. Alright. So, we’re going to look first at the central nervous system. A big part of that being the brain itself. It is the control center of the neurological system and of the body within itself. It is protected by three different things. The first being, the meninges, which is connective tissue membranes that cover and protect It is also provides the nourishment for the central nervous system. The second being the cerebrospinal fluids or CSF is how that is normally abbreviated. It works to cushion the brain. It also helps to prevent injury. So it’s kind of like a fluid sac that forms around the brain to protect. But it also provides nourishment as well. And then the last piece being the skull which we all know is a very hard bone that surrounds the brain and it works to protect the brain. Alright. Continuing on with the central nervous system. The second piece would be the cerebrum. Your cerebrum is the largest portion of the brain. The most outer layer of the brain or the gray matter is your cerebral cortex. Your cerebrum is responsible for all of your conscious behavior and you can see it is divided into four lobes and it’s in two hemispheres. You got the right side of the brain and the left side of the brain but these four lobes are on both sides of the brain. So, we’ll start with your frontal lobe and this is the picture straight from your book. It kind of shows you what occurs within that section of the brain. It controls your speech, your thoughts, your emotions, a lot of your voluntary movement, your judgement, your reasoning, your ability to have concern for others. So, frontal lobe controls quite a bit of things and you will notice as you move onto the next one, which is the parietal lobe, speech is mentioned in there as well. So some of these lobes kind of cover for each other so you can hope that if one area is damaged, that maybe the other area would pick up and cover a little bit. Your parietal lobe helps you differentiate between different shapes, it also helps to control your temperature, to know pain and to know the difference in temperature. So it helps you understand the difference between hot and cold. You have your occipital lobe which is what controls the vision. So you can see it says back towards the back portion of the brain. Then you have your temporal lobe which mainly deals with your memory and your ability to smell. The second piece, you can see this is like a switchboard. The second piece we’re going to talk about is the cerebellum. It works with your muscle movement. It controls your balance and your ability to control your body movement. So, it really works with the smooth skeletal muscle movement. It maintains your equilibrium which is your balance and your muscle tone as well. The third piece is the diencephalon and this the piece that I really felt like is your main switchboard. There is several different pieces within the diencephalon one being the thalamus and this is where all this is where input is processed. So this is kind of like the operator of the brain. All of your signals that you’re getting from the rest of your body comes into the brain through the diencephalon through the thalamus portion. It receives those signal, it determines where they need to go and then sends them on to where they need to go. Another portion of the dienchephalon is the hypo- thalamus. it is the autonomic control center. This is key because it influences activity such as blood pressure, heart rate. How strong of a heartbeat that you have. Your digestive motility. Your respiratory rate and depth. Your perception pain. Your perception of fear. It controls your body temperature. It controls your food intake, how much water you take and then your sleep cycles as well. So you can see a lot occurs in your hypothalamus area and hopefully you can see too by some of the things I have mentioned, as to how some of these pieces and these overarching concepts that we are covering will start to tie in together and how they kinda interrelate to each other. In your third piece of the dienchephalon is the epithalamus. It helps control your moods, your sleep cycles and it also contains the piece called the choroid plexus which is where you cerebrospinal fluid is formed. Next, we have our brain stem. Your brain stem is the basic piece that controls our ability to function in our life itself. So, if your brain stem becomes damaged, then there is a very strong chance that you will not live past that point. It influences blood pressure by controlling vasodilation. It helps to regulate the respiratory rate and rhythm. It is also responsible, the next time you develop hiccups, you can blame your brain stem. If you develop a coughing spell or a sneezing spell, you can blame your brain stem. It sits between the cerebrum and the spinal cord and it helps to connect those pathways from the higher structures that are located within the skull to the lower structures throughout the rest of the body. Then the last piece would be for the central nervous system would be your spinal cord. It is approximately 16 inches in length and it’s a continuation of the medulla oblongata. It passes through the skill, at the foramen magnum and then it becomes a vertebral column all the way down to the first lumbar vertebrae. It is protected by meninges, cerebrospinal fluid as well as your boney vertebrae. It helps transmits impulses to and from the brain. So not only does it send impulses up to the brain which ascending but it also sends impulses away from the brain which is descending. Then you have your peripheral nervous system. Your cranial nerves. There are 12 of them. You’re going to become very, very familiar with them over the next week or so. They originate within the brain. They serve different parts of the head and neck. The first two pair, (sneeze), excuse me, sorry, originate in the anterior of the brain and then the remaining 10 pairs originate within the brain stem. As we move further into this and we learn more about the cranial nerves, you will need to know the cranial nerve number and that is always in roman numeral format. You need to learn the name of the cranial nerve. You need to learn whether or not it is a sensory nerve a motor nerve, or if it has both capabilities and then what activity it does, like how we test for that nerve. Part of that we’ll learn once you get into the lab setting. Then you also have spinal nerves and dermatomes. There are 31 different pairs of spinal nerves and they are name according to where they come out of the, or about where they are see. So you can see, you have 8 cranial nerves C1 through C8, then you have 12 thoracic nerves T1 through T12, 5 lumbar nerves, L1 through L5 and then you have 5 sacral nerves, S1 through S5. And then dermatomes are the areas of the skin that are innervated by the cutaneous branch of one spinal nerve. So all of your spinal nerves except for C1 serve some cutaneous region. So C1 is the only one that really does not have some type of dermatome. And then the last part of this, I want us to look at some of the developmental changes that occur between infants and older adults because those are usually the two biggest areas that we see the biggest changes within the neurological system as part of normal growth and development. In infants, their growth is very rapid during the fetal period. So as a new born baby, there are several things reflexes that they have as soon as they are born and then they begin to disappear after about one month of age. The first one being the sucking sensation. So if you rub part of their cheek or if you automatically stick something like your pinky within their mouth, they automatically have that innate ability to suck on that pinky or if you put a pacifier in their mouth, they automatically know what to do with that. Stepping, if you ever hold a baby upright, it’s little feed will move like it’s trying to walk. Rooting is where you touch their side of their cheek, they will automatically turn their head towards that sensation. Startle or moro reflex is where you bump into their crib, suddenly like all of their arms and legs will just kind of flare out like their startled. Babinski is where if we touch the bottom of their foot, all of their their toes will kind of spread out like they they’ll spread out, I can’t think of what I was trying to say. The babinski is a good thing. We want to see that until they are about two years old. After the age of two, if we stimulate the bottom of their foot, their toes should curl in. If they do not, then that is an abnormal reflex. So we will still check for babinski in adults to see what their toes do. Do they curl in which is abnormal. I’m sorry, let me rephrase that. As an adult if we are checking for the babinski response, if their toes curl in that’s normal, that is what we want to see. If their toes flare out, that is abnormal. Their toes should only flare out which is a positive babinski response up until the age of 2. After the age of 2, their toes should curl in. Their cry, their cry is, as I am sure we have all heard very strong, we want to hear that strong cry. We do not want it to be a very weak or a more shrill cat-like sound. Their head circumference. We typically measure that at the level of their ears across their forehead and you’ll learn a lot more about that. as you move into your Peds section and then of course we always assess a childs fine motor skills and they compare it against certain bench marks and milestones so we can determine if the child is growing according to national standards. Then we flip over to our older adult and there are lot of things that occur that are part of the normal aging process and these processes are very subtle, they are very slow so it’s very hard sometimes to see the decrease in their neurological function and a lot of times they have changes that we just attribute to their age, but a lot of these changes can also occur from different medications that they are on, they can occur with infections or illnesses such two biggest ones being Parkinson’s Disease and Alzheimer’s Disease. So just because you can see the list there, you have your impulse transmission decreases, your reaction to stimuli decreases, your reflection, can’t talk, your reflexes are diminished the coordination is not as strong, their senses are not as acute, their muscle mass and tone decreases, so we have to be careful and not just lump that into, “oh well it’s because their old.” There could be something else going on. Like confusion, confusion we automatically chalk that up to because they’re old. Well, a lot of times confusion is the first sign of an infection in an older adult patient. So these are some of the things we have to keep in mind when we’re looking at the older adult. Alright, so that’s it for this little section and like I said it’s just a basic review of your anatomy & physiology, so when we meet in class you can see you’ve got way more of an outline and we will go over all of that in class and wh at all of that means. If you want to go ahead and fill some things in from your book and from your reading, then that way you will be able to listen more in careful, that would be great! But otherwise, just come to class with the outline and we will fill it out and talk about things there. Alright? Have a great evening.

Leave a Reply

Your email address will not be published. Required fields are marked *