welcome to your introduction for the neurologic system during this lecture we will be reviewing anatomy of the neurologic system basic functions of the neurons and some aspects of the neurological assessment here we will begin our review of the neurologic systems anatomy please keep in mind that this is an abbreviated review from information you would have learned in your anatomy courses when talking about the neurologic system we primarily break it up into two different subsections the central nervous system and the peripheral nervous system the peripheral nervous system is made up of the 12 pairs of cranial nerves and 31 pairs of spinal nerves and it works to make sure the central nervous system can interact with the rest of the body now nervous tissue of the peripheral nervous system has the potential to regenerate as long as the damage isn't too close to the spinal cord or the damage isn't too severe the central nervous system consists of the brain and the spinal cord although truth be told some look at the spinal cord just as an extension of the medulla in the brain stem the central nervous system is the computer that runs your body as its function is to receive interpret and respond to stimuli from your peripheral nervous system the nervous tissue of the central nervous system does not regenerate if it is damaged the spinal column is what we call the collection of all 33 vertebrae in the human body there are seven cervical vertebrae 12 thoracic vertebrae five lumbar vertebrae five vertebrae that are part of the sacral region now all five of these are fused together and the coxix at the very bottom of the spinal column are four vertebrae that are all fused together as well the spinal cord is given protection by the spinal column however the brain needs to be protected as well one of these methods of protection are the meninges now the meninges are layers that actually wrap around both the brain and the spinal cord the meningis have three layers and the outermost layer is what we call the dura mater it is the thickest layer and it sits closest to the bone other than acting as a cushion it also helps to drain venus blood from the vein from the brain the arachnoid layer is the middle layer if you were able to look at it it would look like a spiderweb which is the reason it has its name while vascular as well it helps by creating a space for cerebrros spinal fluid to be drained and absorbed into the bloodstream helping to keep the pressure of the CSF in balance then the innermost layer of the meninges is called the pomater the pomater is one of the most delicate and fibrous of layers it helps hold blood vessels in place as well as anchor the other layers to the brain itself another protective measure for the central nervous system is cerebral spinal fluid abbreviated as CSF this fluid helps to provide cushion for the brain and spinal cord it is constantly formed in the lateral ventricles of the brain where it then circulates through the subacoid space and down the spinal column csf can then be reabsorbed into the venus sinuses where it is eventually circulated into the body to be eliminated csf helps to remove waste products from the central nervous system and also helps to provide nutrients to the tissues itself over the next few slides we will be going over how a nerve impulse works and what are some of the components of that impulse neurons are the basic functional unit of the nervous system we classify neurons in two different methods first you have your aerant neurons which help bring impulses towards the central nervous system eerant neurons take impulses away from the central nervous system towards the peripheral nervous system now eerant neurons can be further divided into autonomic neurons which help regulate involuntary body responses such as blood vessel constriction whereas somatic neurons the other classification work to provide impulses for voluntary movement such as skeletal muscles a nerve impulse travels from neuron to neuron via the neuronal syninnapse also commonly referred to just as a syninnapse which is a small gap where the axon of one nerve intervates at the cell head of another cell the chemicals at these synapses are what we call neurotransmitters now there are multiple neurotransmitters that do many things in the brain but in general we classify them as either excitatory which can make the nerve impulse transmission faster such as dopamine or serotonin or they are inhibitory and make the impulse slower such as GABA through your nursing education and into your career you will learn more about the individual trans neurotransmitters and the first neurotransmitter that we look into for nerve transmission is acetylcholine as the nerve impulse reaches the end of the nerves it arrives at what we call the neuromuscular junction at this point acetylcholine is released from the axon of the nerve and binds to receptors on the muscle to cause a contraction afterwards the body will release acetylonsterase the enzyme that breaks down acetylcholine and allows the muscle to stop contracting different neurologic disorders can impact the levels of acetylcholine or acetyloline eststerase but you will notice that varying levels of each can appear similar in clinical manifestations not enough acetylcholine can cause a small or potentially no action potential so the muscles are not innervated but the same can be seen if someone has too much acetylonsterase and the opposite can be said about too much acetylcholine and not enough acetyloline eststerase having reviewed the basics of the neurologic system it is now time to cover the basics of the neurologic assessment for nurses we know you have gone over this already in your health assessment course so we will just be skimming the surface as this is more of a refresher when looking at a more basic or generalized neuro assessment one of the first things we look at is the level of consciousness of our patients are they alert are they oriented to person place time and situation and in which we're really looking at are their responses appropriate for your question we also want to look at is your patients what your patients speech patterns look like is their speech slurred or clear and when they speak is it hesitant does it come out pressured or is it normal then we look at their face is their face symmetrical or is their drooping then we can also look at this is when we ask our patients to stick their tongue out for us does their tongue deviate or does it stay at the midline these are some of the first things we look for when performing a neuro assessment other things we look at with our basic or general neuro assessment are our patients pupils are their pupils equal round reactive to light and accommodation this as you will recall is your assessment for pera we also look at your patients strength assess their grip strength is it equal is it expected for their age we do look at both of our patients hands and feet with a push or pull aspect please keep in mind when assessing strength it is best practice to assess both sides simultaneously or at the same time the other thing we like to ask our patients about in our assessment is sensation are they feeling numbness or tingling anywhere or are there just any changes in how things are feeling to them this is another time it is always important to see if things feel the same bilaterally in regard to sensation we want to discuss the concept of dermatomes dermatomes are area of the body that are related to specific spinal nerves in the peripheral nervous system damage to a specific nerve can impact sensation and even function in that dermatome now if someone were to have a spinal cord injury then a lot of times you will see sensation and function impacted not only in one dermatome but possibly in all the dermatomes below that as well now the specific assessment for dermatomes is more commonly done by your provider and not a nurse with that being said a nurse can be provided on the job training so that they can perform a dermatome test now with your cranial nerve assessment it is important to remember that a full cranial nerve assessment isn't typically done as part of your everyday everyday general neuro assessment unless your patients have neurologic concerns it is also important to know how to assess for each cranial nerve so for you in this course not just remembering what cranial nerves do but how would you as a nurse assess for it as a review for the Glasgow Coma Scale the GCS remember we utilize it to assess level of consciousness of our patients the GCES has three different categories involving eyeopening response which can total to four points a verbal response which can total to five and a motor response which can go up to six points this means that 15 is a perfect score on the GCS what this also means is that three is the lowest score that can be given so even a patient who has passed away would still have a GCS of three now most commonly in the medical field a GCS less than 10 is considered emergent and a GCS less than seven many providers will consider those patients to be in a coma now a couple notes to think about with our GCS especially in regards to the motor response part of the score when it says that a patient localizes pain that means the patient will still cross the midline of their body so if you provide a stimulus on the left side of their body they will still use their right arm to try and prevent that stimulus abnormal flexion is what we call decorticate posturing and abnormal extension is derate posturing which we will cover or we have an image of on the next slide there are two different types of body posturing that I mentioned in the Glasgow coma scale they are decorticate posturing which is considered abnormal flexion and disserate posturing which is considered abnormal extension depending on where the neurologic issue happens can be indicated by the type of posturing with decorticate posturing the dysfunction is in the se cerebrum of the brain where if your patient has disserate posturing the issue is in the brain stem or pawns as you may intuit it disserate posturing typically indicates a more life-threatening issue let's briefly discuss the Babenski reflex now this is checked on the bottom of the foot where if you were to provide a sensation on the bottom of the foot from the heel towards the ball of the foot and the pinky toe and then over to the greater toe a positive reflex the toes would flare up and out in an absent binsky reflex the toes would curl downwards now in adults a negative Babensky reflex is normal if an adult patient has a positive Babensky reflex it can indicate a significant neurologic problem however if you are taking care of neonates or infants the Babensky reflex if it's positive where the toes flare up that is actually normal in infants in regards to your neurologic assessment sometimes you do need to provide the patient a painful stimuli or stimulus here are some quick notes about that if you do have to provide a painful stimulus only do it if it is essential and the patient is unresponsive to other stimuli if your patient's family is present please let them know what you were doing and why otherwise it looks like you were trying to hurt their loved one now what do you do for a painful stimuli if you need a central stimulus attempt something like a trapezius squeeze or applying sub supraorbital pressure which is pressure above the eye you can also prov do a sternal rub on a patient however a sternal rub because it is midline will not cause the patient to cross the midline to prevent it thus potentially altering your GCS score now if you need to provide a peripheral stimulus that's painful you can always try the perunal sorry the perunual pressure which is in that bottom image on this slide where you apply a pen or pencil to a fingernail and push down and provide pressure now here are just a few final notes in regards to being a nurse who performs a neurologic assessment which really is all of us as nurses remember to report any neuro changes to the provider whether this is positive or negative if you see pupilary changes in your patient remember that those are a late sign of a problem and are thus urgent comparatively level of consciousness changes are one of the first changes that we see happen in our patients and then we talk about vital sign changes in our patients vital signs can change depending on what the neurologic issue is present some things you might notice and you will learn about more in later semesters is that a patient's systolic blood pressure will increase if they have an increased intraraanial pressure and at the same time their pulse will decrease with that increased pressure in the ICP