we will discuss the nervous system in this section when a person is performing an occupation that's meaningful to their life the person needs to uh receive uh the stimulation from the external world and processing the information and then make a decision to for an motor output so that this person um can respond to uh deal world the whole process um is the function of the nervous system within our our human body so specifically the nervous system coordinating uh our body systems to facilitate our performance in occupations uh it help us to regulate our emotion sensation and perceptions it help us to regulate or determine and response through a muscular or uh and or organ actions this is an overview of the N system within our human body there is a centr nervous system called CNS that includes brain and spinal cord there is peripheral nervous system called pns that basically describe um all the nerves coming out from the spinal cord including 12 pairs of cranial nerves spinal nerves uh plaxes and also ainal branches and there is another system called an s or um autonomic nervous system that regulate our response to stress or control the smooth muscles and for um the purpose of this course we will uh just give us give you a brief introduction of this because you will learn much uh in detail in Neuroscience course as I mentioned earlier our human body received the sensory information uh from the sensory receptor um in our human body there are three major type of uh sensory uh receptors the first one is uh mechano receptors that is sensitive to anything mechanical kind of changes and we have thermal receptors that's specifically for uh temperature and we have no C receptors that's specifically for uh pen for um stimulation that may um cause some damage so after uh we receive the sensory uh information uh the sensory neuron which is the the unit of uh nervous system or nervous tissue will uh take the information and send it back to our uh uh information process center um which is um the spinal cord through through the spinal cord and enter um enter the dorsal root of the spinal cord and through the spinal cord the uh the information will be sent uh to the brand uh for information processing and then um the brand uh will send a signal for an out output a motor output through the ventral rout or uh anterior anterior um Horn uh through spinal core and send the output to the peripheral nervous system if we go back to see the uh structure of the neuron um you um there's um axone um that's basically is the nerve that contain all the information and um surrounding the axon there's myin myin is um is you can see that as a a protection to axel and it also can increase the um the speed of sending the information so you can imagine without the aone the uh information can can be slower to be uh delivered and um so this is the uh roughly a general um idea of how we receive the S sensory signal or a stimulation and then take it from the peripheral nerve and then enter the spinal cord and enter uh to the brain and then the brain send an output signal to spinal and to the U the peripheral nerve for an an output so now let me give you a quick uh intro or quick review of the central nervous system like I said you will learn uh much in detail in Neuroscience course so um the brain uh we have the skull uh the Bony structure to protect the brain so looking at the skull we have a frontal parial ocal and temporal bones right here that these kind of bones are you can see this the form is irregular so basically they're nonmovable uh bone bony structures that we use to protect the brain so inside um the uh the skull uh there there is a cerebrum that consists of two hemispheres and each uh hemispheres has um a diff four loopes which we will talk more about that so basically there's a uh motor processing center and then sensory processing center we call it uh motor cortex and somato sensory cortex and you can see um each area of the cortex have its own representation of the body parts that it represents according to the research the more uh we use the bigger the representation area um that we can expect for example if I talk more if I have you know a lot of facial expressions then this area will be larger than my hand or even my my legs if I you know do things a lot if I use my hands a lot then this area will be larger than other areas so that being said The more we do the better um or the bigger area of representation area that we will have in our U cortex so roughly uh the frontal L is in charge of the personality uh the molter movement and U speech the parietal lobe is a uh Center for uh uh or gross sensation like touch pressure and fine sensation like texture weight size shape and it is also Rel relate to reading skills for temporal L um it's um it's a center for Behavior the hearing and language reception and understanding and area for the uh occipital L uh which is in the back here it's a center for vision and is also a center to for us to recognize the size shape and color so these four loopes are uh within the um cortex area if we go deeper in the cerebrum we will we will see um up Thalamus here and hypothalamus here and Thalamus is the center for body sensation and how we perceive the pain um hypo um Thalamus right here is the center for um our Behavior if we go deeper we we will see the basal gangar um here so the basal gang basically uh they're in charge of the coordination of the movement so these are uh the cerebrum um area if we go deeper we will reach to the brim Stam area and brim stem is consist of uh three uh different um area the first one is the m brand is right here and then the pawns and then the medular area right here so these three together we call it uh the brim standand the brim standand is basic basically the vital U function um kind of Center that uh regulated uh regulating reflex um and um um some uh heart rate and uh respiration so um we can move to uh the posterior area where is the cerebellum um um is located the cerebellum right here um is um the center of controlling the muscle coordination muscle tone and posture so together the brain uh the brain um has uh the cerebrum um the brim stain and the cerebella so when we travel down to the spinal cord through um the the me brain or sorry um the brim stain uh and then we continue this um um travel through the spinal cord spinal cord uh basically it transmits information between the brain and the rest of the body um so in in human body um the spinal cord is protected by the spine but the Bony structure of the spine only reached to if if we are uh um the adult the Bony structure only uh ends at the L2 so the rest of it you can see it looks like the horse t it's called CA equina which basically uh from L2 to S5 U these portion we call it called a equina and uh it does not have a bony structure to protect uh the spinal cord and uh within the spinal cord there is the um cerebral spinal fluid AKA um CSF run through um the spinal cord um how we name U each level of spinal cord is basically based on the spinal nerve that's coming out from the spinal cord um using the spine for example uh for the C spine the uh spinal nerve can to come above the H the the spine so C1 is uh the nerve above the C1 C2 is one above the C2 except uh for C8 because there's only seven bones so C7 is uh above and C8 is below the C7 and um starting from the T1 all nerves are coming below um the the bone um so um the central nervous system has its own uh sensory map and motor uh Innovation map for the central nervous system um when we are looking at the sensory map we call it uh this as dermatomes so dermatomes you can see is uh symmetrical um on both side of the body and it's uh basically labeled as uh um the level of the spinal cord so in short you can see um that this the C spine innovates uh the upper extremity the T um spine or you know the dermatome the T U spines kind innovates the trunk the L is for the interior uh side of the lower extremity and S is for the posterior side of the lower extremity and for the motor uh control map we call it myotone for the spinal core or the central nervous system um each level has uh its own um key muscles what what we see here is roughly C3 through C5 it uh innovates uh the diaphragm C5 also innovates biceps and then C8 innovates uh the Palmer into oci and then um T levels innovates the trunk muscle and L again um is for the low extremity and S is for the low extremity what's special for the sensory and motor is um um the area will will not be covered by only one um spinal nerves so that being said if I'm have injury at the C5 and typically C5 and C6 they're kind innovated the similar area so um I may lose uh Innovation from the C6 but I still have control from the C5 so I'm parti uh injured in the sensation area and for the motor area so that make it really important for us to do evaluation to really see um um how our clients are are doing so this is another example of um you know um the level the key muscles or key functions that the spinal cord is in charge of and this is a table just for uh my effort to help you memorize this like for example C5 is for shoulder and elbow flexor C6 is for RIS extensor C7 is for trif and and so on