Sensory (Ascending) Tracts in the Spinal Cord

I've run dr. Mike here in this video we're going to take a look at the spinal cord and we're gonna have a look at a sending pathways these are sensory signals that are being sent from our external internal environment to our brain and brain stem now what I've drawn up here is a spinal cord so let's pretend I've pulled out your spinal cord and I've sliced through the spinal cord right at the lumbar area so this is Rand here and we're looking now bird's-eye view into the spinal cord a couple of things that you can see first thing is here in the middle you've got what we call grey matter now this grey matter is simply where one neuron will speak to the next neuron so this is where neurons synapse this is where conversations I had this is where information is integrated right now the rest of it everything else out here is called white matter and they are pathways they're highways that are either going up to the brainstem and brain or they're going down so they can be shut out and away from motor signals so everything going up which is a sending or afferent is going to be sensory information everything going down is going to be motor or efferent information now on the left hand side we've got motor descending effort this side we've got a sending afferent or sensory information so in this video we're just going to focus on everything go into the brain for sensory information okay couple of things as well firstly every time some sort of sensory information is going into the brainstem so think about let's just say I were to touch something with my fingertip sensory information is going down my arm into my spinal cord now it enters the spinal cord from the back so all sensory information will come into the spinal cord via the back all motor output is going to be coming out via the front so dorsal sensory anterior or ventral motor now when this sensory information comes in it's got a couple of decisions that can make you can see I've highlighted some green areas here on the spinal cord these green areas are highlighted in the pathways they can take up to the brainstem and brain all right let's have a look depending on the type of sensory information if it jumps into what we call the dorsal column medial niska's pathway okay terrible name but if it jumps into this pathway and goes up to the brain it's because it's going to be some form of fine touch so that's if somebody were to touch my arm or hand like this fine touch or conscious proprioception proprioception is knowing where you are in your own space you know how much your arm is contracted because there are muscle spindles and Golgi bodies that are in your joints that tell you how contracted a muscle or joint is this is important for knowing where you are in your own space it's why when you close your eyes you can touch your nose okay so that type of information is going to jump into the dorsal column medial lemniscus pathway go up to the brain now if it originates if this sensory information originates below thoracic level 6 below thoracic level 6 it's going up by the fasciculus graceless that's the pathway it's going up if it's happening above t6 it's going to be coming in by the fasciculus cue notice so there the different highways that this sensory information can take now I'll get the spinocerebellar spine oh referring to the spinal cord cerebellar is referring to the cerebellum this is that small brain it literally means small brain you find at the back and underneath the syrup the cerebrum and what that's there for is for proprioception and balance again knowing where you're on your own space and balance so here the type of information we're getting in is going to be unconscious proprioception okay so this unconscious proprioception can come in either go via the dorsal or ventral spinocerebellar tracks that's these two here what are the difference differences between the two well the dorsal spinocerebellar tract simply will take information from the same side that comes in and bring it straight up on the same side of the brain to the cerebellum the ventral spinocerebellar will bring information in throw it to the other side bring it up and then throw it back to the other side before it goes to the cerebellum it seems to be that the dorsal spinocerebellar sends information during movement and the ventral spinocerebellar sends information about that movement as we move down we'll get the anterior lateral system this anterior lateral system has two major types the lateral spinothalamic and the ventral spinothalamic okay the lateral spinothalamic which you can see here is very important when it comes to pain and temperature so this is sending information about pain and temperature and as you can see when it comes in if it's more medial so towards the midline of the spinal cord it's bringing information from the cervical or neck region then as it goes more lateral the thoracic lumbar and sacral region so for example if information is coming in about pain in my foot it'll come in and go on to the most lateral aspect of the lateral spinothalamic tract if it's coming in about pain maybe my arm for example it's gonna go all the way to the middle aspect okay the other thing about pain is when the signal comes in it crosses immediately to the other side okay so this is also for touch as well any time somebody touches your hand or puts a painful stimulus on the hand it's going to go into the spine and ultimately cross to the other side if it's pain it crosses immediately if it's touch it won't cross until it gets up towards the brainstem alright the lateral like I said is pain and temperature and the ventral spinothalamic is crude touch so crude touch is going to be pressure based touch as well and as you can see it comes in via this little pathway as well now in the next video we're going to talk about motor output coming down

Channel: Dr Matt & Dr Mike

Views: 22,116

Rating: 4.9498434 out of 5

Keywords: sesnory, ascending pathways, sensory pathway, sensory tracts, spinal cord anatomy, spinal cord white matter, touch pathway, pain pathway

Id: oCcxOtFiD2k

Length: 5min 49sec (349 seconds)

Published: Sun Apr 12 2020