 Hey everybody, Dr. O here. In this video we're going to cover the ascending sensory pathways in the spinal cord, but we're going to start here with the sensory homunculus. Remember that a homunculus is a functional map, so we're looking at the post-central gyrus of the prideal lobe here, and it's a weird-looking human, but the larger a structure is on this drawing, the more neural input it receives, or the larger part of your cerebral cortex is involved in that area. So as you can see, this looks quite a bit like the motor homunculus, the head and the lips and the tongue are large, but you'll notice that the pharynx, the throat, is really large because it takes a lot more neural input from the throat area and then also the genitals. So it takes a lot more sense, there's a lot more sensory input from the genitals than motor commands to the genitals. So they both look funny, they both look somewhat similar, but there's a couple differences there. So that's a functional map of how much of the primary sensory cortex is involved in receiving information from a given area. Okay, so the ascending pathways, simple way to remember, most of them is they start with spinal. So you see a spinal cerebellar, spinal thalamic, there's information is starting low and traveling up. Remember, all ascending information is sensory. Doesn't work with the dorsal columns or posterior columns, but most of the time they start with spinal. So here we see, let's start with the anterior spinal thalamic tract. This image uses ventral, that's going to be sending information about crude touch and pressure up towards your brain. Then we have the lateral spinal thalamic tract. That's going to send information about pain and temperature. So those are going to be the two spinal thalamic tracts. Next we do have those, I call them the posterior columns, but this image uses the term dorsal columns. That's fine. This is going to be fine touch, vibration, pressure, and the one I think of the most is proprioception. So fine touch, vibration, pressure and proprioception information is traveling up the posterior columns or the dorsal columns. As you can see here, this is going to be broken down further into the vesiculus gracilis and the vesiculus cuneatus. So the difference, vesiculus gracilis is sending information from the lower half of the body. Vesiculus cuneatus is sending information from the upper half of the body. Next we have the spinal cerebellar pathway. So obviously this is sending information up towards your cerebellum. So this is going to be proprioceptive information. Remember the cerebellum is responsible for balance and posture and coordination. You can't do that without information from your muscles and your joints and these types of things. So the spinal cerebellar pathways are going to send information to the cerebellum. There are two. You can see them here. The anterior or ventral spinal cerebellar tract, spinal cerebellar tract, hard one to say, and the posterior or dorsal spinal cerebellar tract, here's the difference. The anterior spinal cerebellar tract crosses, the information crosses the other side of the body. The posterior or dorsal spinal cerebellar tracts, the information does not cross and that's pretty rare. Almost always information crosses from one side of the body to the other. As a reminder, so here we see the dorsal columns and the spinal thalamic tracts and notice they do cross over. So not only does the right side of your brain control the left side of your body, but the right side of the brain receives sensory information from the left side of your body as well. That's that crossing over process you can see happening here in these pathways. Okay, so those are your ascending sensory spinal pathways. I hope this helps. Have a wonderful day. Be blessed.