all right ninja tears let's continue our discussion on this four-part series on the descending tracks if you guys haven't already seen it go watch the video on the particular vestibular spinal tract in this video we're gonna focus on the Ponto reticulospinal tract now you guys are gonna like this because I have these guys set up in a specific order to where we can remember them easy okay we'll talk about it towards the end but the Ponto reticulospinal what is its overall function that's what I want you guys to remember so the big things that I want you guys to get out of this is not only the descending fiber is the pathway itself but to remember what is its function what does it do because in situations in which these these actual muscles aren't carrying out that function we might think hey it might be something wrong with the Ponto reticular spinal tract so we should always understand what the overall function of it is and not get too caught up in all these actual descending fibers and mix of mess that we can see here so the Ponto reticulospinal what is its big function it's primarily for activating extensor muscles so you're gonna love that right so extensor muscles that is its main function is to innervate the extensor muscles so if you can remember the stimulus spinal Ponto particular spinal they perform the same function the Ponto reticulospinal is more of an assister though it's helping it's assisting the lateral vestibular spinal tract and medial vestibular spinal tract in this extension muscles alright the extensor muscles but now Ponto reticulospinal if you remember i've talked about a bunch of different videos you have a kind of a mixture of grey and white matter structure that extends all the way from the midbrain down to the medulla it's called the reticular formation it's important to basically alerting our cerebral cortex and arousing it letting it know what's the most important stimulus at that point of time but there's some special nuclei that are located within the pons that are important for this actual descending tract so in the ponds are gonna have some special nuclei here you're gonna have some special nuclei and what these guys do is they send down these descending fibers okay so they have these descending fibers we already know that okay so if we got we'd bring this guy down right so coming from the actual pons the reticular formation within the pons we're going to have these descending fibers coming down here and as they come down if we're being particular these guys come more within the kind of like the ventral alright the ventral white column here so they're gonna come down more along the lines of the ventral white column so they're gonna descend down through the ventral into the ventral white column now as they're doing that they give off collaterals right they give off their termination sites to these different cell bodies within the anterior or ventral gray horn then from here it can continue maybe it's one it wants to go down a couple more spinal cord levels right because it can supply many many different types of spinal cord levels and this is going to go here and this will also go bring this one a little bit more over here this one also go right here and this one will go right here right so it's going to be able to supply this anterior or this ventral gray horn now when these fibers needs descending Ponto reticulospinal tract goes down it descends right into the actual ventral or anterior white column it gives off its extensions into the anterior ventral gray horn - what its gonna go in supply again what type of structures here gamma motor neurons all right and it's also gonna supply alpha motor neurons and these gamma and alpha motor neurons are gonna do what they're gonna go out and stimulate the different extensor muscles so this is why this is important okay to remember this stuff is basically the important thing is to remember what is its overall function so if you compare you combine these two together the vestibular spinal tract and the Ponto reticulospinal tract remember that they both are supplying extensor muscles the actual nucleus for this originates within the pons part of the reticular formation descends down through the anterior or ventral white column and then synapse is on the cell bodies of the anterior or ventral gray horn via the alpha motor neurons and the gamma motor neurons then from that these guys can go out to different types of extensor muscles and so when it supplies the extensor muscles remember what is the alpha motor neuron doing it's causing the contraction of the extra fusil muscle fibers right it's causing contraction of the extra views of muscle fibers and the gamma is causing the contraction of the intrafusal muscle fibers to keep those muscle spindles taut now now that we understand the Ponto reticulospinal and the vestibular spinal tract I want you guys to remember to combine these two together they're very pretty very pretty and what is it the stimulus spinal for the very and the pretty for the Ponto reticulospinal these two are primarily important with extensor function alright so last thing here I want you guys to remember something okay so we know the pathway we know what it's serving now in the vestibular spinal tract we said that there was a specific stimulation for right whether it was coming from the fastidian nucleus in the cerebellum or whether it was coming from the inner ear structures well this is constantly getting information from a sending track so you know there's ascending tracts that are coming up here right we've talked about the many different times there's different ascending tracts we talked like you had the dorsal column medial meniscal pathway we'll also have the spinothalamic tract there's so many different there's the spinal reticular tract but the whole purpose is that as those ascending tracts were coming upwards they give off collaterals to the reticular formation that can then cause stimulation to these actual nuclei here within the pons to send down these descending fibers to go to different extents or muscles and again as they're traveling down they go through the anterior or ventral white column and then go to the extensor muscles now I didn't mention it in the vestibular spinal tract I should have done that I wasn't specific enough but remember these actual vestibular spinal tracts they're also going within the anterior or ventral white column because they don't forget that also okay so now now that we know that we've pretty much covered everything we would need to know about the Ponto reticulospinal tract I hope it made sense in the next video and part three of this we're actually going to talk about the rubra spinal tract hope to see you guys there [Music] you [Music]