hi everybody and welcome back to miss Angler's biology class I am Miss angler in today's video we are going to be doing a continuation of homeostasis in the previous video we did controlling sugar blood glucose levels with insulin now we're going to look at controlling glucose with glucagon now if you are new here don't forget to give this video a thumbs up and make sure you're subscribed with your notifications turned on because I post every Tuesday and Thursday and if you want to see a video answering a question you may have or a topic then don't forget to put it in the comments below and I might make a video answering you now to continue our lesson on glucagon I want you to know that I have actually taken one of the pages out of my cheat sheet study guide this is the grade 12 one but it's exactly the same in the grade 11 and both of those cheat sheets are available on my website Miss anger. co.za it's going to make studying so simple and easy for you think about all those endless Pages you have to study the cheat sheet summarizes and doesn't leave anything important out ever so let's first of all break down what exactly glucagon is doing glucagon remember is going to increase the blood sugar levels and we would use this example um if we were given a question in an exam where it said um this particular person has an eaten in a very long time explain how they increase their blood glucose levels so essentially someone is fasting and their body needs to maintain cellular respiration with the stored glucose that they have and so we need to release that and so that's really important is that you always as I've said before in the beginning of your answer and your explanation you always need to say there was a decrease in glucose level remember that is our stim stimulus right that's going to start this whole process off now our stimulus needs to go somewhere and that is going to be in this case our control center which is going to be the pancreas now the pancreas is both the control center and the receptor because it has specialized cells within itself that is going to detect that there is not enough uh glucose and those cells are going to be alpha cells and they are going going to um pick up that we don't have enough blood sugar and it's going to then send a signal to the liver so that we can get more uh sugar now this is important before I continue on our journey um I want you to know that most often Matrix and grade 11s They forget the name of the cells and so it's really important for us to know that these are alpha cells that create glucagon and beta cells create insulin please know the cells these receptor cells they're also the cells that are going to secrete out the various hormones so please know their names so now that the alpha cells have detect there is a drop in glucose now what they're going to do is they're going to secrete this very important hormone glucagon now glucagon is then going to be sent to the liver now theer is the effect but I just want to pause here for a moment I want you to notice that maybe you are aware at this point that when we make insulin insulin is is sent to both the uh liver and the muscles but in this answer you will notice only the liver is mentioned and it's really really important everybody that there is no muscles involved in your answer and if ever ask you why the reason why no muscles are ever asked to give up their sugar to increase the blood glucose level is simply because muscles need energy all the time and if you were to try and like Rob them of their sugar you would run the risk of affecting that muscle's performance and efficiency so instead what we do is we go to where we've stored our excess sugar and remember we stored that excess sugar let's remember the spelling is really important if you look down here gluca uh glycogen becomes glucose via glucagon so I'm just going to write that out because the words are very very similar to one another and I know that we can get kind of confused so we take glycogen which is stored sugar and we convert it to glue ose and how do we go from glycogen to glucose we use gluc gone I want you to know that most often we get these words confused and the spelling is wrong and that's ultimately why we don't get our marks you've really got to know the names of the sugars versus the name of the hormone and as you can see they're very similar in their spelling I like to remember that glucagon has has an o in it just like the word hormone has a o in it and that's how I know that that's the hormone and not the sugar let's get back into our little Loop though of homeostatic control and what we have is once the liver has converted glycogen to glucose we now have a response where our blood glucose levels are going to increase which is great because we means we can still be efficient and finally and I end off with this final Point here there is a negative feedback loop because once we have enough sugar I want you to note that you are going to then have a drop in glucagon levels because you're not going to keep them high right you don't want to use all your stored sugar you don't want to waste it once the sugar levels are back up to normal you don't need to continue to convert those um stored sugars into usable glucose so you stop secreting glucagon and you allow the glucagon levels to drop and go lower down and that's why we call it a ative feedback because all you're doing is you are increasing the amount and decreasing the amount and increasing the amount and decreasing the amount and that allows you to hover at a nice Norm now you'll notice that these Pages because they come from my study guide they have some really important Pro tips and that can be things like for example you always need to note what is actually happening to the glucose level in your answers I already mentioned the statement about the liver being the only one that secretes out um any stored sugars and that finally that these hormones are what we call antagonistic hormones which is glucagon and Insulin they work in the opposite of one another now if you like this video don't forget to give it a thumbs up and make sure you are subscribed with your notifications turned on and if there is any question that you want to ask please leave it in the comments below and if you'd like to get your hands again on a copy of my cheat sheet then you can get it on Miss angle. co.za or if you are on my YouTube membership program then you get a copy for free I'll see you all again soon bye