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Transkrypcja filmu video (w języku angielskim)
- Let's say you have a piece of chicken that's been lying on the counter top, un-refrigerated for a few days. That chicken will start to spoil, and as it spoils, some bacteria will start to grow on it. This could be many different types of bacteria, but the one that I want to focus on in this video is called Staphylococcus aureus. This bacteria is responsible for causing a type of food poisoning known as Staphylococcal enteritis. If you've ever had food poisoning, you'll know that the many symptoms include things like Diarrhea, vomiting and nausea, dehydration and a fever. Let's say you eat this piece of chicken, and it enters your gastrointestinal tract. So, besides your mouth and esophagus, the first thing it'll enter is your stomach. The stomach contains a very acidic environment. This can be pretty useful, because it can be used to aid in the digestion of proteins, and it can also be used to kill off nasty pathogens. This acidic environment is actually pretty extreme. So a lot of bacteria can't survive in it. The Staphylococcus aureus bacteria is no different. So maybe you eat some of that chicken, right? That bacteria ends up in your stomach. That bacteria may start to die off, but it's actually pretty sneaky. It'll actually start to release these chemicals called Enterotoxins. These Enterotoxins can survive the acidic environment. So, even if the bacteria starts to die off, the Enterotoxins will still be around. They can then make their way into the small intestine. So we have a lot going on here, so let's actually focus on a small portion of the small intestine in this little box. On the left, we have the wall of the small intestine. This space over here, is really just the Lumen. The Lumen is just the interior space of the small intestine where the food and the water will pass through. Here, across this green layer, you have those epithelial cells. These will be responsible for digesting and absorbing the food and water that goes through. Now, the enterotoxin actually enters the small intestine. When it enters the small intestine, this is when you start to see a lot of the symptoms. One thing to keep in mind is that this Enterotoxin is also referred to as a super antigen. An antigen is something that the immune system may recognize as characteristic of some kind of foreign particle or foreign pathogen. Maybe you have a T-cell over here. When it encounters that antigen, it will start to release these chemicals called Cytokines. Now, antigens don't usually activate every single T-cell they encounter, because they're pretty specific. Super antigens, however, are not specific. They will activate many, many, many more T-cells. Now, you have this overwhelming release of all of these cytokines. These cytokines can then go on to do a bunch of different things: One, they can actually prevent a lot of these epithelial cells from doing their job. That is, they prevent them from absorbing all that food and water. So all of that stuff that you ate and drank will just pass through as diarrhea. They can also trigger some of the vomiting centers of your brain to force you to vomit that stuff out. Because of all this water isn't being absorbed into your system due to the vomiting and diarrhea, you're going to experience some dehydration as well. So, this is how a lot of those symptoms can arise just because you have only the enterotoxin. Note that the bacteria isn't even in the small intestine. So, let's say you're experiencing all of these symptoms. You may go to the doctor to confirm what pathogen, exactly is causing these symptoms to occur. So, when you go to the doctor, they're actually going to collect some stool samples. That stool sample will then be sent off to a lab where they'll evaluate its contents. So remember, you may not actually have the bacteria in your system, because that bacteria died in your stomach. What they may look for, instead, are the enterotoxins. So maybe they find these enterotoxins in your stool and there's a pretty good chance that you have Staphylococcal enteritis. Then how can we treat it? Well, like all forms of food poisoning and gastroenteritis, one of the best things you can do is to just drink a lot of water and fluids. This is really to overcome the dehydration that you may be experiencing. Another thing you can do, and this is something you could even consider if you have other forms of gastroenteritis or food poisoning is to adopt what's called the "BRAT diet". This is really just a synonym for bananas, rice, applesauce and toast. The reason why it might be a good idea to consider going on this diet while you have these symptoms is because all of these foods are very low in fiber. Why is that important to us? Well, fiber actually adds a lot of bulk to the stuff that we're processing in our gastrointestinal system. So, the more bulk that you're trying to digest and absorb, the harder it is for your gastrointestinal system to really process all of that food. Therefore, if you eat these foods that are low in fiber, you won't be adding as much bulk, and your system will be able to process them more easily. Now, hopefully, you won't have to stay on this diet for too long, because usually, this type of food poisoning doesn't last very long. The vomiting typically lasts up to 24 hours, and the other symptoms typically resolve in about two to three days. And of course, the best way to really avoid getting this type of food poisoning is to eat clean food. Make sure you're always storing the food appropriately, make sure you're refrigerating your food, or freezing your food whenever necessary. Then of course, cooking your food really well, and drinking clean water.