The Respiratory System

okay chapter 19 is over the respiratory system so the respiratory system remember is the most common portal of entry for microbes so this is where we get a ton of microbes getting in all the time because we are constantly breathing and anything we breathe that's in the air is at least temporarily going to get into the respiratory tract so overall the respiratory system is divided into two sections the upper respiratory tract which includes the mouth the nose sinuses throat basically everything from the throat up and then the lower respiratory tract which is going to be the trachea and then the bronchi bronchials and alveoli that are all in the lungs so basically from the neck down defenses for this is we have basically a lot of things to catch or push out microbes so we have like our little nose hairs we have cilia that we'll see here in a second lining our entire respiratory system beating back and forth back and forth back and forth we also have mucus along although celia so if a microbe gets in ideally gets stuck in the mucus and then the cilia will push it up either back towards the mouth and nose for us to cough or sneeze it out or it'll push it further down towards our esophagus for us to swallow and send into our stomach to get chewed up by stomach acid so here's that image of those celia especially so you can see those long little hair like structures coming off of those cells and you can see in this case two little bacterial cells trapped in the cilia and the mucus and then those cilia will move them again either up towards the mouth depending where they're at or at least to the esophagus to get swallowed so as far as normal biota goes it depends on where we're at in the respiratory tract the upper respiratory system has thousands of microbes that are normally found there they have that commensal relationship or beneficial relationship with us and then on top of it we have pathogens coming in all the time because we're breathing all the time our lower respiratory tract on the other hand up until very recently was believed to be sterile new research shows that just like the blood we do have low levels of colonization for a few species but there's still not much in there one thing to note for the respiratory system is that smoking greatly is going to increase the chance of a respiratory illness not to mention cancer and all the other things that comes with smoking but this is because the every time you smoke a cigarette it actually stuns those cilia those little hair like structures for about 20 minutes they become basically paralyzed so then while you're breathing for those next 20 minutes or so any microbes that get in they're not going to get pushed out so they immediately can start growing and kind of moving their way wherever they want to go on top of that they've found with the human genome project that smokers and nonsmokers have different microbiota that naturally live in their respiratory tracts and they haven't decided yet if this could possibly be a link to cancer or not or if it's just smoking but there's definitely that difference so this chapter we're going to break down diseases based on where they're infecting so we're going to start by looking at the upper respiratory system first so remember this is going to include basically everything from the throat up so we're going to have the nose the sinuses the mouth the back of the throat which is the pharynx the tongue basically everything in that area so starting with pharyngitis more commonly just called strep throat so this can be caused by a variety of bacteria or viruses the most common bacteria is streptococcus pyogenes which is why it's typically called strep throat generally we'll just kind of lump these two together again it can be caused by viruses generally if you have a viral form of pharyngitis it's usually a more mild disease it's usually less painful than a bacterial infection transmission for either is respiratory droplets or direct contact with mucous secretions which cover your mouth right reservoir is humans although it's especially for streptococcus pyrogenes it is a normal microbe for many people it's rarely an endogenous infection you usually have to catch it from someone else prevention treatment there is no vaccine you basically just have to use good hygiene make sure you're washing your hands and then if you are sick make sure you're covering your mouth don't be gross if you cough or sneeze cover your mouth for bacterial infections you could have antibiotics that are sometimes helpful like penicillin for treatment but if it's a viral infection it's just waiting it out but again usually those are more mild the biggest thing with pharyngitis is a sore throat painful swallowing you could also have red swollen tonsils sometimes you can have white patches or streaks of pus which is shown on the far right pleasant sometimes you can also get red spots on the soft or hard palate which is shown on the left image there those are more specific to bacterial infections but not always moving on to the common cold so this is caused by a virus there are hundreds and hundreds of different viruses that can cause the common cold most of them are going to be rhona viruses but you can also have coronaviruses no that is not the same as the coronavirus but i know that's confusing now reservoir is in humans transmission again is typically from someone that's infected via respiratory droplet or indirect contact like touching someone touching something that someone like sneezed or coughed on or fomites the viruses will enter the upper respiratory tract either through the nose the eyes or the mouth and start releasing histamine histamine is what causes like during allergies the itchy eyes watery eyes stuffy nose sneezing sore throat all those can also sometimes cause a fever as well treatment is you can take antihistamines like benadryl and things like that but that's really only for relief it will do nothing to actually get rid of the virus you can also take zinc again that one's kind of up in the air whether it actually does anything or not it kind of depends on the person it starts to hinder some viral reproduction but again there's so many viruses that can cause the common cold it's not always a guarantee moving on to cyanide this just means a sinus infection or inflammation of the sinuses so this can be bacterial or viral it can even sometimes be fungal infections sometimes you can even have just allergies cause a sinus infection transmission can be direct or indirect contact if we're talking about a virus if it's bacterial fungal sometimes it can be an endogenous infection sometimes it can even be an accidental inoculation like accidentally breathing in spores from like gardening or something if it's a fungus and then allergies of course is just your body overreacting to things like pollen or something like that or pet dander either way symptoms are just inflammation of those sinuses which causes pressure sometimes so much pressure can actually cause pain in like the front of your face where those sinuses sit kind of like right behind the nose and in the front of the forehead prevention is mostly just hygiene as far as viruses and a little bit of bacteria but really there's not much you can do if you get it you get it treatment again there's really not a whole lot you can do especially if it's viral which is the more common if you have antibiotic or antifungal sorry if you have bacterial or fungal infections you can take antibiotics or antifungals and then if it's allergies you can take like allergy medicine but typically by the time you get to a science infection you just kind of have to tough it out for a while or just deal with symptoms next otitis media this is just more commonly known as a middle ear infection so again there are lots of different things that can cause this bacteria and viruses both i've listed the five most common bacteria under there streptococcus pneumoniae hemophilus influenzae morexela cartalus streptococcus pyrogenes and staphylococcus aureus by far the most common as far as bacteria go and then viruses again there's so many reservoirs humans as far as prevention goes because it's caused by so many things there's really not much treatment for streptococcus pneumoniae there is a vaccine but really by the time kids are the age of two almost uh 70 of kids have had at least one case and then by the time their age like five it's almost like 95 percent of kids have had at least one case of ear infection i was a charming child i'm sure my mother loved me by the time i was two i'd had 13 ear infections and i was a screamer so that was fun i'm sure i don't know why she had another kid after me treatment depending on what type kind you have bacterial or viral you could take broad spectrum antibiotics or antivirals sometimes if you get them so often sometimes they'll put a tube in your ear to help drain things out i was one ear infection away from getting the little tubey tube so that's fun transmission it's kind of interesting for otitis media because it's usually an infection from somewhere else in the body so this is a secondary infection typically from somewhere like a sore throat things like that that works its way up through what's called the scushion tube which basically just is a little tube connecting the bottom of the ear into the back of the throat to control things like pressure so essentially what happens the bacteria moves its way up there and then the white blood cells follow it our little immune system fighters they start killing off the infection but when they do the dead cells build up white blood cells build up and it starts creating pus in the middle ear charming that's what you see in the image there you're welcome of course if you have anything blocking the ear it's going to cause difficulty hearing it can also cause severe ear pain because you're creating pressure inside there because that tube is where you're supposed to drain out pressure eventually it can actually cause a torn eardrum which of course will lead to deafness if it's if it's bad enough or if it happens often enough and then our last upper respiratory infection is going to be diphtheria this is caused by a bacteria known as corny bacterium diphtheriae reservoir in humans transmission is respiratory droplets usually i don't care that you know virulence factors but for this one i do want you know that this type of bacterium makes a toxin known as diphtheria toxin because that's what's going to be kind of the thing creating all of the issues for this disease so essentially what happens is you get that upper respiratory tract infection the bacterium starts growing and it starts releasing those toxins from the diphtheria cells those start to build up and start killing other cells around them you also have your immune cells start going in and trying to kill the diphtheria molecules or sorry the diphtheria cells so you basically get this buildup of bacteria and dead tissues and toxins all of that ends up creating what's known as a pseudo membrane or a fake membrane across the throat that can actually start blocking the airway and can lead to suffocation and death treatment is you can take antibiotics with antitoxins because you have to get rid of not just the bacteria but also the toxin that's building up there is a prevention you have a specific type of vaccine you can take that has that diphtheria toxin in it or a part of that diphtheria toxin in it known as dtap and td so this is showing some of those symptoms so you can see the infection on the membrane of those tonsils you can see that white thing start building up and of course that's blocking these two are blocking about half of the airway but that can eventually cause complete blockage and suffocation minimum it's causing trouble breathing and neck swelling and of course pain okay moving on to infections of the entire respiratory system so these next couple of diseases are going to affect both the upper and lower respiratory tracts so here we're going to have everything going from the mouth all the way down to the little lungs to the little alveoli where we're going to have gas exchange happening which are the little like kind of look like grapes little cloud looking guys in the right side of the image so starting off with the flu or influenza so a lot of people call the flu a variety of cases but really influenza or the true flu is only by when it's caused by an influenza virus which there are several we'll group them into three categories or three serotypes known as influenza a influenza b and influenza c of which there are several strains of each influenza a is generally the one that causes most epidemics if you've ever heard of like h1n1 things like that those are generally the ones that we get really worried about influenza b this is more local outbreaks it's kind of a moderate disease and then influenza c is a more mild disease but all of these are considered the flu but generally when people say they have the flu there's really no guarantee they know it's influenza unless they actually went and got tested sorry so transmission for the blue is inhalation either of aerosols or droplets or you can have fomites touching something that like someone sneezed on or coughed on like i just did and then like touching your mouth touching your face and getting infected that way generally influenza starts as an upper respiratory tract infection but then moves into the lower respiratory tract it starts by causing like fever chills headache body aches coughs stuff you know sore throat extreme fatigue the biggest thing to note is that a lot of times when people say they have the flu they also get like upset stomach diarrhea for true influenza there are no intestinal effects so if you have that you don't really have the true flu you have just like the generic what people say oh i have the flu it's not influenza though for influenza there's a one percent mortality rate and that's mostly mostly due to secondary infections like pneumonia is pretty typical that if someone gets influenza especially if they're older or really young they can get pneumonia afterwards but influence itself causes anywhere from twelve thousand to sixty thousand deaths every single year even with just a one percent mortality rate so it's still a lot of deaths prevention and treatment so there is an annual vaccination generally the vaccination has one of several types of the inactivated viruses so they tend to focus on a couple strains of a b or c of those um the problem with that is we'll see here in a second is that they have to start making these over a year and a half in advance so for like 2020 they started working on these in like 2018 so they have to do like some math and statistic nonsense that we don't care about that basically helps them guess which type of influenza is going to be the one that's going to be most common that year and then they start making the vaccine for it well sometimes they're not as accurate as they would like to be so that's why some some years it seems like even if you got the vaccine you still get sick but on top of that there are just so many different strains that even if they picked the right serotype the virus could have mutated there could be a different strain all these different things currently there is a vaccine in the works that works against all types and would not need to be given yearly but it is still in the test run and of course it's very expensive it's very detailed it takes a lot of time but this has actually been in the work for about five [Music] six years now so hopefully that will be getting the human trials soon there is treatment for for influenza but that's really only if you have one of those really severe cases this was actually one of the first viral diseases where they did make effective antivirals and by effective we mean if you take them early on infection by like day two they might have an effect so antivirals still in general are not always the best but it's the best we have at the moment so again usually i don't focus too much on virulence factors but for influenza we have two virulence factors that are very important the h spikes and the n spikes these are both used basically to cause disease in the host the h spikes which you can see are like the little blue triangles in the image there on the outside of the cell these are used for attachment to host cells they basically stab into a host cell and hold tight and then the n spikes are used to release the virus from the cell they basically act like a little tunnel that the virus dna can travel into the next cell the reason we care about those h and n spikes is because they are constantly changing viruses are known for their ability to cause genetic changes when they mutate and this can lead to issues with our immune system remembering them one of our big advantages of our kind of higher level of immune system is that it keeps a memory of every disease it comes into contact with so then the next time you see it hopefully it won't get you sick the reason that we have to get a vaccine every year for the flu is because there are so many different types and because it mutates so often that the even our memories of the flu don't really hold up because it looks different enough that our body doesn't recognize it so two terms that are important for influenza are antigenic drift and antigenic shift so an antigenic drift is when there are mutations in the genes that code for those h or n spikes and it could just be a little change might just be one change in amino acid but this allows the virus to basically hide from our antibodies or hide from our immune system inside our body antigenic shift on the other hand is complete changes in the genome there are generally only 10 genes in any influenza virus regardless of influenza a influenza b influenza c doesn't matter that involve making those h and n spikes usually this is due to genetic recombination or basically the combining or switching of dna between totally different strains that are inside the same organism insane inside the same host the same time which ends up create creating a completely new strain of the virus that our bodies have never seen before and of course our vaccines won't work for so this image is just showing how that happens so for example there's duck influenza virus in blue there's human influenza virus and orange both of these viruses not only infect ducts and humans so duck infects ducks human infects humans but both of them can also infect a pig because that host now is holding both of those influenza viruses there's a chance that they could swap information over and then you end up with an entirely new strain of human influenza virus that has duck spikes on it that our body has never seen before our vaccines are prepared for and that can get us sick even if you have the vaccine next moving on to pertussis more commonly called whooping cough so this is caused by a bacterium known as bordetella pertussis reservoir as humans transmission is through respiratory droplets so there is a vaccine called the dtap vaccine for pertussis that holds basically fragments of the pertussis cells and there's also treatments that you can use antibiotics for this specific type of disease infection and symptoms so generally again it begins as an upper respiratory tract infection where it starts causing cell death because it releases a toxin at this point it typically causes really severe kind of short or staccato coughs that are happening often enough that it leads to exhaustion they can actually be strong enough that they can break ribs and create a lack of oxygen to tissues because you're coughing so much you can't get enough air in this is generally broken down into three different stages the cataract stage is pretty much like the common cold you get sneezing runny nose itchy eyes watery eyes all of that sore throat then the pyroximal stage is where you get those violent coughing stages this is where you typically get the whooping of the whooping cough and this is due to basically your coughing so much so hard that you're like gasping for air in between because you when you're coughing you can't breathe and then you can get eventually into the convalescent stage where if you remember from previous units convalescent stages where that bacterium or that virus is going down in numbers in your body and your body is essentially recovering but your immune system is weak at the same time so this stage leaves you susceptible to other respiratory infections so this graph is just showing that in the past like 100 years or so we've greatly reduced the number of pertussis cases worldwide and in the us with that's mostly with the invention of those different vaccines and different forms of the vaccine which is the dtp the dtap and the tdap that you see in the top image there in recent years though from like 2 000 ish until now we're starting to see more and more pertussis cases coming back that's for a variety of reasons one of which is the anti-vaccine movement another is that we're starting to reach the point where people are kind of aging out of the first vaccine that they might have gotten and now they're getting it when they're older even though it's far more common for kids to get it we're also seeing some basically just more people in in the same area we're seeing denser populations in like big cities so you have kids that haven't gone through their full vaccinations that are getting it things like that which is why we rely so heavily on herd immunity to make sure those types of kids don't get it but the anti-vaccine movement is putting a big damper on that and then again we have people kind of aging out ideally vaccines last for the entire lifespan but i really most of them only last for about 20 years or so before our body starts to forget it and so we're seeing elder populations starting to get whooping cough again and then our last disease for both upper and lower respiratory tracts is respiratory syncytial virus or rsv so this is a virus of course as the name says transmitted through respiratory drops and fomites most commonly symptoms typically are once it infects the respiratory tracts it causes these syncytia which are giant basically mutated cells that have several nuclei in the respiratory tract causes breathing problems because you have these just huge clumps of cells essentially there is no vaccine for this but you can get passive antibodies for kids that are at high risk like if they have some kind of immune system disorder or something that would make them more likely to get this there is a treatment but this is usually only used for severe cases which typically cur occur in babies generally older kids and adults usually only get like a cold when they get this virus but babies get pretty severe coughing bouts congestion hard to breathe all the general just kind of issues with messing with the lungs type thing um pretty much everyone has gotten this disease at some point typically by age two almost every kid has had it and in that there's about a hundred thousand that are hospitalized each year for it some don't ever really figure out that it's rsv they just think they have like maybe pneumonia or bronchitis because it kind of kind of replicates some of those symptoms and they treat it with broad spectrum antibiotics which does not always work in this case does not work because it's a virus but it helps the symptoms until the virus kind of works its way out of the system all right and then moving on to infections of the lower respiratory system so remember this is everything basically from the neck down starting with the trachea or the windpipe and then moving into the lungs with the bronchi the bronchioles and the alveoli so one of the biggest diseases of the lungs is tuberculosis this is caused by mycobacterium tuberculosis a type of bacteria that's found in humans transmitted through respiratory droplets essentially what happens with tuberculosis is there are kind of two stages primary tuberculosis is where you get the first infection of the lungs where bacteria are basically eaten up by the white blood cells through the those phagocytes and they start just kind of like clumping around this bacteria what happens is those cells and the bacteria die off forming these hard little nodules called tubercles which is how the disease gets its name in the lungs other than forming those tubercles though there are no symptoms at this point so this is also known as a latent form of this disease at some point though you'll move into secondary secondary tuberculosis or reactivation of tuberculosis and this occurs later could be months could be years at some point though it'll wake up and those tubercles will basically release a ton of bacteria that will start causing things like chronic cough fever weight loss just essential tissue damage all throughout the lungs so it's important to note two things in the latent form the person doesn't feel sick even though the bacteria are present they're not causing any symptoms it's also important to know that they are not contagious at this point you can't pass these on if the person's in a latent form of tuberculosis in active form though in that reactivation secondary tuberculosis that's when people feel sick that's when they're contagious that's when they can pass them the bacteria around because the bacteria are back out in the lungs and in the throat so you don't need to know these stages but this is just showing the process of making those tubercles so on the top you have one of these little bacterial cells going around a little macrophage there and then you see they basically just start leaving the blood and start clumping up around any infected cells so those are all macrophages forming an early tubercle at some point they've circled in all the bacterial cells creating this little clump of macrophages and bacterial cells the macrophages die off and then the bacteria kind of lyse out of the macrophages and start kind of eating away the inside of this tubercle at some point it becomes this hard little nodule this hard ball this tubercle inside the lungs and then at some point it will rupture releasing the bacterium like you see in the bottom image there back into the bronchial back into the lungs where now the person can pass it through those respiratory droplets so the images there are showing lung tissue with those tubercles in them so you can see the white tubercles those are not those fully formed tubercles yet but those white little puffy masses in the lungs and then the bottom image there that's just full of tuberculosis your lungs shouldn't have that brown gunk that's all just dead tissue and tubercles and okay treatment and prevention there is a vaccine called bcg this is actually a live stream of bovine tuberculosis or tuberculosis for cows that's been made a virulent which means it can't actually cause disease it's not widely used in the u.s though because we don't have a ton of tuberculosis naturally in the population versus places like asia that deal with it quite a lot this is a pretty routine vaccine treatment for tuberculosis is awful because it can go into that latent stage and hot the bacteria can hide in those tubercles it is really hard to treat it takes prolonged treatment with multiple antibiotics and i'm talking like several months to a year of like three or four different drugs to get through the active and the latent stages the biggest problem with treatment is that people are non-compliant they don't go through their entire drug regimen they start to feel fine they stop taking them whatever it is and this has led to several strains of multi-drug resistant and extensively drug resistant tb multi drug resistant is still treatable but now you end up having to take five or six different drugs for up to two years extensively drug resistant is almost almost nothing you can do it's basically like treating symptoms at that point so this is just showing worldwide where tb is such a kind of issue you can see the us we really don't deal with tb that often tuberculosis that often which is why we don't routinely have that vaccine you can see places like asia see places like southern africa all have really high cases of tuberculosis and unfortunately have a lot of drug resistant tuberculosis as well this is more a look at the tuberculosis in the u.s we do of course have tb but it's not as bad as other countries if you compare it to other countries we're practically non-existent but we do have cases here and there and of course it tends to be where we have a lot of people but not always like you can see alaska there's not a ton of people in alaska but we do have cases there next we're looking at pneumonia so this is an inflammatory condition where the lungs start filling with fluid specifically the alveoli which are the little sites of gas exchange where you take in oxygen and get rid of carbon dioxide this is caused by many many many many many different organisms which we'll see here in a second overall those symptoms are pretty much the same for whatever pneumonia whatever organism is causing pneumonia you get chest pain when breathing shortness of breath coughing you can even get kind of blood stained or rusty looking phlegm that's because you literally have blood coming out of the lungs pneumonia is one of the worst diseases for kids more kids under the age of five die of pneumonia than any other infectious disease because it's pretty hard to treat because there are so many different organisms that can cause it and a lot of the times it's a secondary infection it can be a primary infection but oftentimes it's a secondary infection like after influenza where the immune system is already low so then pneumonia kind of takes over there are tons of cases every year for example just in the u.s there are anywhere from two to three million cases each year over uh 45 000 of those end up in death so we've grouped pneumonia for this chapter into two groups community associated and healthcare associated community association is just the one like going around living your life and then health healthcare of course is dealing with like hospital infections like nosocomial infections so this is listing the seven most common community associated pneumonia causes some of which are bacterial some viral some fungal streptococcus pneumoniae legionella species and mycoplasma pneumonia are all bacterial honza virus and respiratory viruses are of course viruses and then histoplasma capsulitum and pneumocytus girolovisi those are both fungal infections for pretty much all of these it's either going to be vehicle transfer or droplet contact like respiratory droplets for prevention the only one that has a vaccine is streptococcus pneumonia the very first one on the left there all the rest are pretty much just avoiding the reservoirs of different organisms that cause it or just general hygiene for example honda virus is carried in mouse droppings so avoiding like mouse infestations things like that um histoplasma capsidulum the fungus the third one from the right there it's commonly found in batten bird droppings so again avoiding those at all costs which anything involving bat i'm out you don't need to tell me twice most of these do have treatments um the only two that don't really have treatments are hantavirus it's just supportive treatment so it's not actually fixing the virus and then the other virus respiratory virus is there is no treatment it's just you get through it or you don't unfortunately just a few of the distinctive features here the mycoplasma pneumoniae the third one from the left is the one that's typically known as walking pneumonia and then the fungal infection second from the right there pneumonia cysteralpsy that's most commonly occurs in aids patients where they have that practically non-existent immune system left and then looking at healthcare associated pneumonia again this is caused by a variety of bacterium both gram-negative anger and positive but these are specifically endogenous infections typically caused by aspiration where you get bacteria from the upper respiratory tract or the stomach into the lower respiratory tract into the lungs usually through like a ventilator of some kind prevention is basically just making sure equipment is clean and making sure patient's head is elevated and just proper education things like that it can be treated usually with broad spectrum antibiotics although we're starting to see some bacteria that are again antibiotic resistant so that's going to be an issue there are over three hundred thousand cases a year in the united states alone um anywhere from point five to one percent of patients will get some kind of health care associated pneumonia which is unfortunate because we're you know we tout that we're one of the best health care as far as like um you know technology and things like that and yet still this many people getting sick but again it's just because mostly bacteria is everywhere and then our last disease for the laura respiratory tract and for this chapter is histoplasmosis so this is caused by a fungus specifically a dimorphic fungus called histoplasma capsulatum so remember dimorphic means that it changes its shape it morphs and in this case because it's a pathogen it's going to morph at different temperatures so in the body it's going to be one thing out in the environment it's going to be another so reservoir for this is going to be soil in the environment and transmission is going to be inhaling the spores from the fungus when they're inhaled they're basically going to cause acute pneumonia acute pneumonia or really fast pneumonia infection in immunocompromised people this infection will eventually get into the blood and start affecting the organs causing lesions and breakdown of pretty much every organ making it almost always fatal luckily there is a treatment and anti-fungal treatment the reservoir for this virus is found in bat and bird droppings and the reason i mention it it's not in your textbook but the reason i mention this disease is because it's pretty common in this area as you can see from the map here um but it's basically a fungus that again likes the nitrogen in bat and bird droppings so we see it wherever you have places with a lot of those things like caves for bats things like that we actually had at my previous job there's a prison not far from my previous school that i worked at in danville illinois where about four or five years ago now inmates were feeding birds just for something to do out at wreck time and so they were getting huge bird population and they had this huge outbreak of histoplasmosis because of all the bird droppings in that area and inmates started breathing in the spores from the fungus that started growing okay and then like always we have these two images this one showing the different diseases and what causes them and then last one again our look at deadlines versus communicability um this one is a little less clear you can see like tb and diphtheria more deadly and slightly less communicable but things like pertussis especially has that big jump where you can see it's not very deadly at all but extremely communicable okay that's it for chapter 19.

okay chapter 19 is over the respiratory system so the respiratory system remember is the most common portal of entry for microbes so this is where we get a ton of microbes getting in all the time because we are constantly breathing and anything we breathe that&#39;s in the air is at least temporarily going to get into the respiratory tract so overall the respiratory system is divided into two sections the upper respiratory tract which includes the mouth the nose sinuses throat basically everything from the throat up and then the lower respiratory tract which is going to be the trachea and then the bronchi bronchials and alveoli that are all in the lungs so basically from the neck down defenses for this is we have basically a lot of things to catch or push out microbes so we have like our little nose hairs we have cilia that we&#39;ll see here in a second lining our entire respiratory system beating back and forth back and forth back and forth we also have mucus along although celia so if a microbe gets in ideally gets stuck in the mucus and then the cilia will push it up either back towards the mouth and nose for us to cough or sneeze it out or it&#39;ll push it further down towards our esophagus for us to swallow and send into our stomach to get chewed up by stomach acid so here&#39;s that image of those celia especially so you can see those long little hair like structures coming off of those cells and you can see in this case two little bacterial cells trapped in the cilia and the mucus and then those cilia will move them again either up towards the mouth depending where they&#39;re at or at least to the esophagus to get swallowed so as far as normal biota goes it depends on where we&#39;re at in the respiratory tract the upper respiratory system has thousands of microbes that are normally found there they have that commensal relationship or beneficial relationship with us and then on top of it we have pathogens coming in all the time because we&#39;re breathing all the time our lower respiratory tract on the other hand up until very recently was believed to be sterile new research shows that just like the blood we do have low levels of colonization for a few species but there&#39;s still not much in there one thing to note for the respiratory system is that smoking greatly is going to increase the chance of a respiratory illness not to mention cancer and all the other things that comes with smoking but this is because the every time you smoke a cigarette it actually stuns those cilia those little hair like structures for about 20 minutes they become basically paralyzed so then while you&#39;re breathing for those next 20 minutes or so any microbes that get in they&#39;re not going to get pushed out so they immediately can start growing and kind of moving their way wherever they want to go on top of that they&#39;ve found with the human genome project that smokers and nonsmokers have different microbiota that naturally live in their respiratory tracts and they haven&#39;t decided yet if this could possibly be a link to cancer or not or if it&#39;s just smoking but there&#39;s definitely that difference so this chapter we&#39;re going to break down diseases based on where they&#39;re infecting so we&#39;re going to start by looking at the upper respiratory system first so remember this is going to include basically everything from the throat up so we&#39;re going to have the nose the sinuses the mouth the back of the throat which is the pharynx the tongue basically everything in that area so starting with pharyngitis more commonly just called strep throat so this can be caused by a variety of bacteria or viruses the most common bacteria is streptococcus pyogenes which is why it&#39;s typically called strep throat generally we&#39;ll just kind of lump these two together again it can be caused by viruses generally if you have a viral form of pharyngitis it&#39;s usually a more mild disease it&#39;s usually less painful than a bacterial infection transmission for either is respiratory droplets or direct contact with mucous secretions which cover your mouth right reservoir is humans although it&#39;s especially for streptococcus pyrogenes it is a normal microbe for many people it&#39;s rarely an endogenous infection you usually have to catch it from someone else prevention treatment there is no vaccine you basically just have to use good hygiene make sure you&#39;re washing your hands and then if you are sick make sure you&#39;re covering your mouth don&#39;t be gross if you cough or sneeze cover your mouth for bacterial infections you could have antibiotics that are sometimes helpful like penicillin for treatment but if it&#39;s a viral infection it&#39;s just waiting it out but again usually those are more mild the biggest thing with pharyngitis is a sore throat painful swallowing you could also have red swollen tonsils sometimes you can have white patches or streaks of pus which is shown on the far right pleasant sometimes you can also get red spots on the soft or hard palate which is shown on the left image there those are more specific to bacterial infections but not always moving on to the common cold so this is caused by a virus there are hundreds and hundreds of different viruses that can cause the common cold most of them are going to be rhona viruses but you can also have coronaviruses no that is not the same as the coronavirus but i know that&#39;s confusing now reservoir is in humans transmission again is typically from someone that&#39;s infected via respiratory droplet or indirect contact like touching someone touching something that someone like sneezed or coughed on or fomites the viruses will enter the upper respiratory tract either through the nose the eyes or the mouth and start releasing histamine histamine is what causes like during allergies the itchy eyes watery eyes stuffy nose sneezing sore throat all those can also sometimes cause a fever as well treatment is you can take antihistamines like benadryl and things like that but that&#39;s really only for relief it will do nothing to actually get rid of the virus you can also take zinc again that one&#39;s kind of up in the air whether it actually does anything or not it kind of depends on the person it starts to hinder some viral reproduction but again there&#39;s so many viruses that can cause the common cold it&#39;s not always a guarantee moving on to cyanide this just means a sinus infection or inflammation of the sinuses so this can be bacterial or viral it can even sometimes be fungal infections sometimes you can even have just allergies cause a sinus infection transmission can be direct or indirect contact if we&#39;re talking about a virus if it&#39;s bacterial fungal sometimes it can be an endogenous infection sometimes it can even be an accidental inoculation like accidentally breathing in spores from like gardening or something if it&#39;s a fungus and then allergies of course is just your body overreacting to things like pollen or something like that or pet dander either way symptoms are just inflammation of those sinuses which causes pressure sometimes so much pressure can actually cause pain in like the front of your face where those sinuses sit kind of like right behind the nose and in the front of the forehead prevention is mostly just hygiene as far as viruses and a little bit of bacteria but really there&#39;s not much you can do if you get it you get it treatment again there&#39;s really not a whole lot you can do especially if it&#39;s viral which is the more common if you have antibiotic or antifungal sorry if you have bacterial or fungal infections you can take antibiotics or antifungals and then if it&#39;s allergies you can take like allergy medicine but typically by the time you get to a science infection you just kind of have to tough it out for a while or just deal with symptoms next otitis media this is just more commonly known as a middle ear infection so again there are lots of different things that can cause this bacteria and viruses both i&#39;ve listed the five most common bacteria under there streptococcus pneumoniae hemophilus influenzae morexela cartalus streptococcus pyrogenes and staphylococcus aureus by far the most common as far as bacteria go and then viruses again there&#39;s so many reservoirs humans as far as prevention goes because it&#39;s caused by so many things there&#39;s really not much treatment for streptococcus pneumoniae there is a vaccine but really by the time kids are the age of two almost uh 70 of kids have had at least one case and then by the time their age like five it&#39;s almost like 95 percent of kids have had at least one case of ear infection i was a charming child i&#39;m sure my mother loved me by the time i was two i&#39;d had 13 ear infections and i was a screamer so that was fun i&#39;m sure i don&#39;t know why she had another kid after me treatment depending on what type kind you have bacterial or viral you could take broad spectrum antibiotics or antivirals sometimes if you get them so often sometimes they&#39;ll put a tube in your ear to help drain things out i was one ear infection away from getting the little tubey tube so that&#39;s fun transmission it&#39;s kind of interesting for otitis media because it&#39;s usually an infection from somewhere else in the body so this is a secondary infection typically from somewhere like a sore throat things like that that works its way up through what&#39;s called the scushion tube which basically just is a little tube connecting the bottom of the ear into the back of the throat to control things like pressure so essentially what happens the bacteria moves its way up there and then the white blood cells follow it our little immune system fighters they start killing off the infection but when they do the dead cells build up white blood cells build up and it starts creating pus in the middle ear charming that&#39;s what you see in the image there you&#39;re welcome of course if you have anything blocking the ear it&#39;s going to cause difficulty hearing it can also cause severe ear pain because you&#39;re creating pressure inside there because that tube is where you&#39;re supposed to drain out pressure eventually it can actually cause a torn eardrum which of course will lead to deafness if it&#39;s if it&#39;s bad enough or if it happens often enough and then our last upper respiratory infection is going to be diphtheria this is caused by a bacteria known as corny bacterium diphtheriae reservoir in humans transmission is respiratory droplets usually i don&#39;t care that you know virulence factors but for this one i do want you know that this type of bacterium makes a toxin known as diphtheria toxin because that&#39;s what&#39;s going to be kind of the thing creating all of the issues for this disease so essentially what happens is you get that upper respiratory tract infection the bacterium starts growing and it starts releasing those toxins from the diphtheria cells those start to build up and start killing other cells around them you also have your immune cells start going in and trying to kill the diphtheria molecules or sorry the diphtheria cells so you basically get this buildup of bacteria and dead tissues and toxins all of that ends up creating what&#39;s known as a pseudo membrane or a fake membrane across the throat that can actually start blocking the airway and can lead to suffocation and death treatment is you can take antibiotics with antitoxins because you have to get rid of not just the bacteria but also the toxin that&#39;s building up there is a prevention you have a specific type of vaccine you can take that has that diphtheria toxin in it or a part of that diphtheria toxin in it known as dtap and td so this is showing some of those symptoms so you can see the infection on the membrane of those tonsils you can see that white  thing start building up and of course that&#39;s blocking these two are blocking about half of the airway but that can eventually cause complete blockage and suffocation minimum it&#39;s causing trouble breathing and neck swelling and of course pain okay moving on to infections of the entire respiratory system so these next couple of diseases are going to affect both the upper and lower respiratory tracts so here we&#39;re going to have everything going from the mouth all the way down to the little lungs to the little alveoli where we&#39;re going to have gas exchange happening which are the little like kind of look like grapes little cloud looking guys in the right side of the image so starting off with the flu or influenza so a lot of people call the flu a variety of cases but really influenza or the true flu is only by when it&#39;s caused by an influenza virus which there are several we&#39;ll group them into three categories or three serotypes known as influenza a influenza b and influenza c of which there are several strains of each influenza a is generally the one that causes most epidemics if you&#39;ve ever heard of like h1n1 things like that those are generally the ones that we get really worried about influenza b this is more local outbreaks it&#39;s kind of a moderate disease and then influenza c is a more mild disease but all of these are considered the flu but generally when people say they have the flu there&#39;s really no guarantee they know it&#39;s influenza unless they actually went and got tested sorry so transmission for the blue is inhalation either of aerosols or droplets or you can have fomites touching something that like someone sneezed on or coughed on like i just did and then like touching your mouth touching your face and getting infected that way generally influenza starts as an upper respiratory tract infection but then moves into the lower respiratory tract it starts by causing like fever chills headache body aches coughs stuff you know sore throat extreme fatigue the biggest thing to note is that a lot of times when people say they have the flu they also get like upset stomach diarrhea for true influenza there are no intestinal effects so if you have that you don&#39;t really have the true flu you have just like the generic what people say oh i have the flu it&#39;s not influenza though for influenza there&#39;s a one percent mortality rate and that&#39;s mostly mostly due to secondary infections like pneumonia is pretty typical that if someone gets influenza especially if they&#39;re older or really young they can get pneumonia afterwards but influence itself causes anywhere from twelve thousand to sixty thousand deaths every single year even with just a one percent mortality rate so it&#39;s still a lot of deaths prevention and treatment so there is an annual vaccination generally the vaccination has one of several types of the inactivated viruses so they tend to focus on a couple strains of a b or c of those um the problem with that is we&#39;ll see here in a second is that they have to start making these over a year and a half in advance so for like 2020 they started working on these in like 2018 so they have to do like some math and statistic nonsense that we don&#39;t care about that basically helps them guess which type of influenza is going to be the one that&#39;s going to be most common that year and then they start making the vaccine for it well sometimes they&#39;re not as accurate as they would like to be so that&#39;s why some some years it seems like even if you got the vaccine you still get sick but on top of that there are just so many different strains that even if they picked the right serotype the virus could have mutated there could be a different strain all these different things currently there is a vaccine in the works that works against all types and would not need to be given yearly but it is still in the test run and of course it&#39;s very expensive it&#39;s very detailed it takes a lot of time but this has actually been in the work for about five [Music] six years now so hopefully that will be getting the human trials soon there is treatment for for influenza but that&#39;s really only if you have one of those really severe cases this was actually one of the first viral diseases where they did make effective antivirals and by effective we mean if you take them early on infection by like day two they might have an effect so antivirals still in general are not always the best but it&#39;s the best we have at the moment so again usually i don&#39;t focus too much on virulence factors but for influenza we have two virulence factors that are very important the h spikes and the n spikes these are both used basically to cause disease in the host the h spikes which you can see are like the little blue triangles in the image there on the outside of the cell these are used for attachment to host cells they basically stab into a host cell and hold tight and then the n spikes are used to release the virus from the cell they basically act like a little tunnel that the virus dna can travel into the next cell the reason we care about those h and n spikes is because they are constantly changing viruses are known for their ability to cause genetic changes when they mutate and this can lead to issues with our immune system remembering them one of our big advantages of our kind of higher level of immune system is that it keeps a memory of every disease it comes into contact with so then the next time you see it hopefully it won&#39;t get you sick the reason that we have to get a vaccine every year for the flu is because there are so many different types and because it mutates so often that the even our memories of the flu don&#39;t really hold up because it looks different enough that our body doesn&#39;t recognize it so two terms that are important for influenza are antigenic drift and antigenic shift so an antigenic drift is when there are mutations in the genes that code for those h or n spikes and it could just be a little change might just be one change in amino acid but this allows the virus to basically hide from our antibodies or hide from our immune system inside our body antigenic shift on the other hand is complete changes in the genome there are generally only 10 genes in any influenza virus regardless of influenza a influenza b influenza c doesn&#39;t matter that involve making those h and n spikes usually this is due to genetic recombination or basically the combining or switching of dna between totally different strains that are inside the same organism insane inside the same host the same time which ends up create creating a completely new strain of the virus that our bodies have never seen before and of course our vaccines won&#39;t work for so this image is just showing how that happens so for example there&#39;s duck influenza virus in blue there&#39;s human influenza virus and orange both of these viruses not only infect ducts and humans so duck infects ducks human infects humans but both of them can also infect a pig because that host now is holding both of those influenza viruses there&#39;s a chance that they could swap information over and then you end up with an entirely new strain of human influenza virus that has duck spikes on it that our body has never seen before our vaccines are prepared for and that can get us sick even if you have the vaccine next moving on to pertussis more commonly called whooping cough so this is caused by a bacterium known as bordetella pertussis reservoir as humans transmission is through respiratory droplets so there is a vaccine called the dtap vaccine for pertussis that holds basically fragments of the pertussis cells and there&#39;s also treatments that you can use antibiotics for this specific type of disease infection and symptoms so generally again it begins as an upper respiratory tract infection where it starts causing cell death because it releases a toxin at this point it typically causes really severe kind of short or staccato coughs that are happening often enough that it leads to exhaustion they can actually be strong enough that they can break ribs and create a lack of oxygen to tissues because you&#39;re coughing so much you can&#39;t get enough air in this is generally broken down into three different stages the cataract stage is pretty much like the common cold you get sneezing runny nose itchy eyes watery eyes all of that sore throat then the pyroximal stage is where you get those violent coughing stages this is where you typically get the whooping of the whooping cough and this is due to basically your coughing so much so hard that you&#39;re like gasping for air in between because you when you&#39;re coughing you can&#39;t breathe and then you can get eventually into the convalescent stage where if you remember from previous units convalescent stages where that bacterium or that virus is going down in numbers in your body and your body is essentially recovering but your immune system is weak at the same time so this stage leaves you susceptible to other respiratory infections so this graph is just showing that in the past like 100 years or so we&#39;ve greatly reduced the number of pertussis cases worldwide and in the us with that&#39;s mostly with the invention of those different vaccines and different forms of the vaccine which is the dtp the dtap and the tdap that you see in the top image there in recent years though from like 2 000 ish until now we&#39;re starting to see more and more pertussis cases coming back that&#39;s for a variety of reasons one of which is the anti-vaccine movement another is that we&#39;re starting to reach the point where people are kind of aging out of the first vaccine that they might have gotten and now they&#39;re getting it when they&#39;re older even though it&#39;s far more common for kids to get it we&#39;re also seeing some basically just more people in in the same area we&#39;re seeing denser populations in like big cities so you have kids that haven&#39;t gone through their full vaccinations that are getting it things like that which is why we rely so heavily on herd immunity to make sure those types of kids don&#39;t get it but the anti-vaccine movement is putting a big damper on that and then again we have people kind of aging out ideally vaccines last for the entire lifespan but i really most of them only last for about 20 years or so before our body starts to forget it and so we&#39;re seeing elder populations starting to get whooping cough again and then our last disease for both upper and lower respiratory tracts is respiratory syncytial virus or rsv so this is a virus of course as the name says transmitted through respiratory drops and fomites most commonly symptoms typically are once it infects the respiratory tracts it causes these syncytia which are giant basically mutated cells that have several nuclei in the respiratory tract causes breathing problems because you have these just huge clumps of cells essentially there is no vaccine for this but you can get passive antibodies for kids that are at high risk like if they have some kind of immune system disorder or something that would make them more likely to get this there is a treatment but this is usually only used for severe cases which typically cur occur in babies generally older kids and adults usually only get like a cold when they get this virus but babies get pretty severe coughing bouts congestion hard to breathe all the general just kind of issues with messing with the lungs type thing um pretty much everyone has gotten this disease at some point typically by age two almost every kid has had it and in that there&#39;s about a hundred thousand that are hospitalized each year for it some don&#39;t ever really figure out that it&#39;s rsv they just think they have like maybe pneumonia or bronchitis because it kind of kind of replicates some of those symptoms and they treat it with broad spectrum antibiotics which does not always work in this case does not work because it&#39;s a virus but it helps the symptoms until the virus kind of works its way out of the system all right and then moving on to infections of the lower respiratory system so remember this is everything basically from the neck down starting with the trachea or the windpipe and then moving into the lungs with the bronchi the bronchioles and the alveoli so one of the biggest diseases of the lungs is tuberculosis this is caused by mycobacterium tuberculosis a type of bacteria that&#39;s found in humans transmitted through respiratory droplets essentially what happens with tuberculosis is there are kind of two stages primary tuberculosis is where you get the first infection of the lungs where bacteria are basically eaten up by the white blood cells through the those phagocytes and they start just kind of like clumping around this bacteria what happens is those cells and the bacteria die off forming these hard little nodules called tubercles which is how the disease gets its name in the lungs other than forming those tubercles though there are no symptoms at this point so this is also known as a latent form of this disease at some point though you&#39;ll move into secondary secondary tuberculosis or reactivation of tuberculosis and this occurs later could be months could be years at some point though it&#39;ll wake up and those tubercles will basically release a ton of bacteria that will start causing things like chronic cough fever weight loss just essential tissue damage all throughout the lungs so it&#39;s important to note two things in the latent form the person doesn&#39;t feel sick even though the bacteria are present they&#39;re not causing any symptoms it&#39;s also important to know that they are not contagious at this point you can&#39;t pass these on if the person&#39;s in a latent form of tuberculosis in active form though in that reactivation secondary tuberculosis that&#39;s when people feel sick that&#39;s when they&#39;re contagious that&#39;s when they can pass them the bacteria around because the bacteria are back out in the lungs and in the throat so you don&#39;t need to know these stages but this is just showing the process of making those tubercles so on the top you have one of these little bacterial cells going around a little macrophage there and then you see they basically just start leaving the blood and start clumping up around any infected cells so those are all macrophages forming an early tubercle at some point they&#39;ve circled in all the bacterial cells creating this little clump of macrophages and bacterial cells the macrophages die off and then the bacteria kind of lyse out of the macrophages and start kind of eating away the inside of this tubercle at some point it becomes this hard little nodule this hard ball this tubercle inside the lungs and then at some point it will rupture releasing the bacterium like you see in the bottom image there back into the bronchial back into the lungs where now the person can pass it through those respiratory droplets so the images there are showing lung tissue with those tubercles in them so you can see the white tubercles those are not those fully formed tubercles yet but those white little puffy masses in the lungs and then the bottom image there that&#39;s just full of tuberculosis your lungs shouldn&#39;t have that brown gunk that&#39;s all just dead tissue and tubercles and okay treatment and prevention there is a vaccine called bcg this is actually a live stream of bovine tuberculosis or tuberculosis for cows that&#39;s been made a virulent which means it can&#39;t actually cause disease it&#39;s not widely used in the u.s though because we don&#39;t have a ton of tuberculosis naturally in the population versus places like asia that deal with it quite a lot this is a pretty routine vaccine treatment for tuberculosis is awful because it can go into that latent stage and hot the bacteria can hide in those tubercles it is really hard to treat it takes prolonged treatment with multiple antibiotics and i&#39;m talking like several months to a year of like three or four different drugs to get through the active and the latent stages the biggest problem with treatment is that people are non-compliant they don&#39;t go through their entire drug regimen they start to feel fine they stop taking them whatever it is and this has led to several strains of multi-drug resistant and extensively drug resistant tb multi drug resistant is still treatable but now you end up having to take five or six different drugs for up to two years extensively drug resistant is almost almost nothing you can do it&#39;s basically like treating symptoms at that point so this is just showing worldwide where tb is such a kind of issue you can see the us we really don&#39;t deal with tb that often tuberculosis that often which is why we don&#39;t routinely have that vaccine you can see places like asia see places like southern africa all have really high cases of tuberculosis and unfortunately have a lot of drug resistant tuberculosis as well this is more a look at the tuberculosis in the u.s we do of course have tb but it&#39;s not as bad as other countries if you compare it to other countries we&#39;re practically non-existent but we do have cases here and there and of course it tends to be where we have a lot of people but not always like you can see alaska there&#39;s not a ton of people in alaska but we do have cases there next we&#39;re looking at pneumonia so this is an inflammatory condition where the lungs start filling with fluid specifically the alveoli which are the little sites of gas exchange where you take in oxygen and get rid of carbon dioxide this is caused by many many many many many different organisms which we&#39;ll see here in a second overall those symptoms are pretty much the same for whatever pneumonia whatever organism is causing pneumonia you get chest pain when breathing shortness of breath coughing you can even get kind of blood stained or rusty looking phlegm that&#39;s because you literally have blood coming out of the lungs pneumonia is one of the worst diseases for kids more kids under the age of five die of pneumonia than any other infectious disease because it&#39;s pretty hard to treat because there are so many different organisms that can cause it and a lot of the times it&#39;s a secondary infection it can be a primary infection but oftentimes it&#39;s a secondary infection like after influenza where the immune system is already low so then pneumonia kind of takes over there are tons of cases every year for example just in the u.s there are anywhere from two to three million cases each year over uh 45 000 of those end up in death so we&#39;ve grouped pneumonia for this chapter into two groups community associated and healthcare associated community association is just the one like going around living your life and then health healthcare of course is dealing with like hospital infections like nosocomial infections so this is listing the seven most common community associated pneumonia causes some of which are bacterial some viral some fungal streptococcus pneumoniae legionella species and mycoplasma pneumonia are all bacterial honza virus and respiratory viruses are of course viruses and then histoplasma capsulitum and pneumocytus girolovisi those are both fungal infections for pretty much all of these it&#39;s either going to be vehicle transfer or droplet contact like respiratory droplets for prevention the only one that has a vaccine is streptococcus pneumonia the very first one on the left there all the rest are pretty much just avoiding the reservoirs of different organisms that cause it or just general hygiene for example honda virus is carried in mouse droppings so avoiding like mouse infestations things like that um histoplasma capsidulum the fungus the third one from the right there it&#39;s commonly found in batten bird droppings so again avoiding those at all costs which anything involving bat i&#39;m out you don&#39;t need to tell me twice most of these do have treatments um the only two that don&#39;t really have treatments are hantavirus it&#39;s just supportive treatment so it&#39;s not actually fixing the virus and then the other virus respiratory virus is there is no treatment it&#39;s just you get through it or you don&#39;t unfortunately just a few of the distinctive features here the mycoplasma pneumoniae the third one from the left is the one that&#39;s typically known as walking pneumonia and then the fungal infection second from the right there pneumonia cysteralpsy that&#39;s most commonly occurs in aids patients where they have that practically non-existent immune system left and then looking at healthcare associated pneumonia again this is caused by a variety of bacterium both gram-negative anger and positive but these are specifically endogenous infections typically caused by aspiration where you get bacteria from the upper respiratory tract or the stomach into the lower respiratory tract into the lungs usually through like a ventilator of some kind prevention is basically just making sure equipment is clean and making sure patient&#39;s head is elevated and just proper education things like that it can be treated usually with broad spectrum antibiotics although we&#39;re starting to see some bacteria that are again antibiotic resistant so that&#39;s going to be an issue there are over three hundred thousand cases a year in the united states alone um anywhere from point five to one percent of patients will get some kind of health care associated pneumonia which is unfortunate because we&#39;re you know we tout that we&#39;re one of the best health care as far as like um you know technology and things like that and yet still this many people getting sick but again it&#39;s just because mostly bacteria is everywhere and then our last disease for the laura respiratory tract and for this chapter is histoplasmosis so this is caused by a fungus specifically a dimorphic fungus called histoplasma capsulatum so remember dimorphic means that it changes its shape it morphs and in this case because it&#39;s a pathogen it&#39;s going to morph at different temperatures so in the body it&#39;s going to be one thing out in the environment it&#39;s going to be another so reservoir for this is going to be soil in the environment and transmission is going to be inhaling the spores from the fungus when they&#39;re inhaled they&#39;re basically going to cause acute pneumonia acute pneumonia or really fast pneumonia infection in immunocompromised people this infection will eventually get into the blood and start affecting the organs causing lesions and breakdown of pretty much every organ making it almost always fatal luckily there is a treatment and anti-fungal treatment the reservoir for this virus is found in bat and bird droppings and the reason i mention it it&#39;s not in your textbook but the reason i mention this disease is because it&#39;s pretty common in this area as you can see from the map here um but it&#39;s basically a fungus that again likes the nitrogen in bat and bird droppings so we see it wherever you have places with a lot of those things like caves for bats things like that we actually had at my previous job there&#39;s a prison not far from my previous school that i worked at in danville illinois where about four or five years ago now inmates were feeding birds just for something to do out at wreck time and so they were getting huge bird population and they had this huge outbreak of histoplasmosis because of all the bird droppings in that area and inmates started breathing in the spores from the fungus that started growing okay and then like always we have these two images this one showing the different diseases and what causes them and then last one again our look at deadlines versus communicability um this one is a little less clear you can see like tb and diphtheria more deadly and slightly less communicable but things like pertussis especially has that big jump where you can see it&#39;s not very deadly at all but extremely communicable okay that&#39;s it for chapter 19.

Transcript for:The Respiratory System

Transcript for:
The Respiratory System