| 00:01 | Yeah. Ok. Ok, Uh, let's get started here. |
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| 00:30 | , 14, uh, we only a couple of flights left on |
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| 00:35 | So, um, then 16, 16, 17 immune system. |
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| 00:43 | It's gonna start the immune system, , in a few minutes. |
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| 00:48 | uh, that will go on to week and then, uh, on |
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| 00:53 | 17. So, uh, see back to weekly quizzes, um, |
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| 01:00 | , uh, so just be aware that coming up due on Monday. |
|
| 01:05 | , uh, let's see. exam two was opened up yesterday. |
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| 01:10 | I forgot to, like I mentioned in today's email. So, |
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| 01:13 | do take a look at it if got questions. Uh, let me |
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| 01:17 | , but give yourself a chance to through it. See if you can |
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| 01:20 | through the questions, few minutes, if you can figure it out. |
|
| 01:23 | not, I'll, I'll certainly let , uh, let me know. |
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| 01:27 | . Uh, let's see what So, uh, our exams not |
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| 01:32 | another three weeks yet, but uh, scheduler for that will open |
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| 01:38 | Friday for that exam. Ok. , um, anyway, uh, |
|
| 01:45 | approaching the end here. Ok. let's, uh, look at. |
|
| 01:55 | again, as I mentioned several times , 14 is a lot of |
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| 02:00 | right? So you've got a um list here. I just, I |
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| 02:06 | literally just went through the slides and , just put them and group them |
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| 02:09 | together. OK. So, uh why this is really just writing these |
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| 02:15 | out and just remembering them? Um So the uh uh last |
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| 02:24 | OK, we talked about uh the last very last thing we talked |
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| 02:29 | was epidemiology, right? So that's um data, you know, basically |
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| 02:35 | at data uh which are um data instance, instances of disease. Um |
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| 02:45 | looking at it in different ways uh it to, to um maybe find |
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| 02:52 | cause of a disease to find out you can prevent disease. Um try |
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| 02:58 | use it to, to um figure what's the source of the illness? |
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| 03:03 | Is there a particular demographic group that's susceptible to it? So, lots |
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| 03:08 | different ways to use the data. And these are some examples here, |
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| 03:12 | three ways. So what they describe um descriptive, analytical and um uh |
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| 03:21 | the other one, other name, other one is called uh experimental. |
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| 03:27 | . And grand there is some overlap these because they're all looking at |
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| 03:31 | OK? All three of course but in um descriptive epidemiology, I |
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| 03:36 | realized uh Jon Snow, anybody if know who Jon Snow is Game of |
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| 03:43 | I feel like, so that's not Jon Snow, obviously, although they're |
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| 03:47 | British, I guess. Uh, , but anyway, mm, |
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| 03:53 | um, so he used, this , and his study was kind of |
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| 03:57 | the fact, uh, more or so cholera outbreak in London, which |
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| 04:02 | a very common thing during that these , like mid 18 hundreds, I |
|
| 04:06 | , uh, people used the main going through London, that's kind of |
|
| 04:09 | water source for everything both to use dump into. Um And so water |
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| 04:15 | be pumped there uh in various neighborhoods like a old fashioned you might be |
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| 04:20 | of, you know, back, in these days, you know, |
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| 04:22 | pumped water with one of these things out of a spout in the middle |
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| 04:26 | a neighborhood and that's where people go their water. And so just by |
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| 04:30 | around to these neighborhoods, he just looked at um death records of |
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| 04:35 | People had died from cholera and then kind of went from house to house |
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| 04:41 | asking, ok, who, who your family had it? Where were |
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| 04:45 | at uh before they became sick, kind of things and they kind of |
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| 04:49 | together a map of, of the um in downtown London and saw a |
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| 04:55 | number of cases where the red arrow at and then it was traced to |
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| 04:58 | , a particular pump and it had faulty uh contaminated or some something when |
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| 05:05 | changed it out uh to a brand pump, the instances of cases went |
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| 05:11 | down, but you wouldn't have known if, if you hadn't done this |
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| 05:14 | of these studies. And so um what we call descriptive. And so |
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| 05:20 | analytical is obviously looking at a ton statistical data, this is what Florence |
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| 05:26 | did. Um looking at uh So typhus is a disease that is |
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| 05:35 | um a disease of poor sanitary bad hygiene, um close quarters being |
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| 05:44 | . Um It could be um you , it's carried by fleas, uh |
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| 05:51 | types of fleas and ticks, Ok. Uh Many are carried by |
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| 05:56 | , mice and rats and things. so, um it produces kind of |
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| 05:59 | a fever and uh um headache and symptoms become worse after that. But |
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| 06:07 | it was a common uh in this and before this time, it was |
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| 06:10 | common because of course, didn't have sanitary conditions we do nowadays in most |
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| 06:15 | . And so that contributed heavily to disease. But she was interested in |
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| 06:19 | at, you know, what is nature of this compared to our |
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| 06:24 | right? Looking at military members of military compared to just the average, |
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| 06:28 | know, civilians. Ok. And is the difference in terms of |
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| 06:33 | these cases of typhus? And so me just flip, flip forward real |
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| 06:37 | just to show you. So he just looking at this is actually looking |
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| 06:40 | both typhus and cholera, you they label it contagious diseases. But |
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| 06:46 | was basically looking at both of these primarily typhus. So, cholera is |
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| 06:49 | waterborne, you know, uh, contaminated water. And so, |
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| 06:54 | of course, in the military, , they're, you know, they're |
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| 06:57 | together, uh, at this you know, they may not have |
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| 07:01 | best hygiene, uh, uh, not bathing regularly, stuff like |
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| 07:06 | Um, she also e especially, know, for those that are just |
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| 07:11 | that were in England, right? a higher than the, than the |
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| 07:14 | public. Ok, 0.2 versus But then when you look at soldiers |
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| 07:19 | in war, war time, in a, uh, I forget |
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| 07:24 | Crimean War, uh, that it much higher. And so, |
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| 07:28 | attributed to that, she attributed, saw, she investigated this and |
|
| 07:32 | ok, what's different here in this compared to these other two groups is |
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| 07:38 | poor nutrition, right? So that , that's gonna lower your immune system |
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| 07:43 | unsanitary conditions, uh, poor you know, poor, um, |
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| 07:48 | day to day conditions overall. And all together contributing to, um, |
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| 07:52 | , these higher instances of typhus. so when she saw this and |
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| 07:57 | well, let's do Xy and Z minimize these things to get better |
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| 08:02 | clean up, uh, bathe et cetera, et cetera. And |
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| 08:07 | course, instances go way down to to 2%. Pretty significant. |
|
| 08:13 | And so apparently she, she had this 1000 page report with a bunch |
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| 08:17 | tons of graphs and data and numbers things. Uh That's of course, |
|
| 08:21 | definitely fits it being an analytical um do you call analytical um epidemiology? |
|
| 08:29 | . The experimental, it is kind like uh basically setting up an |
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| 08:34 | a control group and a and a experimental group in similar ways. I |
|
| 08:39 | have briefly talked about this earlier but back in the first chapter. But |
|
| 08:46 | he insti instituted the use of an antiseptics ansis. And so in the |
|
| 08:53 | , he was working at um he that uh the in the hospital, |
|
| 09:01 | the the ward where women went to give birth, that there was a |
|
| 09:05 | high incidence of this disease called child fever is kind of the layman's term |
|
| 09:11 | fever is the medical term. It's to uh streptococcus bacterium um acquired during |
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| 09:19 | . Uh the baby uh can contract as well as it can spread into |
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| 09:24 | uterus and then also affect the So both mother and baby can be |
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| 09:29 | . Um And so he said, , what is, what's contributing to |
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| 09:33 | ? Because he saw this group here the hospital that had a really high |
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| 09:37 | of this disease. And then he um you know, women that didn't |
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| 09:43 | to the hospital gave birth outside the or uh used a midwife that they |
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| 09:50 | outside the hospital that they were, much lower instance of this. And |
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| 09:53 | he looked and saw what's the common here. Well, uh, these |
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| 09:58 | groups, um, washed their That was a regular practice of washing |
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| 10:03 | as a woman is about to give . And in the hospital, the |
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| 10:08 | , um, Maternity ward. no, um, where women were |
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| 10:13 | birth, uh, the doctors that , that were the young doctors. |
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| 10:19 | so they would be like 1st, year medical students that would come out |
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| 10:24 | a um uh uh Cadaver ward. , of course, as a |
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| 10:29 | you work on cadavers, you study the body and how it works |
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| 10:32 | whatnot. They would come directly from to the maternity ward, of |
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| 10:36 | dirty and bloody in hands and not and not depriving way. That's, |
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| 10:41 | what contributed to the high instance of child had fever. And so when |
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| 10:45 | instituted said you aren't going in there you wash your hands. And so |
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| 10:50 | that, I mean, the numbers dropped much like the uh what we |
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| 10:54 | with, uh, with, uh like a rate that's that like that |
|
| 11:01 | se drop just again, just washing hands, right. So, |
|
| 11:06 | but actually in, back in the it was uh a much harsher soap |
|
| 11:10 | . It was this Li Live which is actually very, almost like |
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| 11:14 | your hands with bleach almost, So, uh that definitely is gonna |
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| 11:18 | any bacteria and likely kill some of own cells on there. But uh |
|
| 11:22 | did definitely lead to this drop in number of diseases. OK. Of |
|
| 11:26 | particular one referring to uh child bed . So, um no, we |
|
| 11:33 | heard of uh clinical trials, you , when your drug is on the |
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| 11:36 | , then you test different groups, ? Could be uh one who gets |
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| 11:40 | placebo, one doesn't these kind of that all falls into the the uh |
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| 11:46 | of experimental epidemiology. OK. So the case reporting, so I mentioned |
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| 11:55 | already as well. So case reporting nationally notifiable diseases kind of goes hand |
|
| 12:00 | hand. OK. So there let me just quickly show do not |
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| 12:06 | this table obviously, but um these the nasty notifiable diseases. Uh And |
|
| 12:13 | what you might think, you communicable diseases, obviously, things like |
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| 12:17 | , mumps, uh et cetera, uh influenza COVID. Um And then |
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| 12:24 | all of your sexually transmitted diseases fall this group. Uh and then certainly |
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| 12:28 | number of others. OK. And with this data, of course, |
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| 12:33 | you can um see if there's an is, is what's going on and |
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| 12:39 | to break that chain of transmission, call it OK. To, to |
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| 12:44 | to contain the disease. So uh information to have. So we can |
|
| 12:50 | and it's basically all that information is put together in this publication here |
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| 12:58 | which covers every infectious disease, I even non infectious diseases too. |
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| 13:05 | on a weekly basis, you they track all this data if they |
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| 13:08 | something that's, you know, spiking or what have you, then they |
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| 13:12 | on the course and, and, follow it to see if it become |
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| 13:16 | significant. Um, and you, know, if you're interested, you |
|
| 13:19 | , we just Google that and you , you can see the actual weekly |
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| 13:23 | here. The ones at the end the year are kind of interesting. |
|
| 13:26 | kind of overview of, of the year and the, and, and |
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| 13:30 | has every infectious disease in the number cases that are during the year. |
|
| 13:36 | , but, uh, and so that, the, the terms, |
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| 13:39 | you see morbidity and mortality. So, um, I'm sure you |
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| 13:46 | heard of mortality, obviously. So rate, number of deaths, |
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| 13:49 | It's about deaths from these diseases. , morbidity is, is the uh |
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| 13:55 | or rather the instance of a specific . Ok. You don't necessarily die |
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| 13:59 | it, but you report it people are reported to have it. |
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| 14:04 | been confirmed from testing that they have disease, uh whether they fall into |
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| 14:09 | mortality category, of course, depends they die from. Hi, this |
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| 14:27 | number than mortality, mortality and morbidity . That's like 100% mortality rate. |
|
| 14:35 | ? You get the symptoms of disease you die, right? So you're |
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| 14:38 | gonna be the same. Ok. , I mean, I guess it |
|
| 14:44 | be close if it was something like but even with that it's not, |
|
| 14:48 | not equal. So generally morbidity is be higher, right? You have |
|
| 14:51 | lot of people that come down with , right? Contributing to the morbidity |
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| 14:57 | . But how many are gonna actually ? Right. Much less are gonna |
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| 15:00 | than actually. Yeah. Does that sense? That morbidity is gonna be |
|
| 15:05 | mortality? How they relate? Um . So I see that that ends |
|
| 15:15 | . OK. Any questions about right? OK. So let's uh |
|
| 15:22 | we're going to innate community. So parts here, innate and adaptive, |
|
| 15:26 | community. 17. Uh and that is one of those uh uh you're |
|
| 15:31 | kind of work on it yourself, ? So the, I think the |
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| 15:35 | should be available, the lecture video stuff. So go ahead and take |
|
| 15:40 | look at that stuff already for for 17. OK. And we'll |
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| 15:44 | through that next Thursday. OK. I have a bunch of questions and |
|
| 15:50 | kind of frame it around that. again, you've seen this already 100 |
|
| 15:54 | , but again, just to we're not gonna focus on this is |
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| 16:00 | this really host offensive. OK. Which of course relates to, you |
|
| 16:07 | , do you come down with What's your level of resistance or you're |
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| 16:12 | so resistant? You, are you susceptible? OK. Of course, |
|
| 16:15 | relates to your, your immune obviously. Ok. So with the |
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| 16:19 | immune system, that's what you come of the, you know, come |
|
| 16:25 | , right? You're born and you've got that innate immune system already |
|
| 16:29 | , not, you know, as baby, obviously, not at the |
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| 16:32 | level as it will a few months years from that point. But you |
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| 16:37 | have, obviously skin, that's a barrier, certainly part of innate immune |
|
| 16:41 | . You have mucous membranes lining your cavities and whatnot. That's, that's |
|
| 16:45 | of it. Um We all we call the innate immune system, |
|
| 16:52 | . OK. And there's a reason that, but let's look first at |
|
| 16:55 | question here just to see if we uh uh come up with something |
|
| 17:00 | So I remember so as we go this, your, your innate and |
|
| 17:05 | immune system, you can look at as 12 and three in terms of |
|
| 17:10 | . And one way to visualize that really if you're a, if you're |
|
| 17:14 | pathogen out here, right? And comes into the body, OK? |
|
| 17:19 | are the layers that's going through, ? As it penetrates deeper into your |
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| 17:24 | if it does. OK. And that's one way to look at it |
|
| 17:27 | terms of first line, second third line. OK. Um Let's |
|
| 17:37 | . Um So as you're answering so specific versus non-specific, so |
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| 17:44 | the immune system is the adaptive immune . OK? Because it relies |
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| 17:50 | on um binding of components to each antigen antibody very often. So there's |
|
| 17:59 | , there's a different specificity to it it involves a binding OK to an |
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| 18:04 | . OK. And that's what sets motion. All the things that |
|
| 18:09 | OK. Your, your innate immune is not all, there is molecules |
|
| 18:15 | in certain in parts of the It's not all centered on that. |
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| 18:20 | about microbes coming in and you have barriers that they can encounter and may |
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| 18:27 | may not get through, but it's as specific as the adaptive immune |
|
| 18:32 | OK. So let's count down here 10. All right. Um |
|
| 18:48 | that's uh yeah, it, you're correct. It's fever, fever |
|
| 18:52 | , is I think more of a line defense. OK? And so |
|
| 18:57 | look at um both sides of this here. Here we go. So |
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| 19:04 | non-specific and specific. OK. So system falls in that category, |
|
| 19:11 | Um And so first line, so I said, picture microbe here is |
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| 19:15 | in, right? What's it gonna first skin skin barrier? Then if |
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| 19:20 | like gets into your nose or maybe mucous membranes line your nasal |
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| 19:24 | Um you ingest it, right? mucous membranes coat your throat and then |
|
| 19:31 | uh test. And so basically, a colleague of mine that teaches a |
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| 19:37 | and human phys. Uh this gives analogy that the body is a |
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| 19:42 | OK. It goes right through, through your mouth. Butt. |
|
| 19:46 | It's the whole, right exposed to environment, right? But they have |
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| 19:51 | f around your guts and everything else it. So, of course, |
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| 19:55 | what goes through the hole is what breathe in uh ingest. And of |
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| 20:01 | , that will contain uh micros, they encounter, right, the mucus |
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| 20:06 | as they pass through. So, so skin these membranes uh and don't |
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| 20:12 | forget your, your own microbiome, ? They're, they're a part of |
|
| 20:17 | certainly as well. OK. Now gonna be uh somewhat redundant because um |
|
| 20:25 | your first line defense, you can at these especially um skin and mucus |
|
| 20:35 | um as a physical barrier. But they also produce a chemical |
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| 20:41 | which means skin and mucus membranes produce and those chemicals also can interact |
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| 20:48 | in uh counteract pathogens that come So, so your first line of |
|
| 20:55 | is both a chemical physical and chemical as, as you'll see um second |
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| 21:01 | effect. So getting past your, um first line, then second line |
|
| 21:08 | kind of characterize as cells, specific that are meant to interact with pathogens |
|
| 21:14 | get rid of them and also So I call like inflammation, |
|
| 21:20 | these I call processes, these of are particular cell types right now, |
|
| 21:27 | the processes of course involve cells. ? But you one of your main |
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| 21:33 | to find infection, of course is foc cytosis, literally just engulfing pathogens |
|
| 21:39 | , and breaking them up. I . So, uh so there's a |
|
| 21:44 | of a number of um cells and processes that are part of the second |
|
| 21:48 | of defense. And so the third , which we won't get to until |
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| 21:51 | week, from the day is your immune system. So this requires um |
|
| 21:58 | , it only gets activated. So the respond two, that's what |
|
| 22:10 | that system, right? Um And uh it's, that's why we have |
|
| 22:17 | , that's what we call it So you have um cells in your |
|
| 22:21 | system that their immune system will recognize . Ok? Um Antibodies is one |
|
| 22:30 | production of antibodies. You can of the thousands, if not millions |
|
| 22:34 | potential engines out there, you can produce antibodies to each and every one |
|
| 22:39 | them allergies are about kind of a response to certain antigens. What in |
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| 23:06 | case, the uh and so uh cells and B cells, I remember |
|
| 23:16 | also a couple of other types and also gonna see is that there will |
|
| 23:22 | cell types that will bridge that both . You have cell types that both |
|
| 23:30 | part of the adaptive and inane. they were kind of connected to. |
|
| 23:38 | um so ha knowing I just told now, let's uh see this is |
|
| 23:46 | , this is a and which responds , right? Ory and Nate. |
|
| 23:56 | I'm not going to run the timer this one all winding down. All |
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| 24:29 | . Counting down from four. yes, it, they gonna be |
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| 24:39 | they, and, and it really to do with that, that having |
|
| 24:44 | , well, the engine, the response or response to antigen, which |
|
| 24:52 | what the adaptive immune system relies Ok. Um, there are 22 |
|
| 25:00 | . One is, um, ok. Identify, find it, |
|
| 25:11 | to speak. Ok. And then it. Uh It's gonna be |
|
| 25:23 | not scientific but uh I'll just say stuff. OK. I'll elaborate on |
|
| 25:33 | . Of course, it's uh a too bad but do stuff means |
|
| 25:37 | so uh identifying to recognizing and finding right? There is a time element |
|
| 25:41 | that doesn't happen instantaneously, right? Then you buy an engine and then |
|
| 25:47 | then induces a lot of stuff going inside the cell. Now making different |
|
| 25:54 | of molecules, et cetera, et . And then, um that, |
|
| 25:59 | then leads to so the new stuff then those antibodies leave or it so |
|
| 26:04 | finds the engine and then stuff right? More stuff happens. So |
|
| 26:09 | uh uh for now this is, is why you, we'll get the |
|
| 26:13 | and bolts uh next week. But um so yeah, it, this |
|
| 26:18 | takes time, right? So of , the, the Navy service is |
|
| 26:21 | there, right? It's, it's barrier, it stops or OK. |
|
| 26:26 | again, I put the kind of terms in this, uh, |
|
| 26:31 | chattered together here. Ok. So get, I broke it down in |
|
| 26:36 | of chemical defenses, physical barriers or the skin mucus membranes, right? |
|
| 26:41 | , different cell types we see Ok. Um, another cell type |
|
| 26:48 | that immune system relies on antigen. , this is another one, cytokines |
|
| 26:54 | something you'll hear over and over. . So these, it's basically a |
|
| 27:00 | term, chemicals that, um, tell other cells of the immune system |
|
| 27:07 | to do. Uh And they have variety of different functions as you'll |
|
| 27:12 | Um And names the cytokine is kind the generic name, but there are |
|
| 27:17 | names for all these things. Um then here are some uh processes here |
|
| 27:23 | this box. OK? Um PS . Not sure. You know what |
|
| 27:29 | is yet, we'll talk about Uh figy tosis. The other thing |
|
| 27:35 | uh the type of pathogen your body to deal with. OK. Will |
|
| 27:43 | two different strategies. OK? You're have pathogens who do their thing. |
|
| 27:51 | now this is in your body. ? Do their thing by being outside |
|
| 27:55 | , right? So what we call pathogen. OK. But then there |
|
| 28:00 | types that go inside your cells and their motive infection, right? |
|
| 28:06 | for example. Uh So you have in intercellular and intercellular pathogens, but |
|
| 28:11 | have to have two very different ways dealing with that. OK? Because |
|
| 28:15 | a pathogen is inside a cell, kind of hidden from the body. |
|
| 28:21 | . And so there has to be way to identify those kind of infected |
|
| 28:26 | and there is all right. so there's gonna be ways to deal |
|
| 28:29 | both. OK. So, you , rule of thumb typically is phagocytosis |
|
| 28:36 | work if it, if it's inside a cell. Right. Certainly, |
|
| 28:41 | it's outside, you can just something the foc cytosis engulf it and chew |
|
| 28:44 | up. Uh So we, we see there's different strategies for for what |
|
| 28:50 | of pathogen is and how we can be. And we used to call |
|
| 29:08 | lamps, lamps, PMS M AM . Yes. What it did. |
|
| 30:29 | so thank you positive, right? all of it. Um And |
|
| 30:44 | and also your book doesn't go into and I'm not gonna touch you on |
|
| 30:47 | , but cells have to receptors, have a bunch of cells in your |
|
| 31:25 | that have these um uh and, when they encounter a pathogen like |
|
| 31:31 | then that, that signal sort of a sets in the motion of production |
|
| 31:41 | cytokines. OK. As I you have a lot of different |
|
| 31:45 | OK? From you just a OK. I will mention these as |
|
| 31:50 | go through. But uh is the the with octopus with a bunch of |
|
| 32:34 | arms, right? That would be active but no arms, right? |
|
| 32:42 | an OK. You see the positive an infection somewhere is to get your |
|
| 33:06 | to that site. And so right? There's, there's movement toward |
|
| 33:11 | chemical. And so that's what that . OK. So if you have |
|
| 33:16 | skin cut or wound or something here whatever, these chemotactic signals will draw |
|
| 33:24 | immune system cells there. Uh inflammatory , fever, um that will go |
|
| 33:30 | that. Uh not today, but time. Uh so again, these |
|
| 33:33 | typical responses. We've all had we've all had inflammation, right? |
|
| 33:38 | are specific responses really. Uh inflammation really about um containing infectious agent where |
|
| 33:49 | entered the body, so to So if you have like a splinter |
|
| 33:52 | , and it's contaminated and you have infection that the inflammatory response is meant |
|
| 33:57 | kind of contain it right there and let it spread. Um, fever |
|
| 34:04 | its own use, ok? Um T and B cells. So that's |
|
| 34:09 | the adaptive. So again, these just four things, five things, |
|
| 34:15 | cytokines do a bunch of other stuff well. OK. But all, |
|
| 34:20 | kind of activating some part of the system. Ok. So back to |
|
| 34:24 | ? So think of this system on slide here, this total like receptor |
|
| 34:31 | , right? This is really it's, it's the the it's like |
|
| 34:37 | the um you smell smoke in a and you pull the fire to alert |
|
| 34:43 | . That's kind of what this The toilets are kind of to alert |
|
| 34:47 | body. Let's get uh let's get kind of thing. Ok. And |
|
| 34:54 | wouldn't do that and outside of kinds that will uh get certain cells to |
|
| 35:00 | as needed. Ok. So to receptors are kind of the alarm |
|
| 35:06 | So to like receptors themselves, these , right? These things do not |
|
| 35:11 | anything, right? They don't have role in killing a pathogen. Their |
|
| 35:17 | is in warning the body of a pathogen is present and let's get, |
|
| 35:22 | do something. OK. That's what is, right? Um So |
|
| 35:28 | it's probably obvious to you, but it's like the total receptor is not |
|
| 35:33 | cell, it's a protein on a surface that interacts with A P A |
|
| 35:39 | and that activates it. Yeah. OK. So first line defenses. |
|
| 35:44 | it's going to be a little bit , as I said. So we |
|
| 35:46 | at it first as a physical So skin of course, is a |
|
| 35:51 | uh thick layer of, of multiple of cells. OK. Epithelial |
|
| 35:58 | And so that in itself provides a barrier. But then you put in |
|
| 36:04 | kind of um protein material that kind holds it together and covers it. |
|
| 36:08 | rich in keratin. OK. Keratin very and it, it's on the |
|
| 36:15 | of your body, but it's very on your fingernails because that your fingernails |
|
| 36:19 | basically you hair. OK. But but your body is covered with this |
|
| 36:25 | is covered with this as well. it makes it very, almost i |
|
| 36:29 | Impenetrable but very stout barrier. But do have of course natural openings in |
|
| 36:35 | skin, right? You have uh , right? Um sweat glands, |
|
| 36:40 | hair follicles. So these are kind can be natural openings where bacteria may |
|
| 36:44 | able to enter. Ok. And course, you have a cut or |
|
| 36:50 | a way for bacteria to penetrate your through a wound. That's typically what |
|
| 36:54 | call subcutaneous infection. OK. So membranes of course line, which means |
|
| 37:01 | the G I tract, obviously gu respiratory tract, et cetera. |
|
| 37:06 | And they typically have a structure like uh a basement, we often call |
|
| 37:12 | basement membrane. Don't need to worry that term. But as the blue |
|
| 37:17 | of like the foundation and then on of that, you have various |
|
| 37:21 | this should be cells from your intestine cells are part of that. Um |
|
| 37:26 | so, but again, very very dense uh and often producing uh |
|
| 37:33 | I'll uh I'll just here, membranes some sort of a secretion as what's |
|
| 37:38 | mucus is a secretion right? To the cells moist uh in the intestine |
|
| 37:44 | serves also the function of a lot food pass through. Um but mucus |
|
| 37:50 | nature of it can also help track uh plus your, your um Celia |
|
| 37:59 | your throat formed this thing called the , you're a senior. Well, |
|
| 38:22 | 40 of P and those hairs, stuff, right? Just like filia |
|
| 39:11 | your throat. Um, ch and . Uh, so you always have |
|
| 39:18 | eyes. Well, some are your , uh, but that, you |
|
| 39:24 | , tears are for that to kind keep washing eyes, wash micro out |
|
| 39:29 | , we wash over your teeth and . Um, so, and |
|
| 39:36 | and then as well, ear walking does have a function testing it |
|
| 39:40 | It may be, uh, the bugs in your ears, ok. |
|
| 39:46 | as well make insect anyway. Um uh and certainly a digestion, |
|
| 39:52 | You eliminate lots of pressure pass through system. Uh epiglottis, that's the |
|
| 39:59 | covers your windpipe, you fall. you don't get things in your |
|
| 40:03 | So yeah, all these are part that helping kind of prevent at least |
|
| 40:08 | best they can microbes from getting into , stopping them where they're at more |
|
| 40:13 | less. Ok. So again, of these or most of these will |
|
| 40:17 | act as chemical uh barriers. So, because they all have secretions |
|
| 40:25 | tends to be kind of a salty , acidic uh because of the kind |
|
| 40:30 | molecules that are produced there. And that in itself is a way to |
|
| 40:34 | of um uh affect what can actually there. Ok. Uh Staphylococcus likes |
|
| 40:41 | conditions, which is why Staph is of the main bacteria you have on |
|
| 40:45 | skin. Um Another one the mucus . So saliva gastric reduce obviously |
|
| 40:52 | very low ph um vaginal secretion is acidic, urine is also actually slightly |
|
| 40:59 | . But the one common thing in in many of these is I circled |
|
| 41:04 | here is Lysol, OK. In places right now, I can, |
|
| 41:14 | that material? That is what they long. OK. So uh so |
|
| 41:21 | a a defense against the bacterial types that have so long. And so |
|
| 41:28 | , as mentioned before, we talked this, that uh this is part |
|
| 41:32 | your immune system as well, your microbiota. So they're mere, they're |
|
| 41:37 | alone to keep other things from taking . Um And they, they produce |
|
| 41:43 | own kind of micro environments that can times prevent things from growing there. |
|
| 41:49 | very essential. Um OK. So line uh physical and chemical barriers, |
|
| 41:58 | after them, our second line. so we start with kind of different |
|
| 42:03 | types, uh specific cell types involved this. So you break down |
|
| 42:08 | so your plasma fracture, your um you have a protein fraction, |
|
| 42:14 | plasma that contains antibodies and complement and types of proteins. The um the |
|
| 42:22 | part of this contains what are called elements. So red blood cells, |
|
| 42:25 | blood cells um are basically are um of hemoglobin and hemoglobin binds oxygen. |
|
| 42:38 | . Uh Red blood cells don't have nucleus. OK. Um But uh |
|
| 42:45 | also are not really cells or fragments involve in clotting. Uh But the |
|
| 42:50 | types, of course, are your , your white blood cells um of |
|
| 42:55 | types. And so these, this of granulocytes and a granulocytes. Uh |
|
| 43:02 | little bit deceiving because um they they all can have Granules. |
|
| 43:11 | It's just that when you look at under a light microscope, it's much |
|
| 43:16 | obvious in these types. Neutrophils, , eosinophils, you look at it |
|
| 43:20 | go. Oh yeah, that's that's a granny appearance thing. We |
|
| 43:23 | lots of Granules. Ok? Um just not as visible under the microscope |
|
| 43:28 | these guys all, they all they have. Ok. But anyway, |
|
| 43:32 | , it's uh some type of It's uh it's a historical thing and |
|
| 43:37 | never changes, but that's, that's they still refer to them, the |
|
| 43:40 | sites and a granular sites. Um so we'll go through each of these |
|
| 43:46 | . Um All right, nut. neutral shows are gonna be your early |
|
| 43:51 | in infection is neutrophils that are your foc cytic cell types that do the |
|
| 43:59 | of the work initially, right? So neutrophils are in blood. So |
|
| 44:04 | see, there's 70% and don't worry much about these percentages. Uh but |
|
| 44:10 | just to show that they are, know, in the highest quantity of |
|
| 44:13 | blood. And so if they're in blood and you have an infectious agent |
|
| 44:20 | in your tissues outside the blood, , then you have to get them |
|
| 44:25 | of the blood into the surrounding Ok. And that's what neutrophils |
|
| 44:29 | Ok. So the eggs of it is all part of that inflammatory |
|
| 44:35 | which will work next time. But uh but you know, I pulling |
|
| 44:43 | everywhere in your body, they're in bloodstream and you have to get them |
|
| 44:46 | of your bloodstream and there's mechanisms that have to happen, but they are |
|
| 44:50 | primary infection fighters early on. They taken over later. Um 01 more |
|
| 44:58 | . So you might look at the , the cell types, they have |
|
| 45:00 | a weird um morphology. Well, , they look weird inside. They |
|
| 45:07 | these purple blobs. So this is , this is actually the DNA the |
|
| 45:12 | and, and they just form these like sacks inside, they're all |
|
| 45:18 | but that's just how they look. what they call them. Uh |
|
| 45:23 | uh nuclear polymorph like it means mini kind of nucleus. Uh It's kind |
|
| 45:29 | a weird fea feature of those Um basophils, basophils, unlike neutrophils |
|
| 45:35 | not fo cytic cell types. Their is to um release toxins typically and |
|
| 45:42 | types of uh cyto, right? so um yeah, so um lots |
|
| 45:56 | chemicals are released by basal pills, you see that the amount in their |
|
| 45:59 | is not, not that high. , uh if you have hay |
|
| 46:03 | things like that, you can probably your basal pills. Ok. Um |
|
| 46:09 | . So these are big acidic uh this big contributors as neutrophils, but |
|
| 46:16 | they do can act is in very pathogens. Not by large. I |
|
| 46:21 | , we talked about these worms right? Uh Those, those can |
|
| 46:25 | attacked by eosinophils. Their, their is often to produce lots of toxins |
|
| 46:30 | , and they actually interact with large . Um So again, large craft |
|
| 46:37 | to be something like a big helminth something like that, right? And |
|
| 46:44 | will be attracted to the site and actually interact with um have to interact |
|
| 46:52 | antibodies. So we'll see the antibodies interact with different of your immune system |
|
| 46:58 | in different ways. And so the are antibodies to the worm that eosinophils |
|
| 47:07 | also bind the antibody and then you these all together, it's a way |
|
| 47:10 | kind of uh collect a bunch of together. So that when they release |
|
| 47:17 | , right, you have a lot toxin. So it's a way to |
|
| 47:22 | theophil around a big pathogen, Because you're gonna have to like have |
|
| 47:27 | produce a lot of toxin and take of these things down. So if |
|
| 47:30 | can get a bunch of eins there have them hook on to the |
|
| 47:33 | then they release their toxin altogether and it down. So it's kind of |
|
| 47:38 | , how they work. Um but again, these little, these |
|
| 47:46 | things are investigated. A B is for antibody. OK. So like |
|
| 47:51 | said, you know, you'll, see interactions between draw antibodies kind of |
|
| 47:58 | this, right? Like a yay and, and these are all points |
|
| 48:06 | combine. So these, this part , the two that are close |
|
| 48:10 | those B antigen, the bottom part one that combined to a cell |
|
| 48:15 | right? Um, of some And if there is one type that |
|
| 48:19 | do that, there's others that you'll see as well. OK. |
|
| 48:22 | kind of jumping the gun here, because I'll, I'll repeat this |
|
| 48:26 | but just while we're here, it like a good spot. Um So |
|
| 48:32 | uh don't worry if we can get thing wrong because I'm gonna go through |
|
| 48:37 | again anyway, when we get the and antigens. Um So let's see |
|
| 48:44 | else is here. We got. OK. So a gran acidics, |
|
| 48:48 | are your uh macrophages, dendritic So, uh macrophages and dendritic cells |
|
| 48:54 | out as a monocyte. So monocyte circulate in the blood, but then |
|
| 48:59 | go to your lymphatic uh system. your lymphatic system plays a big |
|
| 49:05 | especially in your adaptive immune system. . So your B cells, your |
|
| 49:11 | cells, macrophages, dendritic cells, kind of hang out in your lymphatic |
|
| 49:16 | . That's what they do. So if you have, you had |
|
| 49:19 | infection and your doctor does this on throat, right? See the |
|
| 49:26 | right? Or maybe your armpits OK. And they get painful. |
|
| 49:32 | They're highly concentrated with lymphatic vessels, ? And so they swell because the |
|
| 49:38 | cell types in there are growing and right to fight the infection. And |
|
| 49:42 | what caused the swelling. Um the uh but they are so your your |
|
| 49:49 | and dendritic cells are py but also this function. Ok. They are |
|
| 49:56 | presenting stuff. So again, these cell types that link up with the |
|
| 50:01 | immune system and uh and uh they get activated by your active system uh |
|
| 50:10 | have other functions there, right? engine presentation is a big function um |
|
| 50:17 | really has to do with um to the body to intercellular pathogens. But |
|
| 50:27 | , I'll hold off on that. , we'll wait. But energy burning |
|
| 50:30 | or a PC, they're also called of short. Yes, test some |
|
| 51:20 | . OK. Now, very they are kind of trying to exploit |
|
| 51:28 | activity and expand it by genetically fixing killer cells to be able to be |
|
| 51:37 | at this function and recognize different types tumor cells. So using it to |
|
| 51:42 | a cancer fighting agent, OK. , there's a lot of work being |
|
| 51:45 | on that at the medical center on . Um But our context that we're |
|
| 51:51 | at uh cells are infected. So what happens is let me um |
|
| 51:59 | going to, I just need to real quick to see. OK. |
|
| 52:02 | it. Uh So the MH C , that's the thing we need to |
|
| 52:07 | about that affects a lot of different here. OK. So uh so |
|
| 52:13 | killer cells will look for infected or cells. So the thing is uh |
|
| 52:19 | , I'll elaborate here in a So your cells have uh certainly have |
|
| 52:27 | types of molecules on the surface. . I'm just, and one of |
|
| 52:34 | and they're supposed to, your, normal healthy cells have all different types |
|
| 52:39 | proteins on the surface, but they all have MH C Energen. |
|
| 52:46 | I'm just drawing them like this just , make it obvious. Um So |
|
| 52:54 | think of those as a barcode your, you, the there's a |
|
| 52:59 | on all of your cells that identifies as your cells, right? So |
|
| 53:02 | your own personal barcode on all of cells comprising all your tissues. |
|
| 53:08 | So, and they're supposed to be , OK? When they're not |
|
| 53:13 | that's the signal. Something's weird. not, right. OK. So |
|
| 53:18 | they're lacking or if there are only few this or this when they lack |
|
| 53:26 | have one or two, that's something . The body goes, that's not |
|
| 53:31 | . All right. And so that's natural killer cells look out for. |
|
| 53:36 | . And so they kind of, guess they kind of hover around the |
|
| 53:39 | and they can recognize if they've got usual stuff they're supposed to have, |
|
| 53:44 | ? These things and with lacking that's signal that cells do not what it's |
|
| 53:49 | to be something is wrong with Ok? I'll be infected. |
|
| 53:54 | And so infected cells like with a or other types, they can |
|
| 54:01 | not all of them, but many alter what happens on the surface of |
|
| 54:05 | cell, the type of cultures that up there. And that's what natural |
|
| 54:09 | cells, for example, can detect . And then the signal say get |
|
| 54:13 | of the cell, get it out the body, it's infected something's not |
|
| 54:17 | . But also cancerous cells can also that similar appearance, not all cancer |
|
| 54:23 | , but some can. And that is a signal of the cells, |
|
| 54:26 | normal to get rid of it. that's what natural killer cells do. |
|
| 54:30 | . Kind of look for that. I'll elaborate on MH C and in |
|
| 54:34 | second, but that's kind of what questions about that. So that's, |
|
| 54:39 | kind of what they do. So um and so when they do |
|
| 54:43 | , what do they do? they put this stuff in here uh |
|
| 54:48 | it easier, let's do this and . OK. So uh when you |
|
| 54:58 | to target cell, they will um these perforin. So perfer, so |
|
| 55:07 | of perforate, if you perforate you poke a punch a hole in |
|
| 55:11 | . OK? So perfer are kind like little straws, almost protein |
|
| 55:15 | they stick into the cell and the leaks up and they, and they |
|
| 55:20 | , OK? The enzymes are uh . These So apoptosis is a |
|
| 55:28 | Um It's a, it's a normal of all your cells. Uh It's |
|
| 55:33 | , it's what's called a programmed cell . So when your cells are, |
|
| 55:37 | age and they don't work right anymore something else damages them, the body |
|
| 55:43 | kill yourself, go through apoptosis. right? You had the sun |
|
| 55:49 | right? And you got, your was peeling. That's a way you |
|
| 55:54 | it was red, it probably hurt eventually the skin peeled. That is |
|
| 55:59 | a pop toast is going on. the uh ability come, what that |
|
| 58:03 | to is his so well have So you have two classes, |
|
| 59:06 | One and two. He's just wait I said uh uh 11 different, |
|
| 60:13 | how people interact uh with these uh different ways um and create different |
|
| 60:21 | OK? And those effects can the virus affect itself. OK? |
|
| 60:27 | it lacks m ac antigens. So will be gotten rid of. |
|
| 60:31 | Um The uh um other types interact um other t cell types interact with |
|
| 60:41 | , et cetera. We'll, we'll about that as we get into chapter |
|
| 60:45 | next week. OK. But the is MH C Engines, it's just |
|
| 60:49 | critical to have a system like right? Otherwise, if you had |
|
| 60:53 | infectious agent in you, how would body know that it's even foreign or |
|
| 60:59 | ? Right? So you already have system in place with all your pills |
|
| 61:03 | up all your tissues that have those stamped on them that are telling your |
|
| 61:08 | this is yours. Ok? So something else comes in that doesn't have |
|
| 61:13 | stuff, then your body can oh, that's something not right. |
|
| 61:18 | , foreign energy, right? Do with it. So that's having that |
|
| 61:22 | in place allows you to detect something not part of that system. |
|
| 61:27 | But of course there's even times when body will attack its own, |
|
| 61:34 | That's those, those are your uh diseases, right? So certain tissues |
|
| 61:39 | , you know, your body does them and that's, you know, |
|
| 61:42 | other different reasons. But nonetheless, a system in place like this allows |
|
| 61:46 | to detect something that's not, not same as what, what that is |
|
| 61:52 | pathogens of some sort. Ok. lymphatic system as mentioned is an important |
|
| 61:58 | . So it's not um in terms your uh immune uh immunity, the |
|
| 62:06 | uh you can check against different types , you know, things you breathe |
|
| 62:10 | things you eat. OK? Your your lymphatic tissue will um can be |
|
| 62:17 | dense in certain parts of your Like your spleen is particularly dense in |
|
| 62:22 | tissue, your armpits, your uh uh are very dense, your |
|
| 62:27 | area is very dense in this Um where your T cells, B |
|
| 62:32 | , macrophages, dendritic cells hang Ok. Um The uh uh the |
|
| 62:43 | and your spleen has dense lymphatic tissue filter out agents in your blood, |
|
| 62:48 | example. OK. Uh you have uh um lymphatic tissue with concentrated in |
|
| 62:55 | parts of your skin underneath your skin in your intestinal wall. OK. |
|
| 63:01 | so how a lymphatic system uh it's, it's a system of |
|
| 63:05 | of course, but unlike vascular there's not a heart pumping, in |
|
| 63:13 | , typically through gravity and through muscle and through the, the pulsing of |
|
| 63:22 | , your arteries and arteries and And so picking your arteries because lymphatic |
|
| 63:27 | are very close to these things. . And so that kind of assists |
|
| 63:31 | pumping fluid. Uh basically, with fluid, lymphatic system is designed for |
|
| 63:38 | to pick up fluid that's lodged from capillaries, right. So your veins |
|
| 63:44 | arteries um intersect very, very tiny cell, thick vessels called capillaries, |
|
| 63:52 | ? Called a capillary bed. And that's and these are concentrated in |
|
| 63:57 | in your vital organs. Ok. so it feeds them right? So |
|
| 64:00 | exchange materials in the capillaries, nutrients back and forth. And of |
|
| 64:06 | when that happens, you lose uh from your, you lose blood v |
|
| 64:10 | lose fluid from your your vascular So you have to be able to |
|
| 64:14 | that and dump it back in, ? That's what the lymphatic system |
|
| 64:18 | It collects that, what's called interstitial . Ok? It collects that and |
|
| 64:24 | it uh it dumps it back in around your clavicle, there's points where |
|
| 64:28 | dumps back into your cardiovascular system. so it kind of helps to maintain |
|
| 64:34 | and, and because you do lose from your cardiovascular system and that helps |
|
| 64:40 | it up. Ok. But also a place where your, these cell |
|
| 64:46 | reside. Ok. And so very for that. Um Now, here's |
|
| 64:54 | example of your intestinal uh kind of lymphatic tissue very dense in your intestinal |
|
| 65:02 | . Uh intestines is in these prish . OK. So very dense and |
|
| 65:07 | it looks like in there is you'll these kinds of what are called m |
|
| 65:12 | in between your normal kind of uh cells of the intestine that are about |
|
| 65:18 | food and things, right? And here are some microbes coming through, |
|
| 65:22 | have um immune system cells that neros things that engulf any kind of uh |
|
| 65:29 | microbes that are, that are in to get rid of them. And |
|
| 65:32 | you'll have these, there is a section and you see the dense tissue |
|
| 65:37 | here, pyres all throughout your OK. Um So here, so |
|
| 65:46 | tosis. OK. So again, is one of your main mechanisms fight |
|
| 65:53 | . OK. So your primary ones macrophages, dendritic cells and um |
|
| 66:01 | OK. And so in terms of , they uh can be what are |
|
| 66:08 | watering or fixed. OK. watering like the name applies, you |
|
| 66:13 | , you know, travel throughout your system. Uh uh watering around |
|
| 66:18 | you know, pathogens, what have fixed or stay in one spot. |
|
| 66:23 | , uh very common to have, example, alveolar macrophages that a lifetime |
|
| 66:28 | your lungs and they pick up any of uh microbes that might be |
|
| 66:33 | Um And so the uh granular sites neutrophils, right, infections early in |
|
| 66:42 | infection cycle, how this happens. first get macrophages are are figure to |
|
| 66:57 | cells to the site of affection. one, that's chemotaxis, then stick |
|
| 67:03 | the pathogens, right? That part that is the engulfment process. Take |
|
| 67:07 | in and then break it apart, it OK. So the four step |
|
| 67:13 | . And so um so here you , here's a macrophage. OK. |
|
| 67:20 | part of the binding process is these , right? So not just ingesting |
|
| 67:28 | sizing the cell but also releasing cyto blurt other cells in the body. |
|
| 67:33 | they have that as well. And so um optimization is something we'll |
|
| 67:41 | about later. And so the um sometimes you have microbial types that are |
|
| 67:50 | that bind easier and can be taken than others. Other types are are |
|
| 67:56 | have a very thick capsule. That makes them less able to be |
|
| 68:00 | and taken in, right? That's it's a Vance factor. And so |
|
| 68:04 | do you deal with that while you other chemicals that can code it and |
|
| 68:08 | that can be taken in. That's opsonin do, right. So something |
|
| 68:11 | antibodies complement these coat the pathogen and that's what's taken in, right? |
|
| 68:19 | it easier to fotis. Ok. um ingestion part. So you have |
|
| 68:26 | a vesicle. So it's engulfed right a vesicle called the PGA zone and |
|
| 68:33 | our feeding vesicle and then that fuses the lysosome. Ok? And that's |
|
| 68:38 | of a digestive organelle that will then down the microbes either through production of |
|
| 68:45 | radicals. We talked about that um these are toxic to the cell |
|
| 68:51 | also can have life design to break the cell wall and ultimately getting rid |
|
| 68:55 | it. OK. Now, the about a about this is these can |
|
| 69:05 | um the particles that are you see of these being released, these can |
|
| 69:10 | be be an MH C module and can present. And so microphage can |
|
| 69:18 | be an ancient presenting cell, A PC. And they can do |
|
| 69:23 | by taking some of this material combining MH C molecules in the cell than |
|
| 69:30 | to the surface. And now the is visible to the immune system that |
|
| 69:37 | can then respond in a different OK. That's what the antigen presenting |
|
| 69:42 | does for you. It allows the to see the engine and respond to |
|
| 69:47 | . OK, if I hadn't seen before. So um the uh so |
|
| 69:54 | just mentioned about OP IL optimization that everything is easily favor of th so |
|
| 70:01 | things like a big capsule typically So they enhance that you can produce |
|
| 70:07 | to it. And then those antibodies bound to the pathogen, right? |
|
| 70:13 | then the cell itself has a receptor can bind to that and the |
|
| 70:20 | right? And then the whole thing taken in, right. So it's |
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| 70:24 | way to take something that that's not fit. Ok. Similarly, the |
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| 70:29 | problems can occur, you can coat with uh antibody or complement complement are |
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| 70:37 | of basically a soluble protein factors. , and so that can code the |
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| 70:44 | and can change as well. So a way to take size things that |
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| 70:47 | easily fixed with that. OK. , Opsonin are the molecule that |
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| 70:52 | So it can be an antibody complement is the process technique this way. |
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| 70:59 | ? Um That's a good way to the stop, right? Folks. |
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| 71:05 | for hanging in there. Uh We'll you next weekend and uh go |
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