| 00:03 | Welcome back. It's been a crazy of days. Um, what you're |
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| 00:09 | at here is something I was supposed present last Tuesday and here we |
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| 00:13 | what, two classes away from the test, um, three classes |
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| 00:17 | Uh, so what you're looking at is just the exam average. And |
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| 00:22 | you compare it to the last uh, you can, well, |
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| 00:25 | can see the numbers over there, the average standard DEV high grade was |
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| 00:29 | . So see, it's not You can go ahead and hate that |
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| 00:33 | . The person who got the 100 say anything. Just, just, |
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| 00:37 | , but, you know, the went up a little bit, which |
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| 00:39 | , it's about the same, but went up. Um, but we're |
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| 00:42 | going to focus on the exam so . It just kind of shows you |
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| 00:46 | the performance was. If you look the overall unit performance, you can |
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| 00:52 | that there is a person who's dropped class that hasn't dropped the class |
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| 00:55 | that's kind of pulling things down. generally speaking, this is what your |
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| 00:58 | look like. So if you, you're playing along at home and you're |
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| 01:01 | your grades out. You can use numbers right now to see where do |
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| 01:05 | stand in the class. And notice we don't care about B pluses |
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| 01:08 | we don't care about pluses and minuses . The only day you care about |
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| 01:11 | is what goes on your transcript. . Today, you're asking the question |
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| 01:14 | where do I stand and what do need to do to move myself to |
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| 01:18 | I want to be? Or if in the range where I want to |
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| 01:21 | ? So right now, an A sitting around an 88 a half B |
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| 01:25 | sitting around a 74 C is sitting at 59. And as I |
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| 01:29 | men always failing to be is 50 . And so, um, |
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| 01:37 | if you are in any of those and you want to move up, |
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| 01:40 | just need to ask questions, what I doing wrong? What do I |
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| 01:43 | to do to improve, to bring grade forward? And you know, |
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| 01:47 | you're where you are and you're say, ok, I'm happy, |
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| 01:50 | slack off. I just need to doing what I'm doing. There are |
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| 01:53 | that I can prove to help me up a little bit higher maybe. |
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| 01:56 | if you're down in the range where really unhappy, you don't know, |
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| 01:59 | and see me and we can talk how to study, right? Because |
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| 02:02 | what this boils down to is not the material is hard. And I |
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| 02:06 | find it, usually I talk to who are like, I don't understand |
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| 02:08 | going on. I studied hard and don't see why I'm doing. It's |
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| 02:11 | of the way that you're studying, not, you're not internalizing information correctly |
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| 02:15 | I can teach you how to do . And just so that, you |
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| 02:18 | , I mean that this is actually improvement. So you can see this |
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| 02:22 | comparative. So uh if you look unit one, that's the blue and |
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| 02:26 | can see how all the orange is over off to the right a little |
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| 02:30 | . And so as time is you guys are improving and you should |
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| 02:34 | good about that. You shouldn't focus the numbers, you should focus on |
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| 02:38 | am I and where do I want be? All right, don't look |
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| 02:43 | the number go. I got a . That means I'm failing the class |
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| 02:45 | English. Yes. In science No. Right. It's different over |
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| 02:54 | because we do everything on a All right, with that in |
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| 02:58 | we have a lot of stuff to . You have been put on, |
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| 03:01 | your shoulders, you have to do that hasn't been done by your generation |
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| 03:05 | a long time, which is to on your own and be responsible for |
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| 03:09 | material that you've been learning. And are jumping into the middle of the |
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| 03:14 | system, which is kind of Right. It's like, how do |
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| 03:18 | know if I'm studying? Right. , if you've learned the skills to |
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| 03:21 | , which I hope I have been upon you, you're going to do |
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| 03:27 | . All right. The idea is learn for, look for learning |
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| 03:29 | What am I trying to learn And what we're going to do is |
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| 03:32 | going to look at the structures from stomach downward through the lower digestive |
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| 03:37 | And we're going to ask the what do they do? All |
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| 03:40 | And then we're gonna deal with the process of digestion on Thursday. |
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| 03:45 | with that said, I'm gonna make really easy for you for so for |
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| 03:49 | stuff that you missed last week on , I'm gonna make it real |
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| 03:53 | All right. And I'm gonna just with a little story here. A |
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| 03:57 | of years back. I was teaching a classroom and my laptop died, |
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| 04:01 | ? And I'm teaching the digestive I'm like, all right. How |
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| 04:05 | I teach 200 people the digestive system pictures. It's like, oh, |
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| 04:10 | , this is actually really, really . The digestive system has four basic |
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| 04:14 | and you should have picked up on while you're reading and while you're doing |
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| 04:18 | the problems, the four functions are , absorption, secretion and digestion, |
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| 04:26 | ? You can put that acronym any you want to dams or mads or |
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| 04:31 | or whatever you want to, And then what you can do is |
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| 04:34 | can think about this. I told at the beginning of this unit, |
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| 04:37 | said we're working on systems now that tubes, right? So we start |
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| 04:41 | one end of the tube and we to the other end of the |
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| 04:43 | What is the beginning of the digestive ? Tube? The mouth? |
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| 04:47 | That's great. All right. And get to the dirty stuff. What's |
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| 04:49 | back end of the tube? The ? All right. So everything between |
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| 04:54 | mouth and the anus is something you're have to know about. And if |
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| 04:57 | whole digestive system deals with those four , you just got to ask |
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| 05:01 | well, what are the structures and role do they play in those four |
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| 05:04 | ? And how do they do OK. So each time you look |
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| 05:09 | something new, you could actually, could literally do this. And this |
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| 05:11 | what I did in the class, did a chalk talk. That's what |
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| 05:13 | call when we go up to the and sit there and write things |
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| 05:16 | We just did a grid and we mads and we put the different structures |
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| 05:20 | we just kind of went through. . Well, what's this structure? |
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| 05:22 | does it play in terms of What does it do here? What |
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| 05:25 | it do here? Do you just it all out? Everything you need |
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| 05:28 | know about the digestive system fits on page. Pretty simple. Right. |
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| 05:32 | there might be more details in some you'll find out that. Oh, |
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| 05:34 | , this one didn't play a role digestion. There is no digestion. |
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| 05:38 | I don't have to put anything here you might find this, all it |
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| 05:40 | is absorption or you might find it does digestion, absorption, secretion |
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| 05:44 | motility. It might have all four them. So each one of them |
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| 05:48 | going to be unique in that sort way. And so our starting point |
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| 05:51 | is gonna be in the stomach and stomach plays a role in three of |
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| 05:56 | things. You guys did the Let me just see how well you |
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| 05:59 | the reading. Which one does it do? Which one do you not |
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| 06:03 | which one absorption? It doesn't absorb . It plays a role in |
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| 06:09 | It plays a role in motility and plays a role in secretion. All |
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| 06:14 | . So all of a sudden now like, ok, now I've just |
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| 06:16 | to ask the question, what's doing ? And so what we're going to |
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| 06:19 | is we're gonna start here. and I guess I should probably have |
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| 06:22 | little thing to see if you go for a couple of days and you |
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| 06:27 | remember all your pieces parts, Um So we're gonna start here in |
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| 06:34 | stomach. Now when we say right? The stomach, a lot |
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| 06:39 | people think of it in terms oh, it does all the work |
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| 06:42 | the truth is it doesn't do all work. It, it is a |
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| 06:45 | kind of unique structure where, what does is that the food that you |
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| 06:49 | in your body, that you chew and you turn into these little tiny |
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| 06:53 | goes down to the stomach and the plays a major role in storing that |
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| 06:56 | up while you break it down All right. So it has that |
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| 07:02 | role of storage. Think about when eat food, like when you |
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| 07:07 | you know, globing is right. know, glor is when you eat |
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| 07:11 | much food, you're sitting around like shouldn't have eaten that. And then |
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| 07:16 | said, oh, I'm gonna have too. I did that last |
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| 07:19 | My daughter had, she's a girl . So she has all the |
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| 07:25 | We had way too many cookies at house and I was full and I |
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| 07:28 | the peanut butter sandwich cookies. I two. I was just, it |
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| 07:33 | wrong nine o'clock at night. I miserable. Right. So, what |
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| 07:37 | doing is it's storing up that material it's going to play a role in |
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| 07:41 | it down further, both chemically and . All right. So when we |
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| 07:45 | about digestion, remember there are two , there's a chemical digestion, a |
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| 07:49 | digest, mechanical digest. The easy think about is chewing, right? |
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| 07:53 | piece of food. Put it in mouth, you break it down in |
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| 07:57 | little piece of parts. It's Right. Remember seafood? Ah, |
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| 08:01 | you ever see that, do that ? No. Yeah. Seafood. |
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| 08:04 | . So, you've broken it That's digestion. That's a, that's |
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| 08:08 | mechanical digestion. And then the chemical is breaking up the little tiny molecules |
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| 08:12 | the smaller bits. And so it's to play a role in both those |
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| 08:17 | then what it's going to do is going to slowly feed the material that's |
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| 08:20 | broken down small, small enough into small intestine for further digestion. All |
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| 08:26 | . So it's not the end place digestion occurs. Now, in terms |
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| 08:30 | secreting what it does, it's gonna a couple of enzymes that are responsible |
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| 08:34 | breaking down two basic materials. The one is proteins. So when you |
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| 08:40 | of the stomach, think I'm breaking proteins, but I also break down |
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| 08:45 | , OK. We're going to look Thursday at the process of breaking down |
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| 08:51 | the different types of stuff that you . And there are four different things |
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| 08:54 | you put in your body as carbohydrates fats proteins. And the one |
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| 08:59 | everyone always forgets is nucleic acids. right. And we're going to see |
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| 09:03 | going to break those down. But is the place where that protein digestion |
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| 09:07 | primarily taking place, but some fat is taking place there. It secretes |
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| 09:12 | acid. You've heard that but this not a material that actually plays a |
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| 09:17 | in digestion, actually aids in And so I've also mentioned it plays |
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| 09:22 | role in the process of digestion by . So we can see here, |
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| 09:27 | gonna be secreting, we're gonna be things down. So there's digestion and |
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| 09:32 | we also have mixing which is All right. And so that's kind |
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| 09:36 | its role now, structurally, it a whole bunch of little tiny |
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| 09:39 | parts, which makes this list makes look big and hard, but it's |
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| 09:43 | all right. It's an open chamber behaves like a multiple chambers. All |
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| 09:49 | . So you can hide stuff up one area while the other parts are |
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| 09:53 | things. It's kind of a weird . It's kind of like a loft |
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| 09:57 | you can kind of point to an and say over there, that's the |
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| 10:00 | area, that's the eating area. is the bathroom area even though it's |
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| 10:04 | open up. All right. So kind of the same sort of |
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| 10:07 | So the Cardia is the area near esophagus. That's where food coming |
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| 10:11 | the mouth travels down through the esophagus enters via the cardia. There is |
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| 10:15 | sphincter there. And one of the that you can kind of identify the |
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| 10:19 | where new things are happening is you for where sphincters are located. So |
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| 10:23 | a sphincter at the top of the and the sphincter kind of at the |
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| 10:25 | of the esophagus. So that's why a compartment unto itself. And now |
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| 10:30 | have that sphincter that separates out the and the stomach. So now we |
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| 10:34 | a different compartment, it does something . And on the bottom end, |
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| 10:37 | have another sphincter. So the stomach set off because it does something |
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| 10:41 | So the cardia is basically just that area where we first enter in, |
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| 10:46 | prevents materials from working their way back into the esophagus. All right. |
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| 10:51 | it kind of closes it off. , the fun is this region up |
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| 10:54 | , it kind of sits above. if you see here's the esophagus, |
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| 10:57 | I put a line there, there's small region that sits above the |
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| 11:01 | that's what we'd say. And the is kind of a place where we |
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| 11:04 | the food. And if you look it muscle wise, it's actually |
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| 11:08 | very thin layer of smooth muscle. guess this picture doesn't show it that |
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| 11:12 | . All right. So then as move down this region, the very |
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| 11:16 | portion is referred to as the body the lowest portion down here is referred |
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| 11:20 | as the Pylorus. All right. most of the work that we're going |
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| 11:23 | be talking about is taking place between body and the Pylorus. All |
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| 11:27 | it doesn't mean that the fungus and aren't involved. It's just that all |
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| 11:30 | action is taking place in those primary . And then you can see |
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| 11:34 | we have these regions that this is to as the lesser curvature. The |
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| 11:38 | outer portion is called the greater Um And if you look uh internally |
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| 11:43 | the stomach, if you were to at it, you'd see that there's |
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| 11:45 | sorts of folds. And I think textbook talks about this is if you |
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| 11:48 | from region to region in, in digestive system, you're going to see |
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| 11:52 | unique type of folding taking place. if you've ever run your tongue on |
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| 11:56 | top of your mouth, you can the bumps and the ridges, right |
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| 12:00 | the hard palate that would be considered folds, right? Your esophagus has |
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| 12:05 | folds, your stomach, these ruga unique folds. And when you look |
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| 12:10 | in just a moment, we're going see there's unique folds in the small |
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| 12:13 | and the large intestine and they're all for, for their functionality. All |
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| 12:18 | . Um Let me see if I've anything off here. Oh, |
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| 12:20 | in terms of the, of the muscle, you're going to see that |
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| 12:23 | we move from the fungus, it's , really thin, the smooth muscle |
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| 12:26 | very thin. And then we're going , as we move down, it |
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| 12:29 | thicker and thicker. And you can of see here, they're trying to |
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| 12:32 | there's a thick muscle down here. right. And there's a significance to |
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| 12:37 | . Now, if you're to dive and start looking at. Well, |
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| 12:41 | me look at the structure, what's on in here. Well, if |
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| 12:45 | get down in the ruga in those , what you're gonna see that |
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| 12:49 | it's, it's unique. It has long deep pits that are associated with |
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| 12:54 | are called gastric pits. And in gastric pits, you're gonna have a |
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| 12:58 | bunch of different types of cells and only highlighted a couple of them. |
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| 13:02 | right. There are more than But for our purposes, this is |
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| 13:05 | we need to know. OK. it's here where the secretion is being |
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| 13:10 | place. Now, on the surface the mucosa, we have an epithelium |
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| 13:15 | then down deep, we have these cells that are also epithelial, but |
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| 13:20 | are less uniform than what you find here on the surface. Now surrounding |
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| 13:26 | mucosa or underlying this mucosa is the and there are three layers. So |
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| 13:32 | an outer, middle and inner. you see on this picture, you |
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| 13:35 | see here is the outer, there's middle, there's the inner. And |
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| 13:38 | you can see structurally how they are on the outside, we have |
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| 13:44 | All right. So whenever you're having tube structure, you're always going to |
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| 13:47 | smooth muscle around them. So you a longitudinal one that goes the length |
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| 13:51 | the structure and that's what you see . You'll have a circular one that |
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| 13:53 | around, which allows you to So longitudinal allows you to stretch and |
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| 13:57 | expand or to shrink. The circular you to squeeze, but not every |
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| 14:02 | has this third layer which is oblique oblique means at an odd angle. |
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| 14:07 | right. So long, you then that would be circular would be |
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| 14:10 | 90 degrees oblique would be at some angle. And what this does allows |
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| 14:15 | to twist in really weird ways. so you can imagine if my job |
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| 14:20 | to mechanically break something down, just and, and shrinking won't do what |
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| 14:27 | need to do. Twisting. It you to create these really interesting vortices |
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| 14:33 | the fluids that are going to be in the structures. So outside, |
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| 14:38 | muscularis, it's epithelium. If you down deep, you're going to see |
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| 14:41 | unique type of cells underlying that, the muscularis mucosa and there is some |
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| 14:47 | um mucosa that's a little bit but we're really kind of interested in |
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| 14:51 | big mucosa, the muscularis or not the mucosa, the muscularis. |
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| 14:55 | right. And so as we it gets thicker and thicker. So |
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| 15:00 | starts off thin at the fungus along body, it gets thicker and then |
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| 15:05 | you get down to the Pylorus, at its thickest now, in terms |
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| 15:10 | secretions. All right. So whenever see muscularity, you should think this |
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| 15:14 | playing a role in motility, it's materials one way or another. All |
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| 15:20 | . Now, since I didn't give lecture from the very beginning, I'm |
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| 15:22 | to just tell you right now. are two things. When it comes |
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| 15:25 | the digestive system, you are a and you are a cement mixer and |
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| 15:30 | are a conveyor belt. All three those things. I always forget about |
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| 15:34 | conveyor belt. Why are you a ? Doughnut has a hole through |
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| 15:37 | right? You have a hole through . The digestive system starts at the |
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| 15:40 | , ah ends at the anus, you said, that is an open |
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| 15:44 | . So your digestive system, that is literally external to your body, |
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| 15:48 | like the doughnut hole allows for you pass through the doughnut. So 23 |
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| 15:54 | come through you. So you're a mixer. What does that mean? |
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| 15:57 | , it means I'm going to be things in the same way that a |
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| 16:01 | mixer does and that's what this muscularis and you're going to see it even |
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| 16:05 | so in the smooth muscle. And when I also say you are a |
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| 16:09 | belt, you can think of the and the digestive system proper as that |
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| 16:13 | muscularis is pushing things along. So travels from the mouth all the way |
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| 16:17 | . It's not a gravity thing. literally pushing things through the pathway. |
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| 16:23 | right. So the muscularis is doing when it comes to secretions, we |
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| 16:28 | a couple of different types. We're start with the mucus secretions. All |
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| 16:32 | . So, outside, on the of the mucosa, this is where |
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| 16:37 | have these surface mucosa cells, these cells that are more uniform. They're |
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| 16:43 | to the environment of all the other of secretions that make up the gastric |
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| 16:49 | . Right? We said one of gastric juices already was hydrochloric acid is |
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| 16:53 | acid. A dangerous uh acid. . It kind of burns stuff and |
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| 16:59 | things. Yeah. And your body it. So it just kind of |
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| 17:02 | to show you you're, you're a tough cookie. Ok. Well, |
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| 17:07 | need to be a tough cookie because know. All right. Anyway, |
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| 17:12 | this stuff is very, very thick it's very alkaline. So, hydrochloric |
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| 17:17 | acidic, right? It's an it's very acidic. So what you |
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| 17:21 | do is you want to coat the inside of your stomach with something that's |
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| 17:25 | so that it neutralizes the acids that gonna be secreting. All right. |
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| 17:30 | then as you've traveled down into these pits, you're gonna start seeing these |
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| 17:37 | are called mucous neck cells. they're called neck cells because they're in |
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| 17:40 | neck of the gastric pit. All . And what they do is they |
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| 17:44 | secrete a, a mucus, but mucus is watery and it's acidic. |
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| 17:52 | , I just said alkaline and thick the alkaline thick coats. But the |
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| 17:58 | one which is watery is squirted through the other secretions to help make those |
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| 18:07 | juices. All right, they play of a role of protection and more |
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| 18:11 | a role in aiding the process of . But it's still a mucus and |
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| 18:17 | in general are there to coat and protect. But it, it's really |
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| 18:21 | to kind of protect the secretions that being made. So generally speaking, |
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| 18:26 | you see mucus, the purpose of mucus is there to, it's |
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| 18:31 | it's sticky and so it basically grabs stuff. But two, it's kind |
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| 18:36 | immobile. Think about when you have this time of year when you're exposed |
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| 18:40 | all those allergens, right? And do you have the entire time? |
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| 18:46 | , right. It even sounded didn't it? Right. It's just |
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| 18:50 | sticky mucus. And what it's doing it's grabbing all the pollens and |
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| 18:54 | I don't want you going into the into your, into your body. |
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| 18:58 | , that mucus is kind of doing same thing. It serves as a |
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| 19:01 | layer to say, I don't want to penetrate through here. I'll grab |
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| 19:04 | first and it doesn't get easily It stays nice and thick. All |
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| 19:10 | . And so that's why it's protective because of its alkaline nature, it |
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| 19:15 | . So if acid does kind of its way through, it creates this |
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| 19:18 | barrier that slowly uh eliminates it, acidity, it neutralizes it. |
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| 19:27 | we're gonna look at a couple of cells that are found inside those gastric |
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| 19:32 | . The first one is called the cell and it's a weird shaped |
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| 19:37 | I I wanted you to see just the shape. You don't need |
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| 19:40 | note. You're not going to have identify it by picture, right? |
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| 19:43 | it's, it's a unique looking You can look at the microscope and |
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| 19:46 | , man, this thing is It has kind of this w shape |
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| 19:50 | it, it goes by another name oxy. Um but it produces two |
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| 19:55 | things that are important for us to . The first thing that it produces |
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| 19:58 | this material, the substance called intrinsic . And this is one of those |
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| 20:03 | that is poorly named by scientists. means you know, found within, |
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| 20:08 | ? And so this is stuff that found within. We didn't know what |
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| 20:14 | was, but it's there. And they discovered that they said, |
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| 20:18 | it's intrinsically there. So where it's got its name stupidest name |
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| 20:22 | What its job is is it helps to absorb vitamin B 12. Vitamin |
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| 20:26 | 12 is necessary for hematopoiesis. And this is a way to help you |
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| 20:32 | that material into your body so that can produce red blood cells. So |
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| 20:37 | one of the jobs it does. the job that we're more interested in |
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| 20:41 | that it produces the hydrochloric acid that up the gastric or that's found in |
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| 20:46 | gastric juices. All right. So cells make two things hydrochloric acid and |
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| 20:52 | makes intrinsic factor know what intrinsic factor , helps me absorb vitamin B 12 |
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| 20:59 | acid. What does it do? , it's weird. All right. |
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| 21:03 | I said, it doesn't play a in digestion directly. It creates an |
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| 21:06 | where digestion can occur. And what cells do is it pumps out protons |
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| 21:11 | it pumps out chloride ions. It pump out hydro uh hydrochloric acid. |
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| 21:17 | . It's the two substance already And what that hydrochloric acid does. |
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| 21:23 | when it dissociates, you have all protons, it causes other molecules to |
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| 21:30 | apart to open up. So this those of you who took A and |
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| 21:36 | to go back to the dawn of in that first week or first two |
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| 21:41 | of classes. And we talked about and protein structure. And when we |
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| 21:47 | about that, one of the things talked about was denaturation. Do you |
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| 21:52 | denaturation? You denaturation can occur in of two ways I can change temperature |
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| 21:58 | I can change Ph right. And denaturation occurs, a globular protein opens |
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| 22:05 | , right and exposes its internal structures it can't refold back into its normal |
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| 22:11 | . So what hydrochloric acid does it those things that you eat, which |
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| 22:15 | are protist in nature. So think all the proteins you put in your |
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| 22:19 | , whether it be vegetable or right? It's basically a globular |
|
| 22:24 | And what we're doing is we're causing to open up and expose all its |
|
| 22:30 | acid bonds. So all those aine . And then what we can do |
|
| 22:35 | is we can apply enzymes to those and break down the protein into the |
|
| 22:39 | acids. So its job is to the process. It creates uh makes |
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| 22:46 | process go faster. It acts as catalyst is another way you can think |
|
| 22:50 | it. All right. Now, things that it does is that it |
|
| 22:55 | most microorganisms. Have you guys lived the five second rule? We've all |
|
| 22:59 | about this already. You know, drops on the floor, you look |
|
| 23:02 | it, you blow on it because makes it better, right? And |
|
| 23:05 | you eat it. All right. , ok, so it probably picked |
|
| 23:08 | something horrible, but not only does immune system play a role in protecting |
|
| 23:13 | , but your digestive system already just those materials to kind of fall |
|
| 23:18 | Very few microorganisms can survive in an of a low P H like the |
|
| 23:24 | . There are those that can and are the dangerous ones, right? |
|
| 23:30 | for the most part, most other just kind of fall apart and get |
|
| 23:33 | along the way, right? Um with regard to connective tissue, muscle |
|
| 23:40 | , all those other things, they cause that dissociation as well. |
|
| 23:44 | right. So hydrochloric acid, does digest anything? No. All |
|
| 23:50 | That is sometimes a stumbling block. an exam, it doesn't digest. |
|
| 23:56 | creates an environment for diet, digest occur the next cell. So we |
|
| 24:03 | the prial cell. The next cell called the chief cell. And whenever |
|
| 24:07 | think of it, I think of Indian headdress and stuff and it's silly |
|
| 24:10 | I do that, but I just all right. But the chief cell |
|
| 24:14 | the principal cell. The one that's common and its job in the |
|
| 24:20 | which is where it's located is to an enzyme in its incomplete form or |
|
| 24:26 | unprocessed form called pepsinogen. So when see the word an enzyme that has |
|
| 24:32 | G in at the end, it it hasn't been processed yet. So |
|
| 24:37 | about when we learned about um angiotensin , right? Remember that's already in |
|
| 24:43 | in your blood. So, pepsinogen what the cells secrete and then it |
|
| 24:49 | cleaves. In other words, it has enough activity in that inactive form |
|
| 24:54 | clip off the portion that's preventing it working and it will do that. |
|
| 24:59 | hydrochloric acid helps it in the process activating itself. And when pepsinogen becomes |
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| 25:05 | , becomes a molecule called Pepsin. , this is the way you're gonna |
|
| 25:12 | it. You guys heard of you've heard of Doctor Pepper and you've |
|
| 25:18 | of Pepsi, right? All three those were created by pharmacists, |
|
| 25:25 | For medicinal purposes. Did you know ? No Doctor Pepper made up here |
|
| 25:32 | Waco was by a pharmacist. What did was he created his little concoction |
|
| 25:36 | he went along the counter because that what they had all the different syrups |
|
| 25:40 | all the different medications that you Like, remember when mom would get |
|
| 25:43 | bubble gum instead of that icky chok stuff? And it still tasted like |
|
| 25:47 | bubble gum, right? They have these different syrups and that's how they |
|
| 25:50 | Doctor Pepper. He used all the syrups. That's why he gets a |
|
| 25:53 | shape or flavor Coca Cola. What it have in it? Cocaine. |
|
| 25:59 | right. It made you feel right. And Pepsi was designed to |
|
| 26:07 | your stomach. Oh, by the , I should have mentioned Doctor |
|
| 26:10 | you've probably seen their old symbol 4 and six. You've seen that |
|
| 26:14 | Doctor Pepper is a circle and has 10, a four and a six |
|
| 26:18 | it, or 10, 2 and . Not a 4, 10, |
|
| 26:21 | . You know what? Those are when you're supposed to take your Doctor |
|
| 26:25 | . 10 in the morning, two the afternoon, six o'clock at |
|
| 26:31 | Yeah, I know. It's All right. But why did they |
|
| 26:34 | Pepsi? Pepsi? Settle the stomach help in the process of digestion |
|
| 26:41 | Does it? No. All Just tastes good. But that was |
|
| 26:45 | idea. And what Pepsinogen does or does is that its job is to |
|
| 26:53 | down proteins. All right. It a very specific amino acid sequence. |
|
| 27:00 | you can imagine if I have a protein and I can't get to |
|
| 27:04 | I can only cleave the stuff that exposed to and it will take a |
|
| 27:07 | time. But if I denature the right now, I can see the |
|
| 27:11 | and I'm on an enzyme, I come along and go, oh, |
|
| 27:13 | recognize that clip, that, that clip that. And I've taken |
|
| 27:17 | long protein and I've turned it into series of smaller peptides which I can |
|
| 27:24 | digest further in the small intestine. , the other secretion of the chief |
|
| 27:28 | does is called gastric lip ase. just tells you lip ace, it |
|
| 27:32 | you what to digest lipids, right at the end of an enzyme and |
|
| 27:38 | front end tells you what it So it breaks down fats. The |
|
| 27:42 | name gastric tells you where it comes . So if you have a gastric |
|
| 27:46 | ace, there's likely that there's other aces. And if you read |
|
| 27:50 | you learn that the first one was salivary lipase. So we start fat |
|
| 27:55 | in the mouth. We continue fat in the stomach and we'll continue di |
|
| 27:59 | fat digestion in the swung test. that's where uh fat digestion primarily takes |
|
| 28:04 | . All right. So, cells pepsinogen, break down proteins in its |
|
| 28:11 | form. The active form is Pepin then the other is gastric lipase to |
|
| 28:16 | down fats. Ok. The third , it is called the G |
|
| 28:23 | Very, very complicated name. It's name for what it secretes. |
|
| 28:29 | All right, gastrin is not secreted the stomach. All right. It's |
|
| 28:36 | endocrine cell, meaning it secretes into bloodstream. And so what it's doing |
|
| 28:40 | it's secreting gastrin out into the bloodstream signal to all these structures that food |
|
| 28:46 | present and digestion needs to occur. right. So the easy thing to |
|
| 28:51 | about is that it's going to stimulate stomach secretions in the presence of peptides |
|
| 28:56 | proteins. It says, oh, are here. I need to tell |
|
| 29:00 | chief cells to start secreting pepsinogen. I need to tell the parietal cells |
|
| 29:05 | start secreting hydrochloric acid and it helps process of digestion to start. And |
|
| 29:10 | going to also talk to structures in small intestines and say, hey, |
|
| 29:14 | what we got stuff in the get ready. So it's a signaling |
|
| 29:20 | to tell the other systems what's going . So those are the secrets. |
|
| 29:28 | cells. Hydrochloric acid G cells, and lipase G cells, gastrin. |
|
| 29:35 | we keeping it simple? There's a bunch of other stuff in there going |
|
| 29:38 | too. All right, so So good. So let's talk about |
|
| 29:47 | . Talk about secretion, right? I forgot all the mucus cells. |
|
| 29:52 | . And the mucus cells, what's name? Mucus cells? Right? |
|
| 29:56 | right. So next has to do motility what are we moving? |
|
| 30:00 | we do two types of things. do mixing and we do emptying. |
|
| 30:03 | right. So mixing is the process taking those gastric juices and the bowls |
|
| 30:08 | food that you've consumed and mixing those things together to, to create that |
|
| 30:13 | of breaking things down the process of . All right. So that's going |
|
| 30:18 | be the first thing. And so this is mechanical digestion, right? |
|
| 30:23 | , notice that the motility, the of materials results in a mechanical process |
|
| 30:29 | now, the way you can think this is where am I putting |
|
| 30:32 | food comes into the cardia and kind gets shifted over to the fungus. |
|
| 30:36 | we said the fungus has really, light or thin, smooth muscle and |
|
| 30:41 | we have the body where the muscle thicker and thicker. And then the |
|
| 30:45 | is over here in the Pylorus where have the thickest muscle. So, |
|
| 30:49 | we're going to do is we're going slowly deliver packets of food to mix |
|
| 30:53 | the gastric juices. So, what gonna do is we're going to start |
|
| 30:56 | using that muscle to propel food from fungus down into the body and then |
|
| 31:01 | to the Pylorus. Now, I you to think back a couple of |
|
| 31:07 | , maybe you've done this recently. my suspicion is is that the last |
|
| 31:12 | you did something like this was when were about seven or eight years |
|
| 31:14 | maybe younger. I want you to yourself taking a bath and you get |
|
| 31:20 | the bathtub and it's also fun. ? Remember when bathtubs are fun, |
|
| 31:24 | just relaxing and you get in the and you start doing this, |
|
| 31:29 | Start rocking back and forth and what you do? You create this nice |
|
| 31:33 | wave going along with you, You can see where this is |
|
| 31:37 | He's got that big file. because that was the last time your |
|
| 31:40 | let you take a bath, wasn't ? And you get going and it's |
|
| 31:43 | that wave is getting bigger and And finally you get that massive wave |
|
| 31:46 | it's like goes up and boom hits wall and all the water in the |
|
| 31:50 | goes out on the floor and your comes in screaming at you and then |
|
| 31:53 | you in the shower. And that's you became an adult, right? |
|
| 31:58 | , that just, just you and that we were the only two. |
|
| 32:02 | rest of you did that did you ? Yeah. The lady said, |
|
| 32:06 | know, I get to still take . No guys. We got in |
|
| 32:08 | bathtub and it's like this is my pool and I'm using it this |
|
| 32:13 | Well, that behavior that pressure of that fluid forward forward, just like |
|
| 32:19 | rocking is what the mixing is doing it's pushing the fluid forward and it's |
|
| 32:24 | it towards the Pylori and that food going up and hitting that pyloric |
|
| 32:29 | And when it hits that you get retropulsion, all right. And the |
|
| 32:35 | starts coming back the other direction. so the big particles slam into each |
|
| 32:39 | and they break them down into smaller smaller particles. So this is that |
|
| 32:43 | digestion, you're not grinding things you're creating a slurry that's slamming into |
|
| 32:47 | self and becoming more and more fluid the process. And eventually what you'll |
|
| 32:53 | is you'll get down to a really small particle. And when that |
|
| 32:57 | is small enough, it can pass the pyloric sinter. Everyone make a |
|
| 33:01 | , not at me, at the next to you see like that and |
|
| 33:05 | at that little tiny hole that you that right there is the pyloric |
|
| 33:09 | It's a little tiny thing, And so particles that can pass through |
|
| 33:14 | length and can pass through that little hole is what's being propelled. That's |
|
| 33:20 | propulsion portion, right? Or the portion. But anything that's too big |
|
| 33:25 | hitting that wall and is coming back slamming against the stuff that's being pushed |
|
| 33:30 | other direction. And so you're basically things down as they pass to each |
|
| 33:36 | . And when you get them small , it's like an aerosol puffs through |
|
| 33:43 | you're slowly delivering really, really mechanically broken material that's also gone through |
|
| 33:49 | process of chemical digestion, right? I'm taking protein and I'm breaking them |
|
| 33:54 | to peptides are, are smaller and and smaller and it's in the small |
|
| 33:58 | and that other things are going to so far. So good. |
|
| 34:03 | is the stomach that hard? And I spent a long time talking |
|
| 34:08 | I haven't talked to you guys in long. I just want to spend |
|
| 34:10 | talking about this stuff. It's Now, normally, what I do |
|
| 34:15 | when I begin these lectures on I have us pick out a |
|
| 34:19 | but I'm gonna pick out a meal us. All right, because |
|
| 34:22 | I like food and I know that of you guys haven't learned to like |
|
| 34:26 | yet. All right. So I Sorry Julie. I like big juicy |
|
| 34:32 | . Yeah. Big juicy ones, ? We're talking at least a pound |
|
| 34:38 | meat in them. If it's two or one, I don't care. |
|
| 34:41 | want my cheese on there for those you who are all sorry bacon if |
|
| 34:45 | don't like bacon, put something else it. Right. And I want |
|
| 34:49 | thing big and I want you to keep putting condiment. Think about the |
|
| 34:52 | , the layers of cheese. Not slice, not two. How many |
|
| 34:56 | like 12, you know, it's just give me a brick of cheese |
|
| 34:59 | just put it on top of that , right? And then just put |
|
| 35:02 | condiment you can possibly find and then have that bun, you know, |
|
| 35:06 | , well, you gotta have something hold the edges right. And I |
|
| 35:09 | have a burger without fries. So let's just get a bag of |
|
| 35:14 | over here and it can't be just fries. Let's get some chili cheese |
|
| 35:18 | because, yeah. So when you're at like, I, I can't |
|
| 35:23 | this and then we'll have to wash all down with something. What do |
|
| 35:28 | think? Milkshake? Like a, big milkshake like, like this size |
|
| 35:34 | ? And we'll make it. what flavor? I'll let you guys |
|
| 35:36 | the flavor, strawberry chocolate. I can't pick, we'll do both |
|
| 35:43 | maybe cookies and cream just in case dessert. Now, what we just |
|
| 35:48 | there is something that has every type food material that we want it, |
|
| 35:55 | ? We got our fats. Do we have our fats? |
|
| 35:59 | We got our proteins. We had put lettuce on there. So we |
|
| 36:03 | some carbs, some fibers, but have carbs in there with the |
|
| 36:08 | right? And the, and the , right? And then because everything |
|
| 36:13 | from something that was living at one , it all has nucleic acid, |
|
| 36:16 | ? There is nothing unnatural in in that burger. Even if it's |
|
| 36:21 | food, like a Cheeto, it from corn. So it has nucleic |
|
| 36:25 | . All right. So in that , one of the things that you |
|
| 36:30 | do is think about a meal like . It doesn't have to be my |
|
| 36:34 | . It can be your meal, . Whatever your meal happens to |
|
| 36:39 | And just think about when I put in the mouth, what do I |
|
| 36:43 | breaking down when I put that in mouth? When it gets into my |
|
| 36:47 | ? What am I continuing to break ? And when it moves into the |
|
| 36:50 | intestine, what else is being broken at this point? All right. |
|
| 36:54 | it's an easy way to kind of about. Oh, well, if |
|
| 36:57 | has cheese, cheese is fats and . So I'm breaking down fats |
|
| 37:02 | but I don't start breaking down proteins it gets to the stomach. But |
|
| 37:05 | gonna continue breaking down fats. And when I get to the small |
|
| 37:08 | it's gonna do some other stuff, ? So the small intestine or the |
|
| 37:16 | , is kind of what some books to as the lower G I |
|
| 37:22 | Now, I got a very good and it says your book says the |
|
| 37:28 | and half the Du Oman is considered of the upper G I track. |
|
| 37:31 | gives, why do you suck? Wayne? And I said, |
|
| 37:34 | you know, because this makes a of sense because it's a good dividing |
|
| 37:37 | , stomach. And the small intestine a good dividing line. But the |
|
| 37:41 | is, is that, yeah, duodenum is halfway. You don't need |
|
| 37:44 | know that I'm not gonna test you , where is the dividing line? |
|
| 37:47 | right. It's just a nice dividing to think of the PLO to because |
|
| 37:51 | duodenum and, and further down kind work together now or in terms of |
|
| 37:57 | , the hind gut, the mid and the fore gut, uh give |
|
| 38:01 | to these different structures. And so first half of the duodenum is part |
|
| 38:05 | the fore gut, which is also up the stomach and the esophagus. |
|
| 38:08 | so that's why it's considered a part the upper. But that's just to |
|
| 38:14 | I'm a completionist and I need to the question. All right. So |
|
| 38:20 | intestine consists of three part duo deum . In that order, it plays |
|
| 38:25 | role in chemical digestion and absorption. will have motility, it will do |
|
| 38:29 | . But the primary roles there is digestion and absorption. When we get |
|
| 38:34 | down further, we're going to get the large intestine. The large intestine |
|
| 38:37 | the final stage of absorption, It doesn't play a role in |
|
| 38:41 | It absorbs. All right. And between them really attached to the small |
|
| 38:47 | are what are called the accessory So, just like you had salivary |
|
| 38:52 | that accessory organs to the mouth, liver, the gallbladder and the pancreas |
|
| 38:57 | organs that are involved in digestion that associated with the small intestine. All |
|
| 39:03 | , they're the ones that make and in some cases store up the digestive |
|
| 39:09 | needed to complete the process of All right. So we're gonna start |
|
| 39:15 | with the small intestine. All Um And really when we talk about |
|
| 39:19 | , we really just kind of focus the duodenum and then we just kind |
|
| 39:22 | ignore all the other ones. And the reason we kind of ignore the |
|
| 39:25 | ones is because they really just play major role in absorption. But the |
|
| 39:30 | is important because remember we start the of digestion, we need to finish |
|
| 39:34 | . And the duodenum plays that It introduces the remainder of those enzymes |
|
| 39:41 | finish up digesting that milkshake, those with, you know, cheese and |
|
| 39:47 | and that super burger that I I mean, I can't do it |
|
| 39:52 | this portion. So it is a digestive organ. Now, in terms |
|
| 39:57 | length, it's about 20 ft long, ? So it winds back and forth |
|
| 40:01 | is jammed into this little space in with some other stuff and 20 ft isn't |
|
| 40:05 | long. I mean, it feels it, but truthfully, it's, |
|
| 40:09 | not that, that, that All right. Now, with regard |
|
| 40:15 | their sizes, I haven't kind of it out here. So the duo |
|
| 40:17 | almost a foot long. The geum almost eight ft long and the ilium |
|
| 40:21 | the longest portion. And so the plays the role of introducing the secretions |
|
| 40:29 | the uh the material that's coming from stomach. So this is where we're |
|
| 40:34 | to add in all these other And then so the geum plays that |
|
| 40:38 | of OK. Here, I've received secretions and these juices or these |
|
| 40:44 | And so what I'm gonna do is them down further. And finally, |
|
| 40:47 | last one, the ilium plays a in the absorption portion like OK, |
|
| 40:52 | broken down and now I'm going to the things I need. All |
|
| 40:56 | So you can kind of break it in that way as well. All |
|
| 41:02 | , now, in terms of because we all have these unique |
|
| 41:08 | the unique folds that we find here like speed bumps. All right. |
|
| 41:14 | what we have, you can imagine tube and along the length of the |
|
| 41:19 | , you have these ridges that interfere the movement of material, they're called |
|
| 41:27 | . All right, I'm not gonna that because it's just a hard word |
|
| 41:30 | pronounce. But basically these, these , these structures, their job is |
|
| 41:36 | really increase the surface area three Now, what that means is, |
|
| 41:42 | that your effective length of your digestive is not 20 ft, your effective |
|
| 41:46 | at this point, just because of ridges going up and down. That's |
|
| 41:51 | these are right here. You can the folds there and then they're kind |
|
| 41:54 | focusing in. So you can see goes up and down like so it |
|
| 41:58 | threefold. So your effective length is 60 ft. Imagine if you didn't have |
|
| 42:03 | , you'd have to how much larger have to be in order to maintain |
|
| 42:07 | hold on to your small intestine, ? Because you'd have to effectively increase |
|
| 42:12 | size threefold as well. Now, this does like any type of speed |
|
| 42:18 | , is it slows things down? presume you guys slow down when you |
|
| 42:20 | to speed bumps, right? So the idea here is I'm gonna |
|
| 42:25 | things down and the reason for that you want to introduce those materials um |
|
| 42:32 | the secretions that are gonna be added . All right. And this allows |
|
| 42:36 | to engage the material. If it's zipping by, then it would just |
|
| 42:40 | on through you. All right. the idea here is I'm slowing things |
|
| 42:44 | , introducing secretion so I can break material down. All right. |
|
| 42:49 | as you go further along, you see down here in the duo and |
|
| 42:53 | Gegen, you're gonna get more and and more of these. So you |
|
| 42:55 | imagine as the material is pushing through small intestine, the material is slowing |
|
| 43:01 | more. So, right? Because do those do they play a role |
|
| 43:05 | digestion? So I want to spend digesting things. I don't want to |
|
| 43:09 | through until the digestion occurs and I to slow things down so I can |
|
| 43:13 | stuff from it, right? But on these plica, what you have |
|
| 43:22 | little tiny villa. Now I'm gonna back so you can see here, |
|
| 43:26 | the bumps up and down. Those the villa. So the villa sit |
|
| 43:32 | top of the plea and what they is they effectively increase the surface area |
|
| 43:36 | your small intestine another tenfold. So of having a 20 ft long, |
|
| 43:40 | intestine, instead of having a 60-foot , small intestine, you need to |
|
| 43:44 | an effective 600 ft long, small . Now we're starting to make some |
|
| 43:50 | here. All right. And so are little tiny projections that you can |
|
| 43:54 | like. So and in between you have little tiny pits just like |
|
| 43:57 | have in the digest or in the of the stomach, uh penetrating up |
|
| 44:02 | the villa. All right. So imagine that on the surface of the |
|
| 44:05 | , those will be where your actual are located, which is what this |
|
| 44:08 | is showing you. But you can that you have little tiny arterials and |
|
| 44:12 | little tiny capillary system, little tiny coming out and you have the lymphatic |
|
| 44:17 | . These are those lac tails that described. So what you're doing is |
|
| 44:20 | delivering blood too and you're taking blood from. So when absorption is taking |
|
| 44:25 | , that material is entering into the , right? And things that are |
|
| 44:29 | big that can't enter through the capillaries being shunted over to the lactis, |
|
| 44:34 | lymphatics because they're a little bit And so you can carry things that |
|
| 44:39 | get inside those capillaries now associated this is some smooth muscle that's not |
|
| 44:47 | shown in the picture. And what do is that they actually push the |
|
| 44:51 | villa up and down like so like , right? And what that does |
|
| 44:57 | it helps to milk the lacteal. not actually milking it, but what |
|
| 45:01 | doing is you're propelling materials through but you're also creating greater surface area |
|
| 45:05 | in decreasing surface area. And when increase and decrease surface area, you're |
|
| 45:09 | aiding in the process of motility. you're moving materials and you're causing things |
|
| 45:16 | move a little bit. So we have something that's roughly 600 ft |
|
| 45:24 | And then when you get down and at the individual cells, so here |
|
| 45:28 | can see an individual cell, this here would be the villus, |
|
| 45:32 | So there's villas, we're coming in and close. And if you look |
|
| 45:35 | the individual cell, the ay surface the cell, the ones that exposed |
|
| 45:40 | inside has what is called micro All right. And so what you've |
|
| 45:45 | is you've taken the flat surface instead you've done and you've gone up and |
|
| 45:49 | over and over again. And this the effective length of the digestive |
|
| 45:53 | another 20 fold. So instead of 600 ft long, you're now 12,000 |
|
| 45:57 | long. Do some simple math. a little over two miles. Think |
|
| 46:05 | big you'd have to be if you a smooth small intestine, how big |
|
| 46:09 | have to be to have 12 miles small intestine, you have to be |
|
| 46:13 | right now. This is sometimes referred as the brush border. Um and |
|
| 46:19 | kind of looks like a brush, ? And here within these structures, |
|
| 46:24 | are where you're gonna find enzymes that part of the membrane of the cell |
|
| 46:30 | job it is is to do those uh stages of digestion and to help |
|
| 46:35 | the process of absorption um channels and . And so the brush borders where |
|
| 46:41 | the action is taking place, the stages of digestion. Ok. So |
|
| 46:48 | proteins, enzymes increases the surface So your small intestine, even though |
|
| 46:57 | 20 ft long has a lot of things on inside it. Now, in |
|
| 47:02 | of the cells and what they there are different types of cells. |
|
| 47:06 | , there's more cells than what we're here. All right. But this |
|
| 47:10 | of gives you that basic picture of you need to understand. All |
|
| 47:15 | So first off, um we mentioned have these glands, all right. |
|
| 47:20 | these are called the intestinal crypts. this would be the villa and then |
|
| 47:23 | go down, there's the crypt, that right there. What do you |
|
| 47:26 | that is, it's part of the system. What do you think? |
|
| 47:30 | do we call them? Do you Payer's patch? Right? Or player's |
|
| 47:36 | , right? Part of the And so you can see, even |
|
| 47:40 | the little art, the artist was enough to actually show. So you |
|
| 47:43 | already see. I'm, I'm there against anything that my body is trying |
|
| 47:46 | or my body took in that it . So if there's a little tiny |
|
| 47:50 | on that Oreo that I picked up the floor, I've got a way |
|
| 47:54 | fight against it. It's already All right. Now, what are |
|
| 47:58 | doing? Well, we're secreting what called the intestinal juices. So, |
|
| 48:02 | secretion of the stomach are called the juices. We're in the intestine. |
|
| 48:06 | , these are the intestinal juices. right. So here we have goblet |
|
| 48:10 | . These are a type of epithelial that are producing mucus. They look |
|
| 48:14 | goblets. That's why they got their . All right. And what we're |
|
| 48:17 | is we're just greasing the skids. right, we've got this tube and |
|
| 48:21 | pushing stuff through it. We want create a slippery environment so things can |
|
| 48:26 | smoothly through it. And the other is the more you digest, the |
|
| 48:31 | you are left with the indigestible. . And those indigestible while they may |
|
| 48:37 | soft to you, right to your , they might be like big giant |
|
| 48:42 | sticks. And so the mucus helps line and protect against the indigestible |
|
| 48:50 | All right, we have unicellular These are gonna release intro peas, |
|
| 48:55 | is just a fancy word for saying pep, a pepto ase something that |
|
| 48:59 | down proteins. But what it's doing breaking them down from the inside, |
|
| 49:04 | from the ends. So an endopeptidase take a peptide and work from one |
|
| 49:09 | towards the middle or the other end the middle. And intro pease is |
|
| 49:14 | on enzymes or an enzyme that works sequences inside the middle. All |
|
| 49:20 | we have an intro endocrine gland. you see that word endocrine, what |
|
| 49:25 | doing is again, we're secreting into blood and we're secreting two different |
|
| 49:30 | C C K is the abbreviation for very long word, cholecystokinin, uh |
|
| 49:36 | a tough word. And then the one is GP which is glucose, |
|
| 49:42 | peptide. Now, what these two do? Cholecystokinin is a signal like |
|
| 49:48 | . It behaves just like gastrin It's just secreted in the small intestine |
|
| 49:51 | it's signaling to other parts of the to talk about the process of digestion |
|
| 49:55 | to aid. And we're going to with this in just a moment. |
|
| 49:58 | On the other hand, is telling body that digestion is occurring. So |
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| 50:04 | it's gonna do is it's going to the cells responsible for releasing insulin to |
|
| 50:09 | releasing insulin in response to food that's to come, not food, that's |
|
| 50:13 | in the blood. All right. it's a preparatory response. And then |
|
| 50:20 | have some sub mucosal glands that are alkala mucus. And why? |
|
| 50:25 | the material coming from the stomach that down stuff is called chime as a |
|
| 50:30 | word. It's not just gastric it's chime, it's food and gastric |
|
| 50:35 | and we've got to neutralize it now regard to motility. So we got |
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| 50:41 | secretions, we haven't even talked about coming from the accessory glands. |
|
| 50:46 | So we have some pep pep We have mucus, right. We |
|
| 50:51 | signaling molecules that are going cholecystokinin and or and G G IP, |
|
| 50:58 | And then in terms of motility, , here's that conveyor belt thing and |
|
| 51:03 | we can do segment or peristalsis. is what this is. So peristalsis |
|
| 51:08 | just a sequential contraction of circular muscle this, right? It's like squeezing |
|
| 51:13 | end of a toothpaste and squeezing the out. How many of you guys |
|
| 51:17 | too, squeeze your toothpaste from the , right? If you squeeze from |
|
| 51:22 | middle, what happens? Are you like upset? Is it like it's |
|
| 51:25 | , yeah, I can see the on her face. She's like, |
|
| 51:27 | even speak to me about this, ? For though you are O CD |
|
| 51:31 | , it's like I have to squeeze the end and that's kind of what |
|
| 51:34 | is, is I'm just squeezing from end and propelling things forward. And |
|
| 51:38 | using that contraction to use as the tool to propel things forward. For |
|
| 51:45 | of you who are not toothpaste in , you're a middle squeezer, |
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| 51:50 | Just as long as they get the out. All right. But if |
|
| 51:53 | squeezed the toothpaste, you know, the middle in two different places that |
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| 52:00 | is going to be propelled from wherever squeezing towards one another and it's gonna |
|
| 52:04 | things to mix. So if you use aquafresh, you know, AFI |
|
| 52:09 | the three different stripes in it, going to not have three stripes, |
|
| 52:12 | going to have just kind of a of stuff, aren't you? And |
|
| 52:18 | this is the second type, this what segmentation is. So it's when |
|
| 52:22 | digestive system says I'm going to squeeze different places and I'm gonna mix the |
|
| 52:27 | that's between those two points. And this does is it takes materials that |
|
| 52:31 | near the surface of the lumen, of the tube and it pushes that |
|
| 52:37 | inward and it brings the material that's up to the surface. And this |
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| 52:42 | a way to expose the bolus to that's being secreted, but also digested |
|
| 52:49 | to absorptive epithelial cells. And so going to increase the process of the |
|
| 52:57 | picture digestion. Now, a way can think about this. Have you |
|
| 53:01 | had a jab breaker? Right? you take a job breaker and stick |
|
| 53:05 | in your mouth, do you sit ? Can you break it? How |
|
| 53:08 | you, how do you consume a uh a job breaker? It's, |
|
| 53:13 | like licking it, licking it, ? It's a layer at a |
|
| 53:15 | you're literally, it's a layer of at a time. And you're trying |
|
| 53:19 | get to that point where I I finally break it. Right. |
|
| 53:24 | kind of what's going on here. can't get inside that jaw breaker until |
|
| 53:30 | mash it up. Right? And kind of what we're doing here is |
|
| 53:35 | . We know we can't get to middle. So instead we're capable of |
|
| 53:39 | the softer material. So that inside outside, outside, becomes inside. |
|
| 53:44 | I increase the rate at which materials digested and increasing the rate at which |
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| 53:47 | are absorbed. Finally, we get to the last structure, the larger |
|
| 53:53 | , we'll come back to the accessory in a second. All right. |
|
| 53:56 | this isn't very long. It's only 5 ft long. All right, it |
|
| 54:02 | from the ileos junction to the There's three parts, we have the |
|
| 54:06 | , the column and the rectum. it's uh takes about a liter of |
|
| 54:11 | materials uh that have passed all the through the small intestine and it's what's |
|
| 54:16 | to be processed there. And typically is the material that you couldn't properly |
|
| 54:21 | . In other words, you couldn't it down and you couldn't absorb |
|
| 54:24 | And so now you're just dealing with , what we would call the |
|
| 54:28 | the thing that your body can't OK. And that's what's passing into |
|
| 54:32 | large intestine. All right. And here what we're gonna do is we're |
|
| 54:36 | to reclaim a whole bunch of stuff we process. So in the process |
|
| 54:40 | digestion, you're going, you're going donate a lot of water. It's |
|
| 54:43 | about um I think over the course the change, the actual exchange is |
|
| 54:47 | like eight liters. You don't even eight liters of water in your |
|
| 54:50 | But that's how much movement you And what you're going to do is |
|
| 54:53 | going to reclaim all that back. so this time, which is water |
|
| 54:56 | enzymes and uh ions and all the stuff that you couldn't dig. I |
|
| 55:01 | that you were digesting and then you stuff along the way. You're left |
|
| 55:05 | the stuff that I couldn't absorb, digest and water and ions and |
|
| 55:10 | And I'm gonna to reclaim my Would you think that is water important |
|
| 55:14 | you guys? Yeah. I your kidneys fight for it, |
|
| 55:17 | And so your digestive system is also to do it. And so we |
|
| 55:20 | this water and material and we're going turn it into something that's less |
|
| 55:23 | which is feces. All right. is also we're gonna absorb all those |
|
| 55:29 | that we're gonna donate. So when think about feces, it lacks |
|
| 55:35 | It says from that one liter, gonna end up with about 100 mils |
|
| 55:39 | water loss. So only about 10% in that material. And then you're |
|
| 55:46 | store it up until you actually have go. So start with the, |
|
| 55:50 | is the very end. This is Blind Sac. It's everything below the |
|
| 55:54 | Valve. So Ilio sequel. So your ilium. This is your |
|
| 55:58 | hence the name IOS. So this your secu right down here. You |
|
| 56:02 | see them off the edge. We our appendix, very form appendix. |
|
| 56:06 | have very little use of ours. um um mostly organisms that play or |
|
| 56:13 | have uh play or digest primarily Um And usually plants are really, |
|
| 56:20 | hard to digest. Like koala Uh A koala has an appendix that's |
|
| 56:25 | long as it's small intestine. And it basically shutters this stuff over |
|
| 56:29 | It hosts a whole bunch of the bacteria aid in the process of |
|
| 56:33 | the materials down. Um It plays uh as a kind of a trap |
|
| 56:39 | things that shouldn't be in your So it has um a limp tic |
|
| 56:43 | that's there as well. Um But you lose it, I mean, |
|
| 56:48 | who's lost your appendix? I I lost mine at summer camp. |
|
| 56:53 | , it was, it was a week of diarrhea and vomiting and then |
|
| 56:57 | me to the hospital and it's oh, you've got a burst |
|
| 56:59 | We got to take that out. this awesome scar. Yeah, |
|
| 57:04 | it's great. No one here has their appendix, man. You gotta |
|
| 57:10 | eating more bubblegum, one person. gum eater. Yeah. All |
|
| 57:14 | Bubble gum eaters. No, I don't know. It's, it's |
|
| 57:17 | random thing. My cousin as I think he was just jealous. |
|
| 57:21 | I lost mine. So he said gonna do it too. Then we |
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| 57:25 | to the colon colon. So we skum down here. So the colon |
|
| 57:28 | the ascending, transverse, descending Um It has names. So these |
|
| 57:33 | called flexures. So there's the right , there's the left colic. Um |
|
| 57:38 | then down here, um what we is going to be the rectum. |
|
| 57:42 | right, now, what we're not in all this stuff is a whole |
|
| 57:45 | of fat, which is actually, the, it's the mesentery. The |
|
| 57:50 | actually has been, is now considered separate organ. It just hasn't entered |
|
| 57:55 | textbook shed. So just consider yourself . There's one more structure you don't |
|
| 57:59 | to memorize at this point, but seems to have its own necessary function |
|
| 58:03 | the body. Um The mesentery, meso colon. All right. |
|
| 58:10 | in terms of structures, uh if look at the large intestine, you |
|
| 58:13 | of see these kind of bumps, ? These are referred to as |
|
| 58:16 | there's like sacks and what you're doing you're moving the time from hoster at |
|
| 58:22 | host at a host. Um In very, very slow movements, holding |
|
| 58:26 | host together is this smooth muscle? called the tinnia coli, the tin |
|
| 58:32 | basically kind of constrict and create the little tiny sacks and then hanging |
|
| 58:38 | . Those are little tiny bumps of of unknown function. Um At least |
|
| 58:42 | this point, these are the omental . So momentum is, is that |
|
| 58:49 | of fat that hides the, the or is in the, in the |
|
| 58:54 | . So you have the greater momentum the less momentum. Um That's |
|
| 58:59 | Now you get down to that third . So we have the, we |
|
| 59:02 | the colon that goes around and we're talk about what they do here in |
|
| 59:05 | moment, we get to the The rectum is the um um the |
|
| 59:10 | that FEC um last sees before it into the bathroom. There are three |
|
| 59:16 | here and I just, I have set up here with its job is |
|
| 59:20 | separate feces from plati and to put in English, it separates your poops |
|
| 59:25 | your farts. All right. So reason you're able to pass gas is |
|
| 59:30 | you can move the gas down and the feces up high, right? |
|
| 59:36 | that doesn't always happen, but we won't go there. All |
|
| 59:40 | Now, when you get down into anus. All right, there are |
|
| 59:45 | couple of structures. We have these tiny columns. You can see the |
|
| 59:49 | in the cartoon. What that does it serves to help protect the structure |
|
| 59:56 | the anus. Um It is a squamous, so stratified remember multiple |
|
| 60:00 | So it's a protective layer and because removed all this water and you have |
|
| 60:05 | these indigestible in feces, it can kind of dangerous to the cells. |
|
| 60:10 | so only having a portion of the in contact with that feces is its |
|
| 60:17 | . And then in between them, have these little tiny sinuses, these |
|
| 60:21 | spaces in between, these are pumping mucus uh during um um bowel movement |
|
| 60:29 | that you're actually creating a slick surface that the feces travels smoothly. |
|
| 60:36 | there are two sphincters just like in uh urethra. There are two |
|
| 60:40 | We have an internal and external. internal is smooth. The external is |
|
| 60:45 | is skeletal, which means that you can control one relaxes on its |
|
| 60:50 | , right? So if the internal is the smooth muscle, the external |
|
| 60:54 | is the, the uh uh Now, let's talk about motility and |
|
| 61:01 | you'll understand the role here. All . So it does have some |
|
| 61:06 | but these are probably pretty weak and don't do a whole much um within |
|
| 61:11 | hoster themselves, you'll have some So what it does is it takes |
|
| 61:14 | kind of bolus of, of time it's slowly removing water and making it |
|
| 61:21 | and more fecal like. And then it does is it takes it and |
|
| 61:24 | it over the next one and it of churns it and spins it and |
|
| 61:30 | over the next one and so So that's hospital churning and then we'll |
|
| 61:33 | mass movements. Now, these are ones you're familiar with, right? |
|
| 61:36 | go and have a big old meal 20 minutes later. You're like, |
|
| 61:40 | , I gotta go to the bathroom basically what it is is the pressure |
|
| 61:44 | the stomach and the signals from the saying, hey, I'm distended. |
|
| 61:48 | just put a whole bunch of food you got to make room for all |
|
| 61:51 | digestible material that's going to be moving . And so that's what's actually creating |
|
| 61:55 | pressure and the signal to cause you go to the bathroom. This is |
|
| 61:59 | is called the gastrocolic reflex, And then what that does is it |
|
| 62:05 | pressure down onto the rectum where you a defecation reflex. And here what |
|
| 62:10 | is, that's that need. I've to go poop. Now you've, |
|
| 62:14 | said that right? At least, not out loud. You should probably |
|
| 62:18 | in your brain head. It's like it doesn't happen now, it's gonna |
|
| 62:21 | bad. All right, that urge defecate. And so really what that |
|
| 62:25 | , that is the smooth muscle going you can actually go, ok, |
|
| 62:32 | gonna come, but you're in the of a lecture and it's inappropriate to |
|
| 62:36 | to the bathroom in the middle of lecture, right? So what do |
|
| 62:39 | do? Your sphincter? Your, , your external sphincter is all |
|
| 62:43 | no, I'm not gonna let it . Right. And actually part of |
|
| 62:47 | reflex is to cause that sphincter to contract until it's appropriate. All |
|
| 62:55 | And then you go find your way the restroom and then what do you |
|
| 62:59 | ? You relax your external sphincter and , and then those smooth muscles are |
|
| 63:04 | push and help drive out. And course, you can also bear |
|
| 63:08 | use your abdominal muscles as well. , gastrocolic refat flex, that's the |
|
| 63:16 | being full, that creates the defecation , which is the need to go |
|
| 63:22 | the bathroom need or the urge to so far. So good. You're |
|
| 63:29 | , I don't know, man, a lot of stuff here. Remember |
|
| 63:33 | can fit it all in one Have you guys taken micro? |
|
| 63:39 | You know all about these things right? For those who haven't taken |
|
| 63:43 | , you're gonna get to take a at some point. All right. |
|
| 63:46 | , it boils down to this. We have intestinal bacteria. We've talked |
|
| 63:50 | there being bacteria on our body, more bacteria in and on our body |
|
| 63:53 | we actually have personal human cells in body, which is just kind of |
|
| 63:58 | if you think about it. But bacteria that sit in the intestine, |
|
| 64:01 | are beneficial. And what we do we provide them indigestible material for |
|
| 64:05 | digestible material for them. They take indigestible material, they break it down |
|
| 64:10 | get their materials for it. And they do is they give us vitamin |
|
| 64:14 | and they give us vitamin K vitamin B and vitamin K are good |
|
| 64:18 | us. That's why we keep them and let them live inside us. |
|
| 64:21 | then what they do in the process breaking down the, the materials that |
|
| 64:26 | couldn't break down is they produce carbon , they produce protons, they produce |
|
| 64:31 | , methane and then the fun the end and scats. Now, |
|
| 64:36 | you're wondering what are all these Well, hydrogen sulfide is what rot |
|
| 64:41 | smell like. Ok. Methane, too. In I said in or |
|
| 64:48 | Scali, right? Even tells you the name what it is. The |
|
| 64:56 | scat is the term that we use poop. It basically they're the, |
|
| 65:01 | chemicals that make up the odors of . So truth is your poop don't |
|
| 65:11 | . It's the bacteria's poop that do . So someone says your ops. |
|
| 65:16 | , no, no, no, not me. It's the, it's |
|
| 65:18 | bugs inside me. I don't know that's helpful. Right. All |
|
| 65:27 | We're getting down to the last little here. So we just walked through |
|
| 65:31 | entire track or at least from the on downward. So you have the |
|
| 65:36 | , you have the esophagus. Each these things notice that we had a |
|
| 65:39 | between the stomach and the uh uh the small intestine. We had a |
|
| 65:45 | between the small intestine and the large and we have sphincters between the large |
|
| 65:50 | and the bathroom, right? And remember what I said is, look |
|
| 65:54 | the sphincters, the sphincters tell you the dividing lines are. And that |
|
| 65:57 | you to kind of focus in and , OK, if this has been |
|
| 66:01 | , if there is a door between and there, why is this area |
|
| 66:04 | than the one before it? That's kind of what we're, what |
|
| 66:07 | saying. All right, when we to the accessory organs, what we're |
|
| 66:12 | is we're introducing these extra structures that the materials that allow the associated structures |
|
| 66:19 | work with them. All right, the mouth, you have the salivary |
|
| 66:24 | and they're very, very similar to of the structures we're gonna look at |
|
| 66:26 | terms of how they are structured and they secrete pancreas is that structure. |
|
| 66:33 | thing is the pancreas is more complex producing more, more enzymes. But |
|
| 66:37 | we're looking at here with regard to small test and we have three accessory |
|
| 66:42 | that are important. We have the , the gallbladder and the pancreas of |
|
| 66:46 | , the pancreas is the most right? And we're just gonna try |
|
| 66:50 | keep things really simple today. All , gallbladder is the easiest and then |
|
| 66:56 | liver has, it kind of sits between. All right. So, |
|
| 66:59 | the liver by its structure is the gland in your body. We don't |
|
| 67:03 | think of it as a gland but is, it's a, it's an |
|
| 67:06 | gland whose job it is is to in the process of fat digestion. |
|
| 67:11 | right, it produces this material called and its bile that plays that role |
|
| 67:16 | digestion. All right. Now, other roles that it plays in |
|
| 67:20 | We're gonna ignore those other metabolic roles . Um, we have the |
|
| 67:24 | Its job is to take bio that's secreted and that your body no longer |
|
| 67:29 | and it stores it up for later . So basically is kind of a |
|
| 67:33 | where it's like, OK, I bile. So instead of waiting for |
|
| 67:36 | liver to start producing, I've got structure that holds on the bile and |
|
| 67:40 | can secrete that first while the liver playing catch up. And then we |
|
| 67:44 | the pancreas which has multiple roles. an XCN function, has an endocrine |
|
| 67:49 | . We're focusing on the XCN Endocrine function is what regulates blood glucose |
|
| 67:56 | . All right. So, so regard to exocrine XCN, means I'm |
|
| 68:01 | is secreting out of the body. the digestive tract is out of the |
|
| 68:04 | , what I'm doing is I'm secreting enzymes that are gonna play a role |
|
| 68:08 | digestion as well as neutralizing kind. , there's a couple of ducks here |
|
| 68:14 | are important. Um I just want kind of point out um So this |
|
| 68:19 | the entire bill apparatus. All So it's basically all these little |
|
| 68:23 | We have, um, excuse this large thing right here. This |
|
| 68:29 | called the common hepatic duct, It divides into two hepatic ducts, |
|
| 68:34 | left, one's right. So when hear hepatic, you should be |
|
| 68:38 | ok, that's liver. So, two are in the liver, the |
|
| 68:41 | duct is what joins up with the duct. And so the pancreatic juices |
|
| 68:47 | gonna exit out through the sphincter. , it's called the hepatopancreatic sphincter. |
|
| 68:52 | right, there's actually two little One is the major Duodenal paille. |
|
| 68:57 | second one is the minor duodenal paille the two different tracks that you can |
|
| 69:02 | out, uh exit out of. right. So this structure though is |
|
| 69:10 | most of the materials from the, the liver and from the pancreas are |
|
| 69:13 | to be exiting. Um I don't I highlighted on this one, but |
|
| 69:17 | think when we get to the you can see here the duct that |
|
| 69:20 | to the gallbladder is the cystic Um, and we, when we |
|
| 69:25 | about the gallbladder, I think I it there. Now, the liver |
|
| 69:30 | , four lobes. It's huge. protected primarily by your ribs, but |
|
| 69:35 | sits right over here. It's nice massive. Um It sits, uh |
|
| 69:39 | underneath the diaphragmatic muscle or the Um, it has two major |
|
| 69:45 | the left and the right one which can see in the picture here. |
|
| 69:47 | if you flip it over and looked the right lobe, you'd see that |
|
| 69:50 | has two minor lobes, the quad and the coate. Um in terms |
|
| 69:57 | the vascular sugar, this is where gets weird. All right. So |
|
| 70:01 | we have is we have blood coming the stomach this morning in the |
|
| 70:04 | as well as the intestines. They up and they form what is called |
|
| 70:08 | hepatic portal vein. So we deliver blood with materials in them to the |
|
| 70:15 | . From these structures. We also oxygenated blood to keep the cells alive |
|
| 70:22 | the hepatic artery and then material is to be processed in the liver. |
|
| 70:27 | then that blood leaves the liver collectively both the pado portal vein, the |
|
| 70:32 | blood, the oxy blood from the and they join up and form or |
|
| 70:36 | leave via the hepatic vein. All . So the way you think about |
|
| 70:42 | is there's two paths in one path . All right, hepatic artery only |
|
| 70:47 | oxy blood. The hepatic portal vein material and blood from all these other |
|
| 70:53 | to be processed. The hepatic lobule where all the action is taking |
|
| 71:06 | Right now, there are more things on in the liver than what I'm |
|
| 71:09 | to describe. But for our purposes , this is where we need to |
|
| 71:13 | . So if you go down and at a histological section, what you're |
|
| 71:19 | see is you're gonna see these structures lobules and they're Hexagon shape in the |
|
| 71:26 | of the lobule is a vein, ? It's called the central vein. |
|
| 71:30 | each one of them gets their own vein. So you can imagine, |
|
| 71:33 | got thousands of these lobules and inside of these lobules is a central vein |
|
| 71:38 | are all going to converge and eventually that hepatic vein. All right now |
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| 71:44 | the corners of each of the hex so that you can see them |
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| 71:47 | But you can imagine be all the around is we have what is called |
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| 71:50 | triad. All right, the portal , the portal triad consists of three |
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| 71:55 | . All right. The first thing it has is it has a bio |
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| 72:00 | Jele. So here you can see bio duck Joel right now, what |
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| 72:04 | is is a structure that's formed by channel or Kics that is collecting material |
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| 72:13 | the hepatocytes, the cells of the are producing. This is the |
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| 72:17 | all right. So this material is away from the vein towards that |
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| 72:23 | And it's being collected here in the duct, right? And that's what's |
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| 72:27 | to ultimately, or the bio which is ultimately going to go and |
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| 72:30 | the left and the right hepatic ducts will then form that common duct. |
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| 72:35 | that's where all that stuff is It's the bile is going in that |
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| 72:39 | , the blood from the hepatic portal is going to be entering in and |
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| 72:45 | traveling towards the central vein, So you're having capillaries, which are |
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| 72:49 | sinusoids, right? So these are tight capillaries. These are like open |
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| 72:55 | , right. So they have the themselves have contact with the blood. |
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| 72:59 | the blood from the portal vein is towards the central vein via the |
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| 73:04 | And then the blood from the hepatic is going towards the sinusoids and ultimately |
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| 73:09 | the central vein. So we have delivering to and across through the |
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| 73:15 | going towards the central vein, So there's an exchange taking place |
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| 73:19 | And the hepatic sites that are doing exchange are making bile. And that |
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| 73:24 | is being collected through these conic and sent out the other direction. And |
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| 73:30 | is between each of these structures at single corner. So your liver is |
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| 73:36 | busy making bile plus other stuff that not talking about. So what is |
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| 73:45 | ? It's iy gross stuff, When you hear the word bile, |
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| 73:48 | like the bile, right? bile is a whole bunch of different |
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| 73:53 | . And again, I'm not gonna there and here's the list, |
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| 73:57 | The the key thing you're making a , you're making almost a liter a |
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| 74:01 | of bile. And what this does that it plays a role in fat |
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| 74:06 | through the process of emulsification. All , what's a mul? That's a |
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| 74:11 | fancy word and really what a mult is, it takes a fat substance |
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| 74:17 | doesn't want to mix with a watery and it breaks up the surface of |
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| 74:21 | fat so that you make smaller, , fat bubbles so that you have |
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| 74:27 | surface area so you can break things faster. Now, the example I |
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| 74:31 | to make this really easy is you're not gonna understand this because you |
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| 74:34 | eat salads, ladies, you're gonna this. All right. I know |
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| 74:38 | a very sexist thing to say, it's true. Ok. So a |
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| 74:43 | , guys, a salad is a of, of vegetables and you put |
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| 74:49 | on it to make it taste Ok. And one of the dressings |
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| 74:52 | can use is called vinegar and Now, usually vinegar and oil |
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| 74:58 | if you're at a fancy place, separately. But if you go like |
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| 75:01 | the, uh, the cafeteria over or whatever your moody's, it comes |
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| 75:06 | a, in a, in a container. And so what you'll see |
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| 75:09 | it has vinegar and then on the you have oil. And so when |
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| 75:14 | take the vinegar and oil and if just pour it, what you're gonna |
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| 75:17 | up with is because the fat always on top. It's gonna go right |
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| 75:20 | the top and you're just gonna end with salad soup with, in, |
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| 75:24 | vinegar. Right. Which I don't if it tastes good because it's a |
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| 75:28 | , but I don't think it tastes . Right. And you're just like |
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| 75:33 | your head at me. All So what do you do if you |
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| 75:37 | it to taste good? If you to get both the vinegar and |
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| 75:38 | what do you do? Say it ? No, no, we're |
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| 75:42 | What do we do? We All right. That's what you |
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| 75:49 | You're shaking it to cause emulsification. you do is you and then all |
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| 75:55 | fat, which is one big giant being separated from the vinegar gets broken |
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| 75:59 | little tiny bubbles. So the vinegar all around it and eventually the fat |
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| 76:03 | going to be excluded from the So you have to shake it up |
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| 76:06 | . But the shaking portion is what is. You're basically breaking a big |
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| 76:10 | to make a little tiny, small . So what bile does is the |
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| 76:13 | thing, but it doesn't like shake . It's using chemical emulsification and all |
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| 76:18 | little agents that you see there is gonna allow you to break a big |
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| 76:22 | bubble into a little tiny fat which is much easier to digest. |
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| 76:28 | ? Now, the gallbladder we said a role in storing up bile. |
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| 76:34 | so what you can imagine is you've a meal, your body is producing |
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| 76:37 | and it's sitting there churning it out all of a sudden it's like, |
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| 76:40 | , it's time I'm done. Um your sphincter, you know that, |
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| 76:45 | sphincter from the pancreatic sphincter closes. so all that bile is now stuck |
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| 76:51 | the common bile duct and it needs go someplace. And so what the |
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| 76:55 | is is it says, ok, know, do a little bit of |
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| 76:58 | and instead of being leached out, basically gets pumped into the gallbladder and |
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| 77:03 | it removes some water and some other and it concentrates down the bile and |
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| 77:07 | it in the gallbladder. Now you another meal and your body says I |
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| 77:11 | bile, but it's gonna take a for your liver to kind of catch |
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| 77:14 | . So what you can do is can squeeze your gallbladder, add a |
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| 77:16 | bit of water to that and it right into the digestive system until the |
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| 77:22 | kind of catches up. So if know someone who's lost their gallbladder, |
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| 77:25 | have a little bit harder time digesting . It takes a little bit more |
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| 77:29 | , but they still have a right? The gallbladder was just there |
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| 77:34 | provide a quick source for the bile you've already made it, you just |
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| 77:39 | it up. Alright. So that's purpose. So there's a sphincter valve |
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| 77:46 | controls the flow which way it's gonna right when that amp flow is |
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| 77:52 | So it's either gonna go out while making it and oh, I can't |
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| 77:55 | out. So I just go back the gallbladder, ok. So liver |
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| 78:03 | bile which plays a role in fat . We haven't talked about how yet |
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| 78:07 | gonna be Thursday. We talked about gallbladder, gallbladder stores up the bile |
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| 78:12 | I've made too much of it and going to concentrate out. So I |
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| 78:15 | use that first before I start making . And then we have the pancreas |
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| 78:19 | plays a role in producing all the that finish up the process of |
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| 78:24 | And there are a ton of enzymes here. Good news. You don't |
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| 78:28 | to memorize them all. All So endocrine function, this is the |
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| 78:35 | that are responsible for controlling the blood level. So there's insulin in |
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| 78:39 | we're not going to deal with those . That's going to be after the |
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| 78:42 | test. Exocrine. This is going be produced primarily in the Acier |
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| 78:48 | but we're going to see the duct play a role here. But what |
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| 78:50 | doing is producing the pancreatic juices which going to be joined up with the |
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| 78:55 | that play a role in digestion. this is chemical digestion. This is |
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| 78:59 | last stages of digestion. So the cells. So if you look at |
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| 79:04 | structure here, this would be uh would be the exocrine structure. So |
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| 79:09 | have the ascena which are purple and you have this yellow stuff that's the |
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| 79:15 | . And so you can see that have many, many ducks in uh |
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| 79:18 | the end of each duct, you these bubbles of Acier cells, the |
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| 79:22 | converge and form a larger pancreatic duct joins up with the common uh |
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| 79:29 | All right, the Acier cells are for making those enzymes. The duct |
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| 79:35 | make bicarbonate. Ok. Well, bicarbonate? Bicarbonate is an alkaline substance |
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| 79:41 | neutralizes acids. You guys take Tom's , if you have an upset |
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| 79:49 | take it tubs. Right. That's . It neutralizes the acid of the |
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| 79:55 | . So your chi which is acidic going to be neutralized by the bicarbonate |
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| 79:59 | produced by the duct cells. The cells are producing all the enzymes plus |
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| 80:04 | other liquids to make the pancreatic juices break down everything. It includes. |
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| 80:10 | , not the names, pancreatic, tells you where it comes from. |
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| 80:14 | amylase. Amylase is a carbohydrate digestion . All right, we make pancreatic |
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| 80:21 | break down fat. We have a bunch of proteases that we're going to |
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| 80:26 | and break down proteins. And we have uh nu- uh nucleases that |
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| 80:32 | down R N A and DNA. it's one of those four things, |
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| 80:39 | gonna break it down by enzymes that being produced in the pancreas. |
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| 80:44 | the are gonna be bunched together kind by connective tissue that forms a lobule |
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| 80:51 | that has its duct. So you imagine multiple lobules are converging and forming |
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| 80:56 | structures. And that's why when you at a picture of the pancreas, |
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| 80:58 | has this kind of bumpy looking uh that is the lobules. All |
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| 81:06 | Now, remember we mentioned cholecystokinin, how you spell it out right |
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| 81:14 | right? Cholecystokinin was being produced by Duodenal cells, right? And what |
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| 81:19 | doing here is they're producing this material when there is fat presence. |
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| 81:26 | why would I care if fat is ? What do I want to produce |
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| 81:29 | fat is present file? Right. Coley says the kind is a signal |
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| 81:35 | tell me to start producing bile. sorry. It's 9:52. I'm not |
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| 81:40 | close attention. I will stop We'll come back, we'll start back |
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| 81:45 | this file. I know it's been long couple of days. So when |
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| 81:49 | come back, we're going to start with calling sister kind and learn to |
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| 81:53 | it. OK? I have an |
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