| 00:02 | Okay, I think we are up going everything turned on. Uh Let's |
|
| 00:08 | break down into three parts today. a danger with this part right |
|
| 00:13 | The danger in this part is I'm spend 15 2030 minutes talking about the |
|
| 00:17 | . I don't want to spend that time for like five minutes. Then |
|
| 00:21 | that we're going to jump to where left off on thursday, which is |
|
| 00:24 | about membrane potentials. And then we're to pause and then we're going to |
|
| 00:29 | into the nervous system and we're gonna through the nervous system. Then we're |
|
| 00:32 | to pause and jump back to membrane and talk about great potentials and action |
|
| 00:37 | . That is our story for Sound good. Or you feel like |
|
| 00:41 | about football or something? Football, like, okay, let's talk All |
|
| 00:45 | , U of h cannot win a . If we're gonna throw three interceptions |
|
| 00:49 | have one fumble, it will not . It doesn't matter how good we |
|
| 00:54 | , You want to keep going. . I didn't think so. All |
|
| 00:59 | . First up on the paper, should have picked up the topic by |
|
| 01:02 | . You still have time If you if you picked the wrong topic, |
|
| 01:06 | can still change it. Just remember you do change topics, you're jumping |
|
| 01:09 | a different group, let me know I can drop, you know the |
|
| 01:12 | group so we can make that space for someone who might want to change |
|
| 01:14 | topic into that group. When you a topic whenever you're picking any topic |
|
| 01:19 | any class anywhere anytime always write about that you feel comfortable about writing |
|
| 01:24 | Don't write about something you have zero in. If you have zero interest |
|
| 01:28 | it, you will not want to . It will become the most |
|
| 01:31 | horrible, nasty assignment you've ever had period. All right. So look |
|
| 01:38 | the topics kind of get a sense where you want to go. Does |
|
| 01:41 | sound interesting to me? Do I to know more about this? |
|
| 01:44 | You're going to be more interested in this is just generally true if you're |
|
| 01:48 | pushed in a direction for for like I've had students like this, |
|
| 01:53 | not claiming anyone in here is like , but I've had students where their |
|
| 01:56 | are like, you're going to be physician and the student is like, |
|
| 01:59 | don't want to be a physician in , like you're going to be a |
|
| 02:01 | , I don't want to. And they sit there and they dragged their |
|
| 02:04 | the entire way barely passing through the . All right. If you don't |
|
| 02:09 | an interest, you not have a in something, you're not going to |
|
| 02:12 | your effort into it. So make whatever it is that you're doing paper |
|
| 02:17 | life, you have a passion for it is that there's no wrong |
|
| 02:22 | Just find what you enjoy. All . All right. Now, after |
|
| 02:27 | pick your assignment, the good news is that I've set this up in |
|
| 02:31 | a way that every assignment leads to next assignment so it will help propel |
|
| 02:35 | forward and doing stuff. I used have it. Whereas like here to |
|
| 02:38 | your topic over there, that's where paper was. And then people would |
|
| 02:41 | till the very last minute and go I don't know how to do |
|
| 02:44 | It's like no no we're we've made easier. But just remember you're not |
|
| 02:48 | be able to just wait every thursday to get the thing done on |
|
| 02:52 | Okay. Real simple. Of Didn't press about. There we |
|
| 02:58 | All right. Where do you get information? All right. You guys |
|
| 03:01 | the movie? Have you guys watched ? Like three people the rest of |
|
| 03:09 | . Mhm. Put it on the . Yeah. Good bad. And |
|
| 03:13 | ugly, best western ever period. think that's going to be the |
|
| 03:18 | That is the period. All So the good thing the thing that |
|
| 03:21 | want to be spending most of your is in the primary and secondary |
|
| 03:24 | Primary literature is where they do experiments discover what's going on and then report |
|
| 03:28 | it. Secondary literature is what you're producing. It's basically gathering the primary |
|
| 03:34 | reading through it and then kind of oh okay. This is what the |
|
| 03:38 | picture looks like and it summarizes what's on. That doesn't mean you don't |
|
| 03:42 | the secondary literature. In fact you'll probably a lot of it. But |
|
| 03:45 | I want you to do is I you to keep going back here to |
|
| 03:48 | sure that they're telling you the truth not making up stuff. All |
|
| 03:53 | Have you noticed that No one trusts anymore? I mean, I |
|
| 03:58 | just as weak. What's the big this week? Do you want the |
|
| 04:03 | wormer uh Ivermectin? The Nobel prize drug that's used in humans and other |
|
| 04:11 | . All right. Now, the here is does it work for |
|
| 04:16 | The answer is no one knows because no one's tested it. |
|
| 04:19 | Because Covid is new, right? it's used on many types of viral |
|
| 04:25 | . Whole bunch of different types of infections. And if you're one of |
|
| 04:28 | unfortunate kids have got list. Your probably bought something, rubbed it in |
|
| 04:32 | hair. It kills uh life or lice eggs. It's like this wonder |
|
| 04:39 | of killing parasites. Some of you picking the topic of the immune system |
|
| 04:44 | worms. Yeah, the horrible things can live in your body. All |
|
| 04:50 | . But in essence, we don't what it does. And everyone is |
|
| 04:53 | there going this is the way it . And this is the way it |
|
| 04:56 | . And no one's trusting anybody because is politicized. The answer is look |
|
| 05:01 | right. If you go to the literature, you'll find out the truth |
|
| 05:04 | stuff. All right. Now, course. like I said with regard |
|
| 05:08 | Covid and Romek then there's like three out at this point. So jury's |
|
| 05:13 | out. All right. Does it promise? Yes. But is it |
|
| 05:18 | ? No. Actually you guys heard zika virus? Yeah. Everyone in |
|
| 05:22 | . Yeah. Zika. That was that was gonna kill us three years |
|
| 05:25 | . Four years ago. Okay. is one of them that they give |
|
| 05:28 | backed into because it stops the viral from being produced interesting. All |
|
| 05:35 | So, you know who knows? ? But go here. That's where |
|
| 05:39 | truth is going to be found. what people are saying. This is |
|
| 05:42 | we discovered. And then you can out and go yeah, I'm not |
|
| 05:46 | . I really agree with what you or you can look at and go |
|
| 05:48 | , the data supports what you said you can move up. Alright. |
|
| 05:52 | . You want to avoid. Text . Wikipedia time out on the |
|
| 05:58 | If you're using Wikipedia to kind of yourself some background knowledge. Great |
|
| 06:03 | Right? So for example, if forget something like what's a single Myelin |
|
| 06:08 | ? Remember I gave the toxins finger like damn it. I can't remember |
|
| 06:12 | it is. What do I I go to Wikipedia look it up |
|
| 06:15 | quick. Okay. Got it. can move on. All right. |
|
| 06:18 | okay. But it's not a It's a way to give yourself |
|
| 06:22 | Internet, textbooks are the same thing textbooks. There are a good source |
|
| 06:27 | information that's old. All right. Old being the sense that it's now |
|
| 06:32 | common knowledge. So we put it a book. Things that you don't |
|
| 06:35 | to avoid, blogs, avoid anything says dot com. Anything that's a |
|
| 06:40 | or magazine article, primarily because science don't know squat and they don't know |
|
| 06:44 | to interpret. So, anything they say is probably wrong just on its |
|
| 06:48 | because they're just clueless. Not but generally speaking, this stuff is |
|
| 06:53 | incorrect. So you really want to your time up here. But dr |
|
| 06:57 | , I'm talking about this broad project really pretty well established. Yes. |
|
| 07:01 | that's where you go to the secondary . And then what I want you |
|
| 07:03 | do is I want you to push envelope and enter into the primary literature |
|
| 07:07 | see what's new, what's available out . What more have we learned since |
|
| 07:11 | stuff has hit the textbooks. Does make sense? Okay, that's really |
|
| 07:15 | of the goal here. All Where do you get the information? |
|
| 07:21 | , well, you want to go the journals? Well, you can |
|
| 07:25 | your textbook. I don't think your has anything on immunology, does |
|
| 07:29 | Anyone looked anyone bothered to flip through 1400 pages to see if there's a |
|
| 07:33 | on the immune system. Yeah, can go to the textbooks, but |
|
| 07:37 | again, that will give you the information. Uh They have computers so |
|
| 07:42 | you can go and use their search so that you can go look at |
|
| 07:44 | e journals. So your main search . If you hit pub med, |
|
| 07:47 | going to be the sweet spot for field. But there's other areas like |
|
| 07:51 | is a web of knowledge, web science. These are Uh paid for |
|
| 07:57 | university has access to. And then they'll do is they'll give you the |
|
| 08:03 | and the abstract and sometimes they'll point links to the actual journal. If |
|
| 08:07 | pub med, about 70% of them uh free links. So they're open |
|
| 08:14 | or what they'll do is we actually for access to that journal. And |
|
| 08:17 | there's a direct link that you can as long as you're using the university |
|
| 08:22 | . What does that mean? If from home and you and you access |
|
| 08:27 | you may not be able to access journal directly. So you'll have to |
|
| 08:30 | into the library and then access through way. That's basically as long as |
|
| 08:34 | have the university uh internet address on access point, you're in good |
|
| 08:39 | So if you live in the dorms like being in the library except you |
|
| 08:43 | do it in your pajamas weight. can do that at the library to |
|
| 08:46 | pajamas. Yeah. Okay. So do you go for help? Well |
|
| 08:51 | librarians. They're hot. Don't be to talk to him If you don't |
|
| 08:58 | me you haven't been to the library . Go and stop one. See |
|
| 09:01 | they see if I'm lying. See we're right. But basically they'll show |
|
| 09:07 | everything their that's their job is to you how the systems are organized. |
|
| 09:11 | you've never done a uh an article something like that, they can walk |
|
| 09:15 | through the process so they can be uh those group discussions. So the |
|
| 09:20 | that you've joined they're not there for to have really like these long lengthy |
|
| 09:24 | . But if you're like totally lost can always reach out to your |
|
| 09:27 | I've set it up that way that could do it. Um you can |
|
| 09:30 | contact me for any of the assignment that you may have like someone asked |
|
| 09:34 | to is like when is the first do? And I was like let's |
|
| 09:38 | on the 17th not the seventh which what they thought it was. It |
|
| 09:42 | like so I can help you with or if there's like I don't know |
|
| 09:46 | I'm doing, help me help me me. I can probably you know |
|
| 09:50 | of push in the right direction but not going to write your paper for |
|
| 09:53 | . I've already done that. It's exhausting. Um Oh so I'm going |
|
| 09:59 | pause here so like I said I'm try to get through this 10 |
|
| 10:01 | 10 minutes on the clock up there questions and it's okay to ask questions |
|
| 10:05 | prolong this to 25 minutes if No. Yes. Okay. |
|
| 10:11 | All right so the first assignment do what day 17th? Really? The |
|
| 10:18 | which is your topic? But the is the one we're actually going to |
|
| 10:21 | turning a piece of paper. You to have at least 10 sources that |
|
| 10:25 | . Okay now here's the question. you need to use all 10 sources |
|
| 10:29 | the time your papers written? No can actually change your sources up. |
|
| 10:33 | may find that some of your sources . You may find that you need |
|
| 10:35 | sources. And so your source list going to expand and contract depending upon |
|
| 10:39 | information you end up using. Does kind of makes sense? So in |
|
| 10:43 | words this is this is like I'm going I'm really going up. |
|
| 10:49 | you date someone, do you have marry them? No you get to |
|
| 10:54 | yeah I like certain aspects of you you are not my future. And |
|
| 10:58 | that's what the paper is. You read and go yeah there's stuff in |
|
| 11:00 | but you are not part of my . And so you can put it |
|
| 11:03 | there and you can look at the paper, you can say well you |
|
| 11:05 | part of my future and you add to the pile and we're just presuming |
|
| 11:09 | polygamy. Yeah. Yeah. Yeah telling you gonna have fun in this |
|
| 11:16 | . Right? But basically what you is you can decide whether or not |
|
| 11:19 | source is useful. But the hardest is getting started. Right. And |
|
| 11:23 | the first step is to actually find papers. If you can find 10 |
|
| 11:28 | , that means you can find 20 . You can find 20 papers, |
|
| 11:30 | can find 25 or 30 and you go through 30 and you can call |
|
| 11:34 | down back to 15. And if don't like the 15 you can move |
|
| 11:37 | up to 20 again. You see I'm saying. It's there's there's an |
|
| 11:41 | here for you have discernment and deciding is good and what is bad. |
|
| 11:46 | that's really the goal. The second is about putting your outline together. |
|
| 11:50 | go look at the instructions. What asking to do when you find your |
|
| 11:54 | sources to tell me what information out that source is useful. Right? |
|
| 11:59 | would I want that? Because when go and write my discussion outline, |
|
| 12:02 | should have some facts. Hopefully not up hopefully from a source. |
|
| 12:07 | And by having a list of sources the fact that you're getting you're actually |
|
| 12:11 | things into order. Do you see this kind of works? You're gonna |
|
| 12:15 | out writing is really, really And then the hard part of actually |
|
| 12:19 | yourself from putting too many words on paper. You're looking at me like |
|
| 12:23 | way. 2000 is like your Yeah, I'm just teaching you. |
|
| 12:29 | forgot to tell you this is Sea . This is a splash zone. |
|
| 12:35 | Shamu Thank you for the last sometimes you get it to the back |
|
| 12:43 | . All right. Any other questions the paper before we go? |
|
| 12:51 | I don't know what 5000 words So like I said somewhere between 3,000 |
|
| 12:55 | words. Right? So that's kind a really broad range right? Here |
|
| 12:59 | the horrible answer you're ready for Their paper is as long as it |
|
| 13:04 | to be. I hate when teachers that Right? Where it comes in |
|
| 13:10 | ? I don't know what that So about 5000 words is about where |
|
| 13:14 | sweet spot is. All right. really it's used enough words to explain |
|
| 13:20 | you need to explain without over explaining what that under explaining. That's really |
|
| 13:23 | it boils down to and I don't what that turns into. I've had |
|
| 13:27 | turn in really, really short I've had perfect people turn in really |
|
| 13:30 | papers. Both cases are good in cases they're bad. Right? So |
|
| 13:34 | goal here is communication. How many do I need to communicate now if |
|
| 13:39 | imagine me writing? What type of long are my papers based on how |
|
| 13:44 | talk? Yeah, we have to a lot of editing when I |
|
| 13:50 | it's just all right throughout that Throughout those 7000 words. Oh yeah |
|
| 13:57 | mm. Mhm. Yeah. So the question is about all right we |
|
| 14:05 | peer review coming up. So every there's a peer review attached to |
|
| 14:08 | So you turn in the assignment the day the peer review opens up you're |
|
| 14:12 | get three papers for the first three and they're really easy. They take |
|
| 14:16 | like 10 minutes. All right so not I mean for like all three |
|
| 14:20 | them. So it's like so the one is like all right. Do |
|
| 14:23 | have their 10 references? Yes. . It's it's a real basic question |
|
| 14:28 | answer thing. Do they have their references do they have for each |
|
| 14:31 | Do they have a fact attached to ? Yes and that's the sort of |
|
| 14:35 | . So really the idea here is you double checking and so the reason |
|
| 14:39 | do three so we're getting used to idea that we have multiples that we're |
|
| 14:41 | be doing all along. All But the first three assignments are are |
|
| 14:45 | but then when we have to actually reading stuff assignments get a little bit |
|
| 14:48 | . So instead of being 10 minutes do three of them it might be |
|
| 14:51 | minutes to do five of them. be surprised how quickly and easy it |
|
| 14:55 | to read through stuff. Okay. but yes you're guided along the |
|
| 15:00 | Okay anybody else? Yes we have Yes. So, the question is |
|
| 15:09 | I have to stick to description. of you have picked a topic which |
|
| 15:13 | a very general question. Right. how does this system work? So |
|
| 15:18 | . Now can you add to Yes, but the central point should |
|
| 15:23 | addressing whatever that question happens to So, for example, immunity to |
|
| 15:28 | talk about generalities. How does the system respond to viruses if you want |
|
| 15:33 | then focus in and say, you , under the current situation with you |
|
| 15:38 | , these coronavirus is one of the is how you know, we address |
|
| 15:42 | is how the immune system addresses RNA whatever you want. But the key |
|
| 15:46 | has to be that base thing Right? So if you want if |
|
| 15:52 | doing the one on immunity to you don't want to spend all your |
|
| 15:54 | talking about cancer. You want to all your time talking about the immune |
|
| 15:59 | And how it deals with cancer. can pick a specific one if your |
|
| 16:03 | if you like focusing on breast you're like, oh I love all |
|
| 16:06 | immune response to breast cancer. And do that. That's fine. But |
|
| 16:09 | just one example of like 1000. , understanding the baseline is the important |
|
| 16:15 | . Okay, anyone else does paper you nervous? Stop it. It's |
|
| 16:22 | communicating. Do you know how to Jeanette? A text writing papers is |
|
| 16:29 | texting only longer. All right. have to use punctuation in capital |
|
| 16:36 | No emojis. All right. With more questions. Let's move to part |
|
| 16:41 | . Let's deal with membrane potentials. , So, first off, just |
|
| 16:46 | of a general electricity review. Some things we learn probably back in |
|
| 16:50 | Your body is electrically neutral. That very positive charge in your body. |
|
| 16:54 | is a negative charge. How do know it's electrically neutral electrical. New |
|
| 16:58 | Cali. Start talking fast and just I come up and touch you, |
|
| 17:04 | not going to electrocute you. That's how we know we're neutral, |
|
| 17:08 | dr wayne. I can shock you I rub my feet against the |
|
| 17:11 | Yes. You're now carrying a charge the outside of your body, which |
|
| 17:14 | really fun to do. Right? to the cat. All right. |
|
| 17:21 | know this opposites attract same charges Yes. I should be double check |
|
| 17:32 | . Yes. Okay. Well, a good. And remember always check |
|
| 17:36 | light the light on. Yeah, light turns off. Sound goes |
|
| 17:42 | All right. All right. opposites attract so, I mean, |
|
| 17:45 | negative charges and drawn towards each Like charges are repelled. All |
|
| 17:50 | So, negatives repel each other. . Richard tell each other. All |
|
| 17:53 | . Two separate two charges. That energy. Just like students at a |
|
| 17:58 | it requires energy to keep the two attracted to each other apart. Do |
|
| 18:02 | guys remember dances? Did you guys dances? Okay. Every generation. |
|
| 18:07 | gets weirder and weirder. Right. we had dances, Everyone danced |
|
| 18:13 | We had the chaperones had come They would separate us. You |
|
| 18:16 | they didn't like that. The whole close to each other to separate and |
|
| 18:20 | after they walked away, right back again. All right. So it |
|
| 18:24 | energy to keep those charges apart. is, here's our body, here's |
|
| 18:31 | platinum membrane. Here's are like, know, the electrical, electrically |
|
| 18:36 | You can count up all the charges both sides and you'll see the positives |
|
| 18:40 | negatives are equal. But what we here is we have charges that have |
|
| 18:45 | up and then we have charges that not paired up. And so what |
|
| 18:49 | is the ones that haven't paired up attracted to each other on either side |
|
| 18:53 | the membrane and they align themselves on side of the membrane. Now I |
|
| 18:57 | the really dumbest example. You ready the dumb example requires a little bit |
|
| 19:01 | knowledge of Houston. You guys know Lamar high school is. Okay, |
|
| 19:05 | is this school? That's right next tomorrow. High school ST jOHn's I |
|
| 19:09 | it All right there, side by . Lamar is a big old |
|
| 19:12 | A school ST john's is a big private school. All right. So |
|
| 19:17 | it's high school lunch. All At the high school lunch. You |
|
| 19:21 | imagine both schools, there are right? Cause it's high school and |
|
| 19:25 | these couples are giving each other google . They walk out of the building |
|
| 19:29 | lunchtime holding their sack lunches, google I. H. O. I |
|
| 19:32 | you. I love you too. they go and they sit down and |
|
| 19:35 | you have I'm sorry, the sad . Right? They're not paired |
|
| 19:41 | They walk out. It's like, , is me. I don't have |
|
| 19:44 | negative charge. And they walk And because both schools are side by |
|
| 19:48 | , they're separated by a little tiny ft chain link fence. And you |
|
| 19:53 | imagine the paired up stuff are out the out on the lawns, google |
|
| 19:56 | each other. And then the unpaid . They walk out and they stopped |
|
| 20:01 | they look and on the other side the fence is the opposite charge. |
|
| 20:07 | what do they do? They walked the fence and they stand and stare |
|
| 20:15 | the fence. You're Did I paint picture? Okay, good. |
|
| 20:21 | you now understand membrane potentials. In , what we have here is we |
|
| 20:28 | two charges on either side of that that attracted to each other that can't |
|
| 20:32 | anywhere. They can't get close to other because the membrane sits in the |
|
| 20:37 | it's doing the work of separation. right. So, there's potential energy |
|
| 20:43 | . All right. So all we do, let's go to the |
|
| 20:47 | Excuse me the fence open the gate that. And then the charges can |
|
| 20:54 | and give each other google's eyes not the fence. All right. And |
|
| 20:58 | potential energy turns into kinetic energy until reach equilibrium. All right. |
|
| 21:05 | that's what a membrane potential is. right. It's not a charge on |
|
| 21:09 | membrane. It's a charge near the . Its charges that are attracted to |
|
| 21:13 | other that can't reach each other. right. So, that's why it's |
|
| 21:17 | of hanging out there on the So, when you hear the word |
|
| 21:21 | potential, which is a scary word like if I don't know what the |
|
| 21:24 | mean, the potential refers to the energy. So, the membrane has |
|
| 21:28 | energy. It has potential to do and it's measurable, Alright. Measurable |
|
| 21:33 | volts. So, if you take probe and shove it into the cell |
|
| 21:37 | put the outside as the ground, can say what is the difference between |
|
| 21:41 | ground and the probe and it will you in volts how different the inside |
|
| 21:46 | the cell is versus the outside. , this isn't Mila volts not in |
|
| 21:50 | himself. So, it's very, small. So, it's the difference |
|
| 21:54 | charge between those two localized regions right either side of that memory that we're |
|
| 22:01 | at. All right now, there's both an electric There's what we refer |
|
| 22:08 | as an electrical chemical gradient here with to the membrane potential and what that |
|
| 22:13 | us is is that the ions that looking at are following the rules of |
|
| 22:18 | gradients, meaning that I only want move to an area of high |
|
| 22:22 | to an area of low concentration. all understand that one, right. |
|
| 22:26 | the electrical half of that is that follow the same kind of rules. |
|
| 22:31 | typically what we're going to see is the electrical gradient is opposite the chemical |
|
| 22:36 | for a particular ion. And there's point of equilibrium where the movement of |
|
| 22:41 | eye on down its concentration gradient will result in the pull back to the |
|
| 22:47 | direction along its electrical gradient. So to put it in english and |
|
| 22:51 | going to see this in just a is as a positive ion starts moving |
|
| 22:54 | this direction down its concentration gradient, leaving behind a negative charge. |
|
| 23:00 | as positive moves down, it's increasing over here. And then of |
|
| 23:05 | at some point that negative charge is to be as strong as the chemical |
|
| 23:10 | , which is going to draw the island back and then you're going to |
|
| 23:14 | that equilibrium down the the electrochemical gradient really what we're looking. So, |
|
| 23:21 | two things are in opposition. All . Now, you'll hear resting membrane |
|
| 23:27 | All cells are always if they're things are happening all right. But |
|
| 23:33 | we say is that arresting membrane potentials the cell is not just doing its |
|
| 23:38 | . It hasn't been stimulated to do . All right. So, every |
|
| 23:42 | has a resting membrane potential and this membrane potential is constant for that |
|
| 23:49 | What happens is is when we stimulate . That's when we create change and |
|
| 23:53 | can use that change in the membrane to do work. Which is what |
|
| 23:59 | potentials and greater potentials are. what do we have? What is |
|
| 24:06 | ? What are the people? Excuse ? The people the ions, not |
|
| 24:10 | students, the ions. What are ions that are giving goo goo eyes |
|
| 24:13 | each other? Really. That's what interested in. All right. |
|
| 24:17 | these are the big players. sodium , potassium, calcium, phosphate, |
|
| 24:21 | by carbon And the fun one. antibiotic cellular proteins. All right. |
|
| 24:28 | going to pause here and I on . What does that mean NATO charge |
|
| 24:33 | inside the cell proteins, proteins so charged cell proteins. So, don't |
|
| 24:40 | afraid of the big words. Just it down if you see it. |
|
| 24:42 | . So, it tells you we these proteins that are negatively charged inside |
|
| 24:46 | . So, these are all the players. But the ones who are |
|
| 24:49 | interested in are sodium potassium and the negatively charged proteins. All right |
|
| 24:57 | I'm going to show this down here we're going to come back and play |
|
| 25:00 | this a lot. But remember we've looked at this. We said look |
|
| 25:04 | of these pumps, we basically create imbalances between the ions and so, |
|
| 25:09 | you look at sodium for example, lots of sodium on the outside of |
|
| 25:13 | cell. Very little sodium on the of the cell. For potassium there's |
|
| 25:16 | little potassium. We've pumped a whole into the cell and then we haven't |
|
| 25:20 | talked about an ionic cellular proteins. because their cellular proteins, there's lots |
|
| 25:25 | the cell. There's very little if outside the cell. All right. |
|
| 25:31 | , these are kind of their their their values. In terms of their |
|
| 25:36 | Mueller or values, do you have memorize them? No, just lots |
|
| 25:42 | and lots. Depending on which side looking at. Just know where they're |
|
| 25:46 | . All right. So, what want to do is I want to |
|
| 25:49 | look at potassium and explain that So here we have a system where |
|
| 25:55 | put those that potassium and the antarctic proteins inside a fake cell we put |
|
| 26:01 | into a solution of sodium chloride. you look at the number of sodium |
|
| 26:04 | the number of chlorine. Is everything ? Well, I mean, is |
|
| 26:09 | positive and negative charges balanced? On the inside positive negative charge |
|
| 26:15 | So, we have an electrically neutral . We're all in agreement. |
|
| 26:19 | Okay, great. All we're doing looking at positive negative charges. |
|
| 26:22 | yes. All right. In terms chemical balance. Do we have chemical |
|
| 26:26 | . And I saw a lot of going when I was doing that. |
|
| 26:29 | , do we have chemical balance? , we have zero sodium On the |
|
| 26:34 | , we have zero potassium on the , right? zero chlorine, zero |
|
| 26:37 | accelerate protein. So, it's really of it's really out of balance when |
|
| 26:42 | comes to chemicals. All right. , what we're gonna do in our |
|
| 26:45 | situation, we're gonna put a potassium channel in place. All right. |
|
| 26:50 | , this is a great little model they're using a nice round number that |
|
| 26:53 | can divide in half. Four divided is 2. 2 divided by two |
|
| 26:59 | 1. So, see it works , really well. Alright, So |
|
| 27:03 | I am, I'm putting the potassium channel which only allows potassium. So |
|
| 27:09 | is going to move down its concentration out of the cell. Now, |
|
| 27:14 | things, if nothing else was how much potassium would move out of |
|
| 27:17 | cell to equilibrium? Two. You see that? All right, |
|
| 27:23 | We've all learned chemistry. Thank Dr Bean and all the other people |
|
| 27:29 | there that I don't know their Dr Larson maybe I don't know. |
|
| 27:35 | , the problem is, is that channel is only good for potassium. |
|
| 27:39 | , when potassium leaves it leaves behind negative charge, right? So, |
|
| 27:44 | gonna be a point where that negative becomes more attractive than that chemical gradient |
|
| 27:50 | . So there's gonna be a point a potassium leaves and says, well |
|
| 27:53 | is nice. But you know those charges in there? They're pretty |
|
| 27:57 | So I'm going to head on back and it's going to go back in |
|
| 28:01 | cell and go, you know, negative charges are nice. But that |
|
| 28:05 | grading out there, that's pretty And I'm going to come back out |
|
| 28:08 | then it's going to keep doing that and forth, back and forth. |
|
| 28:11 | that's when equilibrium has been met. loose. Yes, Could you |
|
| 28:22 | Right. So, the question is when you're saying a negative |
|
| 28:28 | are you saying it's just as the leaves? That's one less positive |
|
| 28:33 | So, yes, I mean, when we're talking about movement, we're |
|
| 28:37 | watching talking about the movement of a ion. And so the negative charge |
|
| 28:43 | is really on the proteins and this a terrible model because we don't really |
|
| 28:47 | how many, at least in our model here, how many negative ions |
|
| 28:52 | around. You need to balance scary. Looking back back, I |
|
| 28:56 | know how many positive violence you need balance out a negative protein because it |
|
| 29:00 | have multiple sites. Right? But really what it's in terms of |
|
| 29:05 | you know, it's basically equal liberated what we're saying. All right. |
|
| 29:11 | what we have is we have a moving outward, we have that electrical |
|
| 29:16 | moving inward and at some point where said where those two things reach equilibrium |
|
| 29:21 | when that potassium is basically dancing backwards forwards now, why do we have |
|
| 29:25 | negative charge on the inside the antibiotic proteins are stuck on the inside. |
|
| 29:29 | can't leave out that channel and they're too big to be moved anyway. |
|
| 29:34 | . So they serve kind of is negative charge on the inside? That |
|
| 29:38 | an attractive for any positive charge? right. So, the study wants |
|
| 29:42 | go in for two reasons, Why does so do you want to |
|
| 29:46 | with it? I said two reasons concentration and positive charge. It's like |
|
| 29:52 | attracted to that antibiotic cellular protein, I can't get in there because in |
|
| 29:56 | little model, we have no channel it to do so. Right. |
|
| 30:00 | , the only thing in this little that we're looking at is the movement |
|
| 30:03 | potassium. Now this movement where the out to the movement in is that |
|
| 30:11 | potential. So, remember that horrible thing you read way back a couple |
|
| 30:16 | ago about the nearest equation and it like blah blah blah blah math, |
|
| 30:20 | blah blah blah blah more math. extra math. And by the |
|
| 30:23 | let me read it derive the So that was confusing. And you |
|
| 30:26 | to account to God in a fetal . Got into the pillows. Just |
|
| 30:30 | of rocked a little bit right? I said, you don't have to |
|
| 30:33 | this, right? That's what the equation does it calculates out that equilibrium |
|
| 30:39 | . So, we could figure out what point does potassium stop moving? |
|
| 30:47 | know, there's there's no net No net diffusion. All right. |
|
| 30:51 | the nerds to equation, that's the potential. We could do the same |
|
| 30:56 | for or for sodium. Alright, sodium channels, sodium moves in. |
|
| 31:01 | will keep moving in until it reaches equilibrium potential. The point when the |
|
| 31:06 | that that it's carrying with it is attracted back out to where the chlorine |
|
| 31:11 | left behind. So, that value to be if we calculated out 60 |
|
| 31:16 | bowls, do you have to memorize ? No? Is it helpful to |
|
| 31:19 | it? Yes. I'm not going ask him on the test. All |
|
| 31:23 | . Now, why is it helpful know? We'll see here in just |
|
| 31:26 | second. The other slide didn't tell what potassium is was but I'll get |
|
| 31:30 | in a second. Yes, mm. Heard. Yes. |
|
| 31:37 | not yet. We're not. We gotten to the work part yet, |
|
| 31:40 | all we're trying to do is try understand why the ions are moving. |
|
| 31:44 | , there's a chemical gradient there's an gradient. All right. Now, |
|
| 31:48 | time one of those sodium was one those potassium moves, right, you're |
|
| 31:52 | creating problems because both of them are simultaneously. Right? And so what's |
|
| 31:57 | is it's like wait, wait, , wait. You just moved |
|
| 32:00 | You know, I put you in inside the cell, potassium I want |
|
| 32:04 | inside the cell. But you just out and sodium you just moved in |
|
| 32:08 | I put you just outside. So , we're not gonna have any of |
|
| 32:11 | . We're going to go grab you we're gonna put you right back where |
|
| 32:13 | started. And this is what that potassium at pes pump. Does It |
|
| 32:17 | for roughly 20% of that membrane If we go and measure that |
|
| 32:23 | that's going to be about 20% of is accounted for by that pump. |
|
| 32:27 | really what we're doing is we're saying without that pump, if you look |
|
| 32:31 | sodium and its movement, potassium and movement, all those other molecules or |
|
| 32:34 | other items in their movement, eventually sort of equilibrium would come along. |
|
| 32:40 | . And what's happening is we're keeping movement going by constantly moving things back |
|
| 32:45 | where they started. That's what the doesn't creates the potential energy and ultimately |
|
| 32:52 | kinetic energy because it's constantly moving to that we have the membrane potential at |
|
| 32:58 | certain value. Alright, notice. haven't talked about value yet. We |
|
| 33:03 | said how that we got that That's what the next step is echoing |
|
| 33:11 | . I like this microphone right All right. Yeah. Back to |
|
| 33:18 | little chart notice, I'm not even the stuff that I pointed out earlier |
|
| 33:22 | here. We have a little thing our chart that says relative permeability and |
|
| 33:27 | relative permeability basically says is the relative of channels for sodium and potassium and |
|
| 33:35 | for the antarctic cellular proteins, there's ever channels for an ionic cellular protein |
|
| 33:39 | they're big channels are small, right wise for everyone. sodium channel, |
|
| 33:46 | have roughly 50-75 potassium channels. All back to the storytelling, back to |
|
| 33:52 | things in perspective for you have all to a football game or any other |
|
| 33:55 | of sporting event. Yes, halftime comes along, everyone gets |
|
| 33:59 | goes to the bathroom, guys, at the guys, How long does |
|
| 34:02 | take us to go to the bathroom that ladies? How long does it |
|
| 34:06 | you to go to the bathroom? you'll get back around the fourth |
|
| 34:10 | Right, right. You've got massive why its permeability issues. All |
|
| 34:17 | I'm gonna give away secrets today. apologize. Ladies guys, P and |
|
| 34:25 | . Right, guys are looking at like what you know what I'm talking |
|
| 34:29 | , talking about the trough, Where we go in there and it's |
|
| 34:31 | that big old thing, that big metal thanks to the guys are |
|
| 34:34 | I can't believe you're talking about Right? We walk in there, |
|
| 34:38 | walk, we never look at each throats, walks. All right, |
|
| 34:42 | we go and we're basically shoulders shoulder we do our business and they were |
|
| 34:47 | , And then you're out. ladies, you have stalls, you |
|
| 34:51 | people who do your nails and You know, it takes forever. |
|
| 34:56 | know it's a different game. But if a men's restroom was like a |
|
| 35:00 | restroom where you have 10 stalls vs . Trust where you can put 40 |
|
| 35:05 | shoulder to shoulder, not stare at other. Right. You would go |
|
| 35:08 | lot quicker. You're just officer Thank God I'm a woman. All |
|
| 35:14 | . All right. So that's a permeability issue. Right. It's a |
|
| 35:19 | showing. And so what's happening here we say, look, The uh |
|
| 35:26 | equilibrium potential for potassium based on those . We can calculate it out and |
|
| 35:31 | comes out to about -90 million That's when potassium stops moving or there's |
|
| 35:37 | net diffusion. I've got to be of what I'm saying here for |
|
| 35:41 | We can look out. We can that about 60 million volts. And |
|
| 35:44 | we go and look at a real cell that has leaked channels in it |
|
| 35:49 | those ratios, then what we can is the one with the most leak |
|
| 35:53 | can probably have the greater effect on membrane potential. Would you agree? |
|
| 35:59 | , if if if there was just if we can find with leak |
|
| 36:04 | we can find that equilibrium. And we um uh, have more of |
|
| 36:10 | channels relative to this one over then we're basically this one is going |
|
| 36:14 | have a greater effect on what that is ultimately going to be. Does |
|
| 36:19 | kind of makes sense? Right. so that's what's going on. So |
|
| 36:25 | greater permeability for soda or for potassium a larger effect. So that your |
|
| 36:31 | have a membrane potential that looks a like that, -90 more so than |
|
| 36:37 | plus 60. So, if you at it together and this is just |
|
| 36:41 | of painting the picture, right, got lots of potassium inside the cell |
|
| 36:46 | lots of channels for it to leak . So, when potassium leaks |
|
| 36:50 | it's trying to reach -90, We a couple of channels for sodium, |
|
| 36:56 | is leaking in. It's trying to the cell up to plus 60, |
|
| 37:00 | because there's only one channel for every of those, it barely has an |
|
| 37:05 | . It has enough of an effect it drags away from -90. But |
|
| 37:09 | essence because we never reached -19 because never reached plus 60, we have |
|
| 37:14 | flow. So, the cell is constant flux and constant flow. It |
|
| 37:19 | to reach that equilibrium for either Right? And it never can. |
|
| 37:26 | because it never can. That means potential energy that can be used and |
|
| 37:31 | very easily is what we're trying to out. So, for a neuron |
|
| 37:40 | membrane potential is -70 at rest. right. And it's just sitting there |
|
| 37:47 | for something to stimulate it so that can get greater flow so that you |
|
| 37:53 | have work done now to be careful , what we're doing is everything is |
|
| 37:57 | potential because you got potassium trying to out, you got sodium trying to |
|
| 38:00 | in. But if I open I'm gonna have movement or flow and |
|
| 38:05 | going to cause change, that's going be that voltage change that we're going |
|
| 38:09 | use to do stuff with. do that kind of makes sense. |
|
| 38:14 | of sort of over here, kind sort of you ready for me to |
|
| 38:18 | the broader picture sort of nodding of . All right. So where we're |
|
| 38:27 | to do is we're going to pause here. We understand membrane potentials sort |
|
| 38:33 | right. We need to then understand the nervous system is, what we're |
|
| 38:36 | with and then we'll come back and gonna deal with greater potential and action |
|
| 38:40 | . So we can see why this . Okay. And where I |
|
| 38:45 | it's gonna be jumping around a All right. All right. This |
|
| 38:48 | the big picture of the summary. , there's a lot of stuff from |
|
| 38:51 | textbook there, blah, blah, blah. Positive changes in membrane |
|
| 38:56 | That's the abbreviation for membrane potential. . It's basically the difference between the |
|
| 39:01 | the inside the outside, right? a steady state. Um depending upon |
|
| 39:06 | permeability changes in the positive direction, going from negative towards zero is gonna |
|
| 39:13 | a deep polarization. That's an inward of cat ions. Negative change is |
|
| 39:19 | we call the hyper polarization. That's outward flow. And just so that |
|
| 39:22 | have our language Easy to understand. guys remember number lines back in 3rd |
|
| 39:29 | . All right. Those of you . This was that number line. |
|
| 39:35 | , Fideldle. zero in the All right. I'm just gonna use |
|
| 39:39 | terminology here. So we better understand . When you're at zero, you're |
|
| 39:43 | neutral. Eight point beyond zero is polarized. Doesn't matter which direction you |
|
| 39:50 | . This is a negative direction. is the positive direction. Right? |
|
| 39:55 | , looking at me this is the direction is positive direction. Right |
|
| 39:58 | If I'm sitting on zero, that's . If I step away over |
|
| 40:02 | I'm polarized right in the negative If I step away over here, |
|
| 40:09 | polarized, right? Because I'm not zero. Right? If this is |
|
| 40:14 | . If I step right here I'm not on zero so far. |
|
| 40:19 | good. All right. So, polarized myself way over here in the |
|
| 40:23 | direction. Right? If I move towards zero I'm becoming less polarized than |
|
| 40:30 | was before. So, I'm d . If I returned back to my |
|
| 40:37 | position, I'm re polarizing. And if I moved further away from |
|
| 40:43 | I'm more polar than I was when began. So I'm hyper polarized. |
|
| 40:48 | ? So polarized is a state other zero. And I use that as |
|
| 40:53 | frame of reference. All right. that's what that term is. |
|
| 40:57 | I'm going more sorry, more or polarized over here in the negative deep |
|
| 41:05 | , remember is in a positive It's towards zero. If I'm over |
|
| 41:11 | in the positive side, it's Right? Because we're zero. It's |
|
| 41:16 | there. So, if I'm d , I'm moving towards zero. If |
|
| 41:21 | becoming more polarized, I'm moving away zero. So, that's why we |
|
| 41:27 | those particular terms. All right, , we're going to see in a |
|
| 41:31 | bit that I'm gonna start down here the negative. I'm gonna move toward |
|
| 41:37 | . That would be deep polarized. I keep moving beyond zero. I |
|
| 41:43 | change the name. It's still deep . And then when I turn back |
|
| 41:48 | go back to where I started, still re polarization. Alright. So |
|
| 41:53 | though I've crossed the zero line, not extra polarizing or hyper polarizing to |
|
| 41:59 | moon in the other direction. It's that initial movement. All right. |
|
| 42:03 | , I throw that in there because can be a little confusing. All |
|
| 42:07 | . In terms of the language. , we can move on and deal |
|
| 42:11 | little bit with some anatomy here. right. The nervous system. His |
|
| 42:20 | and scary if you like it we whole classes that you get to go |
|
| 42:25 | to learn about the nervous system. . And it is it's probably the |
|
| 42:29 | complex of all the systems. We understand a lot of it. But |
|
| 42:34 | what we have is we have to types of cells. All right. |
|
| 42:38 | again, this is a simplified kindergarten . Just go with it. We |
|
| 42:43 | neurons. Neurons produce electrical signals that then use along their lengths to actually |
|
| 42:53 | the release of a chemical signal to with cells next to it. All |
|
| 42:58 | . So, in a perricone that's in essence what they do. |
|
| 43:01 | distances that were using the electoral signals very long. So, for |
|
| 43:06 | I can produce an action potential in axon. All right. This is |
|
| 43:09 | electrical potential in my spinal cord that travel down the length of my |
|
| 43:13 | down to my big toe. So can wiggle it. All right. |
|
| 43:17 | a pretty long cell. All And so that's when we're talking long |
|
| 43:21 | . That would be an example of long distance. Does it have to |
|
| 43:23 | that long? No, I neurons can also be very, very |
|
| 43:27 | and they communicate to each other very close. Right. But the |
|
| 43:31 | is that using electrical potentials to travel distances, it's much more efficient than |
|
| 43:37 | a chemical. All right. you can have an electrical signaling. |
|
| 43:42 | , most of that. I just their results in the release of a |
|
| 43:45 | signal that communicates to the next Which would be that paragraph type of |
|
| 43:49 | . We refer to those chemicals as . But there are some cells that |
|
| 43:55 | connected to each other and they use gap junctions and thus electrical signalling. |
|
| 43:59 | right. So you can have an signal that's generated one cell that continues |
|
| 44:04 | the next cell, into the next , Into the next cell through those |
|
| 44:07 | junctions. The other type of seller cells. Glial cells are support |
|
| 44:14 | The word glial literally means glue. it's the glue cells that hold the |
|
| 44:19 | together. Okay, They don't directly in electrical transmission. They support the |
|
| 44:27 | and they outnumber neurons roughly. 10 what? So, if you know |
|
| 44:30 | football, how many people are on side? I'm looking at some of |
|
| 44:35 | here who should be able to blurt answer out right away. How many |
|
| 44:38 | are on the side? It's the sport. Come on guys. How |
|
| 44:45 | people on the baseball side? Thank you. Right. I mean |
|
| 44:50 | a soccer side there, I'll hit . Hit that note. 11. |
|
| 44:55 | American football, rugby and soccer all all sourced from the exact same |
|
| 45:00 | It's 11. How many quarterbacks? have an aside one? All |
|
| 45:07 | Only one quarterback on the team. many other players then are on the |
|
| 45:10 | with that one quarterback? 10. the neurons are like the quarterbacks of |
|
| 45:16 | nervous system and the glial cells are the rest of the team. |
|
| 45:20 | we look at the quarterback and we and on were so impressed by accepting |
|
| 45:24 | three interceptions in one game that we winning handily I might add, |
|
| 45:33 | I'm very upset by this weekend time . What is my college? Where |
|
| 45:39 | I go to school? And 2-2 play this week? Anyone now they |
|
| 45:43 | Oklahoma. Ou number two in the . They were getting their butts handed |
|
| 45:48 | him two lane was getting their butts to him in third quarter, two |
|
| 45:50 | came back and was a touchdown a of winning. But they came one |
|
| 45:55 | shy of 1/4 down conversion. So lost. And so when you're already |
|
| 46:01 | for them to lose, it's it's no big deal. But then |
|
| 46:04 | you're like in the last minute of game and you're sitting there, you're |
|
| 46:06 | win, they're gonna win. And they don't, then it's really, |
|
| 46:09 | upsetting. Right? So I'm still grudges and I'm like, oh, |
|
| 46:15 | for lots of reasons. All So I use this example because neurons |
|
| 46:21 | like quarterbacks and they look really, good because all the glial cells are |
|
| 46:26 | them, making them do stuff or them do stuff quarterback can't look |
|
| 46:31 | If the receiver can't catch the quarterback is going to be tackled. |
|
| 46:35 | there's not a line to block for , that makes sense. So that's |
|
| 46:39 | same sort of thing here. So and glial cells now there's an organization |
|
| 46:44 | when I say organization, this doesn't the bodies organized this way. It |
|
| 46:47 | humans look at this system and how can I system? Eyes? |
|
| 46:52 | structure for me to understand it Okay, so there's a lot of |
|
| 46:57 | of the lines here, but there's very simple stuff. All right. |
|
| 47:01 | have two parts. We have a nervous system and the peripheral nervous |
|
| 47:05 | Looking at our bodies here, ignoring red line which is your outlined. |
|
| 47:09 | two systems are the brain and the cord in yellow. That is central |
|
| 47:13 | system. Everything else is blue. peripheral nervous system. Alright. The |
|
| 47:19 | nervous system. Are your nerves? right. You do not have nerves |
|
| 47:24 | the central nervous system. All You might want to put a little |
|
| 47:28 | by that because that's one of I better know the terminology here because |
|
| 47:32 | one might appear on the exam, if you're in my ap class because |
|
| 47:35 | don't listen. Alright, neurons and are two different things. So nerves |
|
| 47:41 | part of the peripheral nervous system. right. They are not part of |
|
| 47:45 | central nervous system. So, if say, where is the optic nerve |
|
| 47:49 | ? Central? Peripheral, The answer always peripheral. If you have the |
|
| 47:52 | nerve in it, it's peripheral. right. The peripheral nervous system is |
|
| 47:57 | information that goes in or comes out the central nervous system. That's why |
|
| 48:01 | nerves the nerves are carrying information to carrying an information away from the central |
|
| 48:07 | system. So spinal cord makes The brain makes decisions. All |
|
| 48:13 | It's a processing, But everything else going in or coming out. And |
|
| 48:17 | , what we do is we can the the in and out first. |
|
| 48:22 | in I'm gonna I'm gonna put a strong accent on these things. So |
|
| 48:25 | can hear it is the a Farrant that's information going in is a |
|
| 48:30 | Alright, information coming out is a . All right. If you are |
|
| 48:35 | other parts of the country where they put the air on everything, |
|
| 48:39 | Then, they're going to say efforts different. Which is very confusing. |
|
| 48:45 | ? So, a parent and eat . All right. Not a different |
|
| 48:49 | different. Which is uh frustrating. right. The somatic division is part |
|
| 48:56 | both the parent and the parent. the motor neurons. They're the things |
|
| 49:01 | let your body move around. So, skeletal muscles. Soma |
|
| 49:06 | So, when you hear somatic think , okay, autonomic is not |
|
| 49:15 | People think that they hear it. go, oh, it must be |
|
| 49:18 | autonomic. These are the neurons innovate glands are smooth muscle, your cardiac |
|
| 49:23 | , not the third. Now, muscle. Right? So, here |
|
| 49:28 | are not in control of these All right. So, they're often |
|
| 49:33 | Mickley controlled. Which is not the thing as automatically, or even |
|
| 49:41 | I like auto magic. It's much . It's like voodoo is like the |
|
| 49:45 | starts it's automatic. All right. we have a division again, which |
|
| 49:50 | sympathetic and parasympathetic. And we'll get those a little bit later. But |
|
| 49:53 | I'm pointing out here in all this from peripheral versus central, all of |
|
| 49:58 | little different subdivisions and stuff just makes easier to put things in a |
|
| 50:02 | Do you like to put things in ? Yeah, we all do. |
|
| 50:08 | . You pulled up a shirt. this a colored shirt Or is an |
|
| 50:12 | shirt? Right. It goes in category. We like to have stuff |
|
| 50:16 | that. And that's what the first neurologist were doing. Was there putting |
|
| 50:21 | in categories so that they could better what was going on. Now. |
|
| 50:24 | right here is a neuron. All . This is a simple simplified |
|
| 50:29 | Here's a cell body. Sometimes called Soma. Alright. Sometimes called the |
|
| 50:34 | carry on. It contains the This is where all of them cellular |
|
| 50:38 | is around the end. We have . Sorry, one. I'll start |
|
| 50:44 | again. 1234567 extensions. All Typically any extension off the soma is |
|
| 50:52 | a dendrite, but we have one . That's a special dendrite. All |
|
| 50:56 | . We call it the axon. axon is the sending dendrite. All |
|
| 51:01 | other dendrites are receiving dendrites. All . So, we call them the |
|
| 51:05 | . We call the acts on the . That was not very helpful. |
|
| 51:10 | call the sending dendrite and axon. call the other ones just dendrites |
|
| 51:15 | How is that? A little bit ? All right, now, I |
|
| 51:18 | this little information here. So, happens? And when this receives a |
|
| 51:22 | , it's going to produce a greater . You're like, I don't know |
|
| 51:26 | greater potential is that's okay. In , I'm going to get to in |
|
| 51:29 | next 30 minutes because we're running out time and I'm starting to drag |
|
| 51:35 | an axon starts here. What is the axon hillock. This is where |
|
| 51:39 | produce action potentials. All right. then that action potential is going to |
|
| 51:45 | along the length of the axon down the axon terminal where it releases a |
|
| 51:49 | to stimulate the next cell produce the great potential in the next cell so |
|
| 51:54 | you can hopefully produce next potential repeat. This is how the cells |
|
| 51:57 | talking and relaying a message from one of the next down the line. |
|
| 52:03 | right, So sell body dendrite axon terminal axon hillock. These are just |
|
| 52:09 | of the cell that you should be of. Now, in order for |
|
| 52:12 | to produce chemicals or release chemicals. have to first get the chemicals down |
|
| 52:16 | the acts on terminal. Remember the bodies where all the organelles are. |
|
| 52:21 | so we have to do is we to make the signal and transport the |
|
| 52:25 | and vesicles down to the very acts terminal, very end of that long |
|
| 52:30 | . And so what we use is use axon or toxoplasma transport. We |
|
| 52:35 | anterograde anterograde is when I'm moving towards axon terminal retrograde is not putting on |
|
| 52:42 | fifties dress and saying, look, from the fifties, retrograde is moving |
|
| 52:46 | the opposite direction. That didn't make lot of sense. The 50s |
|
| 52:51 | But I was picturing someone in a dress because that's right. True Actually |
|
| 52:57 | you guys retro is the 70s. huh. Yeah. Retro 70s. |
|
| 53:04 | . I'm actually watching many of you walking around wearing t shirts that I |
|
| 53:08 | when I was in high school. . My favorite ones when I see |
|
| 53:13 | people were in the led Zeppelin zz stuff. It's like, you don't |
|
| 53:16 | that band. Uh huh. They I don't know I listen to |
|
| 53:22 | My parents left listen to. So knows. All right, neurons are |
|
| 53:27 | by structure. So what you can is you can first look at the |
|
| 53:31 | . He didn't count them. Here's act or here's your cytoplasm, your |
|
| 53:35 | , your your cell body and you go around and say how many dendrites |
|
| 53:39 | I count off that, how many to account there one. So that |
|
| 53:43 | what is called a unit polar neuron has one. Dendrite. But wait |
|
| 53:48 | second. Don't you ever receiving a a sending end. Yes, it's |
|
| 53:52 | unique one. It's actually not truly the unit polar anymore. It's called |
|
| 53:56 | pseudo uni Polar. And basically you a sending in and the receiving |
|
| 54:02 | We don't need to worry about that yet. All right Here this is |
|
| 54:06 | because you have 1-2. And then two it's like we don't care. |
|
| 54:11 | just lots. So it's multi All right, so 1, 2 |
|
| 54:17 | lots. Okay, another thing you do is you can look in terms |
|
| 54:22 | the actual uh let's see what am trying to do here? Oh this |
|
| 54:27 | just structure. So it's just trying show you different types. So with |
|
| 54:30 | to the bipolar for example, there's a lot of these in the |
|
| 54:34 | There's only really two bipolar cells that really kind of spent a lot of |
|
| 54:38 | talking about and they both happen to um located in the special senses and |
|
| 54:47 | both have the name bipolar selling So they're really easy to identify. |
|
| 54:51 | right. But basically what they're doing basically sitting for one signal and they're |
|
| 54:54 | of serving as an intermediate intermediary between other cells. Uh These right here |
|
| 55:00 | super unit polar, basically what you're is you're receiving on one end and |
|
| 55:05 | that signal travels along the length of Axiron is really what it's called. |
|
| 55:11 | it just it completely bypasses that cell . Most of the cells we're gonna |
|
| 55:16 | looking at are going to follow this here which is that pyramidal cell and |
|
| 55:20 | called pyramidal cell because the shape of pair of carrion. But in essence |
|
| 55:24 | it is is basically here the It receives a signal here and then |
|
| 55:28 | out the axon and then this one , what do you think it's |
|
| 55:32 | estelle? It I heard it. Stella star right now. The cartoon |
|
| 55:39 | like a star fish, but it's same principles. Just lots of |
|
| 55:44 | Do you see an accent in this one? Do they want any of |
|
| 55:48 | branches stand out as an ax I'm just a simple yes or |
|
| 55:54 | no. Okay. And the answer that's correct. These are cells that |
|
| 55:58 | find in large networks and so basically can signal in any direction. So |
|
| 56:03 | any particular one stands out as an on Yeah, signals. So, |
|
| 56:12 | think I understand what you're asking. question is, what, what type |
|
| 56:15 | signal is being produced by the Alright, so that's gonna be what |
|
| 56:19 | an action potential. All right. it has a unique characteristic which we're |
|
| 56:24 | to look at here. Hopefully in next 24 minutes we'll see. And |
|
| 56:29 | with the great potentials there, the that you produce greater potential is slightly |
|
| 56:33 | . So let me kind of get it. And if I didn't answer |
|
| 56:35 | question, you didn't answer my You suck. And then we can |
|
| 56:38 | to go from there. Alright. now we're dealing with modality modality just |
|
| 56:43 | is a term that says what type information is it conveying? And so |
|
| 56:47 | ask the question, is it sending to or is it from? |
|
| 56:50 | So if you're sitting information towards the nervous system, you're considering a parent |
|
| 56:55 | a sensory neuron. If you're sending away from the nervous system right? |
|
| 57:01 | are a motor neuron. You're trying tell something to do something. That's |
|
| 57:05 | the seafaring. Alright. Are you it to the body proper? In |
|
| 57:10 | words like you know the skin or muscles? And it's a somatic |
|
| 57:14 | If you're sending it to the viscera the guts, the internal organs, |
|
| 57:19 | considered a visceral neuron. So do think from your stomach? Do you |
|
| 57:24 | you have neurons that travel from your to your central nervous system june |
|
| 57:30 | Yes. If you're traveling to the from the central nervous system to your |
|
| 57:35 | . Can you be in different or affair in which one would you be |
|
| 57:40 | ? Right. So you can be visceral different. You can be a |
|
| 57:44 | a Farrant, you can be a difference. You can be a somatic |
|
| 57:48 | fair notice that each of these things now have four neurons that we've just |
|
| 57:51 | about. Right? And then the weird ones. You can be a |
|
| 57:56 | neuron or you can be a general we never say something is general. |
|
| 57:59 | have to just say you're special. right. We don't just say, |
|
| 58:02 | everyone you're all generals but you're You just point to the special person |
|
| 58:08 | spoke to the special neurons. So are eight types of neurons. So |
|
| 58:13 | can be a special somatic, a or a special visceral. You can |
|
| 58:18 | where I'm going with all this. ? So it's just those different combinations |
|
| 58:23 | regard to glial cells. Remember we they don't conduct nerve impulses. Their |
|
| 58:27 | is to communicate with the nerve or the neurons and the other glial cells |
|
| 58:32 | ensure that the environment for that neuron . So it's kind of the connective |
|
| 58:37 | of the nervous tissue. Alright. of. It's not an actual connective |
|
| 58:41 | . Their job is to maintain the cellular environment. There are four types |
|
| 58:46 | glial cells that are found in the nervous system. There are two that |
|
| 58:50 | focused here in the periphery. Oh , I just said that. |
|
| 58:56 | so again, what do I tell about biologist? We name things for |
|
| 59:02 | they do or what they look Astrocytes. Why are they called |
|
| 59:07 | They look like stars. You know were discovered in Houston? I'm |
|
| 59:10 | I'm kidding. You're you're right, right. I'm just making stuff up |
|
| 59:15 | now. Yeah. But I just that. It's it's it's a fun |
|
| 59:17 | at two o'clock in the afternoon All . Danger sites. This is for |
|
| 59:22 | they look like again. What does go mean many din dro extensions or |
|
| 59:30 | that's why it's called. They're really branches. It's a tree branch. |
|
| 59:34 | ? So many tree branch cell. . So it has lots of |
|
| 59:38 | Micro glia glial self. So it's pronounced micro glia. Because you know |
|
| 59:46 | not make it confusing but micro you be nice to see if it's |
|
| 59:55 | to sleep you knew. Mhm. my computer. All right. And |
|
| 60:02 | the last one happened. Donald said don't know what happened. Email comes |
|
| 60:04 | but it's a different Schwann cells named the person who discovered it. And |
|
| 60:08 | satellite cell basically it surrounds the other . All right now, in terms |
|
| 60:15 | their functionality, I'm just gonna just through them really briefly. So astrocytes |
|
| 60:20 | the neurons. They basically are the and chemical support system. So they |
|
| 60:24 | the nutrients of cell. Once glucose has to pass first through an astro |
|
| 60:29 | to get there and it gets So they're actually getting lactate. They're |
|
| 60:33 | actually getting glucose. Alright, They potassium levels so they monitor the surrounding |
|
| 60:39 | and they also help synthesize synthesize uh usually in the process of breaking |
|
| 60:45 | But they allow for materials to get the neurons helps form the blood brain |
|
| 60:50 | and acts like neural scar tissue. thought I said car tissue up there |
|
| 60:55 | got real nervous. I had a once came to me and said, |
|
| 60:58 | Doctor Wayne when I was a Someone hit me with a pickax right |
|
| 61:01 | . What happened? I'm just I don't know man. That's that's |
|
| 61:06 | stuff. And I said, what is is that when you damage those |
|
| 61:11 | , the neurons that died there replaced scar tissue? All right. And |
|
| 61:16 | scar tissue are glial cells like astro they fill in that space and then |
|
| 61:20 | neurons work around that space to do job. You know? So, |
|
| 61:26 | would be an example of the scar . Just like, I don't know |
|
| 61:29 | you can see a horrible scar here my chin. Why not just All |
|
| 61:34 | . So, there's two different types myelin producing cells, Myelin helps speed |
|
| 61:38 | transmission of action potentials. So in central nervous system we have the logo |
|
| 61:43 | site. So there is the actual body. There's 123 extensions in our |
|
| 61:46 | cartoon here. What it's doing is out and then it wraps itself around |
|
| 61:51 | axon and basically serves as a barrier that acts on and the surrounding |
|
| 61:57 | So action potentials are going to move the barrier is going to jump over |
|
| 62:03 | barrier Schwann cells. It's individual cells the same thing. These are the |
|
| 62:08 | sheets. So, if you've heard island sheets, that's what they're |
|
| 62:11 | They're forming Myelin sheaths. We can many axons or doing one acts on |
|
| 62:18 | cell does one x on microglia. is a really cool immune defense |
|
| 62:24 | All right. So basically sits around does nothing. Just kind of hangs |
|
| 62:28 | . But if you get an infection the beyond the blood brain barrier you |
|
| 62:33 | these things and they act like That's not all they do. But |
|
| 62:36 | like the big one. Um it that they serve kind of as stem |
|
| 62:41 | to for the other cells. But not 100% certain. Now jumping |
|
| 62:48 | remember I said we're pausing and then jumping and pausing. So now we |
|
| 62:51 | what we're talking about. We're talking neurons. We kind of have a |
|
| 62:54 | of what they look like. All . And for the next 17 minutes |
|
| 62:59 | we're gonna do is we're gonna try deal with the question of great in |
|
| 63:02 | potentials. So, in order for eye on to get past this lipid |
|
| 63:06 | layer, it's remember it's water it has to have some sort of |
|
| 63:10 | because it can't pass through this. channels are what allow for honest to |
|
| 63:15 | back and forth. All right. we need to understand that one concept |
|
| 63:18 | understand greater potential in action and action . An action potential is a very |
|
| 63:25 | very large very rapid change in the potential. So remember we said we |
|
| 63:30 | a resting membrane potential. All where we're just kind of sitting there |
|
| 63:34 | nothing and we put probe in and can measure and say, oh, |
|
| 63:38 | difference from the inside of the outside this? So we're saying minus |
|
| 63:42 | Were saying the inside the cell is million volts less than the outside. |
|
| 63:46 | what that minus 70 means. And , what happens is when an action |
|
| 63:50 | occurs, What we're doing is we're up channels, changing permeability and we're |
|
| 63:56 | ions to move so that the inside the cell is no longer negative. |
|
| 64:00 | very positive. Okay, so, a very rapid climb. It's 100 |
|
| 64:07 | change, Right? And then it off, and then we returned back |
|
| 64:12 | our original starting point. Now, you look at this, what I |
|
| 64:16 | to understand, we're looking at a point. All right. It's like |
|
| 64:20 | at her while we're asking the what's going on in the rest of |
|
| 64:24 | classroom. All right. So, only looking at what this one student |
|
| 64:28 | doing when we're looking at one of charts and we're looking at the chart |
|
| 64:32 | time. So, down here, is time that's millennials. So when |
|
| 64:37 | action potential is formed, it moves what is called a non detrimental |
|
| 64:43 | What that means is is once you one, it's always a strong for |
|
| 64:47 | entire time that it exists. All . And really what it is, |
|
| 64:52 | a wave of ions moving in and of the cell? All right. |
|
| 64:57 | , what it looks like it looks the wave. Have you ever done |
|
| 64:59 | wave? We're gonna wake him up the other end already, we're gonna |
|
| 65:03 | the way we're gonna start over You guys got to do the |
|
| 65:06 | All right. Ready? You don't to stand up. Just do the |
|
| 65:10 | . Yeah. It just went right them. We're gonna do it |
|
| 65:14 | Ready. We're gonna be more excited it because have you ever done the |
|
| 65:17 | in the class? No. So be excited about it. Wait, |
|
| 65:24 | , now, I'm going to ask question right over here. How did |
|
| 65:26 | guys know to raise your hands? watched over there? So your responsiveness |
|
| 65:33 | dependent upon the people in front of which is dependent on people in front |
|
| 65:36 | you and so on and so I served as a stimulus. |
|
| 65:41 | And so we're going to do the but because they're the splash zone, |
|
| 65:45 | going to stare at her. Everyone her as we all do the |
|
| 65:49 | Okay. Yes, you gotta do . Right. All right. |
|
| 65:54 | we're gonna do the wave ready? we go. We're watching her. |
|
| 65:58 | right. Now notice when she did wave where did her hands start down |
|
| 66:03 | ? Someplace right, okay. When wave came by her, what did |
|
| 66:07 | do? She lifted her hands They reached a peak and then they |
|
| 66:11 | right back down. Right. So you all do that? Yes, |
|
| 66:17 | if we were charting her and just because she's this is where the probe |
|
| 66:22 | . That's what it looked like. see that. So this is just |
|
| 66:26 | wave at a single point overtime. we're asking what's happening even though what |
|
| 66:32 | saw was this flow, this detrimental . Now if you've ever been to |
|
| 66:35 | sporting bit where they've done the it literally, I was at a |
|
| 66:39 | bowl one year uh Ohio state taxation my wife is an Aggie is the |
|
| 66:44 | that to line went undefeated 1998. forget it. We went to the |
|
| 66:49 | Bowl in New Orleans instead of going the Liberty Bowl where Tulane went undefeated |
|
| 66:55 | saying the sugar bowl to watch texas and M lose pathetically to Ohio State's |
|
| 67:05 | . They had the wave going on bottom deck, on the top deck |
|
| 67:11 | in the middle deck and then on top of it they have nothing else |
|
| 67:15 | do because checks anyone playing football, ? It was awesome. It was |
|
| 67:23 | , you know, it just kept and going and going. Right, |
|
| 67:28 | an action potential once it started, an all or none response. |
|
| 67:34 | You either get an action potential or don't. This is where I upset |
|
| 67:38 | people in the classroom. It's like people are pausing now going what? |
|
| 67:43 | like virginity. You either are or aren't. There's no gray area. |
|
| 67:52 | . Thank you. You guys make day. Really? This is the |
|
| 67:56 | of the day, I'm tired and guys are laughing at my dumb |
|
| 67:59 | I love it. All right. great potential on the other hand, |
|
| 68:03 | very different. A greater potential has strengths or varying magnitudes depending upon the |
|
| 68:10 | of stimulus that you're looking at Again, you can stick a probe |
|
| 68:13 | really what you're doing is you're measuring a single point. So if you |
|
| 68:17 | in a very, very small you're going to get a very small |
|
| 68:19 | . If you stimulate a little bit , you get a stronger response. |
|
| 68:22 | you get even stronger you get a one. And the other thing is |
|
| 68:25 | you also duration is dependent upon stimulus as well. So the longer you |
|
| 68:31 | , the longer the greater potential is to be. So, what we |
|
| 68:34 | here is something that's not in all non response. What we have here |
|
| 68:38 | something that has varying magnitudes and durations upon the magnitude the duration of the |
|
| 68:43 | . All right. And that's where these little color lines represent is |
|
| 68:46 | look here at the brown line. they're basically saying here's a weak |
|
| 68:51 | So you get a weak response. a stronger stimulation, you get a |
|
| 68:55 | response. They're not showing duration, you could do the same thing if |
|
| 68:58 | went out this direction. All So the magnitude is equal to the |
|
| 69:02 | duration is equal to duration is really we're going out here? All |
|
| 69:05 | So, the longer duration longer the potential. All right. Now, |
|
| 69:11 | potentials are kind of like because what doing is we're opening up a |
|
| 69:15 | we're allowing ions to flow through. kind of like throwing a rock into |
|
| 69:19 | pond. So, imagine a still , right? It's peaceful, it's |
|
| 69:24 | . And then, because you're a of peace, you come along with |
|
| 69:28 | big old rock and you throw it there, you get that and you |
|
| 69:32 | what a big splash. Right? then what happens is you get a |
|
| 69:37 | that's pretty strong at the source of splash, and as it moves |
|
| 69:40 | it gets weaker and weaker and weaker weaker and weaker. Right? And |
|
| 69:44 | it's an infinitely sized pond, it eventually die out. But I've never |
|
| 69:47 | across upon that small, usually hit that big basically hit the wall and |
|
| 69:51 | comes right, ricocheted right back. we're just interested in going away. |
|
| 69:55 | , so, that's kind of what's here here, you can see I'm |
|
| 69:59 | up a channel sodium comes in and , if I measured it, I |
|
| 70:03 | see the massive change that's occurring But as I'm going further and further |
|
| 70:08 | , the difference and change is smaller smaller and smaller. And the reason |
|
| 70:12 | that is those sodium are going in . Remember we're opening up the gate |
|
| 70:15 | that Unmatched ion. Right? That island cross is the gate. And |
|
| 70:20 | waiting for him or her? positive charge is waiting for negative charge |
|
| 70:27 | here. So that positive charge comes and says, hey, negative |
|
| 70:30 | I saw you. I'm going to out with you now. And so |
|
| 70:35 | means the next positive ion Has to a little bit further, a little |
|
| 70:39 | further and a little bit further. you can imagine if you start off |
|
| 70:42 | 100 positive charges as you move further , it's like 1980 than 70 and |
|
| 70:46 | and so on. And that's why slowly dying out. Okay, Also |
|
| 70:52 | have ions that are leaking right back again, but we're not going to |
|
| 70:55 | in the mechanics of that one right . Okay, So it's a very |
|
| 71:00 | signal. It dies out quickly. just travels a short distance. And |
|
| 71:05 | it's not a useful tool for signaling my spinal cord down in my big |
|
| 71:10 | . It's very useful for signaling to dendrite, say to the axon hillock |
|
| 71:15 | in fact, that's what we use for. So, an action potential |
|
| 71:19 | going to be dealing with two major to major ions that are going to |
|
| 71:23 | involved. sodium and potassium. All , we looked at membrane permeability |
|
| 71:27 | What do we say? The membrane for sodium is roughly one for every |
|
| 71:32 | potassium. Right? So, if look at the the channels here, |
|
| 71:39 | we're gonna be looking as we're gonna looking at voltage gated channels. All |
|
| 71:43 | . So voltage gated means the thing stimulates the opening and closing of the |
|
| 71:46 | is a change in the membrane There are two of these channels. |
|
| 71:51 | voltage gated sodium channel has three has gates. So it has three |
|
| 71:55 | I am your channel. Stare at . Look at my awesome aw. |
|
| 72:01 | I have one gate. I have greats. First gate is the activation |
|
| 72:06 | . This is the activation gate. I start off, I'm in the |
|
| 72:10 | but capable of opening position over Here's my inactivation gate. Right? |
|
| 72:14 | in the open position so I get . Right? Change the membrane potential |
|
| 72:20 | the opening of the activation gate. , ions can flow through me. |
|
| 72:24 | the moment I opened this one up the moment this act inactivation begins to |
|
| 72:29 | . It's a little bit slower, it closes over time. And now |
|
| 72:32 | in the closed state. So we three states right closed, capable of |
|
| 72:37 | . Open closed must be reset to reset. I never go back through |
|
| 72:43 | middle stage. I have to go one closed, capable of opening open |
|
| 72:50 | , incapable of opening must reset. , I'm reset. You see |
|
| 72:54 | So it's abc back to a It's A. B. C. |
|
| 72:58 | A. You know, you don't to do that. All right |
|
| 73:03 | the reason this is important is because is what's going to allow the exponential |
|
| 73:06 | place. This one's boring. has states one gate gate is in close |
|
| 73:14 | . Gates in the open state. my two states closed. Open, |
|
| 73:18 | . Open, closed. See That's filter gated potassium champ. |
|
| 73:24 | what I'm gonna do. Got seven to explain the exponential in seven |
|
| 73:29 | All right, just follow the bouncing . Alright, at rest. Both |
|
| 73:34 | those voltage gates are closed, They exist. They're they're they're |
|
| 73:38 | They're not counted as part of the . What we have is we have |
|
| 73:43 | leak channels. There's 50 potassium leak . One sodium leak channel per |
|
| 73:48 | So sodium potassium are moving back cross and forth across membrane resting membrane potential |
|
| 73:53 | 70 million volts. That's rest. , so, there is on |
|
| 73:58 | We still have the pumps going You go back to where I put |
|
| 74:02 | right, membrane is being dominated by movement. Triggering event occurs. That's |
|
| 74:12 | Wayne doing this. And everyone following , Right. That's the stimulus stimulus |
|
| 74:17 | along causes a change the membrane Basically what's happening is is you can |
|
| 74:23 | a chemical from the other the neuron door releasing a chemical opening up a |
|
| 74:30 | channel, right opens up that sodium sodium comes in. What's going to |
|
| 74:35 | to the cell. So, he in. Does the inside get more |
|
| 74:39 | , more negative positive. It D . All right, That deep polarization |
|
| 74:45 | a greater potential. It ripples away the axon hillock. If it gets |
|
| 74:51 | enough or if it's strong enough and enough, it can create a major |
|
| 74:56 | . Major voltage change, which causes channels to open up. Right? |
|
| 75:01 | what happens is as I'm opening up or volts or sorry, ligand gated |
|
| 75:06 | channel, sodium comes in causes the of voltage gated sodium channels, which |
|
| 75:14 | more voltage gated sodium channels, which more voltage gated sodium channel. What |
|
| 75:19 | we have? What type of system that positive feedback loop? Basically, |
|
| 75:23 | I take the snowball and roll it the hill, it's gonna get bigger |
|
| 75:26 | bigger and bigger. So if I get a deep polarization strong enough to |
|
| 75:30 | the axon hillock, I can open the voltage gated sodium channels which opened |
|
| 75:34 | voltage gated sodium channels which opened up gated sodium channels. So, what |
|
| 75:38 | see, look at the yellow make sure, nope sorry, the |
|
| 75:43 | line or purple line is you see rise as those channels open and that |
|
| 75:49 | rising and keeps rising steeper and steeper steeper because it's an accumulation of deep |
|
| 75:56 | . All right. Now, once open up all the voltage gated sodium |
|
| 76:00 | , I can't open up any And all I'm doing is I'm just |
|
| 76:04 | straight up threshold is that point where opened up all the voltage gated sodium |
|
| 76:11 | ? Right? So I have no but to start what I start uh |
|
| 76:17 | doing what I've just started. This the all response. If I can |
|
| 76:21 | to the threshold. In other if I can open up all these |
|
| 76:23 | , then I'm gonna keep rising. I can't make it to threshold. |
|
| 76:27 | other words, if I don't open all those channels, I'm not getting |
|
| 76:30 | action potential. That's the alderman responses basically a greater potential. It's a |
|
| 76:39 | of graded potentials, which is kind cool. So, this is one |
|
| 76:43 | those things in a lecture where it's the sense like there's a chicken and |
|
| 76:46 | egg. We just happen to be about the chicken first, I think |
|
| 76:50 | be the egg. I don't know . All right. So, that's |
|
| 76:54 | this rapid rises. That threshold is up all those voltage gated channels. |
|
| 77:00 | you've done that, you've dominated or switching the domination. Remember we started |
|
| 77:05 | as 75 or 50 to 1 and I'm just making up numbers were now |
|
| 77:10 | 1 sodium versus potassium. So, inside becomes positive. All right. |
|
| 77:16 | is trying to approach plus 60. , if you look at this |
|
| 77:19 | does this hit plus 60? Something must have happened. In |
|
| 77:23 | the key thing is when you see graph like this look forward, changes |
|
| 77:26 | . If you see change occurring on graph, that means something happened. |
|
| 77:30 | , what happens? Well, two happen. Remember to gates. So |
|
| 77:35 | said it's important Gate # one opened # two at the top of that |
|
| 77:41 | closed. All right. So sodium Russian anymore. And so would normally |
|
| 77:47 | at that arrow up there at the . Is that it was just kind |
|
| 77:50 | go la la la, la la la and take a sweet time getting |
|
| 77:53 | . But it doesn't take a sweet getting down. It goes down |
|
| 77:57 | very quickly. It re polarizes why of the second voltage gated channel, |
|
| 78:02 | voltage gated potassium channel. All I'm gonna have to end the lecture |
|
| 78:07 | this I think. Which sucks. right, voltage gated potassium channel is |
|
| 78:12 | your slow friend. You know who talking about? The one that you |
|
| 78:16 | a joke to and they stare at for a second and then they get |
|
| 78:20 | joke a couple minutes later, you are rushing to get out of |
|
| 78:23 | I mean, I'm telling you this important stuff. I said this is |
|
| 78:26 | be what I'm going to end I didn't say I was done. |
|
| 78:29 | , voltage gated potassium channels are stimulated the exact same time as the voltage |
|
| 78:35 | sodium channels. They just open a bit later when the other ones are |
|
| 78:41 | . And so by doing that you reverse the flow of ions. |
|
| 78:45 | the flow of charge which causes you go back down and re polarized. |
|
| 78:49 | that's what's going on between the two . And then they close roughly where |
|
| 78:54 | arrow is down over here. But close slow too. So you happen |
|
| 79:00 | overshoot the resting membrane potential. You hyper polarization, right? You're down |
|
| 79:08 | and then they shut and then because the leak channels, things are moving |
|
| 79:12 | and forth and that's going to allow to return back to normal plus the |
|
| 79:17 | . So I think that's where I'll even though Yeah, that's actually a |
|
| 79:21 | good place for yourself because the next deals with refractory periods and that's another |
|
| 79:25 | . So does that all make sense the ready to sprint out of |
|
| 79:30 | Of course it does. Because you're out of here. Yeah. Any |
|
| 79:37 | yet. Okay. Channel influencing how chilling one is um I'm just I'm |
|
| 79:53 | it, is it that is it the channels that are influencing influencing equilibrium |
|
| 79:58 | ? It's all of the above can equilibrium potential is dependent upon um which |
|
| 80:04 | is the guys who want to move permeability as well as the concentration. |
|
| 80:09 | , if I have this regular number channels and all of a sudden I |
|
| 80:15 | it, then all of a sudden changed my equilibrium potential right now. |
|
| 80:19 | a temporary equilibrium potential change, which don't account for. We don't |
|
| 80:23 | We don't do anything. But in what you're saying is equilibrium will be |
|
| 80:26 | when X occurs. We never get X. All right. And so |
|
| 80:32 | we're saying, in essence, is by opening up all these channels we've |
|
| 80:36 | changed the natural resting point, the opening. Mhm. Right. |
|
| 80:48 | Right. So, but it's it's going there, it's not ever going |
|
| 80:51 | get there, because on the way slam the door shut. Right? |
|
| 80:59 | , no. Now, if it , it would basically you'd see it |
|
| 81:03 | that kind of signaled, Right? , what would happen is lack of |
|
| 81:08 | bit again, this is hypothetical, isn't what's really going on, So |
|
| 81:12 | go up and as it's approaching, would reach that, you know, |
|
| 81:17 | that signal. Right? Right. instead what we're doing is we're chopping |
|
| 81:20 | off there and then we're opening up other channel so that it starts coming |
|
| 81:24 | like that you're welcome. Uh this that says the action potential to which |
|
| 81:33 | neurons moved uh is and I picked hillock. Okay, email me with |
|
| 81:40 | screenshot so I can look it And if my question or answer is |
|
| 81:44 | , I always give you credit because, like, double check. |
|
| 81:48 | , that happens, it's just that's a function of having stuff that's true |
|
| 81:52 | all you guys, right. I , if you ever see something like |
|
| 81:55 | doesn't make sense, email me. then if I'm if you're reading the |
|
| 81:58 | incorrectly, which is maybe a couple percent of the time. Right, |
|
| 82:04 | . But most of the time you are pretty good and it's just like |
|
| 82:08 | no that's dr Williams fault. There's happened with the question and let's say |
|
| 82:13 | redid the quiz and you got a grade, you always get the highest |
|
| 82:16 | , always the highest. Right, |
|
