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Reptile Precursors
Updated 110d ago
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. The last experimental. So this is going to involve the event relationship to between more variables. And do much changing on manipulating one of the variables theries as you already talked about both designs. And then we record or collect data, what obser the change in the dependent variable that result from our manipulation of the. That's what we're looking at. We're moving and sh and manipulating one and seeing if it causes an effects or change in the other. That's what we're looking for. So have experimental research, we are looking for causation not just correlation. We're not just looking to see due to variables moved together. No, we're actually looking to see if we make a change in one variable, do we see a subsequent change in the other word? If we make another change in that variable, we shift it more, we change it fast. We take it away. Do we need a consequential change in the independent variableag yet, okay, you're able to shift and manipulate the independent variable and consistently see a change of the dependent variables, then you know you have causation, a change in one causes a change in the other. They've already kind of gone over this multiple things, so I will just briefly say this again, but you've got the independent variable dependent variable, the independent ones you what we're going to manipulate and change, whatever. that looks like. um at a very simple level of experimental research, you can have one level of your independent variable, and then nothing, right? You can have your experimental group and your controller. The group that gets the treatment, that group that does not. So that is your very basic experimental research where you just have two groups and one of them is to control groups. But even still, you should see a change in the depependent variable to the group that is receiving treatment and you should see no change for the group that is not receiving treatment, right? That would be causation. Now, of course, you can have multiple levels of the independent variable, we're not gonna get too much into that. In this course, um, but two is kind of the minimal, right? treatment, no truth, and then you can move beyond that. The dependent variable is the one that is being measured. It is hopefully changing. If you see no change in the dependent variable when you're making changes to the independent variable, you've got a big problem, right? That means that your independent variable that you manipulating actually has nothing to do with the behavior that you're trying to observe. It doesn't impact it at all, and you're going to have no results, no adjacent. It's very disappointing. It does happen. and it's disappointing, but not happen. Um, so it is the uh the outcome orependent measure. Now, something I briefly mentioned that I have gone too much into depth, yet are the confounding variables, so the confounding or they're also called you probably heard them called extraneous variables. These are other variables, other than your independent variables. So anything that is not your independent variable can be a confounding variable, and it can cause and change in the dependent variable if you have not accounted for and controls something that has to be at and avoid it at all costs. Let's say let's say we're doing a study and we are trying to decrease the amount of smoking individuals engage. Hi, so we're trying to help them. We're trying to decrease their smoking paper. And our treatment is going to be some sort of meditation and relaxation techniques that they can learn because of that is based on the research that people smoke war when they're experiencing higher levels of stress. So how can we decrease their stress? Let's teach them various coping mechanisms, deb breathing techniques, meditation techniques, other things that they can do to decrease their stress and hopefully have a decrease in theopy behavior. Okay, great. So we implement our treatment. But what if we forgot to ask participants? if any of them had gotten pug onto to the doctor recently and had some maybe vac about their health, if they received some not so great news about their health, could that be a variable that is intacting how much they decide to smoke after that document? Absute, right? The doctors that said, hey, you' lungs are not looking for good, or you've got something precursors to cancer, we're gonna have to run some tests. That type of news could certainly impact someone who's smoking and could result in a change in their smoking behavior, they might leave that doctor's office and go, okay, wow, I really need to stop smoking. But if we didn't ask them that, we don't know. We don't have that information. So, we've moved forward, we implement our procedure and our treatment, and theyreased their smoking and we go, wow, our treatment works really great. Look at all these people that stop smoking. But in fact, all those people went to the doctor got not so great, there was a decided to not smoke, regardless of whether or not you taught them had a meditate break, right? That is a confounding variable that will throw your data because you did not account for it. Whenever we're doing a study like that, on any type of addictive behaviors for illness, if you're doing a medication study, you have to ask all of those questions. You have to get all of that information up front, because those are come down in variables that can change the behavior that you did not account for and you are not manipulating or control. So now we can't make the claim that if we um, you know, give individuals, um different mechanisms to decrease their stress, it will decrease their snow people. We can't make that claim anymore because that's not what caused the meaning. Or at least we don't know for sure that that's what we're doing. So confoundingles are a big bump. we run into these a lot, and I will tell you that when we are designing a research study um when you're working in a lab and you're working with researchers, it is intimidating to bring a research project to the lab. I mean, I did it a lot inad school. We were required to do this. You have to do this when you're doing research, but you bring your research question and your proposal for how you're gonna run your study to the lab. you put it up there and literally everyone in the room writs it apart. Everyone sits there for an hour or two and says, what about this confounding birdle? What about this? Well, this one's gonna throw your data. Well, this one's not gonna work. Well, you have an accountant for this, they rip it apart. It doesn't feel great in the moment. However, that is how you identify all of the compounding variables and you find a way to account. so that you have good data in the end. It's very important piece of research and experimental research specifically. We do want to avoid them at all costs. Okay, so here's another example. Let's say a researcher investigate whether giving students more time to study, reduces their tests anxiety. Okay. What is going to be the dependent variable here? What are we measuring? What are we looking at? We wouldn't want to take it again. Test anxiety. levels of anxiety when you're taking a test, right? That's what we're measure. We're trying to change that, okay? So that's gonna be the behavior that we're looking at. What is the independent variable here? Time to set, the amount of time that you're set, whatever that may be, okay? So the DV is test anxiety or levels of anxiety will take the test whatever you will word that, that's what we're measuring. Am amount of study time is what we're looking at for the independent version. Now, when you're taking a test, there are multiple things that happen that have nothing to do, maybe, with the amount of time you study. Can we reduce test anxiety by making sure that you study at least a minimum amount of time? Yes, we can reduce your test anxiety a little bit. But there are also other factors that if we if I was running this study as an experimental research, not just as like the naturalistic observation in a classroom, like let's just see if we can help. If I was actually running an experimental res research that many things that I have to account for. I need to account for type of tests. What if I get half of my participants, the tests is the morning and half of my participants the test in the afternoon? That's the I founding variable. Maybe the students in the morning are more stressed out because they didn't have time to relax in the morning and get ready for this test that I'm about to do them yet. Right? They're getting ready, they're in traffic, they're driving here, trying to park and so and so forth. Yes, we might run into that in the afternoon, but you still have got more time in the day. to get ready for it. So that's a confounding marriage, time of test. Another confounding variable would be temperature in the room. If it's too cold or too hot, you've got one room that's hotter, one room that's colder. That can impact someone's test anxiety. When you're feeling anxious, if I'm sure everyone has felt that feeling at one point in their life, it doesn't feel great to then also be hot and sweat. It usually makes that anxiety a little bit worse. You start to feel kind ofustrophobic and you're like, I don't know what's going on. I'm getting really hot. I don't feel good, I'm getting kind of dizzy, like, and your anxiety skyrock. right? So, I wanna make sure that the temperature in my room every time participants are taking the test, it has to be exactly the same, or usually within a couple degrees of the temperature. Okay, so these are just a few examples I can go on and on about all of the things that would impact you while you're having an exam that would impact your test anxiety. I need to help for all of those things, and every participant in all of my different groups would all have to have the same things so that I can truly say it was the amount of set. and it wasn't possibly due to during the room, time of the test, the room that they're in, how close they're sitting to each other and so on. and and that and that's part of the roofing unit ofart process, right? If I came to my lab and just said, oh, I'm gonna do this. They're like, well, what else, what else are you controlling for? I'm like, nothing, you know,'ll be fine. They're gonna rivet apart, right? All of those confounding variables that we need to account for. Um, a study involved investigating how manipulating the accuracy with which feedback is delivered, affects a number of work tasks that can be completed by college. So this is essentially, say, a student is doing a work task, and if I give you no feedback on that, as to whether you're doing it track, if I give you feedback that is correct and it matches, I say, yes, that's correct. or if I give you wrong feedbacks. So that's what we're talking about when we were saying a different type of feedback on your ability to complete a task. So, what is the independent variable here? What are we manipulating? Yeah, that's hypo feedback, right? We're gonna change that. It's gonna be different. What's the dependent variable that we're measured? It's the behavior we're looking at here? Yeah. Uh, number of work task. Correct, yes. How many workops did they actually complete? Do they get more done when they're getting positive feedback? Do they get more done when they're getting no feedback at all? You probably don't get more done when they're getting negative. You back would probably be my hypothesis, but we're gonna look at them, right? We're gonna count how many tasks they get done based on the type of feedback that they are given. And then we see how this impact that dependent varies. How does that impact the behavior that they're engaging? So, there will be questions like this on these things. This is like a perfect example. It will be this exact one, I'll change the words I'll change a thing. And I'll ask you these questions. What is the independent? What is the dependent variable? And sometimes I'll put a confounding variable in there and I'll say like, identify the confounding variable. and you'll hopulate pick one of the choices. So very similar to what I've test questions would look like for something like that. But the good to be able to look at examples and pull these things up about. If you're in any type of research class, statistics class, you need to be able to have this very uh, you guys could go over these ones.. I'm not gonna keep going, but you get you get this. All right. So experiments typically involve two groups at a minimum, which I talked about already, but you're gonna have atom minimum, your control group, and your experimental. The control group is a group of participants that does not receive the treatment. No treatment. Okay. Um, you don't change it. You essentially just measure their behavior, but you don't expose them to anything. Um, so work tasks with the feedback, that would be the control group is no feedback, okay? So we just allow the students to complete tasks as they normally would, we do not interject, we do not give the feedback one way or another. We just sort of let them carry on with their day as they normally would and we count how many works how they could. Versus, the experimental group are the ones that are going to receive some type of treatment. Now, as I've said before, minimally, you've got one experiment group and your control but you can have multiple experimental groups and a controll. And so you can have two or three different types of feedback. Those would be your experimental groups, and you can still have a group that received no feedback. if we're looking at study fine with students, you can look at, you know, two hours, four hours, six hours a week. Those are your experimental groups. the other students, you would sort of just allow them to either or you would prevent them from studying at all, or you just would not manipulate the study time for them, you would allow them to study however long they normally do and have them report on. So you would just basically specify that this group did not have a controlled set amount of set, and then they would report on how many hours they affected. versus the other three experimental groups would have a set amount by the time that you're controlled. Okay. Here's a question, a clinical psychologist conducts a study that involves ten people. He thinks he can cure depression by giving his science a particular type of drug. So he prescribes the drugs and finds his 60 days later, all clients show fewer signs of depression, as the psychologist includes he has cured depression. So what's the problem? There's a lot of problems here, but like, what's the main simple problem with what we understand in this particular research research? What has not been done? Yes.... doesn't describe. There is no controller, right? Every single person got the drug. There's no control group. So how do you know that that drug improved their depression? If you do not have a control group, you have no comparison to make, the whole point of having a control group, the whole reason we do it is so that if the drug does work, let's say that the psychologist is correct, this drug works, it cures depression. If you have a controlled group, we have a group of participants who didn't get the dress, what should happen for them? is someone over here? I take a guy? What should happen for people who are naked? Is it control with this? What do you expect? Yes. Yes, they should save the same, right? They're not getting the drugs. So they shouldn't get better. And then the people in the experimental group who are getting the drug if the drug works, they should get better. And you have that comparison. You now you can definitively say, okay, look at all these people that did not get the drug in my control group, they didn't get any better. The symptoms of depression persisted. But look at all of my participants, my experimental your, we saw a significant improvement in depression symptoms. Okay, now maybe you have a plane. But if you give the drugs to every single person, you have nothing to compare. How do you know what your drug is not something else that you're their depression? Maybe a bunch of people were unemployed and during that time that they were given the drug, they got a job. Back didn't improve someone's levels of depression, especially if it's a situational depression. course, there's a depression that is biologically, you know, that's a different type of depression, but there's also situational depression. And if you have an accountant for every single situation that person is in, those are confounding variables that can impact in this case, levels of depression. Do you know how control group, you have nothing to compare. You cannot make this. big problem. can't rule out any other expavation. So that's why minimally we always have to have at least a control group and an experimental group. And as I said, you can have more than that, but the bare minimum requirement, no treatment, treatment, control group, experiment. So when we use, um control groups and experimental groups, individuals are randomly assigned to each group, and I've kind of talked about this a little bit that the need for this in order to make sure that the participants in each group represents the larger population. That's the, right? You're never going to be able to access the entire population. You're not going to be able to access every single person who's ever experienced depression or has symptoms of depression in a drug site. You're going to have to randomly assign participants to certain groups and hope that they represent the larger population of people that experience symptoms of depression, right? So that is the point of random assignment to different conditions. Usually, the experimenter, I mean, ideally, the experimenter doesn't even know who's in which group, in a drug study that is ideal. We call it a double blind assignment where the participant doesn't know if they're getting a drug or not and the experiments or also does't know if they're getting the drug or not. Why? Because bias can be introduced? If they're participant thinks they're getting the drug, um, they can have sort of placebo effects, right? If you've ever heard of that, the placebo effects, or they think they're getting better because they're underlyression, they're getting the drug. researchers can also treat participants differently based on if they know who is getting the drug and who's not, and that will impact the data that they're collecting on that person's behavior. So, ideally, like the perfect scenario, nobody knows what's going on. There's a lab that assigns the drug and puts it in an envelope and assigns names, randomly and they give the envelope to their researcher and there's a red pill and there's a blue pill, but the researcher doesn't know which one is which. One could be trained it, one could be placebo, we don't know, and that's very important, but kind of nobody knows what's going on. until the end. And that's how you get the best data. out of something like this. Now, group should be comparable to each other. um, they should be assigned to the group based on Chancel, essentially. Um, usually we use some sort of computer programming to randomly assign numbers, two people and then randomly assign those numbers into the groups that were trying to produce. This can be very difficult to do. The smaller your participant pool, in fact, the more impossible this gets. So that's why a lot of research studies try to get so many participants and absorbid an amount of participants, um or why you need to run several studies to build your participant pool, before you can make any sort of claim about your data. because the smaller you participant pool gets, the less representative of the population they will be. because you do need to think about things like, um intelligence or um education level personality type socioeconomic status, ethnicity, um, their income, there's so many things that you have to think about and a smaller you participant will gets, the less representative of all of these things it will be. And then we run into the problem that your participants didn't actually represent the larger population, and your data really only applies to that very small group, and it cannot be applied to the larger group, which is always the goal. The goal of research is to collect data with a smaller amount of people, but you hope that you can go and apply those kinds and those results to the larger population. If you are looking for a drug that cares depression, you want those results to be good and to be representative of the larger population so that you can then produce a drug that can be distributed to people who have symptoms of depression and it cures them, right? You don't only want that drug to work for 60 people that you ran the side with, and that's it. and it doesn't work for anyone else. So, random assignment does help with this, but also large participant groups are going to make sure or ensure that you have a representative family of the larger published. Okay. yeah. So some other important things we have to considerable we're running research. and just terms that you should be aware of, so a confederate is someone who is employed by the researcher or is a researcher themselves that is going to participate in the study and pretend to be a participant. So they're gonna essentially take part in the study. um, the participants will not know that that person is a confederate, obviously it's a secret, so this involves some level of deception, usually in the study that we have to present to our review board and make sure that all of that is okay. But when you use a confederate, it's usually because you are conducting a study that people know they're being observed, they're going to change their behavior. So that's why we have confederates. When I was in grad school, a a grad friend of mine, she was in a different lab, and I was helping with her study. She ran this really interesting study on graphic Ed, so people would eat very, very fast. And I'm not just talking like, you know, kind of fast. We're talking like a burrit that big, is gone in one minute or less, like gone. And so, like barely chewing their food, like, wrap it, rapid, you. And as you can expect, there is a lot of health concerns that come first. We had some children who were rabbit eaters in that study. um there was significant choking hazards that had already occurred with some of those personents because they're eating much too fast, too large in bites. Um, but before we could run our study with children, we had to make sure that it was safe and it was not going to impact them too greatly, so we ran it with college students here on campus. Um and when we first started running it, you realized very quickly that they knew they were being observed, and so they were slowing down their eating. They were still eating fast, but it wasn't quite as fast as they had reported in their interviews when we were trying to pull participants. So what did we do? We got conf better. So we had a sticker researcher in there. and we left, so we who were identified as the researchers, we were like, hey, um, we're gonna be back a little later, and we're just we're gonna ask for your report on how fast you ate, but we gotta go. We'll be back later. Maybe pizza in the middle of the room, help yourselves. And then we actually had another researcher in there who was a participant, but she was a confederate. And she had to eat with them, which was difficult because she had to eat very, very quickly, so that they didn't know that she was a confederate. But that is an example of what we would do. Now, she had a time where she had different time on her too, that she was like collecting data for certain people in different sessions, so we could get a truer representation of how fast those people ate and their behavior was a different because they didn't know that they were being observed. So that is a perfect example when we could use the compatory. Um, replication and I've already sort of talked about this before, but we always wanna ask if we can rep replicate the results that have been found. This is extremely important. Scientific understanding is based on the accumulation of knowledge. The more knowledge we have, the more data we have on a on a body of research, the greater our scientific understanding is of that res research, of that behavior, of that phenomenon or theory, or whatever it is that we're investigated, the more research we have, the better we understand it. Replication is foundational to science moving forward. If we adjust did research for the heck of it, just to entertain ourselves to stimulate our reins or whatever research we just want to do, it doesn't help science, it doesn't move us forward at all. We have to publish it and then other scientists, other researchers have to replicate it and move the science forward. It's an extremely important part of research and without it, it really would kind of be pointless to do research at all. The point is to accumulate the knowledge and move the science forward. I've gonna talk about briefly about significant outcomes. If you take a statistical course, they get into this in great detail. But whenever we're looking at data, we're looking for what is called significant outcomes, statistically significant differences. We're not just looking for minimal differences between our groups, between our control group and our experimentsal groups, or even between our different experimental groups, we're looking for significant changes. big changes, changes that make a difference in people's lives. and a difference in their behavior changes, not just very small minuscule differences that maybe we can kind of say, well, there's a slight change. No, there must be a statistically significant dip. Now, of course, that is determined by the statistical analysis that are run. um, or if you're doing a study that's sort of based on kind of like a real world problem, um, things like when we work with children with autism and things like that, um, or any individual with a developmental disability, we're looking for um learning outcomes, so do they make significant jumps in their learning outcomes or their development? E cognitive or physical development, right? So they need to be meaningful differences as, you know, we're not just looking for tinyunicule changes, we're looking for meaningful, statistically significant differences between our groups. Experimental bias is something we always have to be aware of, these are going to be factors that could impact your dependent variable, a bias from the researcher, a bias from the in from the first incipant. Those can impact the data that you get in the way that they be hidden um any expectations that you are the persistent have can surely impact how they are behaving. We always need to account for that and make sure that we're, you know, making sure that doesn't do. Well is a false treatment. I've already kind of mentioned this before, but we typically see this with any sort of drug study um, but it's just the no treatment. They're given a pill that doesn't have any chemical properties to it, so it shouldn't impact their um system.? So if it impacts them in any way? That's what we need when we say alpha seat. And then finally, I've also talked about this already, but double blind means both the experimenter and the person do not know who's receiving treatment and who's not. That is the ideal standard to lose a another one in experiment, nobody knows. And it prevents
Updated 211d ago
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Introduction to Tissues A. Histology=the study of tissues. B. Although studying tissues can be accomplished using a light microscope, studying cell parts often requires an electron microscope and the study of atoms and molecules can only be examined through special imaging techniques and experimental procedures. Types of Tissues A. Despite the fact the body is composed of trillions of cells, there are only about 200 different cell types. These cells in turn produce only four principle tissue types: 1. Epithelial tissues=covers exposed surfaces; lines internal passageways; and produces glandular secretions. 2. Connective tissues=fills internal spaces; provides structural support, and stores energy 3. Muscle tissues=contracts to produce active movements 4. Nervous tissue=conducts electrical impulses; detects, interprets, and responds to stimuli B. Relative contribution of the four tissue types to the overall weight of the adult body. C. Embryonic origins: There are three types of embryonic tissues from which all adult tissues are derived. a. Endoderm=gives rise to the functional linings of the digestive and respiratory tracts as well as to the associated accessory glands and organs (i.e. liver, stomach, pancreas, etc.) b. Mesoderm= gives rise to the components of the skeletal, muscular, and circulatory systems c. Ectoderm= gives rise to the epidermis of skin and all of the components of the nervous system D. Tissue Membranes 1. Mucous Membranes=composed of epithelial tissues. These membranes line body cavities that open to the exterior environment such as those of the digestive tract, respiratory tract, or urogenital tract. In all cases, these are "wet" or moist membranes because of the secretion of mucous. The moisture helps reduce friction and in many cases, facilitates absorption or secretion activities. 2. Serous Membranes=consists of a mesothelium supported by areolar tissue. These are never exposed or connected to the exterior. Serous membranes secrete transudate, or serous fluid. There are three serous membranes that line the ventral body cavity: a. Pleura=lines the chest cavity and surrounds the lungs. b. Pericardium=lines the pericardial cavity and surrounds the heart c. Peritoneum=lines the peritoneal cavity and lines the surfaces of the visceral organs 3. Cutaneous Membranes=made of stratified squamous and areolar tissue reinforced by dense irregular connective tissue. In contrast to mucous and serous membranes, cutaneous membranes are dry, relatively thick, and waterproof. 4. Synovial Membranes=line mobile joint cavities but do not cover the opposing joint surfaces. Secretes synovial fluid. Although the covering of the synovial membrane is often called an epithelium, it differs from true epithelia in four respects: it develops within a connective tissue, no basal lamina is present, gaps of up to 1 mm may separate adjacent cells, and the synovial fluid and capillaries in the underlying connective tissue are continuously exchanging fluid and solutes. Epithelial Tissues A. Functions of Epithelial Tissues 1. Epithelia provide physical protection. Epithelial tissues protect exposed and internal surfaces from abrasion, dehydration, and destruction by chemical or biological agents. 2. Epithelia control permeability. Any substance that enters or leaves the body has to cross an epithelial tissue. Some epithelia are relatively impermeable, whereas others are permeable to compounds as large as proteins. Most are capable of selective absorption or secretion. The epithelial barrier can be regulated and modified in response to various stimuli. For example, a callus forms on your hands when you do rough work for an extended period of time. 3. Epithelia provide sensation. Sensory nerves extensively innervate most epithelia. Specialize epithelial cells can detect changes in the environment and convey information about such changes to the nervous system. 4. Epithelial cells that produce secretions are called glands. Individual gland cells are often scattered among other cell types in an epithelium that may have many other functions. B. Location of Epithelial Tissues 1. Epithelia=forms sheets or layers of cells that line the body tubes, cavities, or coverings of the body surfaces. 2. Glands=formed of epithelial cells with secretory functions. Two types of glands are found in the human body: a. Endocrine glands=secrete hormones (or hormonal precursors) into the interstitial fluid or bloodstream. These glands are ductless. b. Exocrine glands=secretes non-hormonal substances (milk, wax, enzymes, oil, acids, etc.) onto external surfaces or internal passageways (ducts) that connect to the exterior. C. Characteristics of Epithelial Tissues 1. Polarity=epithelial cells possess two structurally and functionally different surfaces: a. Apical surface=free edge which faces the exterior of the body or the lumen of an internal space. b. Basal surface=attached surface which anchors the cells to adjacent tissues. 2. Supported by a basal lamina=also known as the basement membrane, is a complex structure produced by the basal surface of the epithelial cells and the underlying connective tissue. The underlying connective tissue is composed of two things: 3. Cellularity=epithelial cells are extensively interconnected so that they create an effective barrier that behaves as if it were a single cell. a. Occluding junctions=form a barrier that isolates the basolateral surfaces and deeper tissues from the contents of the lumen. At an occluding junction, the attachment is so tight that it prevents the passage of water and solutes between the cells. b. Adhesion belt=locks together the terminal webs of neighboring cells, strengthening the apical region and preventing distortion and leakage at the occluding junctions. It forms a continuous band that encircles cells and binds them together. c. Gap junctions=permits chemical communication that coordinates the activities of adjacent cells. At a gap junction, two cells are held together by interlocking junctional proteins called connexons which serve as channels that form a narrow passageway to let small molecules and ions to pass from cell to cell. d. Desmosomes=provides firm attachment between neighboring cells by interlocking their cytoskeletons. At a desmosome, the opposing plasma membranes are very strong and resist stretching and twisting. Hemidesmosomes attach the basal surface to the basement membrane. e. CAM=cell adhesion molecules; present in the adhesion belt and desmosomes; transmembrane proteins that bind to each other and to extracellular materials. 4. Avascular=epithelial tissues lack blood vessels; all nutrient and waste exchange occurs as a result of diffusion and osmosis from underlying tissues. 5. Highly innervated=epithelial tissues are supplied with many nerve endings 6. Regenerate rapidly=although the exact rate varies from one type of epithelia to another, most epithelial tissues regenerate within days (rather than weeks or years). D. Naming Epithelial Tissues 1. Almost all epithelial tissues possess a two part name where the first part of their name indicates their arrangement (number of layers) while the second part of their name indicates the shape of the cells. 2. Arrangement of epithelial tissues a. Simple=only one layer thick b. Stratified=more than one layer thick c. Pseudostratified= “false layers”; it looks like more than one layer but in fact its only one layer thick 3. Shape of epithelial cells a. Squamous=thin, flat, and somewhat irregular in shape. From the surface, they look like fried eggs lay side by side. In a sectional view, they look like a pancake with a pat of butter (indicating the nucleus). b. Cuboidal=are about as wide as they are tall; resemble hexagonal boxes with the spherical nucleus located in the center of each cell. c. Columnar=are taller than they are wide; resemble rectangles with the elongated nuclei tend to crowd into a narrow band close to the basal lamina. E. Diversity of Epithelial Tissues 1. Simple squamous epithelium a. Description: single layer of flattened cells with a disc-shaped central nuclei and sparse cytoplasm. b. Function: allows passage of materials by diffusion and filtration in sites where protection is not important. Also secretes lubricant. c. Locations: Kidney glomeruli, air sacs of lungs, capillaries, linings of heart and lymphatic system. 2. Stratified squamous epithelium a. Description: thick layers of flattened cells; often keratinized layer and a mitotic layer. b. Function: protects underlying tissues in areas subject to abrasion c. Location: non-keratinized type lines the mouth and vagina; keratinized type forms the epidermis of skin. 3. Simple cuboidal epithelium a. Description: single layer of cube-like cells with large spherical centrally located nuclei. b. Function: secretion and absorption c. Locations: Kidney tubules, ducts and secretory portions of glands, ovary surface 4. Stratified cuboidal epithelium a. Relatively rare in the human body. b. Most common along the ducts of sweat glands, mammary glands, and other exocrine glands. c. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 5. Simple columnar epithelium a. Description: single layer of tall cells with round to oval nuclei; some cells bear cilia; may contain goblet cells that produce mucus; may contain microvilli. b. Function: absorption; secretion of mucus and enzymes; cilia propel substances. c. Location: non-ciliated type lines digestive tract, gallbladder, and ducts from glands; ciliated type lines small bronchi, uterine tubes, and uterus. 6. Stratified columnar epithelium a. Relatively rare in the human body. b. Most often found lining large ducts such as those of the salivary glands and pancreas. c. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 7. Pseudostratified columnar epithelium a. Description: single layer of cells of differing heights so that nuclei are a differing levels; may contain goblet cells and bear cilia. b. Function: secretion, propulsion by ciliary action. c. Location: non-ciliated type lines male reproductive ducts; ciliated type lines much of respiratory tract. 8. Transitional epithelium a. Description: resembles both stratified squamous and stratified cuboidal. Basal cells are cuboidal or columnar; surface cells are dome shaped. b. Function: stretches readily and permits distension. c. Location: Lines uterus, bladder, and urethra F. Glandular Epithelia are Specialized for Secretion 1. Endocrine glands= “ductless” glands that produce hormones. Secrete directly into interstitial fluids or bloodstream. Examples: pituitary gland, adrenal gland, thyroid gland, etc. 2. Exocrine glands=glands possessing ducts. Exocrine glands secret their substance either on the body surfaces or within ducts. They general demonstrates one of two different modes secretion: a. Merocrine=secrete products from secretory vesicles by exocytosis. Most common type. Example: salivary glands of the oral cavity b. Holocrine=accumulate products until the cell ruptures. Destroys the cell and must be replaced by cell division. Example: sebaceous glands of the skin c. Apocrine=products accumulate within the cells then the apex of the cell pinches off packets that contain the secretion. Example: mammary gland of the breast 3. Exocrine glands are unicellular or multicellular. a. Unicellular=goblet cells that produce mucin which mixes with water to form mucus. b. Multicellular=two structural classes: i. Simple=a single duct that does not branch on its way to the secretory cells (examples: gastric glands, sebaceous glands) ii. Compound= duct divides one or more times on its way to the secretory cells (examples: duodenal glands, mammary glands and salivary glands) Connective Tissues: Supports and Protects A. Location of Connective Tissues 1. Most abundant tissue in the body. 2. Never exposed to the outside environment. B. Characteristics of Connective Tissues 1. All types of connective tissue originate from mesenchyme. 2. Connective tissues vary widely in appearance and function but all forms share three basic components: a. Specialized cells=the cells present in each type of connective tissue helps to distinguish the various types from one another. A few of the cells are listed here: i. Fibroblast cells=produce connective tissue proper ii. Chondrocytes=produce cartilage iii. Osteocytes=produce bone iv. Hemocytoblast cells=produce blood b. Extracellular proteins fibers=three primary fibers are produced in connective tissues i. Elastic fibers=slender, straight, and very stretchy. They recoil to their original length after stretching or distortion. ii. Collagen fibers=thick, straight or wavy, and often forms bundles. They are very strong and resist stretching. iii. Reticular fibers=strong fibers that form a branching network or scaffolding c. Ground substance=material that fills the space between cells and surrounds the extracellular fibers. In some connective tissues the ground substance is gel-like while in others it is liquid based and in others it is rigid or calcified. Ground substance and extracellular fibers make up the matrix of connective tissues. 3. Many types of connective tissue are highly vascular and contain sensory receptors that detect pain, pressure, temperature, and other stimuli. C. Functions of Connective Tissues 1. Establish a structural framework for the body. 2. Transport fluids and dissolved materials. 3. Protect delicate organs. 4. Support, surround, and interconnect other types of tissue. 5. Store energy reserves, especially in the form of triglycerides. 6. Defend the body from invading microorganisms. D. Diversity of Connective Tissues 1. Connective Tissue Proper=includes connective tissues with many types of cells and extracellular fibers in a gel-like ground substance. a. Loose Connective Tissues – fibers created a loose, open framework i. Areolar tissue=most common form of connective tissue proper in adults. It is the general packing material in the body. Attaches skin to underlying body parts and is sometimes called the superficial fascia. All of the cell types found in other forms of connective tissue proper can be found in areolar. ii. Adipose tissue=found deep to the skin, especially at the flanks, buttocks, and breasts. It also forms a layer that provides padding within the orbit of the eyes, in the abdominopelvic cavity, and around the kidneys. The distinction between areolar tissue and adipose is the larger number of adipocytes (fat cells). iii. Reticular tissue=found in the liver, kidney, spleen, lymph nodes, and bone marrow, where it forms a tough, flexible network that provides support and resists distortion. In reticular tissue, reticular fibers create a complex supporting network known as a stroma. Fixed macrophages and fibroblasts are present but these cells are seldom visible. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! b. Dense Connective Tissues – fibers are densely packed together i. Dense regular=all collagen fibers are oriented parallel to each other providing strength along the axis of the collagen fibers. Found in cords (such as tendons) or sheets (ligaments). Tendons connect muscle to bones. Ligaments connect bones to bones. ii. Dense irregular=collagen fibers are non-parallel forming an interwoven network. These tissues provide strength in many directions and are particularly important in areas subjected to stress from many directions such as the dermis of the skin. iii. Elastic=when elastic fibers outnumber collagen fibers, the tissue has a springy, resilient nature that allows it to tolerate cycles of extension and recoil. This elastic tissue is bound between the vertebrae of the spinal column and the erectile tissues of the penis. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 2. Fluid Connective Tissues=have distinctive populations of cells suspended in a watery matrix that contains dissolved proteins. NOT ON LAB PRACTICAL! a. Blood – flows within the cardiovascular system 3. Supporting Connective Tissues=differ from connective tissue proper in have a less diverse cell population and a matrix containing much more densely packed fibers. Supporting connective tissues protect soft tissues and support the weight of part or all of the body. a. Cartilage – solid, rubbery matrix containing chondrocytes. All cartilage is surrounded by a membrane of connective tissue called the perichondrium. i. Hyaline cartilage=found connecting the ribs to the sternum, covering the articular surfaces of long bones, supporting the respiratory passageways such as the trachea, and forming the tip of the nose and part of the nasal septum. Has an amorphous matrix with few visible fibers. It provides stiff but somewhat flexible support and reduces friction between bony surfaces. ii. Elastic cartilage=found in the ear and epiglottis. Has many more elastic fibers within the matrix and is therefore more flexible. iii. Fibrous cartilage=found within the intervertebral discs, the meniscus of the knee, and pubic symphysis. Has many more collagen fibers within its matrix and is therefore very strong. b. Bone – solid, crystalline matrix containing osteocytes. All bone is surrounded by a membrane of connective tissue called the periosteum. NOT ON LAB PRACTICAL! c. Comparison of cartilage and bone. Muscle Tissue in Motion (discussed in detail in Chapter 10-11) NOT ON LAB PRACTICAL! A. Highly vascularized muscular tissue is comprised of elongated cells (called fibers) containing myofilaments (actin and myosin proteins). 
 B
Updated 217d ago
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Here’s a set of flashcards based on the material you’ve shared. The questions (front) are followed by answers (back). You can use these for study purposes. Flashcard Set: Developmental Psychology and Psychopathology Flashcard 1 Q: What are reflexes in newborns, and why are they important? A: Reflexes are unlearned responses triggered by specific stimuli. Some have survival value (e.g., rooting, sucking), while others, like stepping, are developmental precursors to later motor skills. Reflexes also reflect the health of the nervous system. Flashcard 2 Q: What is the Apgar score, and what do its levels indicate? A: The Apgar score assesses a newborn’s physical condition based on five factors (breathing, heartbeat, muscle tone, reflexes, skin tone). • 7+: Good condition. • 4–6: Needs special attention. • 3 or less: Life-threatening condition. Flashcard 3 Q: Define temperament and describe Rothbart’s three dimensions. A: Temperament refers to consistent behavioral patterns in infants. 1. Surgency/extroversion: Active, happy, seeks stimulation. 2. Negative affect: Angry, fearful, not easily soothed. 3. Effortful control: Focused, not easily distracted. Flashcard 4 Q: What is sudden infant death syndrome (SIDS), and what are its risk factors? A: SIDS is the sudden death of a healthy baby. Risk factors include: • Premature birth/low weight. • Sleeping on the stomach. • Parental smoking. • Overheating. Flashcard 5 Q: What is Erikson’s psychosocial theory, and name its first three stages. A: Erikson’s theory focuses on resolving conflicts across eight life stages. 1. Trust vs. Mistrust (birth–1 year): Develop trust in caregivers. 2. Autonomy vs. Shame (1–3 years): Develop independence. 3. Initiative vs. Guilt (3–6 years): Explore and try new things. Flashcard 6 Q: What are the main types of intelligence in Gardner’s theory of multiple intelligences? A: Gardner proposed eight intelligences: 1. Linguistic 2. Logical-mathematical 3. Musical 4. Spatial 5. Bodily-kinesthetic 6. Interpersonal 7. Intrapersonal 8. Naturalist Flashcard 7 Q: What are fluid and crystallized intelligence? How do they change with age? A: • Fluid intelligence: Problem-solving and adaptability (declines with age). • Crystallized intelligence: Knowledge from experience (improves with age). Flashcard 8 Q: What is Sternberg’s triarchic theory of intelligence? A: Sternberg’s theory includes: 1. Practical intelligence: Adapting to environment. 2. Creative intelligence: Dealing with novel tasks. 3. Analytic intelligence: Problem-solving and critical thinking. Flashcard 9 Q: How does emotional intelligence (EI) contribute to well-being? A: EI involves recognizing, differentiating, and managing emotions in oneself and others. It increases with age and improves decision-making, relationships, and subjective well-being. Flashcard 10 Q: Describe the Flynn Effect. A: The Flynn Effect is the observed rise in average IQ scores over decades, likely due to better education, improved nutrition, and enhanced living conditions. Flashcard 11 Q: What is the cumulative-deficit hypothesis? A: This hypothesis suggests that impoverished environments inhibit intellectual growth, with the negative effects compounding over time. Flashcard 12 Q: What are the main goals of early intervention in developmental psychopathology? A: Early intervention aims to: 1. Stabilize symptoms. 2. Treat co-occurring problems. 3. Provide social and educational support. Flashcard 13 Q: How do infants perceive depth, and what experiment demonstrates this ability? A: Infants develop depth perception by around 6–7 months, as shown in the visual cliff experiment. Crawling infants avoid the “cliff,” demonstrating fear of depth. Flashcard 14 Q: What is resilience, and how can it protect against psychopathology? A: Resilience is the ability to adapt and thrive despite adversity. Protective factors include supportive relationships, problem-solving skills, and positive school environments. Flashcard 15 Q: What are primary and secondary control beliefs? A: • Primary control: Acting on the external world to achieve goals. • Secondary control: Adapting one’s internal perspective to align with external circumstances. Flashcard 16 Q: Define “edgework” in emerging adulthood. A: Edgework refers to behaviors that involve risk-taking and pushing boundaries, common among emerging adults due to an underdeveloped prefrontal cortex. Flashcard 17 Q: What are some factors that foster creativity? A: • Freedom to explore ideas. • Supportive and stimulating environments. • Encouraging divergent thinking in schools. Flashcard 18 Q: What is the relationship between IQ and occupational success? A: Higher IQs are associated with professional success, health, and longer life spans. IQ predicts complex problem-solving abilities necessary for advanced work roles. Flashcard 19 Q: How does cognitive development progress in adulthood? A: • Postformal thought: Combines logic with emotion, pragmatism, and subjective factors. • Reflective reasoning matures, enabling nuanced decision-making. Flashcard 20 Q: What are role transitions, and how do they mark adulthood? A: Role transitions, like starting full-time work, voting, or marriage, signify the movement into adulthood, though the criteria vary across cultures.
Updated 268d ago
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