Transcript for:
Anatomy and Physiology Overview

all right so when you signed up for this class you signed up for anatomy but you were automatically signed up for physiology why why can't you just take anatomy by itself and physiology by itself well we call this class anatomy and physiology for a reason let's first go define what anatomy is anatomy is let's write this on the board anatomy is form f-o-r-m form is just another way to say structure okay so on the exam you're going to see the word form form means structure and physiology means function okay so we have form for anatomy and function for physiology now i'm going to write three words on here this tiny little sentence that's composed of three words that is vital for y'all to understand it is form follows function now this is a rule that is going to stick with you for 2401 and 2402 this rule is going to help you understand the human body just these three magic words three simple words form follows function what does that be that means that if you can figure out the structure of something it will help you figure out its function let's say that again if you can figure out the structure of something then it will help you figure out its function form follows function anatomy is form or the structure that is for lab if we were in lab you would be doing anatomy and then in lecture we're learning about function so that's why when you signed up for anatomy you were automatically signed up for physiology why because form follows function if you can figure out the structure of something you can figure out its function now what i'm going to do is we're going to erase this and then i'm going to provide you with some examples i'll give you two examples of how form follows function okay so what i'm going to do is i'm going to draw a cell on here and i want somebody to unmute their mic and tell me what is this cell so here we go okay somebody a neutron i can tell me what what is what is this cell is that a spermicidal cell exactly it's a sperm cell absolutely now what is the job or what is the function of a sperm cell to get to the egg without getting killed yeah it gets to the egg its job and it has a really hard job its job or function is to get to the egg right without getting killed so that way it could fertilize the egg now how does it do its job how does it get to the egg what does it do it travels up its function is to swim right because it has to swim to get to the edge now what does it possess what about its form that what does it have that allows it to do its job what does it have that allows it to swim a fast moving tail a tail now this tail we call in science it's called flagella okay and by the way y'all the male sperm is the only one that has a vagina a flagella that is the only cell that has a flagella all right none of your other cells have a tail only the male so let's look at this because the sperm has a flagella which is that tail that will allow it to do its job or function which is to swim so form follows function if you can figure out the structure of something then you could figure out its function so because this sperm has a flagella which is a tail that will allow it to do its job or function which is to swim now what would happen if this sperm cell did not have a flagella would it be able to do its job its function no so you see that but because it has a tail that will allow it to do its job or function which is to swim to the egg so that way it can fertilize it now if y'all have time uh i recommend that you go on youtube and you search videos for male sperm because it's actually hilarious those of you who don't know if a couple is trying to conceive the they will give you one year to try to conceive and within a year you're still did not conceive the female is still not pregnant you you are now labeled as infertile so what you do is you go to a fertility specialist and the first person he starts off with is the male why because males are very easy all that all the males have to do is ejaculate into a cup which is the ejaculate in the ml is like one teaspoon or five ml and then what they'll do is they'll take a sample of that ejaculate stick it underneath the microscope slide and they will look at the quality of the sperm underneath a microscope now in a healthy male ejaculate now i'm talking about like a male when he is at the height of his fertility all right whatever age that is he will have like 500 million sperm in that five teaspoons all right and that and now and that one teaspoon five mlt will have a 500 million sperm and that ejaculate which is you know a teaspoon 500 million sperm will be in there now don't get too excited because 70 of that sperm is trash and this is in a very robust fertile milk at the height of his fertility 70 of the 500 million sperms are trash only 30 are viable only 30 are capable of fertilizing an egg all right so if you look at some of the uh sperm underneath the microscope they're actually really quite hilarious because you will see like a sperm that looks like this it doesn't have a tail it's mutated it doesn't have a tail or you will see a another sperm and it has a tail but sperm is not exactly very bright and all it's doing is it's going in a tail all right or you will see a sperm with two heads you will see a sperm with two heads y'all i should you not or you will see my personal favorite which is you will see a sperm with no head you will just see a tail whipping around okay again yeah this is like in a very healthy male 70 of a sperm is trash they're not capable they're not viable of fertilizing an egg now if they look at a sperm and they find that you know what no his sperm are viable there's nothing wrong with his sperm you know he's healthy then they will resort to the female because unfortunately the female is uses more intrusive techniques you know it's a bit more tricky we got to get up collect the eggs harvest the egg there's more risk if we look at the females so when you go see a fertility specialist they always start with the males because they're easy they just have to ejaculate into a cup and then we look underneath the microscope at the quality of the sperm but the sperm is just one example of how form follows function if you can figure out the structure of something it will help you to understand its function let's look at a different type of cell i'm going to draw a different type of cell on here and if you don't know what this cell is don't worry don't worry about it we'll learn about it in detail in chapter 12. but here this is another type of cell and i want someone to mute their mic and tell us what kind of cell is this is that a dendritic cell okay you're close it's a neuron right it's a neuron now what is a neuron it is a nerve cell okay this is a nerve cell so this is going to be found in your nervous system all right good job and so what is the function of this neuron the function of this neuron is it's going to collect information from the environment and pass it on to the next neuron so again the function of this neuron is to collect information and pass it on to the next neuron that information is going to pass along this structure which we call the axon but again the job or the function of this neuron is to collect information well so how does it do it what does it contain in its structure what is built into its structure to help it do that function which is to collect information what neurons contain are these extensions which we call dendrites okay what is the job of dendrites dendrites collect information about the environment and they pass it on so again this nerve because its function is communication all right communication that is its function what it contains are dendrites and these dendrites collect information so that way this neuron can pass that information down to the next neuron or down to a muscle when we talk about uh chapter 10. all right but again what would happen if this neuron did not have any dendrites could it do its job of communication no it can't so the fact that it contains dendrites those extensions and their job is to collect information that will allow this neuron to do its job which is communication so you see how form follows function if you can figure out the structure of something that is a clue or a hint as to how it functions form follows functions that is the first rule that you'll have to understand in order to really understand the human body and a and p1 and a and p2 now let's go to the next lecture notes and i'm going to highlight what i think is important so we're on slide number two let me choose the highlighting tool again anatomy studies the form which is a fancy schmancy way of saying structure physiology studies the function okay and form and function are interrelated what that means is form follows function if you can figure out the structure of something it will help you understand its function okay all right we're gonna skip through all of these slides and we're gonna go on slide number six and here they're just expanding on that last bullet which was form and function are interrelated i just want you to highlight again this magic sentence form follows function what we wrote on the board if you can figure out the structure of something that will give you a hint as to how it functions okay all right let's move on let's look at slide number eight all right so this is where we are going to make some comparisons so it's this should have come as a shock to y'all but i'm actually considered a living thing so we're going to be using me as an example of a living thing and we're going to compare it to this white board this white board is actually non-living so i'm living this white board is non-living what is the difference how do we define living versus non-living all right so remember i'm going to be using me as an example i'm the living and this white board is non-living so let's look at slide number eight the first thing that you should see is organization what do we mean by organization what that means is if you were to cut me up and look at my inside world you will see that my organs and the way that my my inside world is organized is actually very complex very structured so my heart is in a certain area my lungs are in a certain area my digestive organs are in a certain area it's all structured it's all organized same thing if i slice alejandro open his inside world his organs are going to look just like mine they are in you know the exact same place and they're organized the exact same way what about this white board if i were to slice through this white board would i see that level of sophistication would i see that level of structure or organization no i wouldn't see it so i am much more structured and organized than this whiteboard okay metabolism this is a big one let's look at metabolism let's write metabolism on the board so when i ask students you know what do you think of when you hear the word metabolism students will say oh oh that has to do with you know your digestive system and how quickly you burn calories do you have a high metabolism do you have a low metabolism when we talk about amp and the human body that has nothing to do with it when we say metabolism in a and p all we mean is all the sums of the chemical reactions in your body the sum of the chemical reactions in your body right so let's look at metabolism let's break it down into two components i'm going to write this kind of like a math equation metabolism has two parts to it the first one is what we call anabolism all right anabolism that is where we go from small to large in other words we are making something imagine taking like individual lego blocks and you're going to bring them together to make to build a lego house right so you're going from small to large that is what anabolism is now let's step back and let's review remember nilo when i told you about this class the first thing when we started lecture i said you have to understand form follow function that is the first rule that you have to understand in order to understand amp1 a and p2 and how the human body works right the second law that you have to understand is there's always going to be in the human body balance balance what do i mean by balance well really what i mean is there has to be opposites because opposites create a balance if you if you remember from your physics i think it was the law of inertia the law of inertia states that for every action there is an equal and opposite reaction that they're just saying that there's always going to be opposites in any situation to create a balance and that's exactly what the human body does there's going to be opposites and those opposites are needed to create a balance so let's look at this here we're going from small to large what is the opposite of going from small to large going from large to small when we go from large to small that is the opposite of going from small to large so imagine your lego house that you just built you're going to break it apart you are going from large lego house to small lego units when you go from large to small we call that catabolism okay catabolism that is where you go from large too small so when we add up all of the anabolism and all of the catabolism that is what gives us our metabolism and all day long erica all your body does is it builds something up which is called anabolism because you're going from small to large and then it tears it down which we call catabolism you're going from large to small build it up tear it down build it up tear it down build it up tear it down that is what we call metabolism okay now does this white board does it display metabolism does it build something up and then break it down no it just is it stays the same it doesn't have to worry about metabolism therefore that is another characteristic that makes me become a living thing and this white board is not a living thing okay so again this white board does not show metabolism where you build something up anabolism and break it down that's known as catabolism the next one again i'm on slide number eight it's called growth and development what do we mean by that well think of you know going from as humans you know think of you know um we go from a single cell when we are fertilized into a fetus into a baby into a teenager into an adult into an elderly person what happens is within that span of time we have undergone growth and development if matthew if you come back and you look at me in 10 years if you come back in 10 years you will see that i have aged i have more wrinkles i have more white hair i am now older right so i've shown growth and development so we would change over time physically we show growth and development again think of a baby as it is growing up it displays growth and development it changes over time does this whiteboard if i come back to this whiteboard in 10 years is it going to age is it going to look any different no it's going to remain the same it doesn't show growth and development so therefore it does not it's not considered a living thing okay let's go to slide number nine responsiveness the ability to sense and react to stimuli what does that mean well let's look at me i am going to go outside right now and in my area it's actually raining so if i go outside like this what's going to happen is the rain is going to fall on me and then i'm going to realize that it's raining it's wet outside go back inside grab my umbrella and go back outside what i've done is i have responded to my environment all right i've responded to my environment or let's say that's you know i go outside in a down coat and it is in the summertime it's 90 degrees i go outside i get hot what do i do i take off my coat so i have responded to my environment what would happen if rain hit this fight board would it do anything no it won't do anything why because it's not responding to its environment it's not considered a living thing all right all right let's move on i'm still on slide number nine regulation this is a big one let's talk about regulation and in fact this is so big that i'm actually going to share screen i'm going to tell you what i want you to highlight i want y'all to highlight homeostasis you're going to see this question on the exam i guarantee it homeostasis the ability to maintain your body's structure and function let's talk about homeostasis we're going to spend some time on homeostasis so talk about homeostasis what is homeostasis trying to maintain a balance sorry exactly i'm going to put that in layman's terms all right let me put it in layman's terms homeostasis all right what that is y'all is sort of like um this steady state this steady state so let's write that down the steady state what does that mean what that means is your body does not like any surprises see y'all we live in two types of worlds we live in two types of worlds there is me and my outside world which is the environment so hey y'all see this around me this is my outside world this is my environment this is what i'm going to be reacting with you know so i'm going to respond to my outside world the environment and then you have the opposite world which is called your inside world that is between you and your organs so i have two types of work me and my outside world which is the environment hi and then you have me in my inside world which is my organs okay so what homeostasis is is your body wants to make sure that your inside world your organs are working and they're doing their job and they are doing what they have to do to keep you in homeostasis homeostasis y'all this is the goal in your life this is the point where you are disease free this is the point where your body is doing its job to keep you disease free and healthy and you may take it for granted but as you age it gets harder and harder for your body to maintain homeostasis your body has to work harder because you know your organs are just tempted to stop doing their job they're like damn it the heart is like damn it i have been beeping you know beating for like 80 years i just want to slow down all right and you can't do that all right so again homeostasis gets very harder to maintain as you age that's why you'll notice older people are grumpier and they're more pissy because their body has to work harder longer to keep them disease free so matthew when your parents are yelling and screaming at you right they're like what do you want to do with your life you could say i want to maintain homeostasis and that's perfectly acceptable okay because your job is not really janelle your job is not really like you know to be a doctor or a nurse or a lawyer and all that positivity your job really is just to maintain homeostasis so next time someone says what do you what are you doing with your are you maintaining homeostasis no one can argue with that all right so again we're going to come back to homeostasis towards the end of this chapter but again homeostasis is like where your body your inside world does not like surprises all right and what happens is conditions in your outside world and conditions in your inside world are constantly changing it's a crazy world that we live in and your body's goal is to maintain everything constant to keep everything constant to keep your heart functioning to keep your lungs functioning evening even as everything is changing around you that is homeostasis because that is the disease free state that is where you want to be okay now there's this white board does it have to worry about homeostasis no it doesn't have to worry about homeostasis at all therefore it is not considered alive all right the next one that you're gonna see underneath that is you're gonna see reproduction this is also a big one what happens is you know two humans are gonna come together and they will make a new human being right two cats will come together to make a kitten two dogs will come together to form a puppy is this white board gonna hook up with another white board to make a baby board i'm not sure i don't know it's life okay get it y'all that's a joke okay oh yeah tough tough crap but again this white board is not going to hook up with another whiteboard and make a baby board right so it's not going to reproduce all living things reproduce whether asexually or sexually they reproduce they have sex cells that will create a new being all right this white board doesn't have to worry about that therefore it is not considered a lie all right so this is how we define living things versus non-living things okay all right let's move on this is a question on the exam slide number 10. this is a question on the exam and it's a short answer question where you have to type the answer out here what we're going to be doing is we are going to talk about the level of organization we're going to start from very simple and move to complex so if i were you i would know this level of organization from simple to complex and complex to simple in other words know it in both directions frontwards and backwards all right so we've already established that i am a living thing now we're going to talk about what is the level of organization in a living thing so we're going to take it a step further and talk about the different levels of organization now if you want to follow along we're going to start off on slide number 11. all right the first basic level is the chemical level okay chemical level now what do we mean by the chemical level well the chemical level is composed of atoms atoms let's write this down atoms okay now what are atoms well let me put it in perspective if you were to take me and put me in a blender and spin me around and run around until you get to my most basic level it's going to be atoms they're they're like my most basic simple level adams look at this y'all i'm going to make a fist i'm going to do this and i'm going to throw my fist towards the wall and as i did that billions of atoms just hit the wall and went everywhere you cannot see atoms with the naked eye but everything that has mass and takes up space is composed of atoms so looking at me i have a big mass and i take up a short load of space i am composed of atoms this marker because it takes up space and it has weight it has mass it is composed of atoms so anything that you can see that has mass and taste of space is composed of atoms that is the simplest level of organization the most basic level now let's draw an atom all right this is how an atom looks like see that it's just a little circle now an atom by itself is actually very boring atoms are single and ready to mingle atoms are looking to hook up okay and so what an atom is going to do is it's going to seek out another atom so what we're going to do is we're going to have an atom seeking out another atom and then these two atoms are going to form a bond between them so you have this now see that so we went from one atom to two atoms that have formed a bond we call this these two atoms now we call it a molecule okay a molecule is simply two atoms that are coming together and they form a bond all right now we're gonna go from molecule to what we call a macro molecule what is a macromolecule well macro means big so in other words now we're talking about hundreds of thousands of atoms coming together to form a big molecule so it looks like this see that i mean it would just go on and on and on this is a macro molecule it's composed of hundreds of thousands of atoms coming together and forming a bond macromolecules are composed of molecules which are composed of atoms okay now classic example of a macromolecule for this class is an organelle what is it cells but let me just introduce the idea for you here you have a cell okay inside of this cell you're gonna have a nucleus and you're gonna have these little structures these structures are what we call organelles l-e-l-l-e means baby so these are tiny little baby organs they are found inside of cells and each organelle here you see like what five organisms one two three four five each organelle has a specific function okay again these organelles are examples of a macromolecule which are composed of molecules which are composed of atoms all right so macromolecule from macromolecule then we are going to switch gears and we're going to become a cell in other words these organelles which are macromolecules are going to come together and they're going to form a cell now let's look at the definition of a cell because this is going to be short answer application question on your exam and it is worth 30 points so y'all better understand this all right so let's look at the definition of a cell i'm on slide number 12. the cell is the smallest living structure the cell is the smallest living structure let me share screen okay what do you notice about this definition what jumps out at you what word in that definition the smallest living structure what word jumps out at you it is living it is living living absolutely living jumps out at you because y'all what is a cell composed of a cell is composed of organelles which are composed of molecules which are composed of atoms well y'all are atoms amber are atoms considered living or non-living they're non-living so this is a question on your exam it is 30 points application how can something that is not living which are atoms they're not living how are they coming together to form something that is living which is a cell so that's 30 points application on i'm just kidding i'm just kidding nobody knows that answer i'm kidding janelle i'm kidding that's not a question on the exam honest matthew he's like okay i've had it dr bakker with your i'm not amused um it's it's not a question on the exam honestly we don't know the answer we don't know how something that is living that is not living which are atoms are coming to form something that is living which is a cell we don't know and i don't expect you to know so again these organelles are coming together to form a cell and this is where things take a turn because now we're jumping into the living territory before a cell we were considered non-living now we are considered living so we're going to go from a cell to a tissue what is a tissue well tissues are where you have groups of cells coming together to form a common or similar function i'm going to give you an example your skin is actually considered a tissue what is your skin composed of hundreds of thousands of cells that are coming together to form the skin and what is the function of the skin to protect you all right by the way y'all they found a new finding i would hate to be the scientist that was tasked with this but apparently they found out the number of cells in a human and it is three trillion you have three trillion cells inside of you but don't get too excited because they're not counting the cells that you shed at a fast rate for example your skin cells you shed like two pounds worth of dead skin cells every single day all right so they're not counting the cells that you shut off so from head to toe you are you're composed of three trillion cells okay anyways you don't have to know that it's not a question on the exam so tissues again they're groups of cells that are coming together what are these cells composed of organelles which are macromolecules or macromolecules composed of molecules and what are molecules composed of atoms okay now these tissues are going to come together and they are going to form an organ an organ so let's talk about something like the heart the heart is an organ but it is composed of groups of tissues that are coming together to perform one specific function what is the function of your heart to pump blood so again these tissues these groups of tissues which are composed of hundreds of thousands of cells by coming together to form an organ and this organ has one specific function in the case of your heart it is to pump blood if we were talking about your kidneys the function of that kidney is to make urine all right but that kidney is going to be composed of tissues and that tissue will be composed of cells all right and then finally this organ is going to come together to form an organ system okay now if i were to ask you you know let's talk about the digestive system you say oh oh oh okay okay your stomach okay the digestive system y'all is not just the stomach the stomach gets all the credit but in reality the digestive system is composed of not only the stomach but the liver the pancreas the intestines the the gallbladder uh all these other organs that are coming together to form the organ system in this case the digestive system all right if i were to say urinary system you're going to say oh oh okay the bladder it's not just the bladder the urinary system is also composed of kidneys ureters they're all coming together to form the urinary system all right so again when we talk about an organ system more than one organ is involved it's not just one organ more than one organ is involved and they're coming together and they're working together to do its function what is the job of the digestive system it is to help you break down and absorb your food the stomach cannot do that all on its own it works alongside the small intestine the large intestine the gallbladder the pancreas all of those different organs are coming together to function in the digestive system and then finally after the organ system we're going to have the orga or organismal organ organismal level all right this is the highest level of organization this is where we're talking about the organism what we mean is all of the organ systems the digestive system the cardiovascular system the the urinary system the endocrine system all of these systems are working together they work separately but they also communicate with one another so for example the heart communicates with your lungs which communicates with you know your urinary system they're all communicating with each other to keep you in homeostasis so an organismal level is the highest level of organization that's where all of these organ systems which are composed of organs which are composed of tissues which are composed of cells which are composed of macromolecules which are composed of molecules which are composed of atoms i feel like that doctor sees book you know the boy who's fall to fly so again um they're all working together for you to reach the organismal level and that will help you to keep you in homeostasis okay all right so again that is a question on the exam two points where you literally have to type out the levels of organization so i would know it going from simple to complex and complex to simple again i would refer because i know you all love your memorization so i would refer to slide number ten okay slide number ten all right here's another question on the exam another question on the exam is for you to list the 11 organ systems i'm going to show you where to find that answer it's worth five points and you have to list or type out the 11 organ systems you can find the answer on slide 17 and 18. okay you don't even have to describe it just type it out it's worth five points and you would be surprised how many students leave that question blank i can't help you okay if you cannot help yourself i cannot help you so your book has an easy way to remember these 11 organ systems i think it's actually in poor taste given the huge amount of crime that we're experiencing in this nation but you know what it helps students so we're just we'll just go through with it they call it murders blink that's l-i-n-c and so each letter represents an organ system so for example m would be muscle u would be urinary r would be respiratory d would be digestive e would be endocrine and so on and so on okay murders link so again on the exam you just have to type out the name of these 11 organ systems you don't have to describe them it's worth five points all right let's move on so we just typed the words out for murders link we're good yeah and you can get the answer on slides 17 and 18. okay all right so now let's fast forward to slide number 23 slide number 23 all right this is where we're going to talk about homeostasis all right so let me share screen so that way i won't try to highlight what i'm emphasizing again homeostasis it is let's highlight the ability of an organism to maintain a consistent or steady state in response to constantly changing conditions remember what we said we said we live in two types of world there is your outside world which is me and my environment that's what i'm gonna respond to and then there's me and my inside world that is my organs and so homeostasis is where your inside world is constantly changing you're outside world is constantly changing but your organs are still doing their job and they're still functioning and they are keeping you in homeostasis all right that is the point where you are disease-free amber you don't have any disease all right so when you are in homeostasis you are disease free so please don't ask me well what about if you have diabetes if you have diabetes you are no longer in homeostasis all right so as long as you are disease free that means you are in homeostasis if you have high blood pressure and you're taking medication you're not in homeostasis all right you're in disease you're not disease free all right so let's move on all right let's talk about slide number 24. this is going to be a question on the exam and it's going to be multiple choice and it has three blanks to it so make sure you'll understand this next concept so what i'm going to do is i'm going to start by giving y'all an example this is a very simple example but please lily do not try this at home all right i always have to make that disclaimer all i'm gonna do y'all watch me i'm gonna take my left hand and let's say that i'm gonna put it on this white board now let's pretend that this white board is a hot stove so all i'm doing is taking my left hand and putting it on a hot stove again do not try this at home all right so somebody tell me what do you think is gonna happen when i put my left hand on a hot stove you're going to pull it away you're going to react exactly i'm going to pull it i'm going to go ah dang that was happening all right so what's going on well let's talk about what's going on we're going to break it down using the scientific language again all i did was i just put my left hand on a hot so then nah i mean that was hot all right what happens is underneath your skin my left hand underneath my left hand right there's skin embedded in the skin of my left hand are these guys okay see this y'all i'm arab and so i use my hands a lot and i will use my hands for teaching demonstrations we have these guys what is this this is a receptor okay this is a receptor so this is going to be found embedded in your left hand underneath your skin you have receptors these guys all up and down your body anytime you have skin you're going to have receptors embedded there and so this receptor in your left hand its job its function is to detect heat okay so you have a receptor like this okay if i were to draw it up on the board it would look like this okay this is a receptor so again this would be this now a receptor like this on its own isn't going to do anything all right because the goal is we got to activate this receptor we want to turn this receptor on to fire a message and that message is going to go to the brain all right so again a receptor like this by itself it's not going to be activated it won't be turned on what do all receptors need all receptors need is a stimulus so what's going to happen is as i put my left hand on a hot stove the stimulus is going to be the heat coming from the hot stone the stimulus is going to be anything a response that's going to activate or turn on that receptor so what happens is the stimulus which is heat is going to brush up against this receptor and it's going to cause this receptor to become activated or turned on so if you want me to draw a stimulus it would look like this see this would be stimulus again in our example it would be heat okay so the heat is the stimulus it's going to brush up against the receptor and it's going to activate or turn on that receptor it's going to cause that receptor to fire now when i say fire what i mean is this receptor in your left hand is going to create a message it's going to convert the stimulus to a message and that message is going to travel all the way from your left hand to your arm hit the spinal cord go up the spinal cord and it's going to land in the brain the brain is what we call our control center the brain is our control center and what the brain does is it's going to receive this information what is the information that information is i just put my left hand on a hot stove that's the information that the brain receives which is the control center so what the control center or the brain is going to do is it's going to think about that information it's going to process it it's going to pull up memories from when you did it's like you know what you're idiot the last time you did this you got second degree burns so it's going to pull up memories past circumstances and then it's going to issue a command what do you think that command is going to be to take your hand off the stove remove your left hand off of the stove absolutely so now the brain is going to issue a command which is take your left hand off of the stove that command is going to start in the brain go down your spinal cord go to your left arm and then its target or effector is the skeletal muscles in your left hand and what it's going to tell them is start contracting what because when the skeletal muscles in your left hand contract it's going to allow you to move your left hand away from the hot stove so let's say this again put my left hand on a hot stove do not try this at home what do i have embedded underneath my left hand in the skin i have these guys these are receptors receptors on their own do not fire they need a stimulus so what is the stimulus in our example the heat the heat from the hot stove is going to brush up against this receptor which is its job is to detect heat and it's going to cause that receptor to fire it's going to convert the stimulus to a message and that message is going to go from your left hand travel to your arm to your spinal cord up to the brain the brain is known as the control center the braid is going to receive this information it's going to think about it it's going to process it and then it's going to issue a command that command is going to start in your brain go down your spinal cord to your left arm and its target organ or effector is the skeletal muscles in your left hand and it's going to tell it start contracting because when the skeletal muscles in your left hand contract that allows you to move your hand away from the hot stove let's go to the board and let's write this as an example with scientific language so let's go to the board again let's use those exact same players and let's see how it rolls out here we go so first we had our receptor okay the first was receptor all right so this was found in our skin in the skin of our left hand okay remember a receptor like this on its own is not going to fire what do receptors need they need a stimulus so the second component was a stimulus in our example that was heat coming from the hot stove that stimulus brushed up against the receptor and activated or turned on that receptor it caused that receptor to fire an electrical message and that message went straight from your left hand all the way up to the brain we call that the control center in our example the control center was the brain now the control center will not always be the brain you're going to have some instances especially when we talk about a and p2 when the control center is going to be the pancreas or it's going to be the thyroid gland so it's not always the brain all right but just for this example we're keeping it very simple we're going to say it's the brain so what the brain is going to do is it's going to think about it it's going to process it it's going to issue a command what is that command going to be remove your hand from the hot stove and that command is going to start in the brain go down your spinal cord out to your left arm and it's targeted or its effector on the exam you're going to see the word effector that means target organ it's going to be the skeletal muscles in the left hand and it's going to tell them to contract why because as the skeletal muscles in your left hand as it contracts it allows you to move your hand away from the hot stove okay all right so again i'm looking at the exam there's one question it is multiple choice it has three parts to it so make sure that you understand these players okay any questions so far before we move on is there something that you still don't understand or you want me to repeat all right let's move on so go ahead go ahead um it's back on the organ system is it the murder link acronym what was the i was trying to write it all down okay i can put it in the chat you want me to put it in the chat please okay everyone in meaning it's murders and again y'all i know i move so fast and i apologize but it's because we are on such a tight timetable and so if there's something that you didn't get in lecture the first time as i'm lecturing live don't worry i will make these recordings available to you later on today once i get them and then you can go at your own pace all right so don't feel overwhelmed don't feel pressured that i gotta understand all this no you don't there's nothing wrong with you if you don't understand it from the first time because i'm just going so fast so again if you don't understand just wait until the lecture comes out and then you can go at your own pace i've had students tell me i did not understand dr bachdash the filtration of the urinary system so i just had to go back re-watch me watch orders until i got it so again there's nothing wrong with you i'm just moving too fast alright so please always stop me and let me know i didn't catch that or could you say that again all right so here this was where we slept where we stopped off slot number 24. these are all parts of the homeostatic system so these are the key players in the homeostatic systems all right so think of them as like actors in a movie these are the uh components to keeping you in homeostasis so we talked about a receptor remember that is the one that is responsible for detecting a change in the environment it could be your inside world it could be your outside world it doesn't matter but its job is specific in our example our receptor was specific for detecting heat all right and then you had your stimulus remember a receptor on its own is not going to do anything it needs to have a stimulus that is a change that is a change in the environment whether it be your inside world or your outside world but there has to be a change and the receptor once it detects that change that stimulus then it will become activated then it will fire um a message the control center that's going to be the one to receive that message from the receptor and it's going to take that message it's going to think about it it's going to process it and then it's going to issue a command in our example the control center was the brain and then finally your effector that is your target organ that is going to be the one who's going to go about and bring about that change in our example the effector was the skeletal muscles in your left hand they had to contract in order to bring about a change so your affector is the one that is responsible for causing a change in response to the stimulus it's your target organ all right here's y'all this is going to be this next part when we talk about homeostatic systems this is going to be short answer application on the exam and it's worth you have two points whenever i say application what i mean is i'm gonna give you a scenario and i'm gonna ask you what's going on and you have to tell me why you know with like what this is and why so basically what that means is you need to make sure that you understand negative feedback and positive feedback because you're gonna have two questions and each question is worth three points a piece and they're short answer application and you have to tell me why all right and you don't have to write me an essay you could just answer these questions in two or three sentences okay all right so let's look at the first one if you want to follow actually you know what first let me share screen i want to tell you what i want y'all to highlight again we're going to talk about homeostatic systems what we mean is these are systems that we have in place to make sure that we are in homeostasis the first one that we're going to talk about is negative feedback and out of all this slide number 25 all i want you to highlight is the very last bullet point it says in negative feedback homeostatic controls respond to move the variable in opposite direction to bring it back into the normal range okay what does that mean i'm going to give y'all something actually i'm going to give you one example okay and i don't like the way the book talks about it because i think that the examples that the book gives are actually very very confusing so i'm going to use a different example all right so we're going to go back to the board and i'm going to use another example to illustrate this point okay so let's stop sharing and let's go back to the board so we're going to talk about blood glucose concentration you're going to ask me what is that all right we're going to talk about the concentration of glucose in your blood glucose is a fancy fancy way of saying sugar anything that is alive needs sugar even bacteria they need glucose or sugar all right why because glucose is going to come from your diet and it's going to combine with oxygen which is coming from the air that you breathe and glucose plus oxygen are going to come together to make atp we're going to talk about atp in chapter 3 but atp is energy in other words this is what keeps your body functioning so you need atp to function where do you get atp from glucose and oxygen so you always have to have a certain concentration of sugar or glucose in your blood all right so let's go to the board and let's draw this line okay so you see here i have two points and then here i have a line now you don't have to know these numbers on the exam but i'm going to use them for teaching purposes this right here anything that falls between these two dots if it's on this if it's in this line that means that this is your homeostatic range okay so you want to be inside of these two dots if you're inside of these two dots that means that you are in homeostasis so there is some room for uh you know some a little bit of wiggle room built into these homeostatic mechanisms but not a lot all right it's kind of like goldilocks has to be just right so anything that falls between these two dots you're considered in the homeostatic range and everything is hunky-dory okay now when we talk about blood glucose concentration sugar in the blood at all times even if you are sleeping you still have to have this baseline of glucose in the blood on the low end it is 70 milligrams per deciliter and on the high end it's 110 milligrams per deciliter again you don't have to know these figures on the exam i'm just using them for demonstration purposes actually i think now it's like 100 milligrams it doesn't matter anyways what this saying is your blood glucose concentration cannot go below 70 milligrams per deciliter and it cannot go above 110 milligrams per deciliter if it falls outside of 70 to 110 then you are no longer in homeostasis okay all right so to illustrate this point what i'm going to do is i'm going to use two students as an example so i'm going to use jamie and i'm going to use brianna all right let's say that jamie you have not had anything to eat since last night's dinner okay you just you did not have anything to eat since last night's dinner so jamie if i were to ask you what do you think the concentration of glucose is going to be in your blood jamie would say well it would probably be below 70 milligrams per deciliter because i didn't need anything therefore i didn't have any glucose therefore the concentration of glucose in my blood would be very low right that's what we would all think well guess what you're actually wrong if we were to measure the concentration the amount of glucose in jamie's blood even though she didn't have anything to eat since last night she would actually be within that homeostatic range how this is one of the many miracles of the human body when your blood sugar drops below 70 milligrams per deciliter what happens is you have this cool organ called the pancreas and what it's going to do is it's going to release a hormone called glucagon and what glucagon does is it's going to leave the pancreas enter the bloodstream and it's going to tell all of your organs especially your liver and the skeletal muscles it's going to tell them start releasing glucose into the blood so your liver your skeletal muscles are going to take glucose that they were storing just for shits and giggles and they're going to move it to the blood all right so then what's going to happen is your blood sugar concentration is going to go back up to be within this homeostatic range so let's say that again uh who was i using uh jamie jamie did not have anything to eat since last night therefore you would think that her blood sugar concentration the amount of glucose in her blood would be low right but you're actually wrong if her blood sugar drops below 70 milligrams per deciliter what's going to happen is the pancreas is going to detect that it's going to detect that her blood sugar has fallen below the homeostatic range and it's going to order it's going to release glucagon glucagon is going to leave the pancreas enter the bloodstream and it's going to tell organs such as your liver and your skeletal muscles stop holding on to glucose stop storing glucose and move that glucose to the blood so now what happens now we're going to start moving glucose to the blood and what's going to happen is now our blood sugar concentration is going to start to increase to be within that homeostatic range this is an example of negative feedback why noel because we started off low our blood sugar was dropping then what happened was negative feedback kicked in and then it caused our blood sugar to increase to be within this homeostatic range in other words we move the variable effect to the opposite direction we start off low we ended up high to be within the homeostatic range let's look at uh rihanna brianna has the opposite problem please do not try this at home brianna just ate 10 powdered donuts all right so she's she obviously has a lot of sugar now in her blood why could she just ate 10 powdered donuts which are very high in sugar so what's going to happen is that powdered doughnut is going to enter her bloodstream and now her blood sugar concentration would be over 110 milligrams right if brianna just ate 10 powder donuts and we measured her blood sugar concentration you would say oh okay okay well it'd actually be over 110 milligrams per deciliter or guess what you'd actually be wrong why what happens is the pancreas is going to detect that her blood sugar concentration was too high it was above the homeostatic range so what the pancreas is going to do is it is going to release this other hormone called insulin and what insulin is going to do is it's going to leave the pancreas enter the bloodstream and it's going to tell your organs especially your liver and your skeletal muscles start moving glucose from the blood to the organs we're going to start storing glucose we're going to move glucose from the bloodstream to the organs what have we just done to the concentration of glucose in the blood because we're moving glucose out of the blood and into organs we have now decreased the concentration of glucose in the blood so that is another example of negative feedback why because here in brianna's example we were we started off with a high blood sugar concentration and then negative feedback kicked in and now we are at a low blood sugar concentration to keep us within that homeostatic range in other words we move the variable in the opposite direction now please don't ask me okay well diabetes if you have diabetes again this does not work why because you are not in homeostasis all right does anyone have a question about negative feedback something that you know you didn't understand or you wanted to ask okay all right so let's go back i'm going to erase this and let's talk about negative feedback so remember negative feedback is a part of what we call homeostatic control these are mechanisms that we have placed inside of us to make sure that we are in homeostasis so homeostatic controls the first one that we talked about was negative feedback all right so negative feedback so the majority of your body processes is regulated by negative feedback in fact if you are a female 98 of your body processes will be negative feedback if you're a male 99 of your body processes will be negative feedback so negative feedback dominates the majority of the body processes inside of your body okay so remember what we said we said that in the human body there has to be opposites why because opposites create balance so what's going to be the opposite of negative feedback what's the opposite of negative feedback it's going to be positive awesome exactly positive feedback positive feedback all right so for positive feedback if you're female positive feedback is two percent of your bodily processes if you're male it's one percent what is the discrepancy why is it in females two percent why is it in males it's one percent what do females do that males can't do actually there's a lot of things that females do that really don't know but i digress what is it that females do that males just can't do menstruation birthing children as well exactly menstruate uh childbirth we we lactate we breastfeed all of these things men men cannot do but women do all right so we're going to