hi so we begin our journey with the introduction to anatomy starting with some of the big-picture concepts like how do we define anatomy and physiology so everybody likes these superhero movies right here's Superman and if we want to know how his laser beam vision works we need to know both something about the structure of his eyes and that will help us better understand how they make the laser beams so when you talk about Anatomy you're talking about this structure of the body or the parts of the body and their relationships to each other and you really need to be thinking about this not just as giving Superman's eyeball and looking at the organ but looking at the microscopic elements of that organ maybe you'd be looking at histology the study of the tissues that make the organ maybe you'd be looking at cytology the study of the cells that make the tissue that make the organ and you know you could look deeper and deeper at individual molecules or atoms or subatomic particles but in the world of anatomy we tend to look at you know from cells to tissues to organs and organ systems this will require of course a lot of learning of the names of these structures and their terminology so like just in this first introduction to anatomy video series you'll have like over a hundred probably mostly new terms to learn that's just the way it goes by understanding these terms then you get into physiology so like your Swamp Thing not a very popular superhero I don't even know if he's a hero or a villain but here you can see some of the chemistry of Swamp things abilities whatever they are here's a chloroplast you know now we're getting into some nitty-gritty on the function of swampthing how does the body ruptures how do they work how do they carry out these vital activities and typically you're looking at a cellular level you might also be looking at physics and chemistry to understand how these things work so you can combine these terms anatomy and physiology into kind of a simple saying if you will which is form and function anatomy is looking at the form you know the structures and physiology is looking at these functions you should have some concept of the class you're taking you know you should be able to define Anatomy it doesn't have to be the way I define it in fact I grabbed a few textbooks and I just captured a few of the different ways these textbooks are defining Anatomy and defining physiology and so you just find something that feels comfortable to you that you can remember for example for physiology the study of mechanisms always kind of stuck with me as a good way to remember what physiology is all about in this course we will do some physiology which is good because that's really the interesting part is how you apply Anatomy into these functions to have this physiology but I'll just be doing a lot of the basic physiology and we really need to do that in anatomy because when you take physiology you're gonna be doing really the high-level very detailed physiology that as we mentioned may include some chemistry and some physics ok so now that we've defined anatomy and physiology let's look at some of the grand themes these concepts that will come up again and again in anatomy and physiology structure does function well necessarily influence what it's made of how its shaped and where it's located and so on so like the eyes of a human will be very different than the eyes of a falcon because what we need them to do will differ if you compare that to like some deep sea creature then they'll be even greater differences based on their function and because of the close association between the form of an organ and what it needs to do it's really impossible that totally separate the anatomy from the physiology let's look at a few examples of this think about eyelids on humans so the function what we need eyelids to do is to clear debris off the surface of the eye and so what we have is a thin mucousy fold that can go down and up but the other part of the function here is that we need the eyelid to be able to do this very rapidly so we can continue to see our environment and so if you look at the cellular and subcellular anatomy of the eyelid then you'll be looking at these special muscle and nerve fibers that will allow the eyelid to do its function so quickly so both the form of my eyelids that you can see now but also the hidden form that you can't see are both related to the function of the eyelid what about in the nasal cavity when you breathe air in through your nose you don't actually want like - nice cylinders of air to enter your nostrils because what if there's a virus or a mosquito or something floating in that cylinder of air you might suck that thing right down into your lungs so what you want is for the air to become turbulent so that virus or that mosquito slams against the mucous membrane lining your nasal cavity and gets stuck there so I can't get in your lungs so the nasal conchae are these little kind of hook like shapes bone shapes and they make the air turbulent so that the air it gets better cleaned now if you mess with form you can typically mess with function so in the case of sickle-cell disease when the red blood cells become misshapen well the function of the red blood cells was to carry oxygen and sickle-cell disease affects and reduces the oxygen carrying capabilities of the blood cells but even a more basic function of red blood cells is like don't get all jammed up inside the blood vessels unfortunately with sickle-cell disease because of that shape they cannot easily pass through these tiny capillaries and they do tend to get jammed up with pretty horrible consequences so form and function and more specifically form following function form being determined by function is a grand theme of anatomy and physiology another one is homeostasis you've probably been introduced to this term before we'll define it as the relative constancy of the body's internal environment sometimes you hear this discuss in the vein of dynamic equilibrium which is kind of this separate thing but dynamic equilibrium is another nice way to think about this because dynamic means change and you really want to understand it homeostasis does not mean constancy it means relative constancy it's kind of constant it's trying to be constant but what's really constant is the change always changing we're always going above and below and above and below our equilibrium point think about body temperature 98.6 degrees Fahrenheit is a nice set point for human body temperature but how often are you really exactly ninety eight point six degrees you're gonna be a little bit hotter sometimes a little bit cooler a little bit hotter and a little bit cooler so things are in flux but relatively constant body temperature right so even with dramatic changes in temperature outside your internal body temperature can stay relatively constant and all your body systems are contributing to homeostasis so I have an image here that we won't study in detail but I want you to think about homeostasis as like a seesaw or killer or maybe a figure-eight pattern all of these are just meant to remind you that there's movement so homeostasis it's not actually stable the other thing to know about homeostasis is that there are certain components that will allow homeostasis to occur let's just look at them if you were to think about some kind of variable let's say blood sugar levels blood glucose levels your body is monitoring your blood sugar levels at all times if you introduce a stimulus let's say lucky chance this isn't a gag I'm gonna eat those video I love lucky jumps by introducing that variable into my body in a few minutes my blood glucose levels will dramatically increase my liver is gonna try to capture some of that sugar but their lucky charms so a lot of sugar will enter my bloodstream that will be picked up by my receptors by these cells that are monitoring blood sugar levels in this case they are beta cells in the pancreas so they'll detect that increase in blood sugar and then in this case the control center is also in the pancreas and that's where it will analyze what the receptors are seeing you'll make a decision and determine what it should do about it and in this case with a whole bowl of Lucky Charms what the pancreas is control center will do is it will decide that some effect must take place it will trigger an effector to carry out a response what response do I want well I want my blood sugar levels fairly constant so the response needs to push those blood sugar levels back down and in this case the effector is also in the pancreas pancreas being a gland and what the pancreas as a gland will do is secrete insulin insulin will allow my cells to take in some of that sugar bringing my blood sugar level down it will engage with the liver to make sure the liver is storing away a lot of that extra sugar and all of these things will help lower my blood glucose levels so when we talk about this I want you to visualize this as blood sugar is going up and homeostasis is causing it to get pushed down and the opposite can be true too right if blood sugar is giving too low homeostasis can push it back up this mechanism is negative feedback this is your body's primary homeostatic mechanism right so it's it happens when the effectors response causes a change in the opposite direction to that of the initial change so it's helping to stabilize that variable return it to its normal limits another example could be body temperature so if your body temperature gets too high then sweating can get it down low again if it gets too low then shivering can get it up again so the opposite direction is why it's called negative feedback so does that mean there's a positive feedback sure it's kind of rare but positive feedback helps complete processes that have definite endings like childbirth so in this case the effectors response is going to intensify the original stimulus imagine if I ate a bunch of Lucky Charms in my blood sugar is shooting up and then the body somehow made it shoot up even higher and higher and higher that's not gonna be good for you but if you're trying to give birth what you want is that uterus to push in to push in to push until the baby's born right so it's going to intensify the original stimulus causing the variable to move farther away from its normal limits to cause a destabilization in the example we can see here as the head of the fetus is pushing on the cervix that triggers the brain to release oxytocin which causes the uterus to contract now the head of the fetus is pushing even harder on the cervix so it's causing the brain to release more oxytocin to push even harder on the uterus to make more pressure on the cervix and on and on and on until there's no more pressure on the cervix another example of this would be blood clotting if you're losing blood at an injury site you want to start to clot that blood a little bit and a little bit more and more and more and more and more until the blood loss stops okay so our final grand theme of a and P after form follows function and homeostasis and the mechanisms of homeostasis is the levels of organization this is pretty basic it just means that the architecture of your body can be arranged from the simplest and smallest to the largest and most complex levels so chemical and molecular of course is very small and simple those make cells cells make tissues make organs organ systems until you have a complete organism we'll talk about each of these briefly but you can also visualize this on a figure and take note here we can already see the 11 organ systems we'll be studying but let's revisit each of those levels quickly so in the chemical and molecular level well you really start with subatomic particles so we're talking like the protons neutrons and electrons that make atoms and then atoms combine to form molecules and as far as your body is concerned you've got sixty plus percent h2o molecules water molecules making up your body but you also have these molecules called proteins lipids carbohydrates and nucleic acids of course there's other stuff gases electrolytes and vitamins as a list but all of these are going to play a role somehow in your body's processes and may be found within cells cells are the smallest living unit in the body cells are full of organelles nucleus and mitochondria we will study cells relatively briefly in this course most of our focus especially in this first unit will be on tissues tissues are when you have similar cells that come together to perform a common function there are four types of tissues epithelial connective muscular and nervous tissue and you will be learning about those very soon but actually I'll give you a little sneak peek into that because after tissues you have organs when you start to combine tissues let's look at the heart as an organ you know that the heart is a muscle it's contracting to pump blood so that's one of the four types of tissues muscle tissue but you know that the heart has valves right so are those made of muscle no those are made of connective tissue that's the second type of tissue in your body the heart is beating so it needs to have kind of a slippery smooth outer lining so it's not causing friction that's provided by epithelial tissue a third type of tissue in your body and if you were to cut the heart out of your body it can beat on its own for a little bit but your nervous system is constantly tweaking the beating of your heart while it's in your body so nervous tissue is also found in the heart so an organ can have at least two but often all four tissue types make the organ and then you throw that organ in with some similar organs that have a common purpose and you get organ systems like the cardiovascular system cardio heart vascular means vessels the heart and the blood vessels make up the cardiovascular system you have eleven organ systems immune system sensory system these are not real systems although some textbooks will organize their chapters around these systems but your official 11 organ systems are provided in the following slides I'm not gonna walk you through all the organ systems what you'll see is that on the next 11 slides you have just a very brief one sentence summary of what that organ system does and the diagram that shows you a few of the major organs of that system so you are responsible to learn that it will help you a lot as we get into the second unit of this course we're just gonna start knocking off organ systems one at a time so you really want to learn the basics of each organ system so that you're a little bit prepared to dive deeper into each system I will give you one last bit of help though before you jump on that and that is thing as a mnemonic device mnemonic you're gonna want to know this term if you don't already a mnemonic device is a bit of wordplay that can help your memory you can take just about anything we learned this semester go to an internet search I don't know why I'm trying not to say Google go to Google it Google the topic and the mnemonic device so organ system mnemonic device or just mnemonic levels of organization mnemonic tissues mnemonic and you'll find that the I don't know billions of people that have taken Anatomy courses many have come up with tricks to help remember this content so one mnemonic device for the organ systems is murders linked murders it's not the best I don't think linked with a/c is a real word but murderous link is going to give you the first letter of each of the eleven organ systems for example muscular urinary respiratory digestive endocrine reproductive skeletal lymphatic integumentary nervous cardiovascular so you're gonna ace anatomy you for sure you can learn really quickly all the organ systems murtis link will help you do that good luck see you next time