Anatomy and Physiology

hi it's mr. Andersen and welcome to my first podcast on anatomy and physiology this is really just an introductory video we'll go into more depth in subsequent videos talking about specific systems but in this video I want to kind of define anatomy and physiology talk about some of the major themes that we'll find and then we'll get into tissues and just a preview of all the different organ systems before we get there though I want to talk about this over here this is an adjustable spanner I always thought this was a crescent wrench but a

specific type of adjustable spanner apparently is a crescent wrench so think for just a second about what are some of the structures on the wrench well right here we have this movable metal we've got a rolling device you've got teeth got this long arm so these are all structures but what do they do well you know this that I can roll this back and forth this will move this in this direction so I can fit different nuts I've got a huge amount of leverage by pushing on this and so basically what we've identified is the

anatomy and the physiology of this tool in other words Anatomy is simply what it is what's the structure physiology is the function and so let's quit talking about tools and talk about the human hand and so there's a term that goes by form fits function and so the form think of that as the anatomy so the form of my hand the muscles the bones the tendons and all of that is going to be the form what it does how it works how it operates all of those things are going to be the function of the

hand and how they work all the way from the nerves that pick up touch to the muscles all of that is going to be the function and so in the back of it your head I always be thinking form fits function anatomy fits physiology okay so basically there are a few themes in anatomy and physiology the first one is called homeostasis and you may we think of just like a home homeostasis means maintaining a stable internal environment and so how do we do that inside our home we use a thermostat and so a thermostat is

basically going to use a feedback loop it's going to use a negative feedback loop if the temperature gets too hi it's going to turn off the heat if it gets too low it's going to turn on the heat and so it's going to keep you at a stable internal environment now what about inside our body we have the same thing we have a thermostat it's the hypothalamus which is right above the roof of your mouth and it basically is going to sense the temperature inside you it's going to be right around 37 degrees Celsius what

happens if your temperature goes too high then your body's going to react it's going to start to sweat and you're also going to start to vasodilate you're going to open up the capillaries near you the surface so it can carry that heat away what happens now is our temperature's going to be depressed if it goes too low what do we do well we could get goose bumps those are creepy looking goose bumps or we could vasoconstrict hold that body heat near the body and constrict moving through the capillaries and our body temperature is going to

increase this is a negative feedback loop but it's a great example of homeostasis and in anatomy and physiology we're going to have to learn a number of these different feedback loops another thing that's important is hierarchy in other words in a house you've got a kitchen in that kitchen you've got a sink in that sink we've got a drain so we've got parts that make up that whole of the house and same thing inside biology we start at the level of an atom which comes together to form molecules macromolecules organelles cells tissues organs organ systems

but not all of this is anatomy and physiology anatomy and physiology really begins at the level of the cells tissues organs and organ systems and so this is going to be our anatomy and physiology area I spent a lot of time here on organs tissues and organ systems as we get up here this gets more into the ecology so we won't spend a lot of time up there but basically this is what we're doing so there's a hierarchy and each time we go up to a bigger classification or a heart a higher level of hierarchy

we're going to have emergent properties that start to show up another thing that you should understand is that those cells then form what are called tissues and so you should have a good understanding of the different types of tissues there are only four in humans and those are epithelial muscle nervous and then connective tissue let's start with epithelial tissue seoyul tissue there are basically two things that epithelial tissues have first of all I should not get too far ahead of myself epithelial is going to be the linings of our organs but it's also going to

be the outside of our body so my skin what you're looking at is epithelial tissue and so we classify epithelial tissue according to its shape and then the number of layers and so there are a few weird terms first one is weird and that is if we have flat epithelial tissue we call that squamous so this would be squamous cells next if it looks like this we call that cuboidal because it's like a cube and then finally if it looks like this then we call that columnar because it looks like a column and so these

are the three different shapes pay attention because I'm going to test you on the next page and then the layering if it's a simple layer we call that simple if it's just one layer of epithelial cells but if it's a number of layers and Rakata call that stratified epithelial cells so let's look at some epithelial cells what they might look like so basically these are all epithelial cells are going to be the lining of organs or the outside of the body so if we look at this one right here that would be simple squamous right

there flat and there's with single layer so like the alveoli in your lungs be an example of simple squamous cells what about this one over here as I pause awkwardly for you to answer that's right that would be simple columnar what about this one simple cuboidal right this would be like the lining of the nephron or some of the glands in your body what about this that's right stratified cuboidal what about this that's stratified squamous yeah that's what your skin is so you're constantly losing that but it offers protection and then this is a tricky

one here I don't think you could answer that unless you've been looking ahead these are actually pseudostratified columnar they're pseudo stratified they look like they're stratified but that's because some of them are fat at the bottom and skinny at the top and some are skinny at the bottom fat at the top and so there are some of these in your lungs that actually have cilia on it and so we would call those let me see if I can get this right pseudo stratified ciliated columnar epithelial cells and so if you learn some of these terms

you're going to do well and you're also going to impress people with all of your big terms next it gets a little easier we've got the muscle cells muscle cells are responsible for motion there are three types of muscle cells those are going to be skeletal muscle cells this would be an example of skeletal muscle cells right over here that's going to move my finger move my arms all movement in my body that I'm in control of is going to be skeletal muscle we also have smooth muscle smooth muscle is not going to be as

regular as this example of smooth muscle are going to be involuntary muscles so the movement of food down your esophagus becomes smooth muscle the movement of food all the way through your digestive system it's going to be smooth muscle I don't have to think oh I want to move food specifically through a certain part of my small intestine it just moves on its own that smooth muscle and then the third type we have it's only found in the heart is going to be cardiac muscle it actually looks a lot like the skeletal or striated muscle

but it's going to have these little intercalated discs inside it and that's going to transmit electrical signals so they can move through because the electrical signals of the heart are going to create the contraction of the heart next we've got the nervous tissue nervous tissue is going to send quick signals throughout your body it's basically made up of neurons and then some glial cells that will help out with that but basically what you have are all of these dendrites on this side they're going to sense a signal they're going to send an action potential down

an axon to another nervous signal or another neuron so that's basically what you're doing right now in your brain nervous tissue the nerves throughout your body are going to be nervous tissue so basically what do we got so far we've got epithelial covering we've got muscle movement we've got nervous so what's left last thing is going to be connective tissue and so connective tissue is going to be kind of a catch-all to everything that we haven't talked about so far and there's a lot of things that make up connective tissue connective tissue is going to

have basically it's going to have living cells but it's also going to have nonliving matrix around it sometimes and so two examples would be loose connective and dense connective so basically if I pull my skin up like that and let it go what's holding it there is loose connective tissue so inside there we're going to have some collagen fibers which make it so I can't pull my skin off my hand but we also have these elastin fibers that are going to bounce it right back and then the more collagen that we have the more dense

it becomes so if we were to grab a tendon for example that's going to be a type of connective tissue but it's going to have way more collagen and it's not going to be quite as bouncy so other types of connective tissue would be like cartilage blood bone fat these are all connective tissue all of these things connect the other types of tissues and so again there are only four different types of tissues inside our body and then the final thing I want to leave you with is kind of a preview of where we're headed

the different systems inside your body and basically what they do if we start with digestive systems basically the job of that is to digest food and then absorb that food into our circulatory system starts with the mouth it actually starts with your eyes when you see some food that you really want to eat next we have circulatory system that's going to move blood and thereby oxygen carbon dioxide nutrients around in your body respiratory system here's those alveoli was talking about a second ago basically taking an oxygen get ready getting rid of carbon dioxide the immune

or lymphatic system is going to be made up of a bunch of lymph vessels so that's going to basically going to take in plasma or liquid that's leaked out of your circulatory system return it to the circulatory system but we also have these lymph nodes and basically those are areas where white blood cells will sit and they're able to fight infection next we have the excretory system it's a way to get rid of nitrogenous waste but it also serves the function of regulating osmolarity in our blood so the kidneys are a big part of excretory

system we then have the endocrine system these are going to be to all the glands inside your body and the hormones that they give off from the pituitary all the way to the ovaries and the testes next we have the reproductive system basically different in males and females but a way to produce offspring nervous system is again those nerves connecting from the brain to the peripheral nervous system and back again so we can respond to our environment integumentary system is going to be the skin nails the hair basically covers our body skeletal system is going

to give us support but it's also going to store important materials inside our body then finally we have the muscular Tory system which is connect using those tendons the dense connective tissue to the bones and allows us movement and so those are the organ systems that's anatomy and physiology again we'll get into more detail with each of these but if you can remember those themes and the idea that structure fits function you're going to do just fine