so here are the 11 organ systems that we're going to learn as you can see there's a lot of information on there there's each system it has a bunch of organs in each system so I've got a free study guide that you can download link in the description for that you can print it out you can take notes on it it's going to have different practice activities that you can do as well as practice exercises like questions that you can answer to test your understanding on all this stuff it's free check it out in the link in the description below all right let's go back to these there are 11 organ systems but what I like to do is kind of categorize them based on their function so we're going to go through them in this order first we're going to look at systems that are dealing with support and movement primarily the skeletal and the muscular and the integumentary system then we're going to look at the systems that deal with integration and coordination basically controlling all of the other systems so that would include the nervous and endocrine then we'll look at two systems involved with transport so moving substances around inside of the body so that's going to be your cardiovascular system throughout your bloodstream as well as the lymphatic system that also includes the immune system in it as well but those are going to be transporting water and other substances throughout the body and then finally we'll look at absorption and excretion so this is going to be bringing things into the body and then removing things out of the body so the digestive system and the respiratory system those will be bringing things into the body when we breathe in or when we eat food or drink and then we'll have all three of these systems really getting rid of stuff from the body whether that's urine or carbon dioxide or our bowel movements right and then finally we've got reproduction and that's going to be of course to produce new offspring and so those are going to be kind of the five groups or categories we're going to use for all of these different systems so let's jump into our first system which is the integimementary system obviously the integimementary system involves your skin so we've got the skin here and this is going to be a cross-section of the skin and if we removed a chunk we zoom way in on it this is what the skin is going to look like we've got the hair of course we also have the fingernails and so those are going to be the three main kind of organs that are part of the integimementaryary system but the primary one is the skin so let's jump in or zoom in on this piece of skin right here we're going to take a look at four functions of the skin and they form the acronym PTSD which helps us to remember uh those different functions the first one is protection right it's the outer layer of our body it's going to prevent things from getting into our body that we don't want such as bacteria and viruses that might be harmful to us it also protect from things like UV radiation so it's not damaging our internal organs and all that so protection is a big part of this the second is temperature regulation so it's going to help regulate the temperature in our bodies several ways that it'll do that for one we've got sweat glands right here that'll produce sweat and when that sweat evaporates that cools off our skin cools off our body you also see that there's blood vessels going up into the skin and so we can regulate the the flow of blood in other words we can allow more blood to flow into the skin or less blood to flow into the skin to help regulate the temperature our skin also acts as an insulator so we've got several layers of skin it's just going to keep um the warmth inside of our body so temperature regulation is a big one hair will help with that as well and then we've got sensation so you can see there are nerve endings that come up into different parts of the skin we got these different sensory receptors those are all the stuff in yellow right there and those are connected to nerves and so sensation is a big part of our skin's function obviously that's connected to the nervous system and then finally vitamin D synthesis and so vitamin D is an important uh vitamin that we need to synthesize but we don't do it throughout the rest of our body we don't produce it um except for in our skin and we use the sunlight in order to do that so anyway those are the four functions of skin protection temperature regulation sensation and vitamin D synthesis uh in the integimementaryary system so PTSD to remember that quick thing If you're feeling overwhelmed by your AMP class or exams or just the sheer amount of information that you're supposed to learn in anatomy and physiology you're not alone that's actually really common but here's the truth the real game changer isn't spending more and more hours studying it's not even watching more of my YouTube videos but it's learning how to learn effectively that's the skill that helps you to actually retain all the information that you're learning and not just wasting time rereading notes and then forgetting all that stuff that you were supposed to learn that's exactly why I created the&p memory lab it's a five-week program where I teach you how memory actually works and how to make the anatomy and physiology content you're learning actually stick in your brain's long-term memory forever you'll save hours of study time feel way more confident going into your exams and move closer to your goal of becoming a nurse doctor physical therapist whatever your career goals are all without the stress and burnout that often comes in the description i'd love to see you in the&P memory lab and to help you achieve your goals all right back to the organ systems our next one is going to be the skeletal system so the skeletal system we're still in support and movement and so the organs of the skeletal system we'll start with those the first is going to be the bones that's the main one that you think of obviously we've got the bones like the skull and the ribs and our humorris for example the next thing we're going to have is joints and we got three types of joints in the body the first is going to be fibrous joints these don't have any movement those will be between like the bones of the skull for example we've got another type of joint which is going to be cartilagynous joints and we can see cartilage here between the vertebrae in our spine and so these are going to be a bunch of cartilagynous joints they allow a little bit of movement because there's cartilage between them and then finally we have something called synenovial joints those would be like the joints in your knee or your elbow or your wrist where there's lots of movement and so you can see an example here in the knee joint and we have this fibrous connective tissue that's connecting the joint that's going to be ligaments ligaments connect bone to other bone and so we have those in the skeletal system and then here we can see if we remove that we've got some cartilage right there that's going to reduce the friction between those bones whenever we have all that movement but the big idea here is we've got ligaments that are going to hold the joints together connect bone to bone all right what about the functions of the skeletal system so several functions here one is going to be structural support so if we didn't have bones we'd kind of just be a big blob without any structure so that structural support is important they're also levers for our muscles our muscles cause us to move and so here we've got an example of uh the bicep muscle and as we bend the arm the bicep muscle is using the bones of the arm as levers for that movement so here let's see let's contract that biceps muscle a little bit there and we'll contract it again and you can see it's pulling on the bone causing that movement of those bones so they act as levers for muscles a third really important function is going to be protection this can protect vital organs one big example of that is the skull obviously inside of our skull we have the brain and so the brain is very important the brain is also very easy to damage and so that's why we have this bone that covers it similarly we have the ribs which protect our heart and lungs we also have the pelvis that'll protect our pelvic organs our reproductive organs and all of that so protection is an important part of the skeletal system and then next um another function is going to be producing blood cells so your blood cells are actually produced in your bones we've got bone marrow we're going to have red bone marrow all throughout here we can see that bone marrow here as well and so the main function of the red bone marrow is to produce blood cells that's red blood cells and white blood cells it's produced in our bone pretty cool and then finally mineral storage and so our bones are made up of calcium and phosphate is kind of the two of the primary minerals calcium in particular is really important to regulate how much calcium we have in the blood and so we'll take some calcium out of the bone or put it back into the bone to make sure the calcium levels in our blood are where they need to be so we use bone to store minerals as well that's the skeletal system bones and joints are the main kind of organs and then we've got a lot of functions there structural support leverage for movement protecting our vital organs producing blood cells and storing of minerals up next we have the muscular system the organs pretty much the only organs are the skeletal muscles of course we've got a lot of different skeletal muscles that cause different movements and actions throughout the body but skeletal muscles is the main one here's an example of a skeletal muscle this is going to be your tricep muscle and we also have tendons tendons are kind of like ligaments but instead of connecting bone to bone they're going to connect the muscle to a bone and so here in our triceps muscle it's going to connect right here to the scapula right here to the humorris right here to the ulna and whenever it contracts that's going to pull on those bones and cause this movement to occur so the skeletal muscles and tendons are the main organs in our muscular system notice I didn't say the other two types of muscles which are cardiac muscle that would be more the cardiovascular system that's the muscle in our heart as well as smooth muscle we have that in our cardiovascular system around our blood vessels we also have smooth muscle in our digestive tract to push food along so really when we're talking about the muscular system we're mainly talking about skeletal muscles the muscles that move our skeleton move our bones now for the functions of the muscular system of course one of those is going to be movement so we've got a person running right here we've got a hamstring muscle right there that's going to be connected to the pelvis as well as down here and so whenever that contracts that's going to cause a movement of that knee joint so movement is a big part of the functions of the muscular system that's not the only function though another one is going to be posture so whenever you're sitting up straight or standing up straight muscles are contracted and some are relaxed in order to help you maintain that posture another one's going to be heat production just think about a time where you felt cold you might start to move around a little bit and the reason that you're doing that is to produce some heat uh and so we have heat production that's produced in our muscles that's an important function keeping us warm through movement so that is the muscular system we've got skeletal muscles and tendons and we've got those three functions movement posture and the production of heat or thermal energy all right up next we have the nervous system we've also moved from those support and movement systems and now we're moving into systems that are dealing with integration and coordination in other words these are going to be the systems that are controlling the other systems of the body and so this will be the nervous system and the endocrine system first we'll start with the nervous system the nervous system is going to include several organs first of all of course is the brain um the brain is going to be the main control center of the body it's going to be processing sensory information it's going to be where your personality and all your thoughts are but it also controls things that you don't think about such as your breathing rate and your heart rate and homeostasis throughout the body so a lot of stuff is going on in our brain extending down from the brain of course we've got the spinal cord i personally have a spinal cord injury i use a wheelchair if you didn't know that um because of a spinal cord injury so I really love the nervous system it's really fascinating one for me so we've got the spinal cord there and then branching out of the spinal cord we have all of our nerves of course we have cranial nerves coming from the brain as well so the brain spinal cord and nerves and we also have sensory receptors that are going to be at the end of a lot of those nerves the sensory nerves at least so those are going to be the main organs we could also add sensory organs like our eyes um our ears things like that we could also add to our nervous system here now the functions one is going to be fast communication and control we're going to compare that in a minute to the endocrine system which releases hormones and that's going to be a slower control but the nervous system is going to be for fast control it sends really fast nerve impulses throughout the body think of every movement that you do that signals are sending from your brain down your spinal cord to the muscles and so that has to be very fast as fast as you can respond to things that's the speed at which your nervous system is working it also deals with sensory processing and so for example like if you feel touch or if you feel like a tickle in your armpit that sort of a thing your brain and your nervous system are processing that sensory information um and and and thinking about what that what that means right next we have coordination of body functions and so this would be things like breathing and heart rate your digestive system your nervous system is really going to be controlling all of those different different responses uh your stress things like that it's all controlled by the nervous system again brain spinal cord nerves and it's going to be fast communication and control and sensory processing it's going to tell all the other systems what to do including our next system the endocrine system so the endocrine system like I said is going to be like the nervous system in that in that it's controlling other systems but it's going to control them more slowly uh rather than kind of quick almost instant responses so our function here is long-term communication and regulation using hormones so this could be on the order of minutes to hours even even to days uh and it's going to do that by releasing hormones into our bloodstream now one thing you'll notice look at all the organs of the endocrine system we've got some in the brain we've got some in here some down here but they're all disconnected from each other the reason they're disconnected is they're all producing hormones which travel through the cardiovascular system so I can overlay onto here our cardiovascular system which we're going to talk about in a minute and that's going to allow these hormones to travel throughout the body and so these organs of the endocrine are not touching each other because they're going to use the cardiovascular system to communicate throughout the rest of the body all right so let's take a look at the organs involved here and we're going to zoom in on the brain first it's not the whole brain but a few parts of the brain that are involved the first ones are hypothalamus this is often controlled the homeostatic control center of the brain the hypothalamus is going to produce a few hormones it's also got some nerve cells which are going to send signals to this next organ right here which is the pituitary gland if you're studying this stuff for the first time just think about the hypothalamus and pituitary gland as two small organs that are can produce hormones that control other organs throughout the body pituitary gland is often called the master gland or the control gland of the rest of the body because it produces hormones that will travel throughout the body and tell other endocrine organs to produce their hormones to control some other specific function so these two organs hypothalamus pituitary are going to be controlling the other kind of glands and organs and stuff throughout the body they produce a lot of hormones we're not going to get into all those in this video we also have the pineal gland it's kind of more on the posterior side of the brain right there it's going to release melatonin which regulates your sleep cycle your circadian rhythm your dayight cycle which is pretty cool so those are three organs in the brain that are part of the endocrine system next let's zoom in right here we've got an organ that's going to be kind of in your neck right there called the thyroid gland the thyroid gland is going to primarily regulate your metabolism so it's going to speed up your metabolism or it might slow down your metabolism metabolism is just really the sum of all the uh proc chemical processes taking place in the body and so we might speed up the chemical processes in our body in order to produce more ATP so that we can uh do more stuff more quickly or we might slow that down um depending on a couple different things that might be going on in the body but the idea here is that your thyroid gland is regulating your metabolism up next on the other side of your thyroid gland you have the parathyroid glands the parathyroid glands are these four really small glands that we see right around in here and those are going to help with regulating your calcium levels in the blood so just think parathyroid calcium your thyroid gland also is involved with that process as well all right up next we have the thymus gland you'll see the thymus gland come up again in the lymphatic system the thymus gland is going to help develop your immune system it's going to release a hormone that's going to help develop tea cells which are a type of immune system cell a white blood cell but it's part of the endocrine system because it's using a hormone to do that that's the thymus gland it's kind of above your heart right there up next we have the adrenal glands the adrenal glands of course will produce adrenaline also one called noradrenaline it's also called epinephrine and norepinephrine but the adrenal glands are going to help you regulate your response to stress it's a little more complex than that but for now just think about your adrenal glands being in control of your stress response underneath that or inferior to that we've got the pancreas the pancreas release two hormones one called insulin one called glucagon and those are going to regulate the blood sugar levels in your body so you might know someone who has diabetes who takes insulin insulin is just a hormone produced in the pancreas that tells um different organs in your body like your liver and your skeletal muscles it tells it to take in blood sugar in other words take sugar out of the blood sto store those in those other organs in order to reduce your blood sugar level so that's going to be the pancreas insulin glucagon but just know it regulates blood sugar all right we've got two more these are also going to show up in the reproductive system one is the ovaries that'll release estrogen and progesterone which are going to control the the ovarian cycle and the menstrual cycle it's also going to develop the secondary sexual characteristics and then second we have the testes the testes will produce testosterone um which are going to help with sperm production and other secondary male sex characteristics so those are part of the uh endocrine system as well as reproductive endocrine because they produce hormones so a lot a lot of organs i went through a lot of information there of course if you're learning this for the first time uh at the beginning of an A&P course let's say you don't need to know all of the functions and all of those hormones once you study the endocrine system specifically you'll learn those a lot more in depth so it might be enough for you right now depending on where you are with your study of A&P that you may just need to know hey endocrine system is dealing with hormones and maybe you can identify some of those particular organs so those are our systems nervous and endocrine for integration and coordination up next we're going to look at some systems dealing with transport that's going to be the cardiovascular and lymphatic system let's take a look at the cardiovascular system its function here is going to be transporting lots of stuff throughout the body uh blood is the main thing that you'll think of but what is blood blood is mostly water it's a lot of nutrients it's going to have red blood cells and white blood cells red blood cells are going to transport oxygen white blood cells are going to be immune system cells to fight off bacteria and other pathogens so it's going to be transporting those gases like carbon dioxide and oxygen it's also going to transport hormones and other waste basically just anything we need to transport throughout the body it's probably going to be going through your cardiovascular system the organs involved here of course we have the heart the heart is mainly a pump it's going to be pumping blood throughout the body it's going to have four chambers we've got the right atrium right ventricle left atrium left ventricle this right side will pump blood to the uh lungs in order to get oxygen the left side will pump blood throughout the rest of the body in order to deliver that oxygen and other nutrients to the parts where it needs to go to in addition to the heart we've got the blood vessels and so you see those blood vessels kind of going all throughout different parts of the body connecting to lots of different organs and this doesn't show all the branches these where they kind of disappear they branch out into smaller and smaller branches basically delivering oxygen to almost every tissue in the body so that's going to be your blood vessels we've got arteries which are sending blood away from the veins most of those are in red in the diagram not all but most and then most of the veins which are bringing blood back to the heart most of those are in blue now your blood's not actually red or blue i feel like I say this in lots of videos your blood is actually always red it can kind of change slightly in the shade of red but we use blue for low oxygen blood to represent it on diagrams and red for high oxygen blood and I've got the lungs in here right as well so you've got the pulmonary artery that's going to pump blood to the lungs and the pulmonary veins which bring blood back to the heart from the lungs the lungs of course is where we get that oxygen from all right one more thing I wanted to show here this is where the actual oxygen exchange occurs so maybe we're going to have blood coming in through here that's going to branch off into what we call capillaries and so oxygen is going to leave the blood here also fluid and other things are going to leave through those capillaries and then we'll get carbon dioxide coming into those capillaries so that we can get that back to the heart and then back to the lungs and we can breathe that out and so this is where that oxygen and carbon dioxide exchange is going to take place in these capillary beds throughout the tissues in the body oh one more thing I want to talk about is going to be the actual blood cells themselves so we've got the red blood cells that we see right there those are going to transport oxygen the white blood cells which are going to fight off bacteria and pathogens we also have things called platelets which are going to help with clotting we have a damaged blood vessel when we're bleeding the platelets and the red blood cells will help to clot that up so we don't lose too much blood and of course those blood cells can be transported through all of our blood vessels like that so that's the cardiovascular system heart blood vessels blood oh blood itself is an organ it's a bunch of different cell types that come together to form one continuous tissue so our blood is an organ it's one of the organs of the cardiovascular system and the main function there is transporting things throughout the body up next we have the lymphatic and immune systems it's kind of two different systems but they're intertwined so much that we often group them together and so the functions of the lymphatic system there's going to be three one is to reduce swelling without the lymphatic system we'd have a lot of swelling in our tissues because we'd have a buildup of water in those tissues so lymphatic system is going to be kind of a drainage system to drain the excess water from the tissues in our body and we can see here it kind of maps on the cardiovascular system we'll see that in another diagram but the lymphatic and cardiovascular system are connected to each other sort of it can help transport fluid back into the cardiovascular system and it's going to do that in a couple spots right in there where it's going to dump that fluid back into the cardiovascular system but just think about the lymphatic system as a drainage system for the excess fluid and therefore it can reduce the swelling here's a picture of that right there so we've got that kind of capillary bed that I drew in the in the last system and we've got some lymphatic capillaries that come up into it so when that fluid leaves a lot of that fluid will come back into the lymphatic capillaries and that'll take that back to a couple veins to to deliver that fluid and reduce the swelling so that's the reducing swelling part it's also going to be used in the absorption of lipids and so whenever we eat food we'll get to the digestive system in a minute but whenever we eat food and we eat fatty foods that's going to end up into our small intestine we're going to absorb that uh those fats and other nutrients right like carbohydrates and proteins but the lipids themselves are they're not soluble through membranes very well so they actually need to go through the lymphatic membranes which is a little bit more space to go through and so lipids are going to be absorbed into the lymphatic system specifically so just remember lipids lymphatic is where that absorption occurs and then next the big function the other one we haven't talked about which is going to be the immune response pathogens that get into the body we need to fight those off and so we use the immune system for that so we've got a couple organs that we need to look at here one is the lymph nodes and the other is the lymphatic vessels just like blood vessels and so we've got those lymph nodes are these little green dots you can kind of see and the vessels are the lines connecting them and so if we zoom in on one of those lymph nodes it looks like this notice we've got some blood coming in that's how the white blood cells which are our immune system cells are going to get there in the first place and we're going to have places where the lymph which is just fluid that it's that it's pulled out of our tissues um is going to be traveling through and the white blood cells that stick in these lymph nodes are going to be scanning to see if there's any pathogens that we need to fight and if there are then we're going to fight off those bacteria and those pathogens and we use a lymph nodes as kind of a scanning center to find those pathogens and then that fluid is going to leave through another vessel and travel on to a new lymph node after that so that's where our lymph nodes are and what they do next we've got a few other organs one is the spleen the spleen acts as kind of a reservoir for blood and it's part of the immune system as well and then we've got the thymus the thymus is up here that's going to develop our T- cells why are they called T- cells the T just stands for thymus and we also have our bone marrow and so I've just got one long bone drawn in here but it's really the bone marrow throughout the body and the bone marrow is where our B cells are going to be developed why are they called B cells well B for bone so the B cells and T- cells are a type of lymphosy or white blood cell that's involved in our immune response both of those are going to start in the bone marrow but then B cells will mature in the bone marrow and then T- cells were will mature in the thymus gland hence they're called T- cells so both of those the bone and the thymus are involved in our lymphatic system as well because they're going to help develop those immune system cells so that was the lymphatic and immune system obviously a lot going on there but just think about the lymphatic system it's a drainage system to reduce swelling but it also does our immune response be the kind of the main two things with that system all right that was transport those systems now we're going to look at absorption and secretion systems all three of these systems are systems that are either bringing stuff into the body or they're helping stuff leave the body or sometimes both so that's what I mean by absorption bringing things into the body excretion getting things out of the body the first one we have here is the respiratory system the function of the respiratory system is going to be gas exchange and specifically that's going to be bringing oxygen into our bloodstream first we bring it like into our respiratory system by breathing in but then ultimately it's got to get into our bloodstream and then the other part of that exchange is we're going to send CO2 out of the body so we'll pull that CO2 out of our blood into our lungs and then we'll breathe it out so we get rid of that CO2 that we don't need so that's the main function of this again we're bringing something in sending something out of the body here the organs involved are going to be obviously the lungs of course that's going to be where that gas exchange is actually occurring and then we've got the diaphragm below that now the lungs are not a muscle you don't actually breathe with your lungs you breathe with your diaphragm so whenever you breathe in you're actually contracting the diaphragm lowering the diaphragm which is going to use kind of a negative pressure difference to inflate the lungs and therefore pull air from outside of the body into the lungs so I started with the diagram the diaphragm and the lungs in this video for that reason now let's trace the path of of air going into the into the lungs we'll start with the nasal cavity it could be the oral cavity if you're breathing air through your mouth but let's say you breathe in through your nose that air filled with oxygen and other stuff like nitrogen it's going to go in through the nasal cavity from there it's going to travel down the throat the back of the throat is called the fairings right there we've got the larynx so fair and larynx your larynx is the vocal cords it's actually inside of this cartilage right there that's the thyroid cartilage your larynx is your your voice box or your vocal cords which are inside of that thyroid cartilage which is there to protect your larynx from there the air will pass through the trachea this is the trachea it's got those cartilage rings which hold the trachea open so you can breathe in and out really easily the trachea then branches off into the bronchi you've got a right bronchus and a left broncus and those will branch into bronchules and then eventually those will branch into something called alvei so the alvei these are going to be the end of those bronchules the alvei are these little sacks right there and these are really really really small you've got lots and lots of these and if you'll notice there are blood vessels actually blood vessels coming in right here because it's going to be low oxygen blood coming in there's going to be the gas exchange occurring right there between the blood capillaries and then the alvoli that blood's then going to leave and go back to the heart it's going to have high oxygen blood so the heart can pump it out to where it needs to go now and then of course whenever you breathe out that air that was in here that did have a lot of oxygen now it's got a lot of carbon dioxide that'll go back and kind of retrace the path so you can breathe that carbon dioxide out here's a little diagram that shows that gas exchange with the alvoli so there's the alvoli here's going to be the blood coming in it's low oxygen it's going to give off the CO2 it's going to receive some oxygen it's going to go back to the heart now you've got air with high CO2 that's going to leave and you'll breathe that air out so that's the respiratory system we've got all those organs we talked about there but the big idea there is it's going to be gas exchange happening all right our next system with absorption and secretion is the digestive system this is another one that's got a lot of organs but there's really three main functions i think it's more important right now probably to know those three main functions uh and those functions are digestion of food now the word digest means to break down or to break apart so digestion means to break apart the next is absorption of nutrients we're not just breaking the nutrients down we also need to absorb those nutrients into the bloodstream so they can get throughout the body to our cells that need those um nutrients and finally the last function is going to be the elimination of waste this is when you go to the bathroom and then you excrete the the fecal matter uh at the end of all this process so those are going to be the three main functions that we're looking at here now let's take a look at all the organs that are involved so we're first going to zoom into the mouth right here we've got the oral cavity we're going to be chewing food this is mainly going to be digestion of food we're not absorbing or limiting anything just yet we're going to be breaking the food down mechanically by chewing as well as a little bit chemically because we've got our salivary glands producing saliva which will help break down some of the food at the chemical level a little bit we also have the esophagus so whenever you swallow food it's going to pass down through here through the esophagus hopefully if you're not talking while you're eating that sort of a thing then you won't have any issue of food going down into your trachea where you could choke on that food or the water that might make you cough it back up but notice that the trachea right there and the esophagus are right by each other so whenever you swallow food this is going to close off right there just to make sure that food goes down the esophagus the esophagus is just a tube to take that food down into the stomach so we have the stomach right there the stomach is going to continue breaking down food it's going to use things like acid it's going to churn to keep doing some mechanical digestion it's going to digest proteins and stuff in that stomach from the stomach it's going to pass into the small intestine so I can I can kind of trace the path here the esophagus down into the stomach from the stomach it's going down through right here this is called the duodum of the small intestine this is going to be where most of the digestion is going to occur if it hasn't already it's in the beginning of the small intestine and the majority of the small intestine as it's winding its way through all of these all this long really windy tube is going to be absorption of the nutrients so all the nutrients we've broken down into small little bits we're going to be absorbing those into our bloodstream or if it's a lipid we'll absorb it directly into the lymphatic system that absorption is going to occur right there that's why we need a long small intestine so we can absorb as much as possible into the bloodstream from there that food is going to pass into our large intestine also known as the colon so the large intestine it's going to enter from the small intestine right there travel up over and then down the main thing happening in the large intestine is going to be absorption of uh nutrients but specifically not the macronutrients like carbohydrates and uh lipids and proteins it's going to be mainly absorbing water and it's going to be absorbing electrolytes like the salts and stuff that are absorbed in the water so those can be absorbed from the large intestine into the bloodstream and of course we'll excrete that out through the rectum and the anus during the elimination part of this so those are the three main functions and the organs of the digestive tract there's three more organs that we need to know for this these are organs that the food does not pass through so they're called accessory organs one is the liver the liver is going to produce something called bile which is going to help break down fats it's kind of like how soap will uh will break down oils it's similar to that it's happening at that kind of chemical level and then we've got the gallbladder which is going to store the bile until we eat something high in fat and then the gallbladder will release it through a little duct here into the duodenum of the small intestine we also have the pancreas the pancreas is this organ right here we saw that earlier in the endocrine system because it releases the hormones to control your blood sugar but it also produces a lot of enzymes to break down the food that we eat and so it's going to pump those enzymes into that douodenum of the small intestine we can see all this a little bit better in this diagram here we've got the liver the gallbladder see you've got these little tubes or ducts that connect those down to the douadum we can send that bile and then we've got the pancreas with a pancreatic duct that's going to send the pancreatic enzymes into the douodenum of the small intestine that was a lot that was kind of an overview of the digestive system again if you're learning this for the first time the main thing right now would be able to to name a lot of these organs and be able to name the three main functions of the digestive system all right our other system involved in absorption and secretion is the urinary system the urinary system's main function is going to be removing waste from the blood a lot of people maybe don't know this but whenever you produce urine and you urinate where did that urine come from it actually came directly from your bloodstream it's going to be filtering out fluid from your bloodstream now why is your urine not red well it doesn't have red blood cells in it which has a particular protein called hemoglobin which gives it the red color so it doesn't have hemoglobin in it so your your blood your your urine is not going to have that red color unless there's something wrong and there's blood in the urine removal of waste from the blood that's going to happen in the kidneys so we have a kidney right there and of course if this is removing waste from the blood we better have some blood going into it and so we've got a couple blood vessels here and we've got the urers which are going to take then the urine which is the fluid and other waste products that have been filtered out of the blood and then we now call it urine but it's just the fluid and stuff that was in the blood that's going to travel down the uriters you've got one on either side of course and what this whole process of filtering this blood out well the purpose of it is to regulate several things one we're going to regulate the amount of water in our blood that's going to help regulate our blood pressure as well we're going to be regulating the amount of electrolytes so we don't want our blood to have too much electrolytes electrolytes are just salts that are dissolved in our blood so we don't want too much or too little of those it's also going to regulate the pH that's going to be the acidity of our blood we need to keep our blood at a certain acidity for our organs and stuff to function and so this is going to be involved in regulating our pH super important we're not going to get into the details of that right now in this video all right we're going to zoom out a little bit that urine that's going to travel through the urers that's going to go into the bladder the bladder is just a storage tank for our urine so that'll start to fill up with urine and when we're ready to urinate we're going to release a couple sphincters on the urethra right here the urethra is just the tube that connects the bladder to the outside and the organs here we already talked about those the kidneys right there the urittors the bladder and the urethra and the main function of this is to remove waste from the bloodstream that's the big one that I would remember from this all right that's our last system um in that category we got one final category which is reproduction of course we've got a male and a female reproductive system to talk about let's start with the male reproductive system oh before we get into that actually what are the functions of this the functions are one to produce and transport gametes gameamtes are going to be the sex cells the sperm cells and the male reproductive and egg cells and the female reproductive so it's going to be producing those and then the other function here is going to be to nurture a developing fetus and that's going to happen specifically of course in the female reproductive system in the uterus right here now I didn't mention on here uh production of hormones but of course these are producing hormones and the testes and the ovaries i just added that to the endocrine system but that's also of course involved in the reproductive system as well now let's take a look at the male reproductive system so here are the organs that we have we've got the testes this is the primary reproductive organ because that's where the sperm is produced as well as testosterone the sperm are going to travel up through this called the epidmus and through this tube called the vasiference we've got a couple organs here the seminal vesicle the prostate which I'll label on here and then we've got one called the bulb urethral gland all of those are going to be producing the fluid or the semen that's going to mix with the sperm that have traveled up through the basins and then of course that's going to travel through the penis right here urine and semen both travel through the shaft of the penis right there to the outside of the body and of course you know the testes right there I said those are the main kind of reproductive organ because they're producing the sperm everything else is really just there in order to transmit that sperm outside of the body to do fertilization and all that kind of stuff now the next thing is going to be the female reproductive system the main organ here the the primary sex organ of the female reproductive system is the ovary and the ovary we can zoom in on it here and we can kind of see the process of the ovarian cycle which we're not going to get into the details of that in this video but we've got an egg cell right there that's going to develop into a follicle and then during ovulation that egg cell is going to get released and it's going to get grabbed up by this ovduct also known as the fallopian tube so here we have the ovduct it's going to suck that into the ovduct and that cell is going to then travel through and if there's a sperm cell present of course that's going to get fertilized in that ovduct and then travel to this organ right there which is the uterus the uterus is going to be the site of implantation and the growth of a fetus if a pregnancy occurs so that's the uterus right there of course during menration if there's not fertilization then when ministration happens that's the lining of the uterus that is leaving the body and then finally down here we have the vagina or the vaginal canal and so those are going to be the main organs of the female reproductive system so we've got the female and the male reproductive system and of course the main function of those systems is to produce and transport the sperm and egg cells and then in the female reproductive system to be able to nurture and develop a fetus and give birth to that fetus and have a new a new human all right so that was a lot of information we went through all 11 organ systems and we talked about them in terms of these five categories a ton of information at this point if you're learning it for the first time especially you need to do something to practice doing some active recall and reasoning with this information to help you like store it in your brain long term so don't forget to go download my free study guide for this topic link in the description for that it gives you some active recall exercises some practice questions things to do to strengthen your understanding your memory of this stuff and if you really want to level up your understanding of anatomy physiology your ability to learn while also gaining access to all the resources that I'm creating don't forget to check out the&P memory lab you can join the wait list for that in the description below hey thank you so much for watching this video here's another video that the algorithm thinks that you might like 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