hi guys must be here welcome to the introduction to A&P this is chapter one and we're going to talk about what is anatomy anatomy is the study of body structures physiology is the study of body functions and why are we studying these topics probably because you are interested in a medical field whether it be a nurse physical therapy PA maybe you're interested in going to PA school and so chapter one is the introduction to am P I'm organisms have specific characteristics that make them a living they have to be able to respond to their environment they have to be able to grow and develop they have to be able to reproduce have movement adaptability and then also all living things are composed of one or more cells so you can add cells here as well levels of organization so within an organism you have organ systems for example digestive system cardiovascular system respiratory system these different organ systems are made up of organs like the cardiovascular system is made up of the heart and blood vessels and then these organs are going to be made up of different tissue types and we're going to talk more about those in the next for the next exam and then you have tissues are made up of cells and cells are made up of molecules actually cells we're going to talk about how they have organelles which help them do a perform a certain function Europe might be familiar with these Kandra endoplasmic reticulum ribosomes if not don't worry we're going to talk about that more in chapter 3 and then all of these organelles are going to be made up of molecules for example a very common water molecule excuse me as water molecules and then these water molecules are made up of atoms for example h2o you've got two hydrogen atoms and one oxygen atom and we're going to talk more about atoms in Chapter two types of anatomy so we have systemic anatomy and when we're talking about systemic anatomy we're talking about organ systems then we have regional anatomy which is anatomy in a particular region of the body you're probably familiar with these whenever we talk about regional terms then we have surface anatomy these are surface markings these are very common actually on bones and they're actually going to help you determine one bone from another let me have gross anatomy and this is anatomy that can be seen without a microscope and then you have microscopic anatomy which requires a microscope and we're talking about histology or cytology here where we're talking about the study of tissues or a study of cells we'll be working a lot with tissues and using the microscope and lab now we'll talk about Tomica position so this diagram actually is incorrect so the feet that should actually should be shoulder width apart you need to be upright to be an anatomical position you need your head and your palms facing forward so your thumbs are pointing outwardly and then your arms need to be by your side and when we use those directional terms that we talked about in lab we are referring to a person in anatomical position which of these backstreet boys is an anatomical position that's right none of them because nobody stands in anatomical position especially when they're trying to like walk around the stage nobody you know walks around with their palms facing forward shoulder width apart so yes then the backstreet boys are in anatomical position here either check your text for a really great example of anatomical position here we're going to talk about body cavities so you have dorsal body cavities and ventral body cavities when you think dorsal I want you to think posterior you can also think the dorsal fin would be located on the back of a fish and so you have dorsal which is posterior and ventral cavities which are anterior I'm going to start here with the dorsal body cavities you have two body cavities within the dorsal body cavity you have a cranial cavity and of our temporal cavity and so the cranial cavity is going to contain the brain and the vertebral cavity or the spinal cavity is going to contain the spinal cord the ventral or anterior body cavity is going to consist of the thoracic cavity and the abdominal pelvic cavity and actually the abdominal pelvic cavity can be broken up into abdominal cavity and pelvic cavity and the thoracic cavity is going to contain the heart and the lungs it's going to be separated from the abdominal cavity by the diaphragm the abdominal cavity is going to contain digestive organs such as the stomach the pancreas the liver gall bladder small intestines large intestines and then the pelvic cavity is going to contain structures such as urinary bladder reproductive organs ovaries for example uterus and rectum so let's talk a little bit more in depth about these cavities so we're gonna start with the thoracic cavity um it can be broken up into two different cavities you have pleural cavities and you have a pair of cardial cavity so the pleural cavities you have two which are going to house the lungs the left and right long okay so pleural cavities contain the lungs the pericardial cavity is going to contain the heart and then you have a region known as the mediastinum which I have drawn in here for you in blue and the mediastinum is going to be located between the pleural cavities it's gonna house the heart the trachea the esophagus and the mediastinum is a region within the thoracic cavity if you will in both the pleural cavities and the pericardial cavities or cavity excuse me the pericardial cavity will have a serous membrane and we're going to talk more about that in just a minute we're going to talk about the abdominal pelvic cavity the abdominal pelvic cavity consists of the abdominal cavity the pelvic cavity and then a sub cavity called the peritoneal cavity and so the peritoneal cavity is a sub cavity of the abdominal cavity the abdominal cavity runs from the diaphragm to the pelvis so extends from the diaphragm to the pelvis and then within that is the peritoneal cavity and the peritoneal cavity is going to house those digestive organs and we'll talk more about that later and then the pelvic cavity like I've already explained it is going to have urinary system structures and reproductive structures serous membranes serous membranes are very important because they help to reduce friction there are three components really of serous membranes you have parietal membrane you have visceral membrane and then you have serous fluid and so the parietal membrane is going to wine the body cavity the visceral membrane is going to touch the organ and then between the parietal and visceral membranes is a serous cavity filled with serous fluid and it helps to reduce friction because these organs like the heart and lungs are going to be expanding and contracting and when that happens we don't want friction up against the the cavities that they are located in the thoracic and the pericardial cavity so we want to make sure that there's no friction and that's really what these serous membranes do so when we talk about serous membranes we have different names for the membrane based on which structure which organ it is surrounding and so for the lungs you would have the sural pleura which would be the membrane surrounding the lung itself then you have parietal pleura which would be the membrane lining the pleural cavity move on to pericardial so you have visceral pericardium this visceral pericardium will surround the heart you also have parietal pericardium which will line the pericardial cavity then you have visceral peritoneum this membrane will touch all those digestive organs in that abdominal cavity you and here is a diagram for you as you can see that the visceral membrane surrounds the organ you have a serous cavity with serous fluid flowing in it and then you have the parietal membrane and then if we make another box all the way around here you can see that the parietal membrane will be lining the cavity in which we are which the organ is located in all right so next we want to talk about homeostasis which is maintenance of the body within certain limits homeostasis is very important for an organism to be healthy outside of those these parameters we have a loss of homeostasis is basically going to mean disease for that organism and so the body maintains homeostasis through two different mechanisms negative feedback and positive feedback and the next couple of slides are going to talk about both of those so negative feedback maintains homeostasis by regulating values around a set point and so there's some technical stuff on the slide that you can also read about in your textbook but I just want to explain it in a little bit simpler way so negative feedback kind of works like your thermostat at home if you set your thermostat for your house to be 70 degrees then when the temperature in your apartment goes up during the day to 71 the air kicks on to bring it back down to 70 which is what you set it at so it recognizes the the temperature here has gone above 70 and we need to go back down to 70 which is what the thermostat was set on now let's say it's nighttime and it cools off and your thermostat now goes down to 69 in your house and what's gonna happen is the heat will kick on because we want to get it back up to 70 degrees which is what you've set it up so we're trying to maintain the temperature of 70 degrees in your house so if it goes above that or below that either the air kicks on or the heat kicks on to make sure that your house is always at 70 degrees your body does this as well it has different mechanisms to help cool your body back down so if you get too warm if you get above that 98.6 degrees Fahrenheit your body recognizes oh it's too hot so you start sweating to cool back down to normal if you get below that 98.6 degrees Fahrenheit then your body will recognize we're too cold and you'll probably start to shiver and that muscle contraction will actually cause heat and will warm your body back up to the normal range another example of negative feedback is blood sugar and how we regulate our blood sugar so I know you guys love Texas Roadhouse rolls just as much as I do I'm telling you they're the best thing on the planet so don't tell my boyfriend I says but I love Texas Roadhouse rolls anyways let's say you go to Texas Roadhouse and you eat a whole bag get of their roles I don't ever eat a whole basket of course but anyways let's say you do that and what's gonna happen is it's going to increase you're taking in all these carbs which are nothing but sugar okay and you also put that lovely summon butter on there so now we're we're talking about even more sugar and so it's gonna rise that blood glucose level now this tadpole looking structure here it is called the pancreas and it detects that high blood glucose and it secretes insulin to try to get your blood glucose level back to normal and so what happens if the liver over here will take up the glucose and store it so it's take the liver takes it out of the blood because we have too much in the blood right so liver takes it out and other body cells will take out glucose and then as these body cells take up this blood glucose the pancreas stops releasing and insulin when those blood glucose levels start to decline back to normal and then you'll return to that homeostatic blood glucose level or the normal range your body also has a mechanism or whenever blood glucose levels get too low as well the pancreas will actually secrete a different [Music] substance for that all right so we've talked about negative feedback how that works now positive feedback is different positive feedback amplifies the response so in positive feedback we're not trying to get back to normal we're actually amplified the response or I like to say accelerating a process so let's start here with the brain stimulates the pituitary gland to secrete oxytocin so during pregnancy the brain tells the pituitary gland to secrete the hormone oxytocin oxytocin is then going to be carried in the bloodstream to the uterus oxytocin causes uterine contractions the muscular layer of the uterus is going to contract and push the baby towards the cervix and then the pushing against the cervix is going to call Merve impulses from the cervix to be transmitted to the brain which tells the brain to stimulate a to eteri gland to secrete more oxytocin more oxytocin is being secreted into the bloodstream the oxytocin causes more uterine contractions the baby pushes harder against the cervix and then the impulses increase and then you can see how this circle keeps going and going until the baby is now being pushed out out through the cervix out of the uterus so it's accelerating this process another example of positive feedback is when you break a blood vessel so maybe you've cut yourself and you have damage to those cells in the blood vessel wall and that's going to release these chemicals that begin blood clotting so it's really importantly your blood clots otherwise we'll lose too much blood and so these chemicals then start a chain reaction in which cells and so fragment and and soluble proteins in the blood are going to begin to form a clot and then as this clotting continues each step releases chemicals that further accelerate the clotting process because we need this blood to clot pretty quickly right so these chemicals that are being released actually further accelerate the process of blood clotting and then this escalating process positive feedback loop here it basically is going to end with the formation of a blood clot which is going to help patch this blood vessel wall it stops you from bleeding out but you can see how these chemicals cause the further accelerate this process the more chemicals that are released the more you have blood clotting so it's accelerating a process here I know that negative and positive feedback can be challenging to wrap your head around sometimes so if you have any questions about it please feel free to ask me and then we talked about gradients so basically a gradient is just a difference in amounts between two areas so basically one area will have a high concentration and then one area will have a low concentration and you can see this on page 26 in your textbook and these gradients can be anything from temperature to concentration to pressure gradients high pressure here low pressure here but nature does not like gradients we like to be even like this pick this diagram here and we're going to talk more about gradients in the next section in chapter 2 and so I'm just gonna say that for and we're going to talk about self cell communication as well and it's really important to trigger feedback loops and coordinate functions you can also see this in page 27 of your textbook we're going to talk about receptors we're going to talk about chemical signals which are neurotransmitters and how these neurotransmitters are going to be very important these chemical signals are going to be very important in triggering electrical signals called action potentials and this is going to be a big concept for a MP we're going to talk about it when we talk about muscle contraction we're also going to talk about chemical and electrical signals when we talk about how nerve cells or neurons talk to each other later on in the semester so take a look at page 27 in your textbook and then I have a little cartoon over here for you are you happy with your current cell provider okay I know kind of cheesy oh well you [Music]