hey guys thank you guys so much for tuning in today today we're going to be talking about the first chapter to anatomy and physiology and this chapter is sometimes called orientation because it's pretty much just introducing you to what's the come in the course general terms and principles so if you made it to anatomy and physiology Pat yourselves on the back that is a big deal because everything you learn in this course is going to follow you from here on out when you take your teas exam there are going to be Anatomy and Physiology questions on the exam when you start the nursing program you will see anatomy and physiology there even when you start your career as a nurse there will be anatomy and physiology please like comment share and subscribe to this Channel and I promise I'll try to make this video as short and painless as possible well what is anatomy and physiology well Anatomy is going to be the study of the human body structure where things are located physiology on the other hand is going to be the study of the human body's function how these structures work now Anatomy is going to take up a lot of the lab portion of the class whereas physiology is going to take up a lot of the lecture time in the class now both structure and function work closely together it's something that we like to call the dogma of anatomy and physiology and this Dogma pretty much states that structure dictates function how something is structured will always benefit its function there are different types of anatomy and physiology there is systemic Anatomy which studies the human body's organ systems there is regional anatomy which studies the different regions of the human body there is surface anatomy which studies the surface markings of the human body and then there are even more specific subfields of anatomy there's gross anatomy which studies the structures inside of organs and organ systems that we can see with our naked eye structures that we don't need a microscope to observe an example of that would be the left ventricle of the heart we can spot out the left ventrical of the heart without using a microscope and then there is microscopic Anatomy the study of structures of the human body that do require a microscope for observation and then even microscopic Anatomy has its specific fields of study there's histology which is the study of tissue and then there's cytology which is the study of cells physiology also has its own subfields there is neurophysiology which studies the brain and nervous system there is cardiovascular physiology which studies the heart and blood vessels and as you can see both cardiovascular physiology and neurophysiology have the organ system that is being studied in its name for example neurophysiology is studying the nervous system neuro means nerve it's in the name and cardiovascular that's kind of self-explanatory there are seven characteristics that an organism must have to be considered aive and I'm sure you guys probably remember the characteristics of life from introductory biology so all of things should be composed of one or more cells which we know cells to be the basic units of Life all living organisms should be able to metabolize these metabolic process processes can build up which is something we know as anabolic metabolism or these chemical processes can break chemicals down in the body which is something that we know as catabolic metabolism cats break stuff down all liven things should be able to excrete waste products that are no longer needed in the body growth all living things should be able to grow in cell size or grow in cell number all living organisms should be able to respond to environmental changes known as stimuli movement all living organisms should be able to move or have movement within them whether it's their cells that are moving or their flow of blood reproduction all living organisms should be able to reproduce cells to replace damaged or old ones this is a process known as mitosis organisms should be also able to reproduce similar Offspring this is something that we know as meiosis levels of structural organization I like to look at these levels as stair steps because they start off small and gradually get bigger and by the time you reach the top of the stair steps you should reach a fully functioning organism the chemical level is the smallest level this can be anything from small tiny atoms these atoms will combine to make larger structures called molecules now depending on book you have molecules might be labeled under its own level called the molecular level but as long as you know that atoms combine to make molecules you'll be fine now these molecules will then combine to form cells this is called the cellular level then these cells will combine and work together to form tissue this is called the tissue level tissue will then combine to form a specific organ this is called the organ level now some of these organs will work together with one another to carry out a function this creates an organ system such as the bones and joints they work together to form the skeletal system and finally all of the organ systems in the body will come together in harmony to form you the organism the anatomical position is the frame of reference used in science and in the medical field in the anatomical position the body is standing up straight shoulders and feet with apart upper limbs at sides of the trunk and head and Palms are facing forward so it's important to always refer to the body as if it's in anatomical position left and right is always refer to the left or right side of the body you are describing not your own left and right as my professor would say it's never about you but always about the patient directional terms are another way to make sure that the locations of the body are referenced to correctly anterior is a term that references the front of the body or an organ for example the esophagus is anterior to the spinal cord it's in front of the spinal cord while posterior is a term that references to the back of the body or an organ for example the spinal cord is posterior to the esophagus meaning that it is behind or in the back of the esophagus now you are probably familiar with the word superior but it has a slightly different meaning in biology so Superior in biology means toward the head which is why this term is sometimes called cranial for example the eyes are superior to the nose meaning that the eyes are closer to the top of the head than the nose inferior which is the opposite of superior means away from the head or toward the tail for example the lips are inferior to the nose now inferior and Superior terms are only used to reference positions on the head neck and trunk for limbs we use proxim imal and distal proximal means closer to the point of origin for example the shoulder is proximal to the Elbow meaning that the shoulder is closer to the point of origin than the elbow now this still means farther away from the point of origin an example of this would be the wrist is distal to the Elbow meaning that the wrist is farther away from the point of origin than the elbow now these are the limbs we're talking about so the point of origin for the limbs is going to to be the trunk medial means closer to the midline of the body for example the ear is medial to the shoulder lateral means farther away from the midline of the body for an example the shoulder is lateral to the chest the chest is closer to the midline of the body while the shoulder is farther away from the midline of the body superficial meaning closer to the surface of the Body for an example the skin is superficial to the muscles deep references structures farther away from the surface of the body and an example of this would be the bone is deep to the muscles the bone is farther away from the surface of the body whereas the muscles are closer than the bone to the surface of the body the body can be divided into two main regions there's the exal region which consists of the hi neck and trunk then there's the appendicular region which consists of the upper and lower LMS now even the sub regions can be divide it into smaller regions I'll actually do a video going over the different regions of the body more in detail because regions of the body are more of a lab topic so your professor probably wouldn't expect you to know too much about Regional terms for a lecture exam not unless you're Professor is a true weirdo planes of section are standard ways of dividing the body and or body parts to examine its inside structure there are three main planes of section there is the sagittal plane the frontal plane and the transverse plane and these three main planes also come with their own types now there's also in an oblique plane which is a less standardized type of plane by the way planes of section and directional terms are not the same thing so I would recommend getting some practice with both sagittal planes divide the body or body parts into right and left sections and there are two types there is the midsagittal plane also known as the median plane this plane is going to divide the body or body parts into left and right equal parts then there is the parasagittal plane which divides the body or body parts into left and right unequal sections the transverse plane also known as the horizontal plane or crosssection divides the superior and inferior part of the body in half it also can divide the limbs into proximal and distal Parts the frontal plane or the coronal plane divides the body or body parts into anterior and posterior sections and I wanted to use an example of an organ for this slide to show you guys that planes can also be used to divide body parts not just the body as a whole and in this example we have a picture of the brain being divided into front and back regions and knowing that the frontal plane gives you a front section and a back section is an easy way to remember this plane because the section that this plane gives you is in the name frontal the oblique plane Which is less frequently used than the other planes is taken at an angle and it's mainly used when examining structures inside of the knee the body can be organized into different cavities and a cavity is any space inside of the human body that is filled with fluid these cavities function to protect our organs so our organs can function properly there are two main cavities of the body there's the dorsal body cavity which is located on the posterior or back side of of the body and then there's the vental body cavity which is located on the anterior or front side of the body and even these cavities have their own subdivisions the dorsal cavity has two subtypes there's the cranial cavity of the skull which protects the brain and there's a spinal cavity located in the vertebral column and protects the spinal cord now both the cranial and the spinal cavity are filled with cerebral spinal fluid this fluid is also called CSF and this fluid is what helps your brain and your spinal cord to stay afloat the ventral body cavity also has two main subdivisions both of these subdivisions are going to be separated by a dome shaped muscle called the diaphragm and the diaphragm is an organ that contracts during breathing the thoracic cavity encloses the thorax area and is going to be located above the diaphragm the abdominal pelvic cavity surrounds the abdomen and the pelvis and is going to be located below the diaphragm and please please note that some of these structures are going to be surrounded by a cus membrane and the cus membrane is going to be a thin sheet of tissue that encloses certain organs and produces cus fluid within the thoracic cavity you'll find three smaller cavities the plural cavity the mediastinum and the pericardial cavity plural cavities have a left and right portion each surround a lung the left plural cavity surrounds the left lung while the right plural cavity surrounds the right lung the medi atinum meaning middle is located between the right and left plural cavities there are two divisions of the abdominal pelvic cavity there's the abdominal cavity and the pelvic cavity now as you can see the abdominal cavity is the area that starts at the diaphragm and ends at the pelvic bone and in this cavity you'll find the digestive system the lymphatic system and the urinary system now the pelvic cavity is going to be the area that occupies the Bony pelvis the abdominal pelvic cavity can be divided into different regions this can be done using the four quadrant system or the non region system now the four quadrant system is achieved by drawing one transverse line along the umbilical region or belly button and then one mid sagittal line and this is a very simple method it'll give us four equal quadrants the right upper quadrant the left upper quadrant the right lower quadrant and the left lower quadrant and the four quadrant system makes it easier to diagnose abdominal pain for example pain in the right lower quadrant could be caused by pain in the appendix the right ovary in women or the last section of the small intestine while pain in the left upper quadrant can indicate pain in the spleen pancreas stomach or part of the large intestine the non region system uses four lines and to achieve this system we draw two parasagittal lines then two lines along the transverse planes the left and right Superior regions are called the hypochondria RC Regions they're named this because they're located right below the cartilage of the ribs hypo meaning below condro meaning cartilage the region between those two is called the epigastric region this is the middle Superior region located above the stomach Epi meaning above Gast meaning stomach the left and right middle regions are called the right and left lumbar Regions they're located in the exact same region as the lumbar vertebrae between those two regions is the umbilical region which is located above the umbilicus the left and right INF free regions are the right and left ilc regions between those two regions is the hypogastric region which is located right below the stomach now this system the non region system is more so used amongst anatomists while the four quadrant system is more commonly used in the medical field cus membranes are thin continuous layers of tissue that fold over on itself to create an enclosed space the cells inside of cus membranes will secrete cus fluid cus fluid is a slippery lubricating liquid for organs this fluid prevents friction between our organs when they rub against one another cus fluid can be found around organs like the heart lungs and some abdominal organs cus membranes have two layers there is the visceral layer which is the inner layer that contacts the organ itself and then there's the parietal layer which is the outer layer the body has three three main cus membranes the plural membrane the pericardial membrane and the peronal membrane plural membranes can be found surrounding the lungs between the plural membranes parietal layer and visceral layer you'll find the paracardial membranes paracardial membrane surround the heart the paracardial parietal layer encircles the heart while the visceral layer or inner layer attaches directly to the heart muscle itself in between both of these layers is the paracardial cavity the parital me membranes surround some of the abdominal organs now between the parietal and viscal layers of the perianal membranes you'll find the perenial cavity which is a fluid filled space so Medical Imaging provides us with an inside view of our patients using radiation and different kinds of medical images will provide us with the view of different planes and different cavities of the body we have x-rays which provide us with a view of internal body structures using ionized radiation and this picture here on the right is a chest x-ray which shows us the thoracic cavity a computed tomography scan also known as a CAT scan provides Imaging using ionized radiation as well and this cat scan image here on the right shows us a transverse view of the abdominal pelvic and perianal Cavities now a magnetic resonance image also known as a MRI will provide us with imaging using magnetic radiation hence the magnetic inside of its name now this MRI image on the right shows us a mid sagittal view of the brain now in anatomy and physiology there is one theme of the entire subject everything you're going to learn in this course from anatomy and physiology 1 to anatomy and physiology 2 is going to be wrapped up into one theme and that is homeostasis so homeostasis is the maintenance of the body's internal environment so if the body shifts from from its normal State physiological processes increase or reduce their activity to bring the body back to its normal state so this can be anything from the body's temperature blood pressure or pH for example if you're too cold the body will shiver to increase body heat or if you're too hot the body will sweat to cool you down many variables of the body such as your temperature or your blood pressure have a set point and the way the body maintains the set point is through feedback Loops these feedbacks lead to Output where the output can be negative or positive so when a change in the body's normal variable or set point is detected actions are triggered to bring the body back to its normal State however there are two types of ways the body can do this the body can do this by decreasing the change in variable which is the negative feedback loop or by increasing the change in variable which is the positive feedback loop so both both the positive and the negative feedback loops respond to change differently but still will result in the body being brought back to its normal State negative feedback loop so let me break it down for you guys when a change in variable is detected and remember a variable can be anything from fluid in the body temperature pH or blood pressure so once a change in this variable is detected a receptor will pick up this change secondly the re receptor will send this stimulus to the control center the control center can either be the nervous system or the endocrine system then the control centor will send information to affectors the affector will initiate physiological processes called a response to bring the body back to its normal State once the normal state is reached the negative feedback loop will end positive feedback loops are way less common than negative feedback loops now positive feedback loops occur when something needs to happen quickly so an example of that can be found in childbirth so we're going to use that as an example to break down how a positive feedback loop works so first the baby's head will touch the cervix and in this example this is going to be considered the change in variable also known as the stimuli the data is then sent to the control center which in this case is going to be the brain the brain will send signals to the uterus which in this case the uterus will be the affector the uterus will then produce the oxytocin hormone and this is a hormone that increases labor contractions during child birth and controls vaginal bleeding after child birth the oxytocin hormone will then stimulate uterine contractions this is going to be your response contractions will then move the baby's head closer to the cervix and contractions will cause more stretching of the cervix and remember we said that a positive feedback loop will result in more of a product and in this example the product is going to be the oxytocin hormone which will lead to more contractions until the baby is born so as you can see in the positive feedback loop the body isn't trying to decrease the change in variable it's reinforcing the change in variable however this feedback loop will still lead to the body reaching its normal state after the baby is born but the body can't give birth to the newborn without increasing output making this a positive feedback loop as I said earlier structure dictates function is a common principle of anatomy and physiology for example the lungs have thin tissue which is good because this allows gases to quickly cross however if the lung tissue were thick gases would take a longer time to travel through the tissue making it difficult to maintain homeostasis gradients exist Whenever there is one area that has more of something than the other things such as nutrient exchange respiration and formation of urine all are driven by gradients there are different types of gradients there's temperature gradients there's concentration gradients which you probably remember from introductory biology and then there is pressure gradients and pressure gradients can either be hydrostatic or osmotic the cells of the body will communicate with one another through chemicals or through electricity to maintain homeostasis cells that are directly next to one another can use an electrical signal to communicate whereas chemical Messengers are more versatile they can be used by cells directly next to one another or cells far away from one another for example a nerve cell will stimulate a muscle cell by releasing chemical Messengers into the space surrounding the muscle cells then the chemical Messengers will lead to a contraction in the muscle and this is an example of how cells communicate I'm so happy to finally get this video out to you guys because I've been trying to do it all week but I really wasn't feeling too good which is probably why I sent like two different people throughout the whole video but please don't forget to like this video please comment down below and tell me which topic of anatomy and physiology you were most excited to learn about this semester please don't forget to share this video And subscribe to my channel also feel free to send me video requests until next time