hello and welcome to the penguin Prof channel in today's episode I want to introduce you to some directional terms and ples of section that we're going to be using uh in the study of human anatomy um first of all I need to describe the anatomical position the point of reference that we're going to be using and uh then I'm going to give you a lot of examples of different terms that we use to describe body regions and how we sort of slice and dice uh images uh so we can better understand where things are speaking of where things are uh Anatomy is not very different from uh traveling um so you want to kind of approach Anatomy like like you approach any kind of Journey um as many of you know flops the penguin loves to travel and when you travel just like when you study anatomy you need three things uh the first thing you need is a current and correct map the next thing that you're going to need is a point of reference so that when you get uh directions or when you when you look at the map uh things actually make sense you have to know where you are in other words and the third thing is you need a Common Language right in order to be able to read the map or understand people uh if you ask for help Anatomy is exactly the same we're going to need a correct and a current map this will come from your textbook Anatomy atlases tons of resources you're going to have to have a point of reference um you have to know where you are you have to be able to use uh understanding of anatomical position you have to know where you are in order for the terms to make sense and you need to speak the language of anatomy right we all have to speak the same language um you know you're going to find yourself in situations like this you're going to be looking at us this is actually a section through the human body and you may have absolutely no idea what this is uh where are you you know we're going to need these terms in order to describe what you're looking at so you can understand uh what you're seeing the language itself the language of anatomy is based in Latin and Greek most of the terms are actually descriptive um even though they can be kind of long and then of course we also have eponyms which are words that are named in honor of people those you just kind of have to memorize I do have a couple of other videos that you might want to look at how to study anatomy and uh medical terminology and those will help you as you uh dive into the study of anatomy but today's video is about position and directional terms so first of all our point of reference is what we call the anatomical position in anatomical position we have the patient the subject standing uh erect this can also be um in the case of a cab for example they're not going to be standing obviously but they will be lying on their back uh with their belly side facing up and in this same position where the Palms are facing up or facing forward the thumbs are facing out to the side that is the anatomical position eyes are facing forward and the feet are parallel to each other um this is a really good time to mention by the way right from left because believe it or not this can be very confusing it is the subjects right or left or the patients right or left not the Observer that matters so for example when we divide the body into four quadrants you're looking at for example the upper right and the upper left quadrant of the subject not you so I can't tell you how many times students will miss points because I will say on an exam you know identify for example right or left if I'm asking about chambers of the heart and they miss the right or left and they complain because how come I didn't get any credit well you misidentified it um if you have a hard time with right and left on yourself um this is just a little tip if you face your palms away from you uh the left hand makes a little L right there so that's kind of a helpful extra little tip but um like I said you really need this because if you're looking at at scans this is an intravenous pygram we use it to look at uh the renal system but you notice this little identifier here so the technician has to place this uh when the patient is getting the scan uh so that we can very easily see which side is right or left and you know this becomes really essential because people do make mistakes and if you misidentify right from left uh you could leave your patient with one diseased kidney instead of one healthy one so that's why we're really uh serious about learning uh right from left um and it does take a little while to get used to okay so some directional terms that we're going to be using using Superior and inferior we also use cranial and coddle but I'm going to mention that in just a second Superior means towards the head or towards the upper part of a structure inferior means low right so away from the head or towards a a lower part and you probably know these terms anyway if you feel Superior right you feel above everybody else if you're feeling a little inferior maybe your sestem is not so great um right so those are sort of terms in common use so I have some examples for all of these terms so the lungs are superior to the liver right so they are above the liver um on the other hand the small intestines are inferior to the stomach okay so that's how we would use those um anterior and posterior can actually refer to the entire body so for example in anatomical position you see the front of the body or the anterior part of the body the other side being the posterior but often we're talking about um from a side view for example things that are towards the front of the body or towards the back of the body we also use the terms dorsal and ventral but I'm going to get back to those in just a second just like the cranial and coddle here so anterior is towards the front posterior is towards the back or behind so how we might use that as an example the ribs are anterior to they are in front of the spine the occipital bone the bone at the back of the head is posterior to the frontal bone right the forehead at the front of the head um the other terms that I mention the dorsal vental cranial coddle we use those a lot more often in non-human animals specifically in quadraped because the terms there make a lot more sense uh you will see them in humans but with quadrupeds they're a lot more common you see you know with other animals you're going to use these terms differently most of you probably know the dorsal fin on a fish dorsal and ventral is colorcoded in Penguins I always find that I don't know really handy anyway um lateral and medial uh you notice a lot of these words occur in pairs so if you draw a line Midway down the body or what we call the midline when you move away from the midline we call that lateral so you're moving out to the side when you move toward the midline we call that medial you're moving toward the midline examples of how we use this uh the lungs are lateral to the heart the trachea is medial to actually both clavicles so the trachea your windpipe is medial to it's actually right on that midline it is medial to the clavicles or your collar bone intermediate means between so for example the clavicle or the collar bone is between it is intermediate between the uh a chromian process of the scapula that's kind of the Bony part that sticks out and the sternum or the breast bone the upper part of the breast bone called the manubrium so the clavicle lies between those two structures so you'll see that term quite a bit proximal and distal um again you're probably familiar with the roots of these words proximal means close to and distal means far from and we're always talking about the trunk of the body unless otherwise indicated so for example the scapula is proximal to the humor so the scapula or the shoulder blade is closer to the trunk of the body than the humorus um the wrist or the bones of the wrist which we call the carpal they are distal to the Elbow that means that these bones the wrist bones are farther from the trunk of the body in anatomical position of course than is the elbow so we use proximal and distal quite a bit superficial or external deep or internal so you can pick and choose which terms that you like you're going to see both of them in very very common use superficial or external means toward the body surface deep or internal obviously means deep or away from the body surface we use these a lot when you're talking about layers of things so for example here's a layer through the skin the epidermis is superficial to the dermis meaning it is external to it is closer to the outside the hypodermis where you see that layer of subcutaneous fat that's called the hypodermis hypo actually means below that is deep to the dermis and then terms like hypodermic needles right make sense those are needles that are injected into the hypodermis contralateral and ipsilateral refer to the the sidedness of things Contra means against so contralateral meaning on opposite sides Ipsy comes from a Latin root that means the same so for example your right and left arms or Wings depending if you're a pengu or not are contra lateral but your right arm or wing and your right foot those are ipsilateral those are on the same side you might think well you know this is pretty obvious why would you need a term for that this is going to be really helpful when we start talking about different skeletal muscles many of them that occur in pairs they can either contract together and they cause one type of action or they can contract you know only one side or the other so these terms actually will be very useful but we don't need to normally refer to them arms and legs it's pretty obvious I think okay and a couple of notes Here on planes of section and how we slice and dice things up so here's a little pop quiz for you what are these what are those well it's kind of a trick question because they're actually two images of the same thing why do they look so different though right this is a question that my students have all the time especially when we jump into histology they look so different the reason is they're cut in different planes so we have different planes of section you see the crosssection on one side and the longitudinal section on the other we're going to explain those in just a second but let me give you an example of what I mean by it's the same thing here's another little pop quiz what are these okay hopefully this is not much of a quiz and you recognize this but it's exactly the same answer it's a cucumber but it's a cucumber in two different sections okay now you get it right so one different style of slicing we call a cross-section and what you're left with is a cucumber that's round the other side when you cut it lengthwise you have a longitudinal section and you have a long skinny piece of cucumber now because you have experienced lots of cucumbers in your life it doesn't matter how I cut it you know what it is but in histology and in anatomy you just haven't seen enough of this stuff so you don't yet recognize it so these are the different planes of sections we have the coronal or frontal section the Al or frontal plane can actually divide into the anterior and posterior side we have a sagittal or longitudinal plane that's a lengthwise slice if you cut right down the midline we call that a mid sagittal slice or mid sagittal plane and then we have the transverse or the crosssection and that's going to be uh how you cut a cucumber into little circles uh just to give you three really quick examples right through the brain we're going to look at the three different planes of sections that I just mentioned so that you can see that of course you're looking at a human brain these are all MRI scans of the same thing the same structure but notice they look dramatically different and that's because when you change the way that you look at something you're going to see dramatically different structures and you're going to use different types of Imaging to see different things but it is a really challenging part of anatomy especially when you get into cross-sectional Anatomy it's difficult to know sometimes where where you are um some tips that I have on this you really just need to look at as many different references as possible look from as many angles at the same thing so you start to see the patterns the other thing is you want to read the captions the captions of every image will tell you what is the plane of section how was that image made you need to know that in order to know what you're looking at so because I'm going to get a lot of questions on this that image I showed you in the beginning now you can see the anterior and the posterior uh what I had labeled there that is the aorta that's the biggest artery of the body where blood leaves the heart for systemic circulation as always I hope that this was helpful thank you so much for 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