The anatomical position is an important position. It is a position that allows us to discuss among each other, locations of body parts and so on, where we're all using the same frame of reference. Here's the anatomical position. So the anatomical position is somebody standing upright, face-forward, with their palms also face-forward, their arms out to the side. You can see a midline drawn in the individual shown in the picture here, showing that the right and left sides are more or less symmetrical. But again, the important aspect here is the anatomical position. Another important aspect that we can use as a reference frame are the planes that are used in reference to the human body. The sagittal plane is a plane that runs down the middle of the body, and more or less splits it into left and right half. A transverse plane is a plane that cuts across the body. And the coronal or frontal plane is a plane that divides the front and the back of the body, running down the side. It's important to get our bearings here, so I'm showing another image of the median or midsagittal, which is a sagittal plane directly in the midline of the body. But the image below, showing a midsagittal cross-section of the head, gives us an example of why this is important to understand these planes of reference. Throughout the text, you might find images like this one here of the cross-section of the head. And we would want to recognize that this is a midsagittal plane, and that we're looking at the side of the head here, as if we've cut through the middle. The frontal or control plane, if we were to cut through the body, as in the image shown above. We might have an image in the text of the various aspects of the body, the right lung, the left lung, the liver, stomach, and so on, as if we've sliced the body, dividing the front and rear portions, so that we could look at the organs of the thoracic and abdominal cavity as shown here. And then finally, a transverse plane would be as if we cross-sectioned the person across the body as shown here. And if we did it in this exact place, we would see an image, perhaps like this, where we're seeing the stomach, the liver, and so on, as if we've cross-sectioned the person at that area of their body. Using these planes of reference as well as the anatomical position, we can start to use common anatomical terms for direction. This image has a lot on it all at once. It's actually got all three planes and so on. If we look at some of these terms, we can use them to start to get used to where things are located in the body. So for example, we have anterior and posterior. The anterior is more towards the front of the body, and the posterior is more towards the rear. So for example, we could say that your sternum is actually anterior relative to your spinal column, which is more posterior. Superior means higher in the body, versus inferior, which is lower in the body. And so we could say my head is superior to my feet. My feet are inferior to my head. Proximal and distal are a little bit challenging, but really it's all about the reference of the trunk of your chest and your abdomen. And so in this case here, we're looking at the shoulder is proximal to your wrist. It's because your shoulder is closer to your chest and your abdomen, to your trunk, than your wrist is along your arm. Your wrist is distal, or further away, it is distal relative to your shoulder. These frames of reference and anatomical terms can be a challenge. So one key strategy is to practice with it. OK? Use these terms as you get used to the content in the course, and ask yourself questions about the body, where things are located in the body, and use these terms in order to describe them. One other common anatomical term we should look at is a lateral versus medial. Lateral is more towards the outside of the body relative to the midline, and medial is closer to the midline. The nice part here is that some of these terms are actually related to terms we're used to in our everyday language, if you will. And so some tricks here for remembering some of these terms can be things like superior. At work, my superior is my boss. Somebody who is over me, above me. And so going back to our example of earlier, the head is superior to the feet. It is above the feet. Somebody who is inferior to me-- or maybe if you heard of a new product that has come out, but it is inferior to the already existing product, we would take that to mean below or beneath, not as good as. And so in this case, we could say the feet are inferior to the head, because they are below the head. Proximal means closer to the trunk. And so if you think of a term like approximate. If I'm meeting you approximately two o'clock in the afternoon, it's around or close to two o'clock in the afternoon. So proximal means close to the trunk. Distal refers to distance or far away. The wrist is distal to the shoulder, further away from the trunk than the shoulder. The medial is meaning more towards the middle. And medial or medium all refer to a middle or medium size. And so medial means towards the middle vs. lateral which means more to the outside. Maybe you have other tricks that you can use for some of these terms. There's just a few to try to make the content stick a little bit better. So let's look at some of the cavities of the body. A cavity is just a space. Think about your teeth. If you get a cavity in your teeth, that's a part of your tooth that has eroded away or rotted away that you need to get the dentist to fix. Overall, in our body though, there are many spaces, and that's what we want to look at here. Body cavities, ultimately, are filled with organs. Another term you might come across in the text and so on is viscera. Viscera and organs mean the same thing. And there are two major cavities in our body: the dorsal and the ventral. And so even though there are other cavities listed in the picture here, the dorsal cavity is shown in orange, and the ventral cavity is shown in yellow. The dorsal cavity is at the posterior side of the body. And this is something we should point out here. Dorsal and posterior basically mean the same thing, the rear portion of the body. And so this is a major cavity at the posterior portion or dorsal portion of the body. Ventral means anterior. And so the yellow region here, the cavity, is the ventral region, because it is at the front, anterior or ventral portion, of the body. The dorsal and ventral cavity then have sub-cavities within them. And so if we look at the dorsal cavity, there's actually the cranial cavity as well as the spinal cavity. The cranial cavity is where you find the brain. And the spinal cavity is where you find the spinal cord. The ventral cavity also has subcategories. We have the thoracic cavity. And then we have the abdominopelvic cavity, which is made up of the abdominal cavity as well as the pelvic cavity. The diaphragm is the area that differentiates between where the thoracic cavity is and the abdominopelvic cavity. It actually splits the two within the ventral cavity. If we look at an image of looking at the anterior portion of this same body, we can see that, within the thoracic cavity, there are actually also sub-cavities. So we have the pleural cavities, where you find the lungs. And then in the middle, you find the mediastinum, which is where you find the heart. OK. So we also want to be able to name and locate the regions of the abdomen. And so when we're looking at someone's abdomen, we can describe where organs are found or if somebody was describing pain they had in their abdomen, we could actually note the pain in terms of where it's actually occurring. And so here are the regions of the abdomen. Some of the names here look somewhat tricky, but again we want to look at some strategies to remember these terms. So let's move the body off to the side here. And let's get our bearings to the abdomen. Whenever we're looking at an image of a body, one thing we need to remember is that the right side of the body is actually on our left side, because the individual we're looking at is the opposite to us. Their right side is on our left side, and then their left side is on our right side. And so what we can see here is that the right side, all the regions, have right at the beginning of their name. And on the left side, they all have left at the beginning of their name. Let's look at the right hypochondriac region. Sounds like a big mouthful, and how am I possibly going to remember that? But remember, earlier on in the video, I said we can often break down these terms to help them make more sense for us. So let's look at this term hypochondriac. Hypo always means low or below. And chondriac is referring to cartilage. And so if we actually look at the ribcage, the lower portion of the ribs that you see behind the word hypochondriac is actually a lot of cartilage. And so what it's saying is this right hypochondriac region is on the right side of the body, below the rib cartilage. If we go through the other names here, we can see well, there's a left hypochondriac region, so that means the same thing. If we look epigastric, epi means above, gastric refers to stomach. And so as you can see here, it's the top part, or above, the stomach. The umbilical region is where our belly button is, and that comes ultimately from the umbilical cord attachment. The hypogastric, hypo means low and gastric means stomach, so it's the lower portion of the stomach. The right and left iliac or inguinal regions, the iliac refers to the iliac crest, which is our hip bone. And you can see that in the image here, just on the line that separates the lumbar region from the iliac region. The reason that the inguinal is in brackets is because inguinal refers to the groin. And so it's the right inguinal region and the left inguinal region, because it's to the right and left of the groin. The right and left lumbar region, think about the small of your back. That is the lumbar region of your spine. And so the right and left lumbar regions are the regions of your abdomen that are to the right and left of that portion of your spine. Finally, another way to look at the abdomen is using quadrants. And so it's a much simpler form than what we just looked at. But we have the right upper and right lower quadrant, and the left upper and left lower quadrant. We've basically divided the abdomen into four parts. OK? Again, when you're working with a patient, their right side is actually on your left hand side, and their left hand side is actually on your right hand side. So that's something that takes a little bit of getting used to. But this is another way that we can actually describe where, maybe, a patient is experiencing pain and so on. We can also look at the organs that are within the various quadrants of the abdomen. For example, in the right upper, most of the liver is there. In the left upper, we have the stomach. In the left lower we mostly have intestine. In the right lower, we mostly have intestines as well as the appendix, which is just below the W and E in this image here. It's another way to communicate among people who are discussing anatomy, so that we're using the same frames of reference, the same terms and terminology, in order to describe areas of the body, and so on and so forth.