Organization of the Body: Body Cavities - Video Tutorials & Practice Problems
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1
concept
Introduction to Body Cavities
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We're not gonna spend some time going over the first real detailed anatomy that you need to know for this course. And that's when thinking about the organs of the body, think about how they're organized and they're gonna be organized in body cavities. So when you think of your body, especially the trunk of your body, you can almost think of it like a big bag of guts, you can cut it open, there's all sorts of organs in there that you can reach in and touch, but organs are in specific places and sometimes they're divided into smaller bags of guts within that big bag. So we're gonna start off by saying that bodies are highly organized and that organs are housed in specific areas. And we're gonna call those areas, body cavities. A cavity is just a space. And so a body cavity is a space within the body, a space where you can put stuff. There are gonna be two main cavities that we're gonna talk about. And as we go forward, we'll talk about some smaller ones. But those first two main cavities are gonna be the anterior cavity, the anterior cavity, the front of the body also called the ventral cavity. This is gonna house the visceral organs. Now, visceral is a word we haven't learned yet, but the viscera just means the organs of the chest and the abdomen. And it comes from Latin meaning organs. So the visceral organs, it's almost a little redundant visceral organs are the organs of the chest and abdomen. So we can see this here. We have a big region in the front of our body that houses all those organs. And we're gonna label that the anterior cavo. Now, the second cavity is gonna be the posterior cavity also called the dorsal cavity. Remember, posterior or dorsal means the back of the body. This is gonna house the brain and the spinal cord. So we can see up here up top we have inside the skull, there's a space for your brain and then coming down through the bones of the spine. There's a space for your spinal cord and we can even divide that up into the cranial cavity, the space that houses the brain or the vertebral cavity, vertebral cavity that houses the spinal cord. But together those are going to be the not label. Now, posterior can we're not gonna talk about the posterior cavity anymore? That's really all you need to know. There's a space in the skull and down through the the spinal column to house the brain and the spinal cord. It's important to note that though, however, sometimes this is not considered a true cavity. So some textbooks, some professors treat this differently. And that's because in some ways the posterior and anterior cavities are similar, they house organs, those organs are in membranes. But for a lot of technical reasons based on structure and development, they're actually quite different from each other. And some people really just like to reserve this term cavity for the anterior cavity. So just check your notes, check your book, whether you should be calling it the posterior cavity something else or whether you just don't worry about it in your course. For now, we're gonna go through the anterior cavity in a lot more detail in upcoming videos and learn about all the different bags your guts can be placed in. I'll see you there.
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example
Organization of the Body: Body Cavities Example 1
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1m
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This example wants us to name at least one organ that is located in each cavity pretty straightforward. So first, we have the anterior cavity. Remember, anterior means the front of the body. We also call it the ventral cavity. We can see that in green here. And it's just the big cavity that takes up the majority of the trunk of your body. So you can name any organ that's in there, any visceral organ we're gonna say uh so I'll just name a few. It could be your lungs, it could be your liver, it could be your bladder, we can go on and on. It could be your heart. It could be your intestines, your stomach. If it's in the trunk of your body, it's in the anterior cavity. The next cavity is the posterior cavity. Posterior member means the back of the body also called the dorsal cavity. And we can see that in purple and that's really just gonna house two main things, the brain and the spinal cord. Now just remember depending on the textbook or depending on your professor, sometimes they want you to learn this as the posterior or dorsal cavity. Sometimes they don't want you to think of it as a cavity because it has these technical differences from the anterior cavity. Check your notes, check your textbook to know for sure with that, we're gonna go into a lot more detail on the anterior cavity going forward and I'm looking forward to it.
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Problem
Problem
During a dissection, three of the following organs can be observed by making a single large incision. One cannot be observed by that same incision. Which organ would require its own incision to observe?
A
Stomach
B
Liver
C
Pancreas
D
Brain
4
concept
Anterior Body Cavity
Video duration:
3m
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We said that most of the body's organs are housed within the anterior or ventral cavity. And we also said that we could break that cavity up into some smaller sections. We're gonna do that now. So the anterior cavity houses most organs, but we're gonna break it into two major sections. Those sections are gonna be divided by the diaphragm, your major muscle of breathing. Now, we can look over, we have an our anatomical model here and you can see from the trunk up, you see the skeleton and you can see the anterior cavity color coded. We won't worry about the color coding just yet. The first thing that I wanna do though is draw in the diaphragm and the diaphragm you draw in just by putting a curved line, kind of pretty close to the bottom of the ribs there. And the diaphragm importantly is a sheet of muscle. It almost completely segregates the organs superior to it and the organs inferior to it, the organs superior to it, we're gonna say are housed in the thoracic cavity. And that's that region color coded blue. On your diagram. The thoracic cavity is your chest cavity. And again, it's the region above or superior to the diaphragm. The thoracic cavity contains the heart and the lungs. Now, it also contains some other stuff, but those are the big ones. And importantly, it's protected by that rib cage and sternum. So back in the skeletal system, we said that the bones can provide protection and I pounded on my chest to say, you know, I can punch my heart and not really worry about it because I have that protection. It really does a good job of protecting those sensitive organs inside. If we go inferior to the ca to the diaphragm, we're gonna see the abdominal pelvic cavity. And I'm gonna outline that in orange here by just sort of outlining both the yellow and the red regions here on the anatomical model, the abdominal pelvic cavity. Well, we can look at those two roots in the word abdominal and pelvic. It's the region of the abdomen and the pelvis. And again, it's inferior or below the diaphragm. We can further break this up into two regions. The first one based on all on those roots is going to be the abdominal cavity and the abdominal cavity is highlighted in yellow. On our anatomical model here in the abdominal cavities, most of your digestive organs, things like your liver, your stomach, your intestines. And currently here, there is no bony protection. It's just your ab muscles in front. And that's why we have the term for a gut punch, right, a punch to the gut is quite uncomfortable because there's no protection inferior to the abdominal cavity, you reach the pelvic cavity and the pelvic cavity is going to be shown in red. On our model here inside the pelvic cavity is the bladder and the internal reproductive organs. Now importantly, there's no clear divider between the abdominal and the pelvic cavity. Like there is like the diaphragm above the abdo abdominal cavity. The pelvic cavity is just defined as that region that's within the pelvis. Remember, the pelvis is the bony structure at the bottom of your trunk that forms a sort of bowl. If it's in that bowl, it's in the pelvic cavity. OK. With that, we have an example and practice problems to follow and then we're gonna break up these cavities even more going forward. I'm excited to do so.
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example
Organization of the Body: Body Cavities Example 2
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1m
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This example wants us to label the cavities within the anterior cavity and list one organ found in each. And we have this anatomical model. We're looking at a sagittal view or a side or profile view of the model. And we can see a, a blue cavity, an orange cavity and a red cavity going down the body. So let's see what they are. So, first off this blue cavity, can you name it and name one thing in it? Well, that's the chest region. The word for chest that we have is thoracic. So that's the thoracic cavity and naming something in your chest should be pretty easy. How about your heart? Your lungs work as well going down. We have this orange cavity. Can you name it? Can you name one thing in it? Well, that middle region here, that is your abdominal region. So that is the abdominal cavity, one thing in your abdominal cavity. Well, how about your stomach? You could also say your liver, your kidneys, your intestines, your pancreas, there's a whole bunch of stuff going on there, most of your digestive organs. And then finally, our lowest one here on the body in red. Can you name it? Can you name one thing in it? Ok. That is the pelvic cavity. And how about the bladder reset the bladder and also the internal reproductive organs. So, in females that would be like the vagina, the uterus fallopian tubes, the ovaries and males that would be some tubes in the glands, specifically the prostate gland. All right. With that, we got some more practice problems to follow. See you there.
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Problem
Problem
What are the two subdivisions of the anterior body cavity?
A
Abdominal and pelvic.
B
Thoracic and abdominopelvic.
C
Dorsal and ventral.
D
Pleural and thoracic.
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Problem
Problem
Boxers are taught to tense their muscles to protect themselves from the impact of punches. This is especially true for punches to the abdomen. Why do you think this is the case?
A
The abdominal cavity holds the body’s most sensitive organs.
B
The abdominal cavity lacks bony protection.
C
The muscles surrounding the abdominal cavity are larger than muscles around any other part of the body.
D
Both A and B are correct.
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