A&PI Lab video lecture covering body membranes and body cavities.
Welcome to part b of
Unit 1 we're gonna be looking at the body cavities
I am Anna Gilletly and I'm going to be giving you a slight tour of this
All right looking at the body cavities
What we're gonna do is we are going to divide them up into dorsal and ventral body cavities
So this is one of those places where we use dorsal and ventral instead of anterior posterior
So you see right here. We've got the dorsal
So the dorsal body cavity has two
sections one the cranial cavity and two the vertebral cavity
Notice that within the cranial you are only going to have the brain and within the vertebral you're going to have the spinal cord
So if I'm describing these things I would say the spinal cord is within the vertebral cavity
Which is within the dorsal body cavity or the brain is within the cranial cavity, which is within
the dorsal body cavity
Okay. Now let's look at the ventral body cavity. So I'm doing that one in red right here
So if you look over here, I have three major cavities
I have the thoracic cavity and
then I have the abdominal cavity and I have the pelvic cavity now the
Abdominal pelvic cavity –zz have imaginary lines dividing them. So sometimes they are called the
abdominal pelvic
Cavity and they are merged the thoracic cavity is nice because we have the diaphragm muscle
That separates it from the abdominal cavity so that completely separates it. It's a very nice boundary line
Again, the abdominal pelvic is an imaginary line. So I look at the right here
There's a bone called the bony feature called the anterior superior iliac spine
It is on the ilium of your pelvis. We'll talk more about that in a couple of weeks
So you're going to draw an imaginary line from here all the way over. All right, and the upper part is the
Abdominal cavity the lower part is the pelvic cavity
Typically in the pelvic cavity you are finding a little bit of your colon
rectum
The reproductive organs bladder that sort of thing
Some of your other intestines will dip down in there as well the abdominal cavity you're looking at liver
gallbladder
I'm gonna abbreviate that kidneys
The bulk of your intestines all of that good stuff, okay
Now we have other wait wait, sorry, let me let me back up a little bit. Let's change color again
We're going to go to green. I want to further subdivide that the ceramic the thoracic cavity
I have two pleural cavities here and here. All right, then I have the mediastinum
there
The mediastinum is technically divided up into superior intermediate and inferior for the purposes of this class
just remember mediastinum and then I have the
Pericardial cavity. I wonder if I can change colors to a purple. I don't see a purple. So I'm going to pick yellow
So within the mediastinum I have the pericardial cavity
Okay, and the pericardial cavity is where you have your heart so you may have heard of pericardium pericardial
That's where your heart the lungs are in the pleural cavities in the mediastinum. I
Have the pericardial cavity?
With the heart in it, so you've got the heart
You've also got the esophagus
Part of the trachea is
within the mediastinum
So when I'm talking about things I would say something like the heart is in the pericardial cavity
Which is in the mediastinum, which is within the thoracic cavity
Which is within the verbena wrap the ventral body cavity. Okay. Now these cavities the dorsal and ventral
So those two
Those are the major body cavities where you've got really big organs in them
All right. We've got other body cavities. I've got them up here in orange
these are little ones so like your mouth the inside of your mouth is the world inside of your noses and nasal the
Orbital is where your eye is
Okay middle ear is where your ear bones are
Synovial is gonna be a joint cavity
So we've got other little cavities in the body, but the big major ones are the dorsal and ventral on
Oh my gosh, I just noticed I left out a letter so there should be an S in there. So that should actually read
dor s
al all right next slide
All right, so now that we've got a basic idea of what our body cavities are and the abdominal pelvic cavity
let's talk about our tic-tac-toe board and
our four quadrants now depending on whether you're an anatomist or
A medical practitioner or surgeon? You're gonna use a different system to kind of convey
Regions of the abdominal pelvic cavity if you want to be really really specific
They use what I call the tic-tac-toe board each one of these areas gets a name the epigastric region
So epi means around gastric is the stomach. So this is around the stomach umbilical. Well this belly button thing
It's real term the real name for it is umbilicus or umbilicus. So that's around your belly button. Hypogastric
so hypo means below …gastric is stomach. So this is the area
Down there. All right, so then you've got the lumbar region here, okay
Hypochondriac is there and then you've got the inguinal region and that's your groin range of them. Okay. Let's move on to the next slide
All right for the purposes of this course we tend to use the
Quadrant system more often. So that's just dividing it into four quadrants. You've got right upper right lower
left upper left lower what's important about this is it helps you communicate things so if I'm saying like,
Someone has a knife wedged into their upper right quadrant
Well, then, you know, it's not down here and it's probably not affecting the rectum
And instead it is probably going to be affecting their liver. Okay, or
If they have ruptured their spleen make an incision in the right lower quadrant
Well, then, you know you're about to do something wrong because the right lower quadrant is here and your spleen is over here
so using these quadrant terminology it helps people talk about
What they're looking at and directing other people to look at the same thing
So it's important for communication and to use the right terminology
All right. Let's move on to the next slide
All right, so we're gonna quickly talk about serous membranes
Because we are talking about the body cavities and it's going to be coming up
You're gonna get more into this as you start doing histology
So this will seem a little
Maybe a little overwhelming right now because if we haven't talked about it too much
But you need a preview in order to move on. Okay, so
serous
Membrane also called serosa. All right, so you can call its Rosa or serous membrane
What you want to know is that it's in the ventral body cavity and it is a thin double layer of
tissue
all right all
membranes are going to consist of two things in epithelium, which we're going to talk more about in the next lecture and
a layer of connective tissue
Typically and areolar but sometimes a reticular. Okay, so
You need to know that these are always
Sandwiched together when you've got a membrane whether it's a serous membrane a mucous membrane or a cutaneous membrane
And I'm gonna be saying this a lot as we go over the next couple of weeks and we're talking about tissue types. So
These membranes they reflect or touch so reflect is kind of another way of saying touch
When you're talking about something, so if it reflects up onto the walls of the ventral body cavity
We call it parietal
So whenever you see this you word parietal think wall whereas whenever you see this role you're thinking of viscera
And you may have heard of that word before
So that's basically your guts the viscera of an animal is the guts of an animal so intestines heart liver
kidney, so
The visceral serosa reflects up onto those organs or guts
Okay in between the sandwich layer, this is really important. I have serous fluid
This fluid is secreted by the cells of the serous membrane and what it does. Is it prevents sticking?
Between the two layers
so everything in the body is moving just a little bit and if things can't slide against each other they stick you get
Inflammation, it's painful. It hurts. It's bad. So I want you to imagine a slip and slide
So I think most people have done a slip inside
That's the piece of plastic you put on the ground and you put water on it and you run and you slide across it
Imagine trying to do that with no water
Okay, that's what happens if you don't have serous fluid and it's it's bad it hurts
Okay, and we have different kinds of serosa. We change the name
Depending on where it's located now, let's look at that
All right, so now we're getting to the slide the whole reason
I went over what serosa was was to be able to tell you this part
so
around the lungs
Right here. Okay here and
Here the serosa we give it the name pleura. All right, so the pleura goes around
The lungs okay, if it's going around the heart we call it
Pericardium it's wrong one
Pericardium now notice sometimes I use the word parietal
sometimes I use the word visceral so I can call it a riot or pericardium or
Visceral pericardium and what that tells me is is it close to the wall?
Okay, or is it touching the organ?
Okay, and the same thing with pleura?
I can have parietal pleura up against the wall or I can have this rope Laura touching the lung and
Then within the abdominal Perekop
Abdominal pelvic cavity we call it peritoneum
Okay, and I can have parietal peritoneum or visceral peritoneum
Alright, so that ends
this particular video lecture and
In the next set, we will be talking about epithelial tissues

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