- [Voiceover] Switching from the idea
of being a critical thinker and society roles of science,
we can move into the body more.
Now, even though we're kinda switching gears,
still, thinking critically is very important,
because, really, what makes up the body?
We'll start with looking at
the different structural levels of organization.
I'm sure if you look at the base of the pyramid here,
you can see the organismal level.
You know, it's what the person is.
But what makes up a person?
Well, you're made up of various different organ systems,
things like the urine system,
the cardiovascular system, the digestive system.
But each one of those systems
is made up of several organs.
So, for example, you take the digestive system.
You have your stomach, you have your small intestines,
you have your large intestines.
But then each one of those organs
are made up of several tissues.
Now, these tissues are things like
smooth muscle or epithelial tissue,
things that'll connect things together.
But each one of those tissues is made up of cells,
cells that are working together.
And then if you go beyond that,
each cell is made up of molecules.
Well, molecules are actually groupings of different atoms,
the most simplistic level, the chemical level.
So really, there's six distinct levels of complexity.
And then you reach the organismal level.
So you have your chemical level,
your cellular level, your tissue level,
your organ level, your organ system level,
your organismal level.
Now we have the different systems
found in the body.
So, as we went through that organisation level,
it's these different systems
that help to make up the overall organism.
If you start at the top left,
you have the integumentary system.
Skin, hair, nails.
It's helping to encase the body, keep things out,
as well as keep things in.
Go down to the muscular system.
That's what moves the body, creates movement.
Endocrine system, you're looking at
things that produce hormones.
For example, pituitary gland, thyroid gland.
The skeletal system, bones and joints,
what gives some rigidity to the body.
The nervous system.
Looking at brain, spinal cord, your nerves.
It's what's carrying the actual impulses
throughout your body.
The cardiovascular system.
Hearts, arteries, veins.
They're carrying blood, transporting blood
throughout your body.
The blood is carrying and transporting gasses,
like oxygen and carbon dioxide.
It's transporting nutrients and waste.
Your lymphatic system.
Looking at things like your lymph nodes, your thymus.
They're gonna pick up excess fluid, leaked fluid,
and return it back into the cardiovascular system.
Digestive system, you're looking at things like
your stomach, your liver,
your small intestines, your large intestines.
That's gonna help process the food you eat.
The bottom row, you can see,
is male and female reproductive.
On the male side, you're looking at things like
testes, epididymis, penis.
On the female side, looking at things like ovaries,
uterus, vaginal canal.
If you go to the top right,
you're looking at the respiratory system.
Lungs, trachea, your nose.
It's what helps to bring air into your body
so you can process and absorb the oxygen,
get rid of carbon dioxide.
Urinary system, well, you're looking at the urinary bladder,
ureter, the kidneys, filtering your blood,
and getting rid of waste,
but also removing excess ions.
Those different body systems we were just talking about,
well, some of them are found within certain cavities.
So, for example, you have up here the anterior cavity.
Well, anterior means front, so this is pretty much
what's all found in the front of your body.
You have a couple of different cavities
inside the anterior cavity.
You have what's called the thoracic cavity.
Now, think about where your heart and lungs are,
the upper part of your chest.
That's your thoracic cavity.
There's the two pleural cavities,
which is where each lung is,
and the pericardial cavity, which is where the heart is.
You then have your abdominal cavity.
This'll be encasing things like your stomach,
your small intestines, large intestines,
your liver, your gallbladder,
your spleen, your pancreas.
They're all down right in the main section
of your abdominal region.
And the pelvic cavity is right down in the groin region.
This usually contains reproductive organs,
and you're gonna have a little bit of the
urine bladder in there as well.
But go to the posterior side, well,
posterior cavity is the back side.
It'll be broken up into two things,
the cranial cavity, which is where your brain is,
and the spinal cavity, which is where
your spinal cord is, inside those vertebrae,
the bones you feel along your back.
So here's what it looks like.
If you're looking at the figure
on the right hand side now,
the one you can see the front of the person.
You can see in the top, you have that thoracic cavity,
which is broken into pericardial and pleural cavity.
The diaphragm is what splits the parts.
You can see the diaphragm is labelled right
in the middle of the figure there.
Below the diaphragm is your abdominal cavity.
And then at the very bottom, just in the groin region,
is the pelvic cavity.
If you look on the left side of the screen,
you can see the view from the lateral, or from the side.
You have your cranial and vertebral cavities.
So both those are found within the posterior cavity.
But some of these cavities are gonna have membranes
that help to line them.
We have what's called the serous membrane.
You're gonna find this throughout the abdominal cavity,
and you'll find it in other cavities as well.
But what it's meant to do, is it's a double layer membrane.
There's actually two parts.
One will cover the organ like saran wrap,
one will line the cavity.
The goal: reduce friction,
cause as you move, are your organs moving?
If you bend forward, think about what happens
to your stomach, your intestines.
You're crunching them down.
So it helps reduce friction.
You have mucous membranes.
Think of the things in your nose, in your throat.
Helps to capture any debris that you're
inhaling in, for example.
Synovial membrane, these are found in joints,
joints like your knees, your elbow,
your shoulder, your hip.
They're lining the spaces, and helping to prevent the bone
from contacting bone on bone.
And, the cutaneous membrane.
That's your skin.
So what you see, your cutaneous membrane
is everything you see that is your skin.