Okay, today. We want to cover two things concerning bone. We want to talk about Bone tissue
so there's two different types of Bone tissue and
We'll talk about the composition and kind of the microscopic anatomy of those and then we also want to talk about
Whole bones, there's four categories of bones, so we want to be able to classify bones into one of those four categories
So bone tissue is different than bones themselves bone tissue is the actual
material that makes up your bones, and there's two types of bone tissues one is compact and the other is spongy, so
compact Bone is
Considered much more dense, so you can see this picture over here
You don't see a lot of holes or four spaces in between it so it's very dense. This is due to
Mineral salts calcium and phosphate make up the hardness of Bone also in here you find
Collagen Collagen gives your bone
strength
So usually you find compact bone in outer layers of all because it's compact. It's Dense
It's protective so it's going to protect the whole bone the organ itself
bones our organs because they're made up of several different types of tissue it's also going to
Protect the other type of tissue we're going to talk about is [the] cancellous tissue or spongy
And that's where bone marrow is made so we want to protect that so that we can keep making blood
so the job of Compaq bone is really for support structure um and
protection
so the structural component of
Compact bone, or dense tissue is the Osteon or the perversion system so two words mean the same thing?
this right here this circle set would be called a nasty and
So on inside of the Osteon you have the car version canal that's right here
Through the Haversian canal you have blood vessels and nerves nerve fibers that run through there to
Provide nourishment to the bone as well as innovation
Then you see you have these rings to me these remind me of annual rings in a tree. You've probably seen a tree cut
Horizontally, and you've seen the rings that we can count and see how old the tree is so these rings are called
[Lamela] So this Osteon has one
two
Three Lamela, and that's where the matrix that actually makes up the bone is found
So arranged along this
circle you find
Osteocytes remember that's bone sal site to sell a steep bone. So you find bone cells
They're kind of star shaped
So this is what that cell looks like and you see there are several in this circle now
The Bone cell is found in a pit. I'm going to describe it as
And that that pit is called a lacuna in most
Graphics you won't be able to differentiate between the Lacuna and the osteo site
Because one is sitting inside of the other
so that would be a
Nasty [oh] site sitting in a lacuna now this arrow
Would be that seo site the line is kind of going the wrong spot
Ok the last one is Canaliculi. So that's kind of a fun. Word to say I think um
Canaliculi our little canals so C&C canals so you have the Haversian canal going down the center of
The of the Bone, so that's running parallel with the surface of the bone
and then you have running between each of those layers each of the lamella you have these little
Cracks is the way I like to think of them as and
they're called Canaliculi so blood vessels are going to run between
Little capillaries are going to run between these osteocytes
So that's going to bring nourishment to the Ico site as well as take away waste products from the south
So you might notice that this?
bone Material looks much different
Then the circular bone material that we just looked at a moment ago
So this is called Spongy bone
Spongy Bone also is called cancellous tissue, and I will almost always refer to it as cancellous tissue
So you want to get used to that?
On different resources will use different versions of the word so you want to recognize either name um
we said compact bone is found on the outside of bone protecting it you're going to find the cancellous tissue on the
inside of the Bone um
and
What you notice is that there's lots of spaces in this bone tissue, right? So it's very porous. That's how it gets its name
Sponges as you know have many pores in them, so spongy bone is Porous um
It contains a large number of blood vessels, so this red stuff that you see is
Actually the bone. That's a little bit
that's the confusing part and then oh sorry um and then this is the
Spaces in between the bone so within the bone you find Bone marrow
And like I said there's lots of blood vessels, so it's very well nourished um
In your long bones like in your arms and legs the ends of your bones are called
Epiphyses remember Epi is above [Rokon] so at the end of long bone
You're going to find that those knobs are filled with
cancellous tissue
And then it has a thin layer of the compact on the outside
Ok so the microscopic anatomy of the spongy bone is quite different than the microscopic anatomy of the compact bone
so in the compact Bone, we saw rings of [Lamela] the
Butt over here, you don't see any rings at all right?
So this is called trabeculae, so the red is what we're looking at that's actually the bone
so the red is the Matrix and
the Lamella is what makes up the Matrix right um is in the form of
nothing in particular
it's described as a regular lattice and you know that's where we're going to find our lAcuna and
our osteocytes, so here you see little
Whores? We're going to look for these under the microscope and
Those are the Lacuna. It's easier to def differentiate Lacuna from Osseo site in the compact Bone
[I] mean, [I'm] sorry in the spongy bone then in the compact bone
so
Here you can see this one kind of looks like a black-eyed pea but not the right colors
It has a little dot inside of it. So that little dot is the osteo site, so that's kind of cool
So the spaces between the trabeculae have red bone marrow in them
And why is red bone marrow important because it is the site of hematopoiesis?
Hematopoiesis is the formation of blood so he my blood police's formation of so we usually are referring to
specifically the formation of red blood cells
Okay, are you still with me? So we've talked about two types of bone tissue?
And we talked about where they were found and what makes them up like microscopically?
So now we're kind of shifting gears no longer talking about tissue
We're talking about whole bones big structures
So these bones are made up of those tissues, right?
So there's [four] different types of bones you have long bones by definition
They are long short bones you a lot of times people want to say fingers and toes are short bones
But they don't meet the characteristics of a short phone
so we'll talk about that flat bones are by definition flat and irregular bones as
Its name implies is rather irregular
So for [our] test. I would want you to know two things about the different types of bones first
I want you to know where they're found
Second I want you to recognize their descriptions so short bones are
cuboidal in shape and
They're found in the wrist and in the ankles
also in the Patella the kneecap so wherever you see this turquoise Ii color that's a short bone so um
Typically they r. Cube shipped and then they're filled with cancellous materials with a spongy bone
And then they have a thin layer of compact on the outside, so they're more porous
they probably um have greater shock absorption right and that makes sense you've fallen on your hand and you've
Been thankful that your wrist could take
[okay], so long bones are longer than they are wide so look at this femur bone quite long in comparison to its width
So again look at the turquoise. Where do you find long bones?
You find it in your arms your legs your hands and your feet, but not your wrist or ankle because those are short bones
Some characteristics of the long bone is that the shaft is called the diathesis
so vocabulary terms that is going to be almost all compact Bone and
Then the epiphanies Epi above upon the epiphanies are filled with cancellous tissue
So that's where we find our bone marrow
And there's a thin layer of compact bone on the outside to compact to protect that
cancellous tissue
so flat bones are found in the skull and
in the Thorax so remember the Thorax is the chest so um
characteristic a flat bone is that it's made of two thin layers of compact bone and then
varying amounts of spongy Bone
So I think of this as a sandwich and the two pieces of bread are my compact bone
And then I filled it with Jelly, which is my spongy bone, so I find it in the ribs and in the skull
That's the most common
So that just leaves the irregular bone
So irregular bones are found in the pelvis and in the vertebral Column here's some individual Vertebrae over here
so this [is] similar to a
short bone [in] that it's filled with cancellous material and
Then it has a thin layer of compact on the outside the differences is it just doesn't have a regular shape
So that's all [I] have for you today. We talked about two types of Bone tissue
what makes them up where they're found microscopic anatomy, and we talked about four types of
bone whole bones so the organ itself um
where they're found and how they are composed as
It relates to those two tissue type. So thanks for the same