Connective Tissue : Tissues - Science, Class 9 Video Lecture

connected tissues we're gonna look at
the different types of structures and
cells inside of connected tissues the
general structures include a matrix a
matrix by definition is the nonliving
material between cells I like to think
of connective tissues as jello with
fruit in it so for example if you had
some jello with fruit in it the jello
itself would be considered to be the
matrix this fruit that would be inside
of the jello would be considered to be
the cells let's say that are inside of
the matrix another structure you'll find
inside of connective tissues our cells
called fibroblasts blasts means that
it's a cell that's going to be creating
something so in this case it's going to
be creating fibres inside of the
connective tissue so it's almost full
forming like a scaffold if you will of
fibers inside of the matrix the next
type of cell that you may find in some
connective tissues are effect cells the
fat cells are called adipocytes site
means cell at opponent forms us that it
is a fat cell they contain lipid which
is a storage form now of the fat the
mast cells that can be found in
connective tissues our immune cells
their job is to release histamine
histamine will initiate an allergic
reaction or an inflammatory response
other types of cells that can be found
in connective tissues would be white
blood cells these also function in
immunity collagen fibers can be found
these are proteins and their function is
to resist compression which is why you
know the movie star sticking into their
lips because it's a good structural
protein elastic fibers can also be found
inside of connective tissues elastic
fibers are
important you would probably think for
stretch and although they are important
for stretch moreover they're important
for recoil so they're a protein that can
stretch and then recoil in an example of
that if you you know get up in the
morning and you put your underwear on
you have to pull your underwear out to
step into them you pull them up you let
them go in and they smack back to your
hips that important part about your
underwear let's say is that it just
smacks back to your hips it wouldn't be
very good if you pulled them out stepped
into them pulled them up and then they
fell back down so you get that elastic
fibers although they do stretch are
really important for recoil to go back
to their original position the other
type of fiber that you can find is a
reticular fiber these forms scaffolding
for your soft organs such as your spleen
this picture here is a side of your
textbook kind of showing you some of the
different cells and/or fibers that you
would have the orange squiggly fibers
are your elastic fibers the orange large
fibers would be your collagen and then
the purple cells attached to those are
going to be fibroblasts you can also see
a thin branching fiber in blue that's a
reticular fiber we've got a series of
white blood cells in there and then the
yellow cells that you can see our
adipocytes
or fat cells there are a couple
different types of connective tissues
one of them is a loose connective tissue
or sometimes called areolar connective
tissue this tissue is very very flexible
it allows quite a bit of movement you
can find it around organs around your
muscles and around blood vessels so it
does hold those structures in place but
still allows quite a bit of movement the
next type of connected tissue is a dense
connective tissue dense connective
tissue is very very strong it's
significant in that it resists
stretching along its axis tendons and
ligaments are good examples of a dense
connective tissue again they're really
strong and they resist
pullian stretching forces taking a look
at this picture the bottom left is an
areola or a loose connective tissue the
one up at the top is a dense connective
tissue so you can see in the dense
connective tissue how close the collagen
fibers are packed into one another
another type of connective tissue is
elastic connective tissue this is a
stretchy type of connective tissue and
as a for mentioned we've talked about
how it recoils nicely the stomach and
the urinary bladder are both examples of
organs that would have a lot of
connective I'm sorry elastic connective
tissue in them on days when you eat lots
and lots of food like Thanksgiving your
stomach is going to stretch
significantly however after that food is
digested and moves along the digestive
tract the organs should recoil back to
its original shape in size same thing
with the urinary bladder when you void
your urinary bladder it should recoil
back to its original shape and size
reticular connective tissue is going to
have a lot of reticular fibers in it and
as the result is going to end up being a
network of support the spleen as
mentioned before is a good example of
where you can find reticular connective
tissue as well as in your lymph nodes
taking a look at this picture on the
bottom left we have elastic connective
tissue and on the top right we have
reticular connected tissues there are
also a group of specialized connective
tissues cartilage is one of the
specialized types of connective tissue
cartilage has cells called chondrocytes
Kandra refers to the cartilage site
again refers to cell so by definition
chondrocytes are cartilage cells and the
chondrocytes are sitting inside of a
space called a lacuna so they're the
space in which the chondrocytes it's if
I get back to my example of connective
tissue being jello with fruit in it
remember that the matrix was the
jellow in this case the chondrocytes
would be the fruit they would be the
spaces I'm sorry the the cells so if you
decided to stick your finger into the
jello grab a piece of fruit and pull
that piece of fruit out there would be a
space left where that fruit used to be
that space would be analogous to the
lacunae bone is another type of
specialized connective tissue the cells
however inside of bone are called
osteocyte osteo refers to bone site
again refers to cells so by definition
osteocytes are bone cells
lacunae is the same thing in a bone as
it is in cartilage since bone is alive
the cells inside of the matrix are
sitting in the space called a lacuna the
difference of course is that bone is a
solid matrix where cartilage is more of
a semi solid matrix taking a look here
the bottom left is bone you can see the
characteristic circular pattern the one
above that is cartilage other types of
specialized connective tissue involve
blood plugs made up of a couple
different parts one part of blood is
called plasma plasma is the liquid
component of blood so if you took your
blood donated it put it into a test tube
stuck it in the centrifuge it would spin
it really really fast this plasma would
separate from the cells so the plasma
would be the liquid component floating
on top and all the cells would sink down
to the bottom the other components of
blood are red blood cells and white
blood cells adipose is another category
of specialized connective tissue adipose
tissue is made out of adipose sites and
since we've already looked at what an
adipocyte is we know that it is a fat
cell the function of adipose tissue is
fat storage fat yields a lot of energy
and in the event that your body needs
extra energy you can break down some of
the fat that you've got stored
taking a look again at this picture the
top right is a picture of blood the
little red cells are the red blood cells
and the larger purple cells are the
white blood cells on the bottom you can
see adipose tissue basically adipose
tissue is a self filled with lipids so
lots and lots of fat so much so that the
nucleus of the cell gets pushed off way
to the side so they are big
vacuoles full of fat