So now let's discuss the general features of connective tissue. Connective tissue is made up
of 2 basic components. You have the cells of the connective tissue and then you have the
extracellular matrix which is all the stuff outside of the cell. Connective tissue cells do not
have any free surfaces unlike our epithelial cells and as well the connective tissue is highly
vascularized and has a nerve supply unlike the epithelial tissue which did not contain any
blood vessels. The exceptions to this rule include the tendons and the cartilage which do not
have a high vasculature as well as very little nerve supply. So, there are 3 different types of
tissue cells found in connective tissue. There are fibroblasts, adipocytes, and also several
different types of white blood cells. First, the fibroblasts are large flat cells that are able to
move to the connective tissue and their general function is to secrete the extracellular
matrix. This is going to include the fibers and the ground substance that surrounds the cells.
The 2nd type of cell found in connective tissue is adipocytes. Adipocytes are fat cells that
store a large amount of triglycerides. As you can see, they almost look like they're empty
but in fact they are not empty, that is actually a large content of triglycerides. This is
going to be found below the skin in the subcutaneous level as well as in the fatty tissue that
surrounds a lot of your different organs. Another type of connective tissue cell is macrophages.
This is one of several different types of white blood cells found in connective tissue.
Macrophages are there to destroy the bacteria that get into the connective tissue and they
do this by phagocytosing the bacteria and chopping it up into little bitty pieces. Another white
blood cell is eosinophils. Eosinophils are especially used for fighting off parasitic infections
and are also found in allergic reactions. A 3rd type of white blood cell found in connective
tissue is neutrophils. Like macrophages, these are there to destroy different types of microbes
using phagocytosis. Another type of white blood cell found in our connective tissue are
different types of plasma cells. These cells developed from B cells or B lymphocytes and they
are there to secrete antibodies that are used to attack foreign substances. If there is an
allergic reaction or an inflammatory response, we also have the presence of mass cells which
is another type of white blood cell found in the connective tissue. The mass cells are going to
produce and secrete histamine and this allows for the dilation of blood vessels as well as
the inflammatory response that's able to kill bacteria.