it is very active or not. Well let us move on and
look at the eosinophil. An eosinophil is a
cell that has a job of trying to moderate
or minimize the deleterious effect of some
of the very potent vasoactive mediators.
They have granules in them and they stain
very pink as you see in this section. Those
granules can stain in such a way as to appear
differently when you look at them in electron
microscope. Sometimes the granules are elongated.
They are the specific granules. They are
granules that contain various toxic substances
that help to eliminate parasites and protozoans.
They also have the azurophilic granules shown
here in the slides, the very circular granules.
Those granules contain lysosomes as I have
mentioned before with the neutrophil, but
they also contain enzymes or hydrolytic components.
They can actually break down the parasites
or protozoans that the cell actually ingests
and they can also break down antigen-antibody
complexes that they also ingest. So they are
very important cells for that reason.
They are very important as I have mentioned
there in not only help to deal with the deleterious
effects of vasoactive substances, but they
also have a role in minimizing allergic reactions.
But the main function is to ingest these parasites
and break them down using the granules they have
at their disposal.
Let us move on to the basophil. It is a very
very small cell that is very small in proportion
to the other cell types. It is about 10 to
12 microns in diameter. It is the similar
size then to eosinophils, which are also about
that size, 10 to 12 microns in diameter and
also the neutrophil. The three granulocytes
are roughly the same size, 10 to 12 microns.
But now you know that they are different in
their staining characteristics. The basophil
has bluish, purplish granules within it and
these basophils function just like mast cells.
They have specific granules that secrete histamine
and heparin. Histamine being a vasoactive
agent and heparin being an agent involved
with the clotting mechanism. Basophils are
also very important because they go to a site,
they bind to the immunoglobulin E, an antibody.
These antibodies come in to deal with certain
allergens or antigens and basophils move in
and they bind to that antibody. And once they
bind to that antibody, they are activated.
They are activated to then have the ability
to secrete substances that are vasoactive.
They can open up the blood vessels and therefore
bring in more cells to help combat that allergen
or that antigen. Let us move on to the
agranulocytes, the lymphocytes.