Blood: Eosinophils and Basophils

00:00 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.

00:39 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.

01:10 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.

01:56 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.

02:30 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.

02:46 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.

03:11 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.

03:25 They are activated to then have the ability to secrete substances that are vasoactive.

03:33 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.