The stuff sneezes are made of!

I love pine trees - all kinds of pine trees. But, it seems that I am allergic to their pollen. Those little pollen particles meander their way in the air until I take a breath. They lodge in my nose and some make their way to my sinuses. The mucosal immune system kicks in. One type of mucosal immune system cell called a macrophage can absorb the pollen, carry it to another type of immune cell called a B cells. If I have never encountered that pollen type, the B cell creates an antibody to the pollen. The antibody attaches to a cell type called a mast cell. Soon the IgE-mast cell attaches to another type of immune cell called a basophil. Then, when I encounter this pollen again, the basophil or mast cell immediately secrete powerful chemicals called histamines to fight off the "invaders". The histamines will then dialate the blood vessels causing more blood flow. The increased blood flow can cause other defensive chemicals to be secreted and localize in the area, causing increased fluids leaking into the area (runny nose, itchy, watery eyes, etc) and inflammation (swelling and redness).

Sneeze! Sneeze! Sneeze!

Thank you all for your kind comments. I have been very remiss in commenting lately since I have been working on a number of projects and writing papers. I hope to catch up soon. I do continue to look at many of your pictures and comment on a few each day. Thanks for your patience!