So What Am I Doing Today...?

Identify 3 major portals of entry for microorganisms.

The three main portals of entry are the mucous membrane, the skin, and parenteral.
The mucous membranes include the respiratory tract, the gastrointestinal tract, the genitourinary tract, and the conjunctiva.
The unbroken skin is impenetrable by most microbes though some can gain entrance through our hair follicles and sweat glands. Some things such as the hook worm can bore through intact skin and certain fungi can grow on skin and produce enzymes that break down the keratin and then are able to enter into the skin. Microbes that are deposited directly into the tissues beneath the skin or mucous membranes have taken the parenteral route. This is when your skin is punctured or you are cut or bit or have surgery. It is not the organisms that come in through the opening, but the ones that were present on the needle or knife and what-not before you were poked or stabbed or cut.


Contrast CD4+ T cells with CD8+ T cells.

CD4+ cells are T helper cells. They recognize antigens on the surface of the antigen presenting cells and then activate macrophages. This induces the formation of cytotoxic T cell and stimulates B cells to produce antibodies.
CD8+ cells are cytotoxic T cells and are CD4-. They destroy target cells. These cells recognize the antigens on the surface of all cells and kill the host cells that are infected with viruses or bacteria. They recognize and kill cancer cells. They recognize and destroy transplanted tissue. These cells also release a protein called perforin which forms a pore in the target cell which, in turn, causes lysis of the infected cells. The CD8+ cells undergo apoptosis when the stimulating antigen is gone.

...are you guys excited yet!!!??

If you are...HERE's some bloody stuff for you.
I've got to get back to studying for my test now...