Bodily Defenses Image Map

Cell Operations of the Liver

           All substances that are absorbed in the digestive tract enter the veins that drain the gut and are carried in this venous blood to the liver. Think of the liver as the gatekeeper between the intestines and the general blood circulation. This is one of the few cases where venous blood comes INTO an organ. Because you have been told that the liver detoxifies chemicals, do you see why the liver gets its input of blood from the blood that drains from the gut?

Relation of the liver to other organs in the abdomen. The liver lies just under the diaphragm and on top of the stomach. It is attached by a large vein to the stomach and small intestines.

The liver detoxifies numerous toxins. It also destroys drugs, such as alcohol, nicotine, and prescription medicines, because these things are not normal to the body.  Some medicines have the bad side effect of damaging liver cells. It is like a war between liver cells and the medicine, because the liver is programmed to destroy foreign chemicals and cannot know that medicines are supposed to be good for the body nor know which medicines may damage the liver cells in the process of destroying the drug.

How do you suppose any organ could specialize to detoxify? One approach is taken by the kidney. The liver takes a different approach, involving two steps. If we examine the liver under a microscope, we see rows of liver cells with small spaces in between that act as a filter to remove dead cells, microorganisms, and chemicals as the blood flows slowly through the liver.  This filter includes cells that engulf ("eat") the sludge that is left trapped in the filter.

       Once inside the Kuppfer cells, the sludge must be broken down.  There are two phases of detoxification in the liver.  Phase one includes an enzyme,  cytochrome p-450, to detoxify the bad stuff.  This means that the harmful chemical gets broken down into smaller parts that are not harmful to the body.  Phase two detoxification is when the Kuppfer cells add materials to the chemical to be broken down, and this new chemical is not harmful to the body.  This addition of materials to a harmful substance is called conjugation.  Once phases one and two have been performed, the sludge is ready to be added back to the regular blood stream and secreted as waste, and it never harms the body. We have a wonderful, life-saving detoxification plant.


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