Diplomate, Board Certification of Emergency Medicine
Chairman, Department of Emergency Medicine Ma'ayenei Hayeshua
Hospital
We have been discussing the way the body deals with poisons
and byproducts, and the kidney was recognized as the chief
processor of poisons that can be dissolved in water. Other
poisons and byproducts are dealt with differently.
First, the digestive tract and the respiratory tract are
extremely careful not to let just anything in. Your nose and
mouth are equipped to prevent large invaders simply by the
size of their openings. Liquids in your mouth slow down
things like bugs that may fly in and allow you to spit them
out. Likewise, your nose can sneeze and your mouth can cough
out large invaders.
Hairs in the nose trap a lot, as well as little hairs in the
respiratory tract called cilia that push dust and small
particles out. Often, poisons are bitter tasting and a person
will spit them right out (careful, this isn't always true --
antifreeze, for example, is sweet tasting and very
poisonous), and poisonous gases often smell bad (true for
sulfide gases, chlorine and smoke, but not true for carbon
monoxide). Things such as pebbles and dirt that may be
ingested are not absorbed at all and go right through the
digestive tract, being discharged as stool.
However, some poisons invariably are ingested, and this leads
us to speak about the liver. The liver is the largest
internal solid organ in the body and is essential. The liver
performs many functions. It makes gall, which aids in the
digestion of fats and other insolubles. It has a role in
blood formation, especially factors in the blood that are
necessary to clot. It also metabolizes poisons and
byproducts, which are then released into the digestive system
to be sent out in the stool.
The liver is full of blood since blood is filtered through
it, and it is also the site where many of the medications we
use are processed. For example, ibuprofen and aspirin are
acids that dissolve in water, so they are processed primarily
in the kidneys, but paracetomol (acetaminophen, Tylenol,
Acamol and others) is processed in the liver. While
paracetomol is a very safe drug, an overdose is treacherous.
Ibuprofen is easier for the kidney to deal with in an
overdose, since the kidney has just to filter it out with
fluid; however the enzymes needed to deal with a paracetomol
overdose in the liver are overwhelmed and failure can occur.
All medications, especially those that are over the counter
should be used with caution.
It is easy to see that liver injury can result in bleeding,
inability to clot, and internal poisoning, such as occurs in
liver failure. The medical word used to describe the liver is
the prefix "hepato" so many of the diseases are called things
like "hepatic failure" and "hepatitis," which just means
liver failure and liver inflammation, respectively. We'll
discuss the disease states next week. Write me in care of the
Yated.
A message from Glaxo, sponsor of this column. Every
story of cancer, lo aleinu, is sad and we as
physicians must do our best to preserve dignity and comfort.
Vomiting is a difficult problem in these patients. The most
positive anti- vomiting drug known to many was first marketed
by Glaxo and it is called Zofran. Speak with your
physician.
