One Awesome Organ!
The liver is a much underappreciated organ, in my estimation. The heart, the lungs and the brain get all the glory it would seem, but, as anyone with a liver problem will tell you, the liver is another vital organ that you cannot live without. This amazing organ is located in the right upper abdomen just below the lungs and diaphragm and, perhaps signaling its importance, it is tucked under the right rib cage for protection. It is the largest solid gland in the body and is divided into two lobes, the right being larger than the left. The bulk of the work is performed by hepatocytes which are the cells comprising most of the liver. Nearly two quarts of blood pass through the liver every minute.
The Power to Regenerate
The liver is one of the only organs that has retained some ability to regenerate itself after an injury. The kidney is another hard-working organ that shares this ability, although to a lesser extent. It is an interesting side note that the more highly evolved the organism, the less ability it has to regenerate. Most high school students are familiar with the planaria worm, which when split lengthwise or crosswise will regenerate into two separate individual worms. And further up the evolutionary scale, salamanders are able to regenerate limbs that have been amputated. So, in the highly evolved human being, the liver holds a special place among the many other incredible organs of the human body in that it has retained some of this ability to regenerate itself.
Functions of the Liver
So why do I love the liver? Let me count the ways. Let’s take a quick look at some of the functions this hard-working organ performs that make it so important? Among some of the many things the liver does for us, it:
-produces immune factors and removes bacteria from the bloodstream to combat infection.
-regulates bile production and excretion which helps digest food and absorb nutrients.
-converts glucose into glycogen for storage, which can be used later for energy.
-helps maintain the proper level of glucose in the blood.
-produces cholesterol and helps regulate its metabolism.
-acts as a filter to detoxify and purify the blood, clearing the blood of drugs and other toxins.
-converts poisonous ammonia into urea which is then excreted in the urine.
-synthesizes plasma proteins such as albumin and clotting factors, helping to regulate blood clotting mechanisms.
-stores vitamins and minerals, such as iron.
Wow! Talk about multitasking! This is one busy organ. Imagine performing all of these functions 24/7 for your entire life. Now you are beginning to see why I have so much respect for the liver.
Liver Tests
There are many tests that can assess liver function and disease, but a few of the most common blood tests that patients should be aware of can be summarized as follows:
-LIVER ENZYME LEVELS: Enzymes produced by the hepatocytes (liver cells) leak into the blood stream when the hepatocytes have been injured, causing elevated blood levels. Examples are SGOT (AST), SGPT (ALT).
-BILIRUBIN LEVEL: Bilirubin is a breakdown product of hemoglobin from red blood cells which is cleared by the liver. Numerous liver problems can interfere with this process, causing the bilirubin level to increase in the blood. Elevated bilirubin is responsible for the jaundice (yellow discoloration) which can be associated with liver disease.
-ALBUMIN AND COAGULATION FACTOR TESTS: Assessing the level of these liver products measures how well the liver is performing its synthetic functions. Example, INR as a measure of how long it takes the blood to clot.
Liver Diseases
Because the liver performs so many essential functions, it plays a significant role in many disease processes. Its role as a filter for removing toxins and the rich blood supply necessary to fulfill this function put it at particularly high risk for injury. As we continue our brief overview of the liver in the next articles of this series, we will look at some of the more common liver diseases, with a special emphasis on hepatitis, and we’ll get a better idea of why it’s so important to be nice to your liver.