What Does the Liver Do?

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Patient Presentation
A teenage boy was talking at dinner one night explaining that a student in his high school had had a motor vehicle accident and was in the hospital. “He’s doing okay but they said he cut his liver. I don’t know what that really means or what your liver really does?” he asked. His pediatrician mother explained that the student might have a liver laceration. “You can still live without part of your liver, but it’s pretty important,” she explained. “It does all kinds of things…,” and she started to list them. His eyes got wider and he finally stopped her. “Okay so I get it. It’s pretty important so I should take care of it right? This is part of the don’t drink alcohol and don’t do drugs talk isn’t it?” he asked. She smiled and said, “You asked the question. I answered it. And yes drugs and alcohol aren’t good for your liver because it is the major detoxifier for your body. They’re not good for any other part of your body too,” she reiterated. “Plus, make sure you always wear your seatbelt. He may have hurt his liver, but he probably saved his life with the seatbelt,” she also added.

Discussion
The liver is one of the largest organs in the body, weighing just over 3 pounds in an adult. It is found in the upper right abdomen, under the right dome of the diaphragm. Grossly, it has asymmetric lobes with the right being larger than the left. The lobes are separated by a fibrous connective tissue band that also anchors the liver in the abdominal cavity. The gallbladder is located on the inferior surface of the liver and stores bile, which is then released into the duodenum. Microscopically, the liver cells are arranged in lobules with canals carrying blood vessels and bile ducts. At any moment about 10-13% of the body’s blood volume is in the liver. Blood with its nutrients, medications and toxic substances comes to the liver from the portal vein. The liver processes the substances and the resulting end products are released back into the blood and eliminated by the renal system, or released into the bile and eliminated by the gastrointestinal system.

Patients with liver problems can present in many different ways including hepatomegaly, jaundice (see below) and abnormal laboratory testing. In children inborn errors of metabolism must be considered.

Some common liver diseases are below.

Learning Point
Liver functions include:

  • Metabolism
    • Bile acid production – eliminates toxins, helps to break down and absorb fat in the small intestine, about 800 – 1000 ml/day of bile is made
    • Protein production
      • Amino acids
      • Coagulants and clotting factor regulation
      • Fat binding proteins
      • Immune factors
      • Plasma proteins – e.g. albumin, lipoproteins, transferrin, carrier proteins
    • Cholesterol production
    • Energy metabolism – e.g. glycolysis, gluconeongensis, lipogenesis, ketogenesis, amino acid production
  • Storage
    • Glycogen storage and glucose homeostasis
    • Mineral storage – iron and copper
  • Toxin breakdown and excretion
    • Alcohol
    • Ammonia
    • Bilirubin
    • Drug clearance
      • Drugs are either activated (often with the P450 catalyzing enzymes) or detoxified (e.g. glucuronidation, sulfonification, oxidation)
    • Heavy metal elimination – e.g. copper, zinc

Questions for Further Discussion
1. What are indications of liver failure?
2. What are indications for a liver transplant?
3. What nutritional changes need to be made for people with liver disease?
4. What are the fat-soluble vitamins?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for this topic: Liver Diseases

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Teitelbaum JE. The Liver and Bile Ducts. Rudolph’s Pediatrics. Rudolph C, et.al. eds. McGraw-Hill. New York, NY. 2003;1473-1477.

Informed Health Online. How Does the Liver Work? Institute for Quality and Efficiency in Health Care. Available from the Internet at https://www.ncbi.nlm.nih.gov/books/NBK279393/ (rev. 8/22/16, cited 1/11/19).

Johns Hopkins Health Library. Liver: Anatomy and Functions. Available from the Internet at https://www.hopkinsmedicine.org/healthlibrary/conditions/liver_biliary_and_pancreatic_disorders/liver_anatomy_and_functions_85,P00676 (cited 1/11/19)

American Liver Foundation. Ways to love your liver. Available from the Internet at https://liverfoundation.org/25-ways-to-love-your-liver/ (rev. 8/4/17, cited 1/11/19).

American Liver Foundation. Your Liver. Available from the Internet at https://liverfoundation.org/for-patients/about-the-liver/ (cited 1/11/19).

MedlinePlus. Liver Diseases. National Library of MedicineAvailable from the Internet at https://medlineplus.gov/liverdiseases.html (rev. 10/28/18, cited 1/11/19).

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Published