Gross anatomy

General structure

  • Largest gland in the body
    • Weight: ∼ 1.2–1.5 kg in adults (2.6–3.3 pounds)
  • Wedge-shaped
  • Consists of four lobes:
    • Right (largest)
    • Left
    • Quadrate
    • Caudate
  • Typically divided into 8 segments
  • Surrounded by the Glisson capsule
  • Porta hepatis structures





As part of the liver's dual blood supply, the portal vein allows tissue to remain oxygenated and preserve function in the event of an obstructed hepatic artery.


  • Glisson capsule and serosa: lower intercostal nerves
  • Parenchyma: hepatic plexus

Distention of the capsule results in well-localized, sharp pain, as seen in ascites, inflammation, or hepatic cancer.


Microscopic anatomy



Energy metabolism
  • Glucose homeostasis
Detoxification and clearance/excretion

Also see “parameters of hepatocellular damage”, “parameters of cholestasis”, and “parameters of hepatic synthesis” in liver function tests.

Breakdown of ethanol

Example of zero-order elimination: A constant amount of alcohol is metabolized per unit time (∼ 1 ounce of alcohol per hour).

  1. Oxidation of ethanol to acetaldehyde by alcohol dehydrogenase (ADH): competitive inhibition of ADH by fomepizole; treatment of methanol or ethylene glycol poisoning to prevent the formation of toxic metabolites [5]
  2. Oxidation of acetaldehyde to acetate by acetaldehyde dehydrogenase
  3. Ligation of acetate and coenzyme A to acetyl-CoA by thiokinase under ATP consumption

When large quantities of alcohol are consumed, acetaldehyde builds up faster than it can be metabolized by ADH. Excess acetaldehyde plays a major role in hangover symptoms.




Clinical significance


  • 1. Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences; 2016.
  • 2. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Philadelphia, PA: Elsevier Saunders; 2014.
  • 3. Chung KW, Chung HM. Gross Anatomy. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.
  • 4. Le T, Bhushan V,‎ Sochat M, Chavda Y, Zureick A. First Aid for the USMLE Step 1 2018. New York, NY: McGraw-Hill Medical; 2017.
  • 5. McMartin K, Jacobsen D, Hovda KE. Antidotes for poisoning by alcohols that form toxic metabolites. Br J Clin Pharmacol. 2016; 81(3): pp. 505–515. doi: 10.1111/bcp.12824.
  • 6. Goh ET, Morgan MY. Review article: pharmacotherapy for alcohol dependence - the why, the what and the wherefore. Aliment Pharmacol Ther. 2017; 45(7): pp. 865–882. doi: 10.1111/apt.13965.
  • 7. Hall JE. Guyton and Hall Textbook of Medical Physiology. Philadelphia, PA: Elsevier; 2016.
  • 8. Sadler TW. Langman's Medical Embryology. Philadelphia, PA: Wolters Kluwer Health; 2014.
  • 9. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. New York, NY: McGraw-Hill Education; 2015.
  • 10. Goljan EF. Rapid Review Pathology. Philadelphia, PA: Elsevier Saunders; 2018.
  • Drake R, Vogl AW, Mitchell AWM. Gray's Anatomy for Students International Edition. Elsevier Health Sciences; 2009.
last updated 04/16/2019
{{uncollapseSections(['cvca_V0', 'Z8cZOV0', 'WvcP_V0', 'c8calV0', '1vc2_V0', 'T8c6NV0'])}}