College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Where is bilirubin primarily broken down in the body?

1. Pancreas

2. Gallbladder

3. Spleen

4. Liver

The correct answer is: Liver

Bilirubin is primarily broken down in the liver, making it the correct answer. The liver plays a crucial role in processing bilirubin, which is a byproduct of the breakdown of hemoglobin from red blood cells. Once hemoglobin is broken down, it is converted into biliverdin and subsequently transformed into bilirubin. This unconjugated bilirubin is lipid-soluble and needs to be processed further in the liver, where it becomes conjugated with glucuronic acid, transforming it into a water-soluble form. This conjugated bilirubin can then be excreted into the bile and eventually eliminated from the body through the intestines. The other options, such as the pancreas, gallbladder, and spleen, have different roles in digestion and blood filtration but are not primarily involved in the breakdown of bilirubin. The pancreas is mostly involved in the secretion of digestive enzymes and hormones; the gallbladder stores bile produced by the liver; and the spleen plays a role in filtering blood and recycling iron but does not significantly contribute to the breakdown of bilirubin.