Bilirubin is secreted by:

Bilirubin is secreted by:

A. Bile salts
B. Bile pigment
C. Secretin
D. CCK

Answer is A. Bile salts

Bilirubin is the main bile pigment that is formed from the breakdown of heme in red blood cells. The broken down heme travels to the liver, where it is secreted into the bile by the liver.

The following is a review of the normal pathway for bilirubin production and excretion and its relationship to laboratory assessment of liver function:

• Step 1: Red blood cells are broken down by the reticuloendothelial system and unconjugated bilirubin in the bloodstream is carried by albumin to the liver. This is known as "pre-hepatic," "free," "unconjugated," or"indirect bilirubin" (normal value = 0.1 - 1.0 mg/dl)

• Step 2: The liver converts or conjugates bilirubin and makes it water-soluble. This is known as "posthepatic", "conjugated" or "direct" bilirubin (normal value = 0.0 - 0.4 mg/dl)

• Step 3: Conjugated bilirubin is excreted via bile salts to intestine. Bacteria in the intestine break down bilirubin to urobilinogen for excretion in the feces (normal value for fecal urobilinogen = 40 - 280 mg/day).
  

This is a trick question or inappropriately worded. Caution must be practised in answering such a question. An appropriate correction would be : Bilirubin is secreted 'via' and not 'by'.