Final answer:
Bilirubin can follow various paths in the body including enterohepatic recirculation, excretion in the urine, and eventually being converted to stercobilin which is excreted in feces. Therefore, the correct answer is d. All of the above.
Step-by-step explanation:
The paths that bilirubin can take within the body include:
Enterohepatic circulation: Bilirubin is taken up by the liver, where it is conjugated and then excreted into the intestine as part of the bile. A portion of this bilirubin can be reabsorbed into the bloodstream.
Excretion in urine: Some reabsorbed bilirubin can be filtered by the kidneys and excreted in the urine.
Formation of stercobilin: In the intestine, most bilirubin is converted into stercobilinogen, and eventually to stercobilin, which gives feces its brown color and is excreted from the body.
Therefore, the answer to the question 'What paths can bilirubin take within the body?' is d. All of the above. Bilirubin, which is produced during the breakdown of red blood cells, travels bound to albumin to the liver, where it is processed and secreted into bile. It can then follow various paths including recirculation, urinary excretion, or fecal elimination as stercobilin.