Final answer:
Jaundice is the brownish-yellow pigmentation of the skin and mucus membranes caused by the accumulation of bilirubin, often due to liver disease or dysfunction.
Step-by-step explanation:
The brownish-yellow pigmentation of the skin, sclera, and mucus membranes is known as jaundice. It occurs when bilirubin, a byproduct of red blood cell breakdown, accumulates in the body due to various reasons like liver disease, liver cancer, or blockage of the bile duct. Increased levels of bilirubin in the bloodstream lead to its deposition in tissues, resulting in the characteristic yellowish discoloration observed in jaundice. Other conditions, such as Addison's disease, can also change skin pigmentation but would result in a bronze color, not the yellowish tinge associated with jaundice.