Surgery>>>>>The Gallbladder and Extrahepatic Biliary System
Question 6#

The solubility of cholesterol in bile is determined by:

A. Cholesterol, calcium, bilirubin
B. Cholesterol, bile salts, lecithin
C. Bile salts, cholesterol, bilirubin
D. Calcium, cholesterol, bile salts

Correct Answer is B

Comment:

Pure cholesterol stones are uncommon and account for < 10% of all stones. They usually occur as single large stones with smooth surfaces. Most other cholesterol stones contain variable amounts of bile pigments and calcium, but are always >70% cholesterol by weight. These stones are usually multiple, of variable size, and may be hard and faceted or irregular, mulberry-shaped, and soft. Colors range from whitish yellow and green to black. Most cholesterol stones are radiolucent; < 10% are radiopaque. Whether pure or of mixed nature, the common primary event in the formation of cholesterol stones is supersaturation of bile with cholesterol. Therefore, high bile cholesterol levels and cholesterol gallstones are considered one disease. Cholesterol is highly nonpolar and insoluble in water and bile. Cholesterol solubility depends on the relative concentration of cholesterol, bile salts, and lecithin (the main phospholipid in bile). Supersaturation almost always is caused by cholesterol hypersecretion rather than by a reduced secretion of phospholipid or bile salts.