80 % of gall stones contain-
**Core Concept**
Gallstones are small, hard deposits that form in the gallbladder, composed of various substances such as cholesterol, bilirubin, and calcium salts. The composition of gallstones varies depending on the underlying risk factors and pathophysiological mechanisms.
**Why the Correct Answer is Right**
The majority of gallstones, approximately 80%, are cholesterol stones. These stones form when there is an imbalance between the secretion of bile salts, cholesterol, and phospholipids in the bile. Cholesterol stones are more common in women, especially during pregnancy and postpartum, and are often associated with obesity, high cholesterol levels, and gallbladder dyskinesia. The formation of cholesterol stones is facilitated by the precipitation of cholesterol monohydrate crystals in the supersaturated bile.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because cholesterol stones are the most common type of gallstone, not pigment stones.
* **Option B:** This option is incorrect because cholesterol stones are not associated with a high concentration of bilirubin, which is a characteristic of pigment stones.
* **Option C:** This option is incorrect because while bile salts can contribute to the formation of cholesterol stones, they are not the primary component of these stones.
**Clinical Pearl / High-Yield Fact**
It is essential to note that the composition of gallstones can influence their clinical presentation and management. Cholesterol stones are often asymptomatic, while pigment stones may cause more severe symptoms due to their association with chronic inflammation and infection.
**Correct Answer:** A. Cholesterol stones.