Which of the following exocrine glandular ducts are not obstructed in cystic fibrosis
**Core Concept**
Cystic fibrosis is a genetic disorder characterized by the production of thick and sticky mucus, leading to respiratory and digestive issues. The disease affects multiple exocrine glands, resulting in ductal obstruction and impaired secretion.
**Why the Correct Answer is Right**
In cystic fibrosis, the thick and sticky mucus produced by exocrine glands leads to ductal obstruction. However, the sweat glands, which produce salty sweat, are not exocrine glands in the same sense as other glands affected by cystic fibrosis. Instead, sweat glands are **eccrine glands**, which are a different type of exocrine gland that produces a watery, odorless sweat. This makes the sweat glands less affected by the thick mucus, unlike other glands such as the pancreas, liver, and intestines.
**Why Each Wrong Option is Incorrect**
* **Option A:** The pancreatic ducts are obstructed in cystic fibrosis due to the thick mucus, leading to impaired pancreatic enzyme secretion and malabsorption.
* **Option B:** The bile ducts are also obstructed in cystic fibrosis, leading to liver dysfunction and cholestasis.
* **Option D:** The intestinal glands are obstructed in cystic fibrosis, leading to meconium ileus and other gastrointestinal complications.
**Clinical Pearl / High-Yield Fact**
Cystic fibrosis is caused by mutations in the CFTR gene, which codes for the cystic fibrosis transmembrane conductance regulator protein. This protein is a chloride channel that regulates the thickness of mucus.
**Correct Answer:** A. Sweat glands.