In cystic fibrosis, chloride ions are transported in which direction relative to the cells in the GI tract and lungs?

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Multiple Choice

In cystic fibrosis, chloride ions are transported in which direction relative to the cells in the GI tract and lungs?

Chloride transport in this context hinges on CFTR channels moving Cl− from inside the epithelial cell into the lumen. In cystic fibrosis, these channels are defective, so chloride cannot exit toward the luminal surface of the GI tract or lungs. As a result, chloride remains inside the cell rather than being secreted into the lumen, which is why this option—chloride trapped inside cells—is correct. This lack of chloride movement into the lumen also reduces water movement into the lumen, contributing to thicker mucus.

Chloride transport in this context hinges on CFTR channels moving Cl− from inside the epithelial cell into the lumen. In cystic fibrosis, these channels are defective, so chloride cannot exit toward the luminal surface of the GI tract or lungs. As a result, chloride remains inside the cell rather than being secreted into the lumen, which is why this option—chloride trapped inside cells—is correct. This lack of chloride movement into the lumen also reduces water movement into the lumen, contributing to thicker mucus.

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