Which layer pumps fluid and is not capable of reproducing?

Prepare for the VisionFirst CEBT Test. Utilize flashcards and multiple-choice quizzes, each offering hints and detailed explanations for optimized learning. Excel in your exam!

Endothelium is responsible for keeping the cornea dry and transparent by actively pumping fluid out of the stroma into the anterior chamber. This pumping is driven by ion transporters like Na+/K+-ATPase, which remove water from the stroma to maintain deturgescence. In adults, endothelial cells do not readily reproduce, so once damaged, they don’t regenerate to replace lost cells. This is why endothelial health is so critical: damage reduces the pump capacity, leading to corneal edema and vision loss.

The other layers don’t do this pumping job. The surface epithelium can heal and regenerate but isn’t the main pump for stromal fluid. The stroma is the thick, organized connective tissue that gives structure and clarity but doesn’t actively pump fluid. Descemet’s membrane is a basement membrane secreted by the endothelium, not a pumping layer.