Final answer:
The epithelial pump mechanism maintains deturgescence in the cornea by actively pumping sodium ions out of the corneal endothelium, preventing swelling. ATPase pumps on the basal membrane of corneal endothelial cells facilitate this active transport.
Step-by-step explanation:
The epithelial pump mechanism helps maintain deturgescence in the cornea by actively pumping sodium ions out of the corneal endothelium, creating an osmotic gradient that allows water to flow out of the cornea. This prevents the cornea from becoming swollen or edematous. The active transport of sodium ions is facilitated by ATPase pumps located on the basal membrane of corneal endothelial cells.