Parietal Cells

This slide shows several parietal cells. Parietal cells have a characteristic “fried-egg” appearance, with a basophilic, peripherally located nucleus and a rather eosinophilic cytoplasm. These cells secrete HCl and intrinsic factor. Under the electron microscope, the parietal cell appears pyramidal, with a central nucleus and many mitochondria. Why may mitochondria be so numerous in parietal cells?