Mitochondria: parietal cells are mitochondria – rich as I see this counting up numbers of these organelles in cells while also tabulating the number of mitochondria which are tethered to desmosomes.  They are large, fat and everywhere, occupying much of the cytoplasm (as opposed to other cells where there are secretory granules or RER and ER machinery. They are quite close to all plasmalemma designations,  e.g. apical, lateral and basal, and even the canalular membranes BUT leaving a consistent small critical space between them.

Just adding a note, they really are sparsely populated with desmosomes and also with desmosomal-mitochondrial tethers — which is surprising i think and out of thosands of mitochondria counted in parietal cells only a few are tethered to desmosomes on the lateral membranes of parietal cells.

In this toluidine blue stained plastic 1 micron thick section you can see the darkish greenish dots around the pale looking canaliculi of parietal cells (arrows) nested closely and packed between the membrane structures.