the characteristic shape (an invagination or canal throughout) of a parietal cell as it produces stomach acid; its walls house active proton pumps; a parietal cell is said to be in an active or canalicular state while the canaliculus is present; see tubulovesicle
Canaliculi are small, microscopic canals between the various lacuna (histology) of ossified bone. The radiating processes of the osteocytes project into these canals. These cytoplasmic processes are joined together by gap junctions.
A canaliculus is an adaptation found on gastric parietal cells. It is a deep infolding, or little channel, which serves to increase the surface area, eg for secretion. The membrane of parietal cells is dynamic; the numbers of canaliculi rise and fall according to secretory need.