Cristae

Definition
noun, singular: crista
(cell biology)
The infoldings or inward projections of the inner membrane of the mitochondrion, which are studded with proteins and increase the surface area for chemical reactions to occur like cellular respiration.
(anatomy)
Crests or ridges projecting from a surface, as in cristae cutis (dermal ridges on palms and soles).
(sense organ)
Sensory epithelium of the vestibular system located within the inner ear, as in cristae ampullaris that sense angular acceleration and deceleration.
Supplement
(cell biology) The cristae greatly increase the surface area on which reactions take place, e.g. electron transport chain of cellular respiration. If they were absent, the inner membrane of the mitochondrion would be reduced to a single spherical shape, and with less reaction surface available, therefore, the reaction efficiency would also be reduced.
Related phrases: crista terminalis.
See also: mitochondrion.