Endolymph

A fluid inside the membranous labyrinth in the inner ear.

A pale transparent fluid within the vestibular labyrinth of the inner ear. Endolymph differs in composition from the perilymph that is outside the vestibular labyrinth: endolymph is similar to intracellular fluid; perilymph, to extracellular cerebrospinal fluid.

Endolymph, a fluid ensconced within the membranous labyrinth—integral structures within the cochlear domain dedicated to maintaining equilibrium—circulates around this complex network in tandem with bodily movement. This dynamic flow agitates nerve receptors nestled within the labyrinth, eliciting them to relay locomotion data to the cerebral command center. An abnormal surge in this endolymphatic volume, a characteristic manifestation, may indicate the presence of Ménière’s disease.