It is secreted by the stria vascularis (colloquially called 'battery of the cochlea') on the outer wall of the scala media.
It has a high level of potassium (K+) and generates a current called the endolymphatic potential, with positivity inside the scala media and negativity outside its wall.
- 1. Hannon. Porth Pathophysiology. Chapter 55.. ISBN: 9781451192896