The cochlea and balance organs have two fluids: perilymph and endolymph. Now, as a biology major Im sure I dont have to remind you about interstitial fluid; the fluid that bathes your cells. Yes, I remember that, replied Julius. Well, the composition of perilymph and interstitial fluid are similar. So whats endolymph? asked Julius. Endolymph is found in the scala media of the cochlea. Dr. Luther pointed to the central canal in the section of the cochlea (Figure 4). It has a very high level of potassium and bathes the sensory or hair cells in the cochlea and the balance organs. Now, this solution is constantly secreted by cells along the length of the cochlea called the stria vascularis. Dr. Luther pointed to the area lining the central canal of the cochlea.