What is special about endolymph?

A remarkable characteristic of the cochlea is the unique composition of endolymph. This liquid fills the scala media, and is very rich in potassium (150mM), very poor in sodium (1mM) and almost completely lacking in calcium (20-30 µM).

What causes endolymph to move?

Vestibular Apparatus This occurs through head movement that causes endolymph to move specialized cells known as hair cells. Hair cells are arranged in rows and contain “tip-links” that connect them and either depolarize or hyperpolarize afferent nerve fibers based on their direction of movement.

What is the importance of endolymph pressure in the inner ear?

In a normal inner ear, the endolymph is maintained at a constant volume and with specific concentrations of sodium, potassium, chloride, and other electrolytes. This fluid bathes the sensory cells of the inner ear and allows them to function normally.

Is endolymph similar to CSF?

The perilymph, which fills the space within the bony labyrinth surrounding the membranous labyrinth, is similar, but not identical, in composition to other extracellular fluids of the body, such as cerebrospinal fluid.

Where is the endolymph located?

inner ear
The endolymphatic sac (ES) is a membranous structure in the inner ear located partly in the temporal bone and partly within the dura of the posterior fossa. It contains endolymph, which is similar in chemical makeup to intracellular fluid (high in K, low in Na).

Can endolymphatic hydrops be seen on MRI?

During the past decade, the morphologic substrate of Ménière disease, i.e. endolymphatic hydrops, has become visible using high resolution MRI techniques 9.

How do you test for endolymphatic hydrops?

There are tests for endolymphatic hydrops, which include glycerine, urea, or sorbitol “stress” tests and electrocochleography. However, these tests have low sensitivity and specificity, and their role in the diagnosis and management of MD is controversial”.