The stria vascularis of the cochlear duct is a

capillary A capillary is a small blood vessel, from 5 to 10 micrometres in diameter, and is part of the microcirculation system. Capillaries are microvessels and the smallest blood vessels in the body. They are composed of only the tunica intima (the inn ...

loop in the upper portion of the spiral ligament (the outer wall of the

cochlear duct Cochlear, the adjective form of cochlea, may refer to: * Cochlear implant, a sensory aid for the deaf * Cochlear nuclei, the ventral cochlear nucleus and the dorsal (or lateral) cochlear nucleus * Vestibular-cochlear or Vestibulocochlear nerve, ...

or scala media). It produces

endolymph Endolymph is the fluid contained in the membranous labyrinth of the inner ear. The major cation in endolymph is potassium, with the values of sodium and potassium concentration in the endolymph being 0.91 mM and 154 mM, respectively. ...

for the scala media in the

cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort ...

Structure

The stria vascularis is part of the lateral wall of the cochlear duct. It is a somewhat stratified epithelium containing primarily three cell types: * marginal cells, which are involved in K⁺ transport, and line the endolymphatic space of the

scala media Scala or SCALA may refer to: Automobiles * Renault Scala, multiple automobile models * Škoda Scala, a Czech compact hatchback Music * Scala (band), an English electronic music group * Escala (group), an electronic string quartet formerly know ...

. * intermediate cells, which are pigment-containing cells scattered among capillaries. * basal cells, which separate the stria vascularis from the underlying spiral ligament. They are connected to basal cells with

gap junction Gap junctions are membrane channels between adjacent cells that allow the direct exchange of cytoplasmic substances, such small molecules, substrates, and metabolites. Gap junctions were first described as ''close appositions'' alongside tight ...

s. The stria vascularis also contains

pericytes Pericytes (formerly called Rouget cells) are multi-functional mural cells of the microcirculation that wrap around the endothelial cells that line the capillaries throughout the body. Pericytes are embedded in the basement membrane of blood capil ...

melanocytes Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and hea ...

, and

endothelial cell The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and th ...

s. It also contains intraepithelial capillaries - it is the only epithelial tissue that is not

avascular Blood vessels are the tubular structures of a circulatory system that transport blood throughout many animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the tissues of a body. They also take waste and ...

(completely lacking

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

s and

lymphatic vessel The lymphatic vessels (or lymph vessels or lymphatics) are thin-walled vessels (tubes), structured like blood vessels, that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessel ...

s).

Function

The stria vascularis produces

for the

, one of the three fluid-filled compartments of the

. This maintains the ion balance of the endolymph that surround inner hair cells and outer hair cells of the

organ of Corti The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses' action potential. Trans ...

. It secretes lots of K⁺, and may also secrete H⁺.

References

External links

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at

University of New England, Maine The University of New England (UNE) is a private university, private research university in Portland, Maine, Portland and Biddeford, Maine, Biddeford, Maine, United States. It traces it historical origins to 1831 when Westbrook College, Westbroo ...

*
Diagram
at IUPUI Ear {{anatomy-stub