From the posterior wall of the
saccule
The saccule is a bed of sensory cells in the inner ear. It translates head movements into neural impulses for the brain to interpret. The saccule detects linear accelerations and head tilts in the vertical plane. When the head moves verticall ...
a canal, the
endolymphatic duct
From the posterior wall of the saccule a canal, the endolymphatic duct, is given off; this duct is joined by the ductus utriculosaccularis, and then passes along the aquaeductus vestibuli and ends in a blind pouch (endolymphatic sac) on the poster ...
, is given off; this duct is joined by the
utriculosaccular duct, and then passes along the
vestibular aqueduct
At the hinder part of the medial wall of the vestibule is the orifice of the vestibular aqueduct, which extends to the posterior surface of the petrous portion of the temporal bone.
It transmits a small vein, and contains a tubular prolongation ...
and ends in a blind pouch, the endolymphatic sac, on the posterior surface of the
petrous portion of the
temporal bone
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex.
The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. Th ...
, where it is in contact with the
dura mater
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...
. Studies suggest that the endolymphatic duct and endolymphatic sac perform both absorptive and
secretory, as well as phagocytic and immunodefensive, functions.
[Wackym PA, Friberg U, Linthicum FH Jr, et al. Human endolymphatic sac: morphologic evidence of immunologic function. Ann Otol Rhinol Laryngol 1987;96:276–282]
Neoplasms of the endolymphatic sac are very rare tumors.
References
External links
Images at wustl.edu
Vestibular system
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