ethmoidal labyrinth

(redirected from ectoethmoid)

labyrinth

 [lab´ĭ-rinth]
the inner ear, consisting of the vestibule, cochlea, and semicircular canals. The cochlea is concerned with hearing and the vestibule and semicircular canals with the sense of equilibrium. (See also color plates.) adj., adj labyrin´thine. 

The bony portion of the labyrinth (osseous labyrinth) is composed of a series of canals tunneled out of the temporal bone. Inside the osseous labyrinth is the membranous labyrinth, which conforms to the general shape of the osseous labyrinth but is much smaller. A fluid called perilymph fills the space (perilymphatic space) between the osseous and membranous labyrinths. Fluid inside the membranous labyrinth is called endolymph. These fluids play an important role in the transmission of sound waves and the maintenance of body balance. The membranous labyrinth is divided into two parts: the cochlear labyrinth, which includes the perilymphatic space and the cochlear duct, and the vestibular labyrinth, which includes the utricle, saccule, and semicircular canals.

Disorders of the inner ear, such as labyrinthitis and meniere's disease, are characterized by episodes of dizziness, tinnitus, and hearing loss.
ethmoid labyrinth (ethmoidal labyrinth) either of the paired lateral masses of the ethmoid bone, consisting of numerous thin-walled cellular cavities, the ethmoidal cells.

eth·moi·dal lab·y·rinth

[TA]
a mass of air cells with thin bony walls forming part of the lateral wall of the nasal cavity; the cells are arranged in three groups, anterior, middle, and posterior, and are closed laterally by the orbital plate which forms part of the wall of the orbit.

ethmoidal labyrinth

The lateral mass of the ethmoid bone, which includes the superior and middle conchae and encloses the ethmoid sinuses.
See also: labyrinth

eth·moi·dal lab·y·rinth

(eth-moydăl labi-rinth) [TA]
Mass of air cells with thin bony walls forming part of lateral wall of nasal cavity.
Synonym(s): ectoethmoid.