Staircase of the Vestibule

The scala vestibule (Scala vestibuli) is an anatomical structure located in the pyramids of the temporal bones and is responsible for the perception of sound. It consists of several stages, each of which has its own function.

The first stage is the cochlea, which is a spiral structure located in the pyramid of the temporal bone. The cochlea is responsible for converting sound waves into electrical signals that are transmitted along the auditory nerve to the brain.

The second stage is the eardrum, which is located on the outer surface of the ear. It transmits sound waves to the first stage of the cochlea.

The third stage is the hammer, which is located inside the ear and transmits sound waves from the eardrum to the cochlea.

The fourth stage is the incus, which is also located inside the ear and connected to the malleus. It amplifies the sound waves transmitted from the hammer to the cochlea.

The fifth step is the stapes, which is located on the border between the pyramid of the temporal bone and the inner ear. It transmits sound waves from the cochlea to the inner ear.

The sixth stage is the oval window, which is located in the inner ear and connects the cochlea to the inner ear. The oval window allows sound waves to be transmitted from the cochlea to the inner ear.

The seventh stage is a triangular window, which is also located in the inner ear. It connects the oval window with the labyrinth of the inner ear.

The eighth stage is the basilar membrane, which is located in the inner ear and is the main part of the hearing organ. It converts sound waves into electrical impulses, which are then transmitted along the auditory nerves to the brain.

Staircase vestibule

The scala vestibule, scala vestibuli (syn. [Vestibular scala] in animals, vestibularis scala), is the longest canal in the cochlear organ. Part of the eustachian tube and only open to air at the beginning. The length of the scala wall in humans is about 35 mm. The length of the canal varies in different animals from 1 mm to 25 mm, the shape varies from straight and spiral to complex and zigzag. Sometimes the canal bends so that it is longer than the upper wall. In some animals, such as bats, elephants, pigs, monkeys, humans, etc., noticeable tubule formation is usually not observed. There are also animals with a closed staircase up to the entrance to the snail's labyrinth, but this feature is mostly visible on the inner surface of the snail. Named in Greek (scala) and means stone pipe. The upper wall of the canal also consists of leathery tissue; a thin horizontal cavity protrudes from the front side of the shell; near the center of the cochlea, part of this cavity is pulled back, gradually passing into the cavity of the folded endolymphatic sac on the side wall in the middle region of the cochlea. The channel behind its outer membrane is lined with columnar cells with embedded nerve endings and perceives sound vibrations, transforming their nerve impulses, and also provides channels for the passage of endolymph to the auditory canal, i.e. communicates with the outer surface of the cochlea. Together with it, it enters the cochlear cavity