Question

The bony labyrinth of the internal ear is divided into three main areas. They are
A. Vestibule, cochlea, perilymph
B. Vestibule, saccule, utricle
C. Vestibule, semicircular canal, tympanic membrane
D. Vestibule, cochlea, semicircular canal

Answer 1

Hint:The bony labyrinth is an extension of the temporal bone. It forms the rigid, bony outer wall of the inner ear. It is made of three parts. These parts are cavities that are hollow and lined by periosteum. These cavities consist of clear fluid, the perilymph, and the membranous labyrinth.

Complete answer:The ear is composed of three major sections called the outer ear, middle ear, and inner ear. The outer ear is responsible for sound waves collection and the middle ear transports these signals to the inner ear. The inner ear is the most complex portion of the ear and consists of various processing units or interpretation and conduction of sound waves to the brain. It consists of the temporal bone which makes up the key processing unit of the inner ear. This unit is called the bony labyrinth or otic capsule.

The bony labyrinth as its name suggests is a bony and rigid structure present inside the ear. A labyrinth refers to a network of pathways. Thus, the bony labyrinth makes cavities of bone being modified into canals of varying shape and function. These cavities are lined by periosteum which is a membrane covering for bones of the bony labyrinth. The bony labyrinth consists of three main units called the vestibule, cochlea, and semicircular canals.
The vestibule is the central part and is situated medial to the eardrum just behind the cochlea. It is present in front of the three semicircular canals. This part of the bony labyrinth is sensitive to the movements of the head.
The cochlea is the part that is involved in hearing. It is a spiral-shaped cavity that makes turn around its axis. Cochlea means snail and thus it looks like a snail shell. It has a partition that separates its fluid-filled chambers.
The semicircular canals are duct structures of the bony labyrinth. These are interconnected tubules that are present to the innermost of the inner ear. These are three in a number called horizontal, superior, and posterior horizontal canals.
Therefore, the right answer is option D. vestibule, cochlea, and the semicircular canals form the bony labyrinth of the inner ear.

Note: The bony labyrinth or the otic capsule is the most sensitive part of the inner ear. It can be easily affected by stress or high pressures. The adult-onset hearing loss called otospongiosis is caused by the defect of the otic capsule. This results in hearing loss.