Question

The membranous labyrinth is concerned with
(A) Hearing
(B) Equilibrium
(C) Both A and B
(D) None of the above

Answer 1

Hint: Membranous labyrinth is a part of the human ear. It is present within the bony labyrinth. Labyrinth is also known as inner ear. Ears perform two sensory functions, namely hearing and maintenance of body balance (both static and dynamic). Hair cells are the auditory receptors and ampullaris and macula are the balancing receptors.

Complete step by step answer:
Each ear is differentiated into three regions, namely external ear, middle ear and internal ear. The external ear consists of pinna and external auditory canal, which helps in passing the sound vibrations to the middle ear. The middle ear consists of an ear drum (tympanic membrane), three ossicles (malleus, incus and stapes). Ear ossicles mainly help in increasing the efficiency of transmission of sound waves.
The inner ear comprises circular canals called cochlea and vestibular apparatus. The inner ear is usually fluid filled and also known as labyrinth. Labyrinth can be differentiated into two regions, namely bony and membranous labyrinth. Bony labyrinth consists of a series of channels into which a membranous labyrinth is present, which is surrounded by perilymph. Inside the membranous labyrinth, the cavity is filled with endolymph.
The coiled portion of labyrinth otherwise known as cochlea consists of reissner’s membrane and basilar membrane.
Organ of corti is present on the basilar membrane, which contains hair cells (auditory receptors). Vestibular apparatus consists of semicircular canals and otolith organs. The otolith organ consists of saccule and utricle. The semicircular canals contain crista ampullaris and saccule & utricle contains macula. Ampullaris and macula are the balancing receptors responsible for maintenance of body balance. The receptors for hearing (hair cells) and balance (ampullaris and macula) are present on membranous labyrinth, and hence it is concerned with both the functions.

Hence the correct answer is option(C)

Note: Remember, in the inner ear the membranous labyrinth, present inside the bony labyrinth contains receptors for both hearing and equilibrium. Both static and dynamic equilibrium are maintained by the balancing receptors. Bony labyrinth is surrounding the membranous labyrinth and it is helpful in protecting the inner soft membranes.