Question

Identify the parts labelled as A, B, C and D in the given figure and match the correct names from the list (i - viii) given below.
(i) Reissner's membrane
(ii) Basilar membrane
(iii) Tectorial membrane
(iv) Organ of Corti
(v) Hair cells
(vi) Otolith organ
(vii) Scala media
(viii) Scala vestibuli

A)A - (ii), B - (v), C - (iii), D - (i)
B)A - (vii), B - (iv), C - (ii), D - (iii)
C)A - (vii), B - (iv), C - (i), D - (ii)
D)A - (vii), B - (vi), C - (i), D - (iii)

Answer 1

Hint: There are three parts of inner ear:
1.Cochlea- It is an auditory region present in the inner ear which changes the sound waves into nerve signals.
2.Semicircular canals- It can sense both balance as well as posture in order to assist in gaining equilibrium.
3.Vestibule- responsible for connecting the two above structures as well as has two more structures that are responsible for balancing as well as equilibrium called the saccule and utricle.

Complete answer:
Following are the labelled parts of the ear:
A. Scala media: It is the middle chamber and is known as scala media. It is filled with a fluid called endolymph, it is discharged by the lining of the epithelium. The base is called the basilar membrane and the roof as the Reissner's membrane.
B. Organ of Corti: The basilar membrane has the organ of hearing called as an organ of Corti.
The last-mentioned includes the receptor cells (hair cells) and supporting cells.
C. Basilar membrane: It is the base of the Scala media.
D. Tectorial membrane: The hair tip is implanted in a smooth, coagulated sheet called the tectorial membrane.

Hence, the correct answer is option (B)

Note: The helicotrema is the portion of the cochlear labyrinth where the scala tympani and the scala vestibuli meet. It is the apex part of the cochlear summit.