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) Ototlith 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

Answer: (B)

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

A. Scala media: The middle chamber is called scala media. It is actually the cochlear duct and is an outgrowth from the saccule. Therefore, it is filled with endolymph, which is secreted by its epithelium lining. The floor is called basilar membrane and its roof , the reissner's membrane.

B. Organ of Corti: The basilar membrane bears on it an organ of hearing called organ of Corti. The latter consists of receptor cells(Hair cells) and supporting cells.

C. Basilar membrane: It is the floor of the Scala media.

D. Tectorial membrane: The tip of hair are embedded in a smooth, gelatinous sheet.

So, the correct answer is 'A- (vii), B-(iv), C-(ii), D-(iii)'.