Question

Given below is a diagrammatic cross section of a single loop of human cochlea. Which one of the following options correctly represent the names of three different parts?

A) B-tectorial membrane, C-Perilymph, D-Secretory cells
B) C-Endolymph, D-Sensory hair cells, A-Serum
C) D-Sensory, D-Sensory hair cells, A-Serum
D) B-Sensory hair cells, A-Perilymph, C-Tectorial membrane
E) A-Perilymph, B-Tectorial membrane, C-Endolymph

Answer 1

Hint: The ear is a sensitive organ of the human body which is mainly concerned with detecting, transmitting and also in transducing sound. Maintaining a sense of balance is another important function which is performed by the human ear. Cochlea is the part of the inner ear which is filled with perilymph which is a fluid. The two parts of the inner ear are bony labyrinth and membranous labyrinth.

Complete answer:
Perilymph is an extracellular fluid situated within the cochlea which is the inner part of the ear. The ionic composition of perilymph is similar to that of plasma and cerebrospinal fluid.
Tectorial membrane is a membrane which has the consistency of a jelly that covers the surface of the organ of Corti. It is located above the spiral limbus and also the spiral organ of corti and elongates to the inner part of the ear.
Sensory hair cell is the mechanosensory cell which helps in both hearing and vestibular function. The organ of corti in the cochlea possess sensory cells which hold the hair cell.

Thus, the correct answer is option D which states that B-Sensory hair cells, A-Perilymph, C-Tectorial membrane

Note:
The human ear consists of three parts which are the external ear, middle ear and internal ear. The external ear is further divided into auricle or pinna, external auditory meatus, tympanic membrane. The middle ear comprises tympanic cavity, eustachian tube and three ear ossicles which are malleus, incus and stapes. The function of the ear is to help humans in hearing and balance.