Chapter 33, Problem 22A

Summary Introduction

Introduction :

Ear helps us to hear things. The primary function performed by the ear is to hear and balance. The receptors in the ear can detect both high and low volumes. Canals of the ear help in maintaining balance.

Answer to Problem 22A

Correct answer :

The correct answer is option (B) tympanum, bones in the middle ear, cochlea, hair cells.

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) tympanum, bones in the middle ear, cochlea, hair cells. The correct sequence of hearing is tympanum, bones in the middle ear, cochlea, hair cells. Sound waves hit the outside ear and enter a short path called the ear canal. The ear canal leads to the tympanum. The tympanum vibrates from the sound waves and transmits these waves into three small bones. The cochlea is an auditory inner ear. Its structure is that of a snail and is present in the inner ear that converts sound into neural input. The cochlea is filled with tiny hair cells and fluid. So, this is the correct answer.

Explanation for incorrect answer :

Option (A) Cochlea, incus, stape, eardrum. This is not the correct sequence. The eardrum is the auditory canal through which sound travels to the ear. Incus, stape are the parts of the middle ear, and after that inner ear has a structure called the cochlea that is filled with fluid and hair cells. So, this is an incorrect option.

Option (C) auditory canal, tympanum, hair cells, cochlea. This is not the correct sequence. The auditory canal has a membrane called the tympanum that transfers the sound waves to the ear. The inner ear has a cochlea that has fluid and hair cells are at the end that transfers the sound waves to the brain. So, this is an incorrect option.

Option (D) hair cells, auditory canal, cochlea, malleus. This is not the correct sequence. Malleus is the part of the inner ear and cochlea has fluids and hair cells. The cochlea is present in the inner ear after the middle ear. So, this is an incorrect answer.