Chapter 33, Problem 24A

Summary Introduction

Introduction :

The ear is the hearing organ. The ear is consists of three parts — the outer ear, the middle ear, and the inner ear.

Answer to Problem 24A

Correct answer :

The correct answer is option (B). B

Explanation of Solution

Explanation/justification for the correct answer :

Option (B) “B” represents Cochlea (Inner ear). The inner ear consists of Cochlea, for hearing and the Vestibular system for balance (labyrinth). If there is dysfunction in the labyrinth or nerve that connects it to the brain, dizziness can result. So, this is the correct answer.

Explanation for incorrect answer :

Option (A) “A” represents Semi-circular ducts. These are three small, fluid-filled tubes in the inner ear that help to maintain your balance. These ducts swell at times and give incorrect signals of equilibrium. A viral infection may be responsible for this problem and hearing may be impaired (labyrinthitis) depending upon the cause. As these are mainly involved in balancing, so they are not responsible for dizziness. So, this is an incorrect answer.

Option (C) “C” represents auditory ossicles (malleus, incus, and stapes). These are a small chain of bones in the middle ear. This transmits sound by mechanical vibration from the outside ear to the inner ear. These are not responsible for dizziness. So, this is an incorrect answer.

Option (D) “D’ represents the Tympanic Membrane. It is also called an eardrum. It plays a role in the transmission and amplification of sound. As it experiences tone, the tympanic membrane vibrates. Then it transmits these impulses to the middle ear ossicles to be further passed on for transduction to the inner ear cochlea. These are not responsible for dizziness. So, this is an incorrect answer.