Question

The tympanic membrane is stretched over a cartilaginous ring. It is
A. Columella
B. Fenestra ovalis
C. Tympanic annulus
D. None of the above

Answer 1

Hint: The ear is the most important and vital sensory organ of the human body. This organ is mainly associated with the detection, transmission, and transduction of sounds. It also maintains a sense of balance which is another crucial function performed by the human ear. It is constructed with different parts.

Complete answer:
The ear is one of the five sense organs of the human body. It is the organ of hearing. There are three parts found in an ear which are the external ear, middle ear, and the inner ear. The external or outer ear is made up of the visible portion known as the auricle, or pinna in humans, and the short external auditory canal.
The tympanum is the external structure that helps in hearing in different categories of organisms such as in birds, reptiles and amphibians. It is also found in some insects also. The tympanum consists of a membrane that is capable of vibrations. It is known as the tympanic membrane. It is an air-filled chamber and sensory organs that is used to detect the sound stimuli. It also separates the outer ear or the external ear from the middle ear or the central ear.
In amphibians, frogs and toads, the tympanum is a large oval shaped external structure and it is made up of non glandular skin. Externally, it is found just behind the ear. The tympanic membrane is stretched on the outer side and it remains slightly stretched over a ring like structure. The ring is made up of cartilage and the stretched membrane is called tympanicus annulus.
The columella is present in the middle ear and it is connected with the tympanum. The internal ear contains an ossicle known as the operculum.
The oval shaped opening present in the inner wall of the middle ear is known as fenestra ovalis. It is also known as the oval window. It is covered by a membrane known as the secondary membrane. It is made up of connective tissues.

Therefore, the correct option is option C.

Note: The inner end of the outer ear is enclosed by the tympanic membrane which is commonly called the eardrum. The middle part of the ear is narrow air-filled. The tympanum consists of the covering known as the tympanic membrane which covers the entry of the ear. It is stretched over a cartilaginous membrane which is known as the tympanic annulus.