Question

Tympanic cavity is part of
a. Middle ear
b. Ear canal
c. Inner ear cavity
d. Cavity of the eyeball

Answer 1

Hint: Ear has three parts namely external ear or outer ear, middle ear and internal or inner ear. Each part of the ear performs a distinct function in transmission of sound waves to the brain. Tympanum is made up of connective tissues and is commonly called eardrum.

Complete answer:

As we all know that our ear is an organ that helps in hearing and balancing and it is divisible into three parts which include outer ear, middle ear and inner ear. The outer ear comprises Pinna that collects the sound waves and directs them towards the Auditory canal which passes on these waves signals to the middle ear.

Auditory canal is lined with wax secreting ceruminous glands.
Tympanum is made up of connective tissues and is lined from outer side by skin and on inner side by mucous membrane.it helps in separating the external ear from the middle ear. Tympanic cavity is located medially to the tympanic membrane and consists of three bones namely malleus, incus and stapes.

Handle of malleus is attached with Tympanum and foot plates of stapes rests on the oval window. Sound waves cause a movement in the tympanum membrane which in turn transmits these signals to the oval window of the inner ear.

The inner ear has a membranous labyrinth that floats within a bony labyrinth in a fluid called Perilymph. It has two parts- utricle and saccule which possess an otolithic organ or maculae. Cochlea is a spiral shell-shaped organ attached with saccule and takes $2\dfrac{3}{4}$ turns. It has three canals: scala tympanum, scala media and scala vestibuli and these are separated by two membranes, a basilar membrane separating scala tympani and scala media and Reisner’s membrane separating scala media and scala vestibuli.

Tectorial membranes lie over the organ of corti and when these are pushed against the membrane, they change the mechanical sound waves into electrical waves which are sent to the auditory cortex of the temporal lobe in the brain via the 8th cranial nerve.
Hence from the above explanation we can see that tympanum cavity is a part of the middle ear.

Hence, the correct answer is option (A).

Note: Middle ear helps in amplifying sound signals 22 times. 10 times amplification is due to ossicles while 12 times it is because of the difference in sizes between tympanum and oval window. Middle ear is linked with Pharynx by the Eustachian tube and it helps in maintaining pressure in the middle ear.