Question

Explain the structure of the human ear with the help of a diagram.

Answer 1

Human ear is a sense organ responsible for hearing and body balance. The outer ear receives the sound waves and transmits them down the ear canal to the eardrum. This causes the eardrum to vibrate and sound is produced.

The External ear or the outer ear consists of:

1. Pinna/auricle is the outermost section of the ear.
2. The external auditory canal links the exterior ear to the inner or the middle ear.
3. The tympanic membrane, also known as the eardrum, separates the outer ear from the inner ear.

The Middle ear comprises:

1. Ossicles are the three tiny bones connected to each other that transmit sound waves to the inner ear. These three tiny bones are stapes, malleus, and incus.
2. Eustachian Tube is a tube that connects the middle ear to the back of the nose. It helps to maintain equal pressure in the middle ear which facilitates the proper transmission of sound waves.

The Inner ear consists of:

1. Bony Labyrinth: The bony labyrinth comprises a vestibule, three semi-circular canals, and spirally coiled cochlea. It is filled with perilymph.
2. Membranous labyrinth : The bony labyrinth surrounds the membranous labyrinth. It comprises sensory receptors responsible for balance and hearing. The membranous labyrinth is filled with endolymph and comprises three semi-circular ducts, cochlear duct, saccule, and utricle. The sensory receptors include cristae, an organ of Corti, and ampullary maculae.