short note on human ear
Answers
Answer:
The ear is the organ of hearing and, in mammals, balance. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. ... The middle ear includes the tympanic cavity and the three ossicles.
Explanation:
Internal ear
It comprises two parts:
Bony labyrinth
The bony labyrinth consists of a vestibule, three semi-circular canals, and the coiled spiral cochlea. It is made of perilymph.
Membranous labyrinth
The bony labyrinth surrounds the membranous labyrinth. It includes the sensory receptors which are responsible for balance & hearing.
External Ear
The outer ear is further divided into the following parts
Auricle
The auricle consists of a thin base of elastic cartilage surrounded by a skin layer.
External Auditory Meatus
It is a slightly curved canal which is protected by bone in its inner part and cartilage in the outer part.
Lined with stratified epithelium and wax glands is the meatus or canal.
Tympanic Membrane
This membrane separates the middle ear and the outer ear.
This portion receives the sound waves and they intensify them.
The centre portion is known as the umbo.
Middle Ear
The middle ear comprises the following parts
Tympanic Cavity
It is a small air-filled space divided by a tympanic membrane from the external ear, and by the bony wall from the inner ear.
Eustachian Tube
The Eustachian tube is a 4 cm long tube that equalises both sides of the tympanic membrane to air pressure. It joins the nasopharynx to the tympanic cavity.
Ear Ossicles
These transmit sound waves from the eardrum to the middle ear.