In this lesson, we will learn about the ear's structure and each part's functions.
The ear is an organ that is used for hearing. It is also used for balance in mammals. Sound localization is aided in vertebrates by the location of the ears, they are placed symmetrically on both sides of the head. The ear is described to have three parts in mammals; the inner ear, the middle ear, and the outer ear.
Blood supply to the ear is different depending on each part of the ear. The outer ear receives blood from a number of arteries. The majority of the blood supply is provided by the posterior auricular artery. The ear’s outer rim and the scalp behind it receive blood from the anterior auricular arteries. The mastoid branch of either the posterior or occipital auricular arteries supplies blood to the middle ear.
A human ear is made up of three parts. The eardrum separates the air-filled tympanic cavity (middle ear) from the ear canal (outer ear). The middle ear has three small bones known as the ossicles that play a role in sound transmission. The ossicles are also joined to the throat at the nasopharynx, through the pharyngeal opening of the Eustachian tube. The otolith organs are found in the inner ear. The semicircular canals and the utricle and saccule belong to the vestibular system, and the cochlea, on the other hand, belongs to the auditory system.
The outer ear is the only part that can be seen therefore, the word ear is often used to refer to the outer part alone. It includes:
The middle ear is made up of the three ossicles and the tympanic cavity. The ossicles are small bones functioning together to receive, amplify, and transmit sound that comes from the eardrum to the inner ear. These ossicles are the stapes (stirrup), incus (anvil), and the malleus (hammer). The stapes is said to be the smallest bone in the body that is named. Sound is transmitted to the inner ear from the outer ear by the three ossicles.
The inner ear lies in the temporal bone in a cavity known as the bony labyrinth. It is made up of structures that are very important to several senses. These structures include the semicircular canals, cochlea, utricle, and saccule. A central area called the vestibule contains two recesses that are fluid-filled, the utricle, and the saccule. The utricle and saccule enable balance when there is no movement (stationary). They connect to the cochlea and the semicircular canals. There are 3 semicircular canals that are arranged at right angles to each other and they are responsible for dynamic balance. The semicircular canals help with balance and eye tracking during movement. The spiral-shaped organ is the cochlea and it is responsible for the sense of hearing.
