The anatomy of the human ear


The human ear is divided into three main parts: the outer ear, the middle ear, and the inner ear. Here’s a whistlestop tour of this most interesting body part, courtesy of the experts at House of Hearing.

The outer ear, also known as the auricle or pinna, collects sound waves and directs them into the ear canal. The ear canal acts like a funnel to amplify sound waves and send them to the eardrum, a thin membrane that separates the outer ear from the middle ear.

The middle ear contains three small bones called the ossicles, which are the malleus (hammer), incus (anvil), and stapes (stirrup). These bones work together to transfer the sound vibrations from the eardrum to the inner ear. In addition, the middle ear contains the Eustachian tube, which helps to equalize pressure on both sides of the eardrum.

The inner ear is where the conversion of sound waves into electrical signals takes place. It contains two main structures: the cochlea, which is responsible for hearing, and the vestibular system, which is responsible for balance.

The cochlea is a spiral-shaped organ that contains hair cells and the organ of Corti. As sound waves reach the inner ear, they cause the fluid in the cochlea to move, bending the hair cells in the organ of Corti. This bending creates an electrical signal that is sent to the brain through the auditory nerve. The brain then interprets these electrical signals as sound.

The vestibular system is made up of three semicircular canals and the utricle and saccule. These structures work together to detect changes in head position and movement and send signals to the brain to help maintain balance.

Both the cochlea and the vestibular system are located in the bony labyrinth, which is a series of interconnected cavities in the temporal bone. The bony labyrinth is filled with fluid, which helps to transmit sound and movement signals to the sensory cells.

Changes to the ear as we age

As we age, our bodies go through many changes and the size and shape of our ears is no exception. The ears are made up of cartilage and skin, and as we grow older, the cartilage can lose its elasticity and firmness. This can cause the earlobe to elongate and droop, and in some cases, the earlobe may become elongated and saggy. Additionally, the skin on the ear may become thinner and more wrinkled, which can make the ear appear smaller.

Another factor that can contribute to changes in the size and shape of our ears as we age is gravity. Over time, the weight of the earlobe can pull it downward, causing it to become elongated. This can also result in a loss of volume in the ear, making it appear smaller. In addition, gravity can cause the ear to become misshapen, with a drooping or collapsing appearance.

The loss of collagen and elastin in the skin can also play a role in the changes to the size and shape of our ears as we age. Collagen and elastin are proteins that provide elasticity and support to the skin, and as we age, our bodies produce less of these proteins. This can cause the skin to become looser and less firm, which can make the ear appear smaller and more saggy.

In addition to these natural aging changes, there are also some external factors that can contribute to changes in the size and shape of our ears. For example, repeated exposure to sun and wind can cause the skin to become dry and wrinkled, which can make the ear appear smaller and less shapely. In addition, repeated wearing of heavy earrings can cause the earlobe to stretch and become elongated over time.

Finally, it is worth noting that the size and shape of our ears can also be affected by genetics. Some people may be predisposed to having larger or smaller ears, or to experiencing more or less changes to their ear shape as they age. Additionally, some individuals may develop medical conditions, such as a form of skin cancer called basal cell carcinoma, that can impact the size and shape of their ears.

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