Anatomy And Physiology

Anatomy Physiology

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Have you ever wondered exactly how ears can detect sound? The human ear is a very delicate and detailed sensory organ. In order to hear sound, the ear must first catch sound waves, and direct them into the hearing part of the ear. The ear then senses these fluctuations in air pressure, and translates these fluctuations into signals that the brain can understand.

But, in order to understand this better, let's take a trip with sound as it travels through the ear on its way to the brain and its many receptors. All of this information was gathered at the website: "How Stuff Works."

Sound is a vibration of matter as it passes through the atmosphere. The human ear receives different vibrations due to the variations of the sound wave frequency. For instance, a higher pitched sound means that "air pressure fluctuation switches back and forth more quickly;" this sound is received as a high pitch. With fewer fluctuations in air pressure, the sound is captured in a lower pitch. Now let's take a look at how the ear catches sound waves.

The outer ear (the Pinna) works much like a baseball glove as it shape catches sound waves, and transports them through the ear canal to the eardrum. The outer ear is designed to catch sound waves and determine their: distance, direction of travel, and pitch frequency. Once these vibrations of sound have reached the eardrum they are intensified by the three smallest bones in the human body.

The eardrum separates the outer ear from the inner ear, and also helps to protect the inner ear from high pitched sounds which may damage its workings. As the sound passes through the eardrum it then travels to the cochlea in the inner ear.

But first these vibrations must be amplified, before they can pass through the fluid of the cochlea. Three tiny bones in the ear the: anvil, hammer, and also the stirrup amplify these vibrations. These three bones work like a piston as they amplify these sound vibrations, and push them into the cochlear fluid.

Once the vibrations pass into the inner ear they are "translated into nerve impulses the brain can understand." The cochlea is the most complex part of the ear, with three adjacent tubes separated by sensitive membranes. One membrane: the basilar membrane is made up of 20 to 30 thousand "reedlike fibers" which extend across its width.

When these tiny fibers are moved, electrical impulses are sent to the cerebral cortex where they can be interpreted by the brain. The brain then determines the strength of the vibrations, and also the direction of travel, and distance of sound. The brain now works as a super computer registering data, and trying to calculate everything into a conceivable order.

The basic concepts of the ear are quite simple, but certain structures of the ear are still very complex. New advancements in hearing are reached every year, but much is still unknown about this tiny intricate part of our body: the ear.

More about this author: Kevin Lamb

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