( ) The outer ear includes the ear lobe and the pinna. The pinna is made of ridge cartilage covered with skin. It funnels sound through the ear canal to the ear drum, the tympanic membrane. The ear drum separates the outer ear from the inner ear. The middle ear is filled with air. As sound is funneled into the ear canal, it causes the ear drum to vibrate. The vibration is transmitted to the three small bones in the middle ear. These bones are called the ossicles and include the malleus (hammer), incus (anvil), and stapes (stirrup). The ossicles amplify the vibration and transmit it to the oval window which separates the middle ear from the inner ear. Also within the middle ear is the Eustachian tube, which connects the middle ear to the back of the nose and throat. It allows air in and out of the middle ear so that the air pressure on either side of the ear drum is equal and keeps the ear drum from bulging or retracting. If the ear drum is stressed then it will not transmit sounds as well and will cause pain. The Eustachian tube also allows fluid to drain from the middle ear. The inner ear is composed of two major structures, the cochlea and the vestibular system. The cochlea is mainly responsible for hearing while the vestibular system is involved in maintaining balance. 126
. Ears pop with rapid changes in air pressure, such as when flying or scuba diving. This causes a precipitous rush of air through the Eustachian tube, causing a popping sensation. This adjustment in the middle ear is necessary to keep the eardrum vibrating normally. In an airplane it is easier for your ears to adjust during take-off than landing. During take-off the external pressure is dropping so the air in the middle ear is rushing out. During landing the external air pressure is increasing and air must go into the inner ear to balance the pressure. But it's a lot easier to let air out of a smaller space and into a bigger space than vice versa. Think of the balloon …: inflating a balloon takes more work than letting the air out. So balancing the air pressure in your ears while you're landing usually takes more effort on your part. ( ) If you are flying with a cold, sinus infection or allergies, your Eustachian tube could be blocked, creating problems . The Eustachian tube can be blocked, or obstructed, for a variety of reasons. When that occurs, the middle ear pressure cannot be equalized. The air already there is absorbed and a vacuum occurs, sucking the eardrum inward and stretching it. Such an eardrum cannot vibrate naturally, so sounds are muffled or blocked, and the stretching can be painful. If the tube remains blocked, fluid (like blood serum) will seep into the area 127 () ()
from the membranes in an attempt to overcome the vacuum. This is called fluid in the ear, serous otitis or aero-otitis. Uncommon problems include developing a hole in the ear drum, hearing loss and dizziness.
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