How many ossicles are in your ear

To hear properly, the pressure on both sides of your eardrum must be equal. When you go up or down in elevation, the air pressure changes and you may feel a popping sensation as your ears adjust. They adjust thanks to the narrow Eustachian say: yoo-STAY-she-en tube that connects the middle ear to the back of the nose and acts as a sort of pressure valve, so the pressure stays balanced on both sides of the eardrum. The vibrations from the middle ear change into nerve signals in the inner ear.

The inner ear includes the cochlea say: KOH-klee-uh and the semicircular canals. The snail-shaped cochlea changes the vibrations from the middle ear into nerve signals. These signals travel to the brain along the cochlear nerve, also known as the auditory nerve. The semicircular canals look like three tiny connected tubes. It's their job to help you balance. The canals are filled with fluid and lined with tiny hairs.

When your head moves, the fluid in the canals sloshes around, moving the hairs. The hairs send this position information as signals through the vestibular say: veh-STIB-yuh-ler nerve to your brain. The brain interprets these signals and sends messages to the muscles that help keep you balanced. When you spin around and stop, the reason you feel dizzy is because the fluid in your semicircular canals continues to slosh around for awhile, giving your brain the idea that you're still spinning even when you aren't.

The Eustachian tube, which opens into the middle ear, is responsible for equalizing the pressure between the air outside the ear and that within the middle ear.

The sound waves enter the inner ear and then into the cochlea, a snail-shaped organ. The cochlea is filled with a fluid that moves in response to the vibrations from the oval window. As the fluid moves, 25, nerve endings are set into motion.

These nerve endings transform the vibrations into electrical impulses that then travel along the eighth cranial nerve auditory nerve to the brain. In green are four rows of hair cells that respond to sound vibrations, and in red are auditory nerve fibers that convey sound information from the hair cells to the brain. Researchers at Johns Hopkins are studying the molecular mechanisms that guide the formation of hair cells.

Studies such as these might be a step towards less invasive treatments for deafness in which molecular cues can be used to biologically regenerate hair cells in the cochlea. This is the tube that connects the outer ear to the inside or middle ear. Tympanic membrane eardrum. The tympanic membrane divides the external ear from the middle ear. Three small bones that are connected and transmit the sound waves to the inner ear. The bones are called:. Eustachian tube. A canal that links the middle ear with the back of the nose.

The eustachian tube helps to equalize the pressure in the middle ear.