Micro Life Zone
Asked by narellesimons to Posty, Edward, Kate, Nathan on 22 Jun 2011.
Keywords: ear, eye, sense
The eyes and ears are pretty complex! Lets start with the ears and follow the sound from the outside of the ear to the inside of the ear and then to the brain.
Sound waves are first caught by your outer ear and flow down your ear canal to your ear drum. The ear drum is a membrane that separates the outer ear from the middle ear. The sound waves travel through this vibrating membrane to the air of the middle ear, and then deeper into your head to the inner ear. The inner ear is one of the most amazing things in your body (in my opinion…) because it is sooo tiny and so controlled! The sound waves cause tiny hairs to vibrate and each of these tiny hairs is attached to a nerve ending that carries the message to the brain. Then the brain does some hokey pokey magic (not really magic but the brain does work in mysterious ways) to interpret the message that the hair cells send.
ALSO the ear is in charge of balance. There are semi circular canals full of fluid within the inner ear. The fluid is free to move so when you tilt your head, the fluid moves and sends messages to your brain that you are tilting. Sometimes when you are sick, the inner ear gets a bit swollen and the fluid can not move very freely. That’s why you get off balance sometimes when you are sick!
Now… the eyes!
Again, lets follow the flow of light. First the light goes through the clear front bit of the eye – the cornea into the pupil and through the lens. The lens is there to focus the light onto the retina at the back of the eye. Actually, the lens causes the image to be upside down when it reaches the retina and it is not until the messages from the retina flow up the optic nerve to the brain that the image gets turned up the right way again! Pretty amazing.
By BRIDGE8 under license from Mangorolla CIC 2019