Peripheral Nervous System

Module 9 The Peripheral Nervous System

How the sense of balance works youtube video                                             
Hearing and balance  youtube video
Taste and Smell youtube video
Vision youtube

The pinna or auricle is the outer part of the ear that is visible as shown in the picture to the right. It helps capture sound waves so those sound waves can be sent through the external auditory canal in order to reach the eardrum, which is also called the tympanic membrane. The vibrations of the eardrum travel through the fluid of the middle ear to the smallest bones of the body.  There are 3 small bones in your middle ear.  Do you remember what they are called? Check at the bottom of this page for the answer.
Sound travels from these bones to the cochlea of the inner ear.  These vibrations stimulate the nerves which send signals to your brain where we hear sound.

LASIK eye surgery in six minutes - Not for the faint of heart!
Cow Eye dissection - video and information found here
Eye Dissection guide by exploratorium
Eye dissection guide by home science tools
Eye dissection video
Label the Eye - online activity

 "Don't shoot 'til you see the whites of their eyes!"  The white part of the eye that you see, is the sclera.  The sclera is the tough, protective outer covering of the eye.

What color eyes do you have? When we talk about the color of your eyes, we are talking about the iris. Interestingly, the iris is a muscle. The iris muscle controls how much light gets into the eye.

The pupil or the dark, black hole in the center of the iris is just that - a hole.  This hole or pupil is where light enters.  The size changes depending on how bright it is.

It's not easily seen in these pictures, but the cornea is a clear covering that is on top of the iris.  Light has to travel through the cornea in order to enter the pupil.  The cornea is the first time that light is focused so that it can enter the eye.

Beneath the iris and not seen in these pictures is the lens. The lens is a flexible, transparent structure that focuses the light onto the retina in the back of the eye. The retina contains rods and cones that send an upside down picture to the brain where we "see".                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          





Answer:
1. Three smallest bones in the middle ear are the malleus, incus and stapes.