| A | B |
| central nervous system | brain and spinal cord |
| nerve cells | organize and conduct messages as small electrical impulses |
| motor nerves | pass messages from brain to spinal cord to rest of body |
| sensory nerves | send messages from outside body to brain |
| lens of the eye | where light passes through on way to nerve endings in back of eye |
| *cornea | covers lense, muscle, iris and pupil |
| *iris | colored part of eye which controls amount of light which enters |
| *retina | where the light is focused in the eye |
| optic nerve | sends messages to brain which interprets what is being seen |
| ear drum | thin membrane that stretches across ear conal |
| inner ear | contains fluid and nerve endings needed for hearing and balance |
| cochlea | hearing organ of the ear |
| astigmatism | blurred vision |
| cataracts | eye lens becomes cloudy |
| crossed eyes | muscles holding eyes can't keep the two balanced |
| eustachian tube | connects ear inner ear and nose cavity |
| epilipsy | seizures caused by excess of electric nerve signals to brain |
| farsightedness | nearby objects are blurred |
| glaucoma | excess of pressure in the eye, can cause blindness |
| meningitis | germ infection attacking outer lining of brain and spinal cord |
| nearsightedness | distant objects aren't clear |
| stroke | damage to brain caused by stopage of blood supply |
| neurologist | specialist in nervous syster and brain |
| *ophthalmologist | specialist in health of eye |
| *otorhinolaryngologist | specialist in ears, nose and throata |
| *electroencephalogram (EEG) | records electrical activity of brain |