1. The Senses

2. The five senses are … Vision, Hearing, Taste, Touch and Smell
All these senses are received as AP’s from sense organs. The brain interprets these messages to provide our sensory inputs as we know them.

3. The Eye
The best way to understand function of the eye is to compare it to a camera. A camera creates images by focusing on an object and allowing specific amounts of light to pass through a hole to create a visual impression on film. The eye functions in much the same way.

4. Focus
When light enters the eye, it passes through the cornea (camera lens) where 2/3 of focus is achieved. The light then passes through the pupil where the iris (aperture) adjusts the amount of light that is allowed to enter. The remaining 1/3 of focus is then achieved when the light passes through the lens (camera lens).

5. Focus Accommodation is one of the focusing mechanisms of the eye.
The shape of the lens can adjust (either thinner or thicker) by tensing or relaxing the muscles of the eye. The focused light finally reaches the retina (film) where it is converted by the rods and cones into a signal that can travel to the brain (film development). Once the image reaches the brain, you have sight.

7. Problems
Changes in the shape and size of your eyes can cause problems that affect the way you see things that are close up or far away. These problems are referred to as refractive disorders. Refractive disorders include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism.

10. The Ear The Ear has two main functions – balance and hearing.
There is an inner, outer and middle section of the ear.

12. Parts of the Ear
Outer Ear: Comprising the pinna, ear canal, and outer layer of the eardrum.\
Middle Ear:
Inner Ear:

13. Parts of the Ear
Inner Ear: The last energy transformation occurs here. Mechanical energy is transformed into the traveling wave pattern of the basilar membrane.

14. Skin Receptors Heat Pressure Touch Cold Pain
All send messages to the brain via sensory neurons

15. Taste Receptors There are four types of receptors on the tongue Salty
Sour
Bitter
Sweet

16. Smell Receptors Smell is a chemical sense (as is taste)
Chemicals enter the nasal passages and are picked up by a mucus layer. Receptors in the mucus pass messages to the brain using the olfactory nerves.
Receptors for smell are much more sensitive than taste receptors.

17. Taste Receptors