1. Chapter 10
SPECIAL SENSES

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State Standards
Health Science
8) Outline basic concepts of normal structure and function of all body systems, and explain how homeostasis is maintained.
19) Understand principles of and successfully perform skills related to Medical Assisting Skills, incorporating rubrics from textbooks or clinical standards of practice for the following
b. Screening for vision problems
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3. Objectives
Students will demonstrate knowledge of anatomy of the eye, ear, nose, and tongue.
Students will perform vision assessments to screen for vision problems.
Students will explore sensory experiences of the different sensory organs through lab activities

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The eye
1 inch sphere
Protected by the orbital socket of the skull, eyebrows, eyelids, and lashes
Continuously bathed in tears from the lacrimal duct in the inner corner of the eye
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THE EYE
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Discussion
With a partner discuss…
What is purpose of tears?
What would happen to our eyes without tears?
Why do we blink? Is this a voluntary or involuntary reflex?
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THE EYE
Sclera - outer layer or white of eye
Cornea - center and front of sclera
Choroid coat - middle of the eye
Iris - colored, muscular part
Pupil - circular opening in iris
Lens - behind iris and pupil
Retina - innermost (third) coat
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THE EYE
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PATHWAY OF VISION
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10. Labeling Draw an eye and label these parts…. Sclera Cornea Pupil Lens
Retina
Optic nerve
Add this to your notes.

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Common Vision defects
Presbyopia- decreased ability to focus on close objects
Hyperopia- (farsightedness)- objects must be moved farther away to be clear
Myopia- (nearsightedness)- objects must be brought closer to be clear
Amblyopia- dimness of vision
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12. Common Vision defects cont.
Astigmatism- irregularly curved cornea
Diplopia- blurred vision
Strabismus-crossed eyes (due to muscle weakness)
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13. Screening for Vision problems
Common screening tools include…
Snellen Chart- assess distance
Reading newsprint- assess near vision
Color testing- color bars on the Snellen chart
Manual Peripheral Vision screening
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Snellen Chart
Colored lines are used to check for presence of colored blindness
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Reading Newsprint
Tests near vision by measuring the ability to read newsprint at a distance of 14 inches (35 cm).
Determines if hyperopia or myopia is present
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16. Steps to Checking Peripheral Vision
Assesses peripheral vision by determining when an object comes into sight.
a. Seats client 2 to 3 feet away from self
b. Has client cover one eye and gaze straight ahead.
c. Begins well outside normal peripheral vision and brings object to the center of the visual fields.
d. Repeats in all 4 visual fields, clockwise.
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17. Activity
With a partner you will be checking each others vision using a grading rubric. You will be performing the following tests…
Distance- Snellen chart
Color- Snellen Chart
Near- newsprint
Peripheral- manual peripheral testing
Document the results of your testing and determine if your partner has any visual defects.
*if you wear glasses (complete activity with glasses and without to observe the difference)
*you will be performing Snellen chart Check offs as part of your test over special senses.

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THE EAR
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THE EAR
The outer ear (Pinna)
collects sound waves and directs them into auditory canal that leads to the eardrum
Glands that secrete wax (cerumen)
Discussion: Discuss with a partner why we need cerumen.
Research: Applying what you know about the types of tissue, what tissue is the outer part of our ear made of?
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The middle ear
Cavity in the temporal bone connects to the throat by the Eustachian tube
equalizes air pressure
Contains 3 tiny bones that transmit sound waves to the ear drum
Hammer
Anvil
Stirrup
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Discussion
Discuss with your partner
Why would we need the ability to equalize pressure between our ear canal and throat?
What are examples of when this happens?
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THE NOSE
The human nose can detect about 10,000 different smells
Odor molecules that pass through the nose get warmed and moistened.
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THE TONGUE
The tongue is a mass of muscle tissue with structures called papillae
Taste buds cover the papilla, which are stimulated by sweet, sour, salty, and bitter tastes
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Group Activity
Read the Smell and Taste lab information located on the website.
In your small groups you will be completing sensory stations and answering the questions located around the room…
1. How is your sense of smell?
2. Smell Accommodation
3. The link between taste and smell
4. Taste sensations
When you are finished answer the Review questions located at the bottom individually
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