Special Senses

General Senses

Associated with the sense of touch

General Senses

Lack specials sense organs, information is gathered by the skin and other tissues

Special Senses

have specialized sense organs

Nerve Impulses

Specialized sense organs in special senses gather sensory information and change it into ____

Vision, Hearing, Balance, Taste, Smell

Special Senses include

Sensory Receptors

Whether the senses are special or genral, they all depend on cells acalled

Vision

Capability of the eye to focus and detect images of visible light

Hearing

Sense of sound perception

Taste

Capability to detect the taste of substances

Smell

The other chemical sense;

Olfaction

other term for sense of smell

Odor Molecules

Possess a variety of features that excite specific receptors strongly

Touch

Perception resulting from activation of neural receptors

Somatosensory

Other name for touch

Tactition or Mechanoreception

Other name for somatosensory

Near Point

Closest point within the eye's accommodation range

Far Point

Other limit to the eye's accommodation range

11cm

Normal eye's near point

Hyperopia

Far-sightedness

presbyopia

a reduced ability to focus on near objects

Myopia

Near-sightedness

Visual Acuity Test

used to determine the smallest letters you can read on a standardized chart held 20m away

Snellen Chart

display consisting of a printed card with letters and numbers in lines of decreasing size; the standardized chart used in visual acuity test (20m away)

Special Chart

Used when the distance is shorter than 20m

Astigmatism

impaired eyesight resulting usually from the irregular conformation of the cornea; common in people with myopia and hyperopia

Refractive Errors

Astigmatism and Hyperopia/Myopia are reffered to _____ because they affect how eyes bend/refract light

Ishihara Color Vision Test

Screening test for detecting presence of Color Blindedness

Shinobu Ishihara

Developed the Ishihara Color Vision Test

Red-Green Color Blindedness

Most common color vision deficiency

Accommodation Reflex

Reflex action of the eye that occurs when you switch away focus from a farther object to a closer one.

Convergence of the eyes, pupillary constriction, lens accommodation

Responses of Accommodation Reflex

Convergence Reflex

Simultaneous movement of both eyes inward when viewing a near object

Fovea

Part of the retina where visual acuity is highest

Convergence Reflex

Holding a pencil in front of the eyes and slowly moving it towards your nose

Double Vision

results when focusing on a very near object which causes your eyes to stop working together

Hearing Tests

Measure how well you are able to hear

Sounds

Translated information from vibrations in the ear drums sent by the nerve cells

Hearing loss

Happens when there is a problem with one or more parts of the ear

Sensorineural Hearing Loss

hearing loss due to failure of the auditory nerve or problem with the structure of the ear

Sensorineural Hearing Loss

hearing loss due to damage in any part of the specialized nervous system of the ear

True

Sensorineural hearing loss is usually permanent

Conductive Hearing Loss

hearing loss due to blockage of sound transmission in the ear

Conductive Hearing Loss

hearing loss due to problems with the bones of the middle ear; sound waves arent able to pass through the middle ear to the inner ear

Infants and young children

Conductive Hearing Loss is usually common in

Mixed Hearing Loss

Combination of Sensorineural and Conductive Hearing Loss

Older Adults

Hearing loss is common in

65

About 1/3 of adults over the age of ____ have some hearing problems

Hearing Test

show whether you have hearing loss in one or both ears and how much hearing is gone

Pure Tone Audiometry Test

Measures the softest or least audible sound a person can hear

Decibels

Loudness of sound is measured in

Sound Localization Test

Is proved to be practical in organization and execution

70%

Results obtained in the validation of a sound localization test suggest that individuals with normal hearing should be able to locate ___ of the presented stimuli

Rinne Test

Evaluates hearing loss by comparing air conduction to bone conduction

Normal

Result in Rinne Test when Air Conduction > Bone Conduction

Conductive Loss

Results in Rinne Test when Bone Conduction > Air Conduction

Air Conduction Hearing

Occurs through air near the ear and involves the ear canal and eardrum

Weber Test

Another way to evaluate conductive and sensorineural hearing losses

Romberg Test

Measures your sense of balance; typically used to diagnose problems with balance composed of visual, vestibular, and proprioceptive systems in a neurological exam

Positive

Result of Romberg Test when the patient sways and loses balance with closed eyes

Tuning Fork

Tool used in hearing test