PHYSIOLOGY OF SPECIAL SENSES

General and Special

What are the two types of senses?

General Senses

senses for touch, pressure, stretch, heat, cold, and pain

body

Receptors for general senses are located throughout the __________.

Special Senses

senses for taste, smell, hearing, equilibrium, and vision

head

Special sense organs are located in the _________.

Visual Acuity Test

test that measures the ability of the lens to focus light reflected from an object to the retina

Hyperopia

condition of farsightedness diagnosed through Visual Acuity Test

myopia

condition of nearsightedness diagnosed through Visual Acuity Test

presbyopia

condition that has difficulty to focus on close objects which is diagnosed through Visual Acuity Test

Snellen Eye Chart

eye testing chart used by eye care professionals to measure visual acuity

Demonstration of Blind Spot

figure (x or dot) disappears when it is focused on the blind spot which lacks photoreceptors

After Image

sensation that tends to persist in the consciousness after the cessation of stimulation

Positive After Image

after image that appears in the same color as the original stimulus

Negative After Image

after image that appears in color complementary to the original stimulus

Astigmatism

caused by abnormal lens or corneal curvature which causes part of the image to appear blurred

dark and distinct

TEST FOR ASTIGMATISM:

• There is no astigmatism if all the radiating lines appear equally __________________.

blurred

TEST FOR ASTIGMATISM:

• There is some degree of astigmatism if some of the lines are _________________ and appear less dark than the others.

Ishihara

what is used to test for colorblindness?

temporal lobe

The ear transmits sound vibrations and their patterns, intensities, and directions of origin to the ________________________ of the brain.

frequency (wavelength)

CHARACTERISTICS OF SOUND WAVES:

• determines pitch measures in cycles per second (cps) or Hertz (Hz)

Amplitude (Intensity)

CHARACTERISTICS OF SOUND WAVES:

• determines loudness measured in decibel (dB)

Weber Test

test in which a tuning fork is used to test for hearing loss

Unilateral

hearing loss is in one ear

bilateral

hearing loss is in both ears

Conduction Deafness

TYPES OF HEARING IMPAIRMENT:

• caused by something that stops sounds from getting through the outer or middle ear

• can be treated with medicine or surgery

Sensorineural (Perceptive) Deafness

TYPES OF HEARING IMPAIRMENT:

• occurs when there is a problem in the way the inner ear or hearing nerve works

Central Deafness

TYPES OF HEARING IMPAIRMENT:

• results from the defects in the central nervous system (auditory cortex) rather than in the ear itself or the auditory nerve

joints and muscles, eyes, and inner ear

3 sensory receptors that are involved in balance

Static Equilibrium

TYPES OF EQUILIBRIUM:

• evaluates position of head relative to gravity (head is motionless)

macula

part of the body associated with static equilibrium

Dynamic Equilibrium

TYPES OF EQUILIBRIUM:

• evaluates changes in direction and rate of head movement

semicircular canals

part of the body associated with dynamic equilibrium

papillae

The tongue which is covered in _______ is the principal organ of taste.

Taste Bud

located in the trenches of the papillae are sensitive to substances dissolved in water

Taste

senses that are a result of the stimulation of sensory neurons by chemical substance

Salty

5 TASTES:

• stimulated by metallic ions

Sour

5 TASTES:

• stimulated by hydrogen ions

Sweet

5 TASTES:

• stimulated by hydroxyl ions

Bitter

5 TASTES:

• stimulated by alkaloids

Umami

5 TASTES:

• stimulated by glutamate (MSG or monosodium glutamate)

tip and anterior

GUSTATORY TESTS:

• NaCl — salty at ______________ part of the tongue

lateral

GUSTATORY TESTS:

• Acetic Acid — sour at the ________ side of the tongue

tip

GUSTATORY TESTS:

• Sucrose — sweet at the _____ of the tongue

posterior part or base

GUSTATORY TESTS:

• Quinine Sulfate —- bitter at the ____________________ of tongue

Solutions

GUSTATORY TESTS:

• ______ are perceived very rapidly

Crystals

GUSTATORY TESTS:

• ________ are perceived after several minutes due to longer dissolution time

Bitter

A.

Sour

B.

Umami

C.

Salty

D.

Sweet

E.

adaptation

The sense of smell has 2 outstanding characteristics:

• Has a high degree of a._________________

• certain odors b.______ others

a = ?

mask

The sense of smell has 2 outstanding characteristics:

• Has a high degree of a._________________

• certain odors b.______ others

b = ?

Masking

ability of a high intensity odor to dominate and exclude any other odors

Smell

receptors that are excited by chemical substances in the air