special senses: olfaction, taste and vision
DESCRIPTION
Types of Sensory Receptors Chemoreceptors – detect chemical cues Ex: taste and smell Mechanoreceptors – detect stimuli via a mechanical distortion of a cell membrane Ex: hearing and touch III. Photoreceptors – detect light Ex: visionTRANSCRIPT
Special Senses: Olfaction, Taste and Vision
Exercise 26, 25, 24 in the lab book Types of Sensory
Receptors
Chemoreceptors detect chemical cues Ex: taste and smell
Mechanoreceptors detect stimuli via a mechanical distortion of a
cell membrane Ex: hearing and touch III. Photoreceptors detect
light Ex: vision Smell (Olfaction) Chemoreceptors in the olfactory
epithelium
respond to chemicals Olfactory Nerve Olfactory Epithelium Taste The
tongues surface is covered
by small projections called papillae Papillae contain the taste
buds There are 10,000 taste buds on the human tongue Each taste bud
has ~100 taste cells Taste Pore Taste Chemicals in food are
detected by taste cells located in the taste buds Taste Cells Taste
Bud Taste Activities Locate the papillae on your tongue Pg.
399
Do Activity 3: Stimulating the taste buds Can you taste the sugar?
The Distribution of Taste
Sweet, Sour, Salty, and Bitter There is now 5th taste Umami is the
distinctive taste found in meat and cheese Led to the creation of
MSG as a seasoning/preservative Plotting Taste Bud Distribution
Does YOUR tongue match this pattern?
Hi, I am Kikunae Ikeda.I discovered Umami in 1907. You can blame
MSG on me. Taste Activities Do Activity 4: Effect of smell on
taste
Fill out the table on Pg. 401 Do Activity 5: Importance of taste
and olfaction on odor identification Fill out the table on Pg. 402
Hearing Outer Ear Middle Ear Inner Ear Middle Ear Bones: Malleus,
Incus, and Stapes Tympanum Semicircular Canals Cochlea Auricle
(Pinna) External Acoustic Meatus Auditory Tube (Eustacean Tube)
Hearing Hearing involves mechanoreceptors in the ear
Sound waves vibrate the tympanum (eardrum) Ear Infection (Otitis
Media)
Inflammation of the mucosal membrane in the middle ear Commonly
caused by bacteria from a sore throat middle ear & throat are
connected by the auditory tube Sensory Adaptation All senses adapt
to stimuli Test with sound pupil Sclera Iris Pupil Cornea The pupil
will change size with light condition The Rods and Cones These are
the photoreceptors of the eye
They occur in the retina of the eye 120 million rods and 6 million
cones in each retina Rods are specialized for low light conditions
Cones are specialized for color vision under high light intensity
The Blind Spot Do Activity 5: Demonstrating the Blind Spot
Why do you have a blind spot? The Causes of Near/Far
Sightedness
Lens over or under compensates when focusing Eyeball is too long or
too short for proper focusing Cornea or lens has improper curvature
Cataract Lens is hard and opaque
Causes problems for focusing light on the retina Glaucoma Aqueous
humor is constantly being created and
drains from the eye Blockage stops drainage, putting pressure on
the retina & optic nerve Astigmatism Irregular curvature to the
cornea or lens causes
focusing problems Other vision tests: Astigmatism Binocular
Vision
Do Activity 8: Testing for Astigmatism Do Activity 10:Testing for
Binocular Vision Color Blindness Normal Vision Color Blind What
Causes Color Blindness?
There are 3 Types of Cones in the Human Eye: Red Cones for red
wavelengths of light Blue Cones for blue wavelengths of light Green
Cones for green wavelengths of light Color Blindness occurs when
one or all of these cone types are not sensitive to the correct
wavelengths of light Occurs in 6% of men and 0.5% of women Testing
for Color Blindness
Color Blindness Test Processing Sensory Information
Sensory register memory system that records information received by
receptor cells (stored as a sensory trace) Specific to each sense
Why need a sensory register? Size of the sensory register? Change
Blindness Test Dissection of the Cow Eye
Blue Book: Pg Yellow Book:Pg Find the structures on your handout
What is the tapetum lucidum? Do you have a tapetum lucidum?