Transcript File

Do:
STARTING POINTS, PG. 444
1. (a) The brain would interpret a loud sound as a bright light
or other image.
(b) It may cause a different visual interpretation, since visual
information is stored in different areas of the occipital lobe.
2. (a) Neurons are no longer responding to the impulse.
(b) It will allow the neurons to detect different odours and
prevent the neurons from becoming overstimulated.
3. Lips > Fingertips > Face > Back of Neck > Shoulder > Palm
of Hand
Depending on the tissue’s function, more sensory neurons
may be required, making that area more sensitive to
stimulation.
Do:
STARTING POINTS, PG. 444
BLIND WALK –
- HOW DID YOU FEEL WHEN YOU FIRST
STARTED?
- DID THIS CHANGE BY THE TIME YOU
FINISHED?
- WHAT SENSES DID YOU USE THE MOST
WITHOUT SIGHT AND WHAT KINDS OF
THINGS DID YOU SENSE?
SENSES
We are constantly receiving information about our surroundings
from our senses.
Touch, taste, smell, sight, and hearing help our brain to determine
what is going on.
Different senses respond to different types of stimuli:
ie. Touch – pressure, heat, pain
Taste/smell – chemicals
Sight – wavelengths and intensities of light
Hearing – sound vibrations
The signals stimulated in the receptors are converted to action
potentials in sensory neurons going to different areas of the brain.
Types of Sense Receptors
Receptor
Stimulus
 Thermoreceptors – detects temperature change.
Thermoreceptors
 Pain Receptors – responds to tissue damage
Mechanical in a variety of ways
Mechanoreceptors ….
 Mechanoreceptors – detects
mechanical forces (touch)
pressure
and vibration (sound)
touch
 Chemoreceptors – chemicalProprioceptors
reception (smell and taste)
balance
 Photoreceptors – detect light,
and are located on the
Chemicals
Chemoreceptors ….
retina.
taste
Temperature change
smell
Light
Photoreceptors …..
rods and cones in eye
Sound (also really mechanical)
Mechanoreceptors…..
Organ of Corti in ear
SENSES
You can “trick” your senses into sensing
other stimuli.
Ie. Pressure on retina = light
Strong light crosswires with senses
from the nose…
ACHOO: Autosomal-dominant Compelling HelioOphthalmic Outburst Syndrome
SENSES
SENSORY ADAPTATION – Once a receptor
has been continuously stimulated,neurons stop
sending signals. I.E. Touch (clothes, hot tub),
sounds
Taste
 When you eat your favorite meal, the saliva in
your mouth helps to break down the food.
 Located in your tastes buds are sensory cell
receptors that receive the chemical signal and
generate a nerve impulse that travels to the
brain, which then tells you what flavor you are
tasting.
 Your taste buds can recognize 4 types of tastes:
 Sweet
 Salty
 Bitter
 Sour
TASTE & SMELL
Our tongue has various receptors
to sense different chemical
signals:
Sour, sweet, salty, bitter, and
umami (glutamic acid)(meat)
Smell
 WHAT? Olfaction (the sense of smell) - is the detection
of chemicals (odors) in the air.
 WHERE? Olfactory cells - located in the roof of the
nasal cavity.
 HOW? When chemicals combine with the receptor sites,
nerve impulses are generated to the brain
where they are interpreted.
 Olfactory receptors also adapt to constant stimuli, which
is why smells fade after constant exposure (ex. The
perfume/cologne you wear)
 Olfactory fatigue – a decreased ability to smell. Can be
caused by a cold (blockage of the sinus cavity) or old
age (loss of receptors)
TASTE & SMELL
The sense of taste and smell are closely associated so that it
is difficult to interpret taste sensations without the sense of
smell.
Plugging your nose makes it difficult to taste foods.
Humans sense 7 Primary Odors:
Camphoric (ex: Mothballs)
Musk (ex: Aftershave)
Floral (ex: Flowers)
Peppermint (ex: Minty Gum)
Ether (ex: Dry Cleaning Fluid)
Pungent (ex: Burning Sulfur)
Putrid (ex: Rotting eggs)
Location of Olfactory System

Let’s Zoom In….
Touch
Touch receptors (mechanoreceptors) are
found in the skin.
Two types of touch receptors are used to
detect light pressure or heavy pressure.
When pressure is detected, receptors are
stimulated, which causes the nerve
impulse.
Sense receptors in the skin

EYE
RETINA
VITREOUS
HUMOR
CORNEA
LENS
CHOROID
LAYER
BLOOD
VESSELS
FOVEA
AQUEOUS
HUMOR
IRIS
CILIARY
MUSCLE
BLIND
SPOT
SCLERA
OPTIC
NERVE
macula or macula lutea
(from Latin macula, "spot" + lutea, "yellow") :
oval-shaped highly pigmented yellow spot
near the center of the retina of the human eye.
Near its center is the fovea, a small pit that
contains the largest concentration of cone
cells in the eye and is responsible for central,
high resolution vision
PARTS OF THE EYE
CORNEA – Window, protection, bends light
AQUEOUS HUMOR – Clear fluid
IRIS – Coloured part of the eye. Opens and closes the
PUPIL to allow more or less light to enter the eye.
LENS – Stretches and shortens to focus images on the
RETINA.
CILIARY MUSCLES – Pull and push the LENS.
VITREOUS HUMOUR – Clear fluid that fills the inside
of the eyeball.
PARTS OF THE EYE
SCLERA – White, outer, protective covering
CHOROID LAYER – Black layer inside the sclera
HAWKS HAVE 600 MILLION
The
lens
is
not
clear.
It
is
RETINA – Innermost
layer
of
the
eyeball;
CONES IN THE CENTER OF contains light
slightly
yellow
to block
THE RETINA
(8X
MORE
sensing cells (RODS
AND
CONES)
THAN
HUMANS).
uv light.
If you CHICKENS
get lens
RODS – Sense
dimONLY
light intensities
(bl. & Wh.)
HAVE
CONES = GOOD
replacement,
you
can
see
SIGHT DURING DAY BUT
CONES – Identify
wavelengths
(colour – 3 types)
uv
light.
BLIND
AT NIGHT.
FOVEA CENTRALIS –Area of highly concentrated
cones (on the retina) for fine focus
BLIND SPOT – On the retina where the optic nerve
conects. No rods or cones here.
LOOK INTO MY
EYES…
IF YOU CAN.
VISION
Light bouncing off objects is reflected into our eyes. It
is bent by the cornea and lens so it focuses on our
retina. The image on our retina is inverted (upsidedown and backwards) then is “fixed” by our brain to
look right-side-up.
VISION – Accommodation reflex to
focus
Distant vision –the lens is less convex because ciliary
muscles relax (are longer) so suspensory ligaments pull
on the lens.
Near vision - requires more bending of light SO the
lens is more convex because ciliary muscles contract &
suspensory ligaments stop pulling on the lens.
Front view of
lens
Side view
Chemistry of Vision
RODS
CONES
125 million
Number of
receptors
6 million
High
Light Sensitivity
Low
Low
Visual Acuity
(sharpness)
High
No-black and
white vision
Light wavelength
distinction
Yes – color vision
Red Green Colorblindness – what does it look like??
Chemistry of Vision
Light and dark adaptation: What tips the balance
of the forward and reverse reactions?
 LIGHT
rhodopsin

retinene & opsin
DARK
Chemistry of Vision
Did you know??......an old wives tale
about eating carrots……
What nutrient do you need
to make retinene?
VISION
Cones in the retina can fatigue (as can other receptors).
When they are exposed to light for a period of time, they
can “remember” the image. This is an AFTERIMAGE.
Positive afterimages and negative afterimages.
A positive afterimage is like when you look at a
bright light then close your eyes and still see the
light.
In a negative afterimage, cones for a certain
colour fatigue so when you look away, you
percieve the opposite (complementary) colour.
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE PICTURE BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
STARE AT THE FOUR DOTS BELOW:
AFTERIMAGES
STARE AT THE MIDDLE OF THE CROSS BELOW:
AFTERIMAGES
http://www.michaelbach.de/ot/col_lilacChaser/index.
html
Einstein? (blur your eyes)
WEBSITES
• http://www.michaelbach.de/ot/index.html
• http://www.michaelbach.de/ot/mot_bounce/
index.html
• Dot
• More optical illusions
• Awareness Test
VISION DEFECTS
NEARSIGHTED
(MYOPIA) –
Can’t see far away
Long eyeball
Correct with biconcave
lens
VISION DEFECTS
FARSIGHTED
(HYPEROPIA) –
Can’t see close up
Short eyeball
Correct with
biconvex lens
VISION DEFECTS
ASTIGMATISM
Lens or cornea is irregular
Why do OLD people need
reading glasses??
• The lens loses elasticity as we age so it
cannot become convex enough to
focus on “near” object.
• SO they/we need glasses for reading
• Feels like being farsighted
• It is called presbyopia
THE EAR
The ear is used for both hearing and for
equilibrium (balance). Tiny hairs in the inner
ear respond to mechanical movement (vibration,
acceleration, or change of position) to generate
a nerve impulse.
http://jetcityorange.com/mosquito-ringtone/
EAR – curiosity/application?…..
• How can mechanical sound waves be turned
into a nerve impulse and then interpreted as
sound?
• Why do ear “pop” when flying or diving?
• Why can’t you tell you’re on a moving train
IF you wake up when it is moving AND
there is no sound AND it is pitch dark?
PINNA
THE EAR
TYMPANIC
MEMBRANE
OSSICLES
SEMICIRCULAR
CANALS
AUDITORY
NERVE
VESTIBULE
AUDITORY CANAL
COCHLEA
EUSTACHIAN
TUBE
Table 1 Parts of the Ear
Structure
External ear
pinna
auditory canal
Middle ear
ossicles (3)
Function__________________
• outer part of the external ear amplifies sound by
funnelling it f rom a large area into the narrower
auditory canal
• carries sound waves to the tympanic membrane
• contains hair and secretes wax to keep dust and insects out
• tiny bones that amplify and carry sound in the middle ear
tympanic membrane • also called the eardrum, it receives sound waves
oval window
• receives sound waves from the ossicles
eustachian tube • air-filled tube of the middle ear that equalizes pressure
between the outer and middle ear
Inner ear
vestibule
• chamber at the base of the semicircular canals that provides
information concerning static equilibrium
semicircular
• fluid-filled structures that provide information concerning
canals
dynamic equilibrium
cochlea
• coiled tube within the inner ear that receives sound waves
and converts them into nerve impulses
Stirrup pushes
on oval window
3 ossicles:
hammer,
anvil,
stirrup
PARTS OF THE EAR
PINNA – Outer part of the ear to collect and amplify sound; direct it
down the AUDITORY CANAL
AUDITORY CANAL– sound travels to the middle ear
TYMPANIC MEMBRANE – “ear drum”; membrane that vibrates
when hit by sound waves.
OSSICLES – tiny bones in the inner ear which act as levers to amplify
vibrations from the tympanic membrane through to the OVAL
WINDOW. Three bones: MALLEUS (HAMMER), INCUS (ANVIL),
AND STAPES (STIRRUP).
OVAL WINDOW – Vibrates the liquid in the COCHLEA.
PARTS OF THE EAR
COCHLEA – Shaped like a snail shell. Contains the
ORGAN OF CORTI – Rows of hairs that “wiggle” with
different sound frequencies and intensities.
EUSTACHIAN TUBE – A tube running to the nasal cavity
to equalize air pressure between the inner ear and the
outside.
VESTIBULE - connected to oval window. Contains two sacs
(utricle and saccule) which establish head position (static
equilibrium).
SEMICIRCULAR CANALS - three fluid filled canals at
different angles used to identify body movements (dynamic
equilibrium).
HEARING
•Sound waves must travel through each medium (gas,
liquid, solid).
•GAS-AIR (OUTER EAR): Sound waves move through the
air, down the auditory canal and then strike and vibrate the
tympanic membrane.
HEARING
•SOLID (MIDDLE EAR): The vibrations are then amplified
as they move through the malleus, incus, and stapes to
relay vibrations to the oval window, the round window below
it, and into the cochlea.
HEARING
•LIQUID (INNER EAR): The cochlea is full of fluid. The
movement of the fluid from the sound waves cause the
hairs on the organ of Corti to bend. This converts the
sound wave energy into electrochemical impulses in
sensory nerves. These nerves can detect pitch and
loudness.
BALANCE (EQUILIBRIUM)
Balance has two parts: static and dynamic equilibrium.
Static Equilibrium:
- Movement along one plane (horizontal or vertical)
-Hairs are contained in fluid filled sacs of the saccule and
utricle. There are also calcium carbonate particles called
otoliths in the fluid.
-When the head is in a normal position, the hairs are upright.
- When tilted, the otoliths and fluid shift and bend the hairs
sending signals to the brain.
BALANCE (EQUILIBRIUM)
Dynamic Equilibrium:
- cilia on hair cells in the ampullae of the
semi-circular canals is bent in response to
movement.
• Epley maneuver
Eye Activities
1. Eye dissection reflections
2. Activities and answers to 2 applications questions
on “old textbook” handout
Ear Activity
1. Complete procedure on p. 464 & record observations.
2. Answer Analysis & Evaluation questions on p. 464
Senses Diploma Practice
EYES & EARS
OLD NELSON TEXT:
PAGE 394: VISION
PART I – VISUAL ACUITY: EYE
CHART
PART II – BLIND SPOT
PART III – DOMINANT EYE
PART IV – STEREOSCOPIC VISION
NEW NELSON TEXT:
PAGE ###: HEARING &
BALANCE
PART I – FACTORS
AFFECTING HEARING
PART II – EQUILIBRIUM
LAB QUESTIONS
LAB QUESTIONS
- HAND
IN SENSES LAB
- DO AND HAND IN SENSES
DIPLOMA REVIEW.
- DO QUESTIONS ON PAGES
466-467 TO PREPARE FOR
SENSES QUIZ.