SOMATIC AND SPECIAL SENSES
SPECIAL SENSES
1.
2.
3.
4.
5.
Smell
Taste
Vision
Hearing
Balance
SOMTIC SENSES
1.
Tactile (touch)
2.
3.
4.
Touch
Pressure
Thermal (hot vs cold)
Pain
Proprioceptive
SENSORY RECEPTORS
Detect environmental
changes
Sensation occur via a
pathway
Stimulus
Sensory receptor
Conduction
Integration
What integrates the
sensation?
The brain!!!!!
TYPES OF RECEPTORS
1.
Mechanoreceptors
2.
Nociceptors
3.
light
Chemoreceptors
5.
pain
Photoreceptors
4.
Touch, pressure, hearing
Chemicals in nose and
mouth
Osmoreceptors
Osmotic pressure
TYPES OF MECHANORECEPTORS
TYPES OF MECHANORECEPTORS
Merkel receptors
Sense fine detail
Fires continuously
Meissner corpuscle
Control hand grip
Fire when stimulus is
added and removed
TYPES OF MECHANORECEPTORS
(CONTINUED)
Ruffini corpuscle
Senses skin stretching
Fire continuously
Pacinian corpuscle
Respond to fine detail
in fingers
Fire when stimulus is
applied and removed
ADAPTATION
Sensors adapt by
Perception of stimulus
fades/disappears
“get use to it”
HOW SENSITIVE ARE YOU?
Measure in mm!!
PAIN
Fast Pain
Slow Pain
Localized in large area
E.x
Why can’t the brain feel
pain?
Localized
E.x
Doesn’t have nocicptors
http://www.youtube.com/
watch?v=tnABHy6tjL8
HOMUNUCLEUS
HOMUNUCLEUS
Is a map that
corresponds body part
to touch sensitivity
The proportion of the
sensory cortex to the
size of the body region
is uneven.
EX. a relatively large
cortical is devoted to
the face and the lips,
and a small area is
devoted to sensations
arising from the trunk.
MAKE YOUR OWN HOMUNUCLEUS ANALYSIS
QUESTIONS
1.
2.
3.
4.
5.
6.
Is your skin’s sensitivity in proportion to the size of the body
part? Is it reversed? Explain how/why this is the case.
What would happen if your skin’s sensitivity in your hands
stopped working?
Why is a small portion of your cerebral cortex devoted to
your arm while a large portion is devoted to your hands and
fingers?
Which receptors allow you to feel fine detail? Where would
you expect to find several of these receptors? Why?
Which type of receptors would you expect to find in your
fingertips? Why?
How different is your homunucleus from your partners?
Where are they different and where are they the same?
HOMUNUCLEUS ANALYSIS
The hands and fingers are more useful for
gathering information and need more sensory
receptors and area to integrate the info
Able to feel fine details with fingers
OLFACTION
(AKA SENSE OF SMELL)
Detected by an olfactory
receptor
Olfactory receptor
Hair like extensions
Not nose hair
In olfactory
epithelium
OLFACTORY PATHWAY
HTTPS://WWW.YOUTUBE.COM/WATCH?V=SNJNO6OPJCS
Odor
absorbed by
receptor
Integrated by limbic
system or temporal
lobe
SMELL AND MEMORY
Odor + limbic system
+ parietal lobe = scent
memory
TESTING OUR SENSE OF SMELL ANALYSIS
1.
2.
3.
How many odors were you able to identify?
Were some odors easier to identify than
others? Why?
Why do you think some odors elicited a
memory?
HOW SMELL IS INTEGRATED BY THE BRAIN
GUSTATION
(AKA SENSE OF TASTE)
1.
2.
3.
4.
5.
Sour
Sweet
Bitter
Salty
Umami (savory/meaty)
How does a cold affect
your sense of taste?
TASTE BUDS
(PAPILLAE)
On surface of tongue
Gustatory Pathway
1. Taste receptors
2. Cranial nerves
3. Medulla oblongata
4. Limbic system
5. Parietal lobe
GUSTATORY PATHWAY
MAPPING TASTE BUDS
Where are the receptors for
salt found?
sweet ?
sour?
bitter?
savory/umami?
The center of the tongue
Not many receptors = does
sense taste very well
HOW THE BRAIN UNDERSTANDS TASTE
Neurotransmitter is
released
Foods taste different
because
Different neurons
are activated
ANATOMY OF THE EYE
HTTP://WWW.HANDWRITTENTUTORIALS.COM/VIDEOS.PHP?ID=38
FLOW OF TEARS
SCIENCE OF TEARS
Tears
Salt, mucus, lysozyme
(kills bacteria)
Are produced to:
Clear, clean and moisten
the eye
Emotions
LAYERS OF THE EYEBALL
1.
Fibrous tunic
2.
Vascular tunic
3.
Cornea
Sclera
Choroid
Ciliary body
iris
Retina
FIBROUS TUNIC
Cornea
Is curved
This varies in individuals
and as you age
Sclera
“White” of the eye
Gives shape
Protects
Point of muscle
attachment
VASCULAR TUNIC
Choroid
Cilliary body
Lines the sclera
Nourishes the retina
Muscle- controls the shape
of the lens
Process- secretes aqueous
humor
Aqueous humor
Nourishes the eye as it
ciculates through both
chambers
VASCULAR TUNIC
Lens
Iris
Changes shape to focus
light on retina
Clearer vision
Held in place by zonular
fibers
Is convex (curves outward)
Colored part of eye
Pupil
Light enters here
Diameter changes in
response to light
RETINA
(CONTINUED)
Fovea centralis
Sharp central vision
Lots of cones and zero
rods
Optic disk
“blind spot”
Does not have
photoreceptors (rods and
cones)
RETINA
Photoreceptors
Rods
Light sensitive cells
Transmit info to brain
E.x. rods and cones
Low light
Sense shades of grey
Cones
Need brighter light
Sense color
INSIDE THE EYEBALL
Vitreous body
Fluid that prevents the
eye from collapsing
Intraocular pressure
Refers to fluid inside the
eye
Balance between
production and drainage
of aqueous humor
RETINA
Types of photoreceptors
1. Rods
Low light
Sense shades of grey
2.
Cones
Need brighter light
Sense color
MUSCLES OF THE EYEBALL
Ciliary muscle
Lateral rectus muscle
Moves eye inward
Medial rectus muscle
Controls diameter of
pupil
Moves eye outward
Orbicularis oculi
Open and close the
eyelids
ANATOMY OF THE EYE ANSWER KEY
2.
Fiberous Tunic
Cornea and sclera
Retina
Vascular Tunic
Choroid, ciliary body and
iris
Cones
Retina
Choroid
Lateral rectus muscle
Sclera
Aqueous Humor
Medial rectus muscle
Rods
Pupil
Ciliary muscle
Intraocular pressure
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
Cornea
Iris
Orbicularis oculi
Fovea Centralis
Pupil
Optic nerve
Vitreous body, vitreous humor
Optic disk
Lens
Rods and cones
Hold the lens in place
Superior rectus and inferior
rectus
True
AMOUNT OF LIGHT
Bright
light
Iris expands
Pupil gets
smaller
Low light
Iris contracts
Pupil bigger
.
TYPES OF CONES
Red cones
Sense red light
Green cones
Sense green light
Blue cones
Sense blue light
THE MANTIS SHRIMP
HTTPS://WWW.YOUTUBE.COM/WATCH?V=PPW9RIY7GUS
Bullet like punch
Punch heats the
water to 8,000 F
Are able to see
cancer
Cancer cells scatter
light differently
It has 16 different
photoreceptor
cells
VISION RATINGS
20/20
20 ft away you see what
the avg person sees
20/40
20 ft away you see what
the avg person sees from
40 ft away
20/10
20 feet away you see what
the avg person sees from
10 ft away
VIEWING OBJECTS
Distant objects (20 ft away)
Light rays are parallel
Lens is flat
Near objects
Light rays are divergent
Lens becomes (rounder)
=accommodation
HOW DOES ACCOMODATION WORK?
TESTING THE BLIND SPOT
Trial
Left Eye
Distance
Right Eye
Distance
1.
At what distance did the
dot disappear?
2.
Why do you think the
dot disappeared?
1
2
3
4
5
Average
TESTING THE BLIND SPOT
Close your right eye. Stand about
20 inches away from the blind
spot tester. With your left eye,
look at the +. Slowly move toward
the image while looking at the +.
At a certain distance, the dot will
disappear from sight. Measure
how far away you were when the
dot disappeared.
Reverse the process. Close your
left eye and look at the dot with
your right eye. Move slowly
towards the image and the +
should disappear. Measure how
far away you were when the dot
disappeared.
TESTING THE BLIND SPOT
Measure how far away you were
when the dot disappeared.
This is when the dot fell on the
blind spot of your retina
BINOCULAR VISION
Allows for
Depth
3D vision
Better binocular
vision
Eyes in front
TESTING BINOCULAR VISION
1.
2.
3.
4.
Have your partner hold two different pencils at
different distances in front of you so that both
pencils can be seen.
With both eyes open, try to grab the pencil that is
furthest from you.
Repeat steps one and two twice. Have your
partner change the pencils distance with each
trial
Repeat steps one through three with one eye
closed
THE VISUAL PATHWAY
THE VISUAL PATHWAY
Images (light rays):
1. Enter the pupil
2. Lens inverts image
3. Optic nerve sends info
to the brain
***crosses over at optic
chiasm (chi-as-ma)
4.
5.
Brain integrates image
Sends Info back
CERUMEN
• Prevents “stuff” from
getting into the ear
AKA Ear Wax
Cerumen
CERUMEN FAIL!
http://www.youtube.co
m/watch?v=ZgLWl1bjH
84
RUPTURED TYMPANIC MEMBRANE
What can cause it to
tear?
Trauma or infection
Treatment
Self healing
May need surgery
DID YOU KNOW . . . . .
Elephants can hear
with their feet!
Have pancinian
corpuscles in their
feet
Nerve impulses
are sent directly to
the brain
OUTER EAR
Pinna
Directs sound waves
towards the external
auditory canal
External auditory canal
Funnels sound toward
the tympanic membrane
MIDDLE EAR
Tympanic membrane
Auditory Ossicles (bones)
Vibrates due to sound
waves
Deliver sound vibrations
Eustanchian Tube
Equalizes air pressure
Drains middle ear
Oval Window
Equalizes hydrolic
pressure
Fluid motion
Cochlea
Transfers vibrations from
ossicles to cochlea
Round Window
INNER EAR
Converts stimuli into
nerve impulses
Semicircular Canal
Equilibrium and balance
ANATOMY OF THE EAR ANSWER KEY
11.
3.
4.
5.
6.
7.
8.
9.
10.
Oval window
Pinna
Eustachian tube
Delivers vibrations to
inner ear fluids
Hammer, anvil, stirrup
External auditory canal
Semicircular canals
Round window
12.
13.
14.
15.
16.
17.
18.
Tympanic membrane,
eardrum
Cochlea
Repels insects &
prevents drying out,
earwax
To connect with oval
window
The cochlea
To prevents things from
getting in
The auditory ossicles
stapes
COCHLEA
COCHLEA
Basilar membrane
Organ of Corti
Vibrates in same pattern as
sound waves
Short hairs = high frequency
Longer hairs = low frequency
What type of relationship
exists between hair length
Cochlear Implant
and frequency?
https://www.youtube.com/watch?v=zeg4qTnYOpw
Negative correlation
https://www.youtube.com/watch?v=I8eHquhr52s
Use of Implant
https://www.youtube.com/watch?v=HTzTt1V
nHRM
BASILAR MEMBRANE VIBRATIONS
https://www.youtube.com/watch?v=KnXFlLFsOk
PHYSIOLOGY OF HEARING
1.
2.
3.
4.
5.
6.
Sound waves enter ear
Tympanic membrane
pushes auditory
ossicles
Cause the stapes to
“hit” oval window
This vibrates fluid in ear
Hairs move
Nerve impulse sent to
brain
HEARING AND AGING
Hairs in inner ear die or
are damaged
Do not regenerate
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