Do:

STARTING POINTS, PG. 4441. (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 HandDepending 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?

SENSESWe 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, painTaste/smell – chemicalsSight – wavelengths and intensities of lightHearing – 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

Thermoreceptors – detects temperature change.Pain Receptors – responds to tissue damageMechanoreceptors – detects mechanical forces (touch)

and vibration (sound)Chemoreceptors – chemical reception (smell and taste)Photoreceptors – detect light, and are located on the

retina.

Stimulus Receptor

Temperature change Thermoreceptors

Mechanical in a variety of ways Mechanoreceptors ….pressuretouchProprioceptorsbalance

Chemicals Chemoreceptors ….tastesmell

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 Helio-Ophthalmic Outburst Syndrome

SENSES

SENSORY ADAPTATION – Once a receptor has been continuously stimulated,neurons stop sending signals. I.E. Touch (clothes, hot tub), sounds

TasteWhen 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)

SmellWHAT? 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 & SMELLThe 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

OPTIC NERVE

SCLERA

CHOROID LAYER

RETINA

FOVEA

BLIND SPOT

CILIARY MUSCLE

IRIS

AQUEOUS HUMOR

CORNEA

LENS

VITREOUS HUMOR

BLOOD VESSELS

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 EYECORNEA – 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 EYESCLERA – White, outer, protective covering

CHOROID LAYER – Black layer inside the sclera

RETINA – Innermost layer of the eyeball; contains light sensing cells (RODS AND CONES)

RODS – Sense dim light intensities (bl. & Wh.)

CONES – Identify wavelengths (colour – 3 types)

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.

HAWKS HAVE 600 MILLION CONES IN THE CENTER OF THE RETINA (8X MORE THAN HUMANS). CHICKENS HAVE ONLY CONES = GOOD SIGHT DURING DAY BUT BLIND AT NIGHT.

The lens is not clear. It is slightly yellow to block uv light. If you get lens replacement, you can see uv light.

LOOK INTO MY EYES…

IF YOU CAN.

VISIONLight 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 (upside-down and backwards) then is “fixed” by our brain to look right-side-up.

VISION – Accommodation reflex to focus

Distant vision Distant vision –the lens is less convex because ciliary muscles relax (are longer) so suspensory ligaments pull on the lens.

Near vision 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

Red Green Colorblindness – what does it look like??

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

Chemistry of VisionLight and dark adaptation: What tips the balance of the forward and reverse reactions?

LIGHTrhodopsin retinene & opsin

DARK

Chemistry of Vision

Did you know??......an old wives tale about eating carrots……

What nutrient do you need to make retinene?

VISIONCones 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.

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE PICTURE BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

AFTERIMAGESSTARE AT THE FOUR DOTS BELOW:

AFTERIMAGESSTARE AT THE MIDDLE OF THE CROSS BELOW:

http://www.michaelbach.de/ot/col_lilacChaser/index.html

AFTERIMAGES

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 EARThe 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?

THE EARPINNA

AUDITORY CANAL

TYMPANIC MEMBRANE

OSSICLES

VESTIBULECOCHLEA

AUDITORY NERVE

SEMICIRCULARCANALS

EUSTACHIAN TUBE

Table 1 Parts of the Ear

Structure Function__________________External earpinna • outer part of the external ear amplifies sound by

funnelling it f rom a large area into the narrower auditory canal

auditory canal • carries sound waves to the tympanic membrane• contains hair and secretes wax to keep dust and insects out

Middle earossicles (3) • tiny bones that amplify and carry sound in the middle eartympanic membrane • also called the eardrum, it receives sound wavesoval window • receives sound waves from the ossicleseustachian tube • air-filled tube of the middle ear that equalizes pressure

between the outer and middle earInner earvestibule • chamber at the base of the semicircular canals that provides

information concerning static equilibriumsemicircular • fluid-filled structures that provide information concerning canals dynamic equilibriumcochlea • coiled tube within the inner ear that receives sound waves

and converts them into nerve impulses

3 ossicles: hammer, anvil, stirrup

Stirrup pushes on oval window

PARTS OF THE EARPINNA – 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 EARCOCHLEA – 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

Ear Activity1. Complete procedure on p. 464 & record observations.

2. Answer Analysis & Evaluation questions on p. 464

Eye Activities 1. Eye dissection reflections

2. Activities and answers to 2 applications questions

on “old textbook” handout

Senses Diploma Practice

EYES & EARS OLD NELSON TEXT:PAGE 394: VISIONPART I – VISUAL ACUITY: EYE CHARTPART II – BLIND SPOTPART III – DOMINANT EYEPART IV – STEREOSCOPIC VISION

LAB QUESTIONS

NEW NELSON TEXT:PAGE ###: HEARING & BALANCEPART I – FACTORS AFFECTING HEARINGPART II – EQUILIBRIUM

LAB QUESTIONS

- HAND IN SENSES LAB

- DO AND HAND IN SENSES DIPLOMA REVIEW.

- DO QUESTIONS ON PAGES 466-467 TO PREPARE FOR SENSES QUIZ.