The Remaining Senses

Unit 6Lesson 3

Objectives

Review the physical properties of sound and light waves.

Compare and contrast the senses of taste and smell, and describe the relationship between the two.

Describe the skin sense in general, and pain perception in particular.

Explain the kinesthetic sense.

Warm Up

Explain the role wave frequency and amplitude play in both vision and audition.

Frequency Light- Influences the color we see Sound- Influences the pitch (hertz) we hear

Amplitude Light- Brightness of visual stimuli Sound- Loudness (decibels) of sound

Review

What is the relation between sight, sound, and the vestibular sense?

Eyes detect changes in body posture and vestibular imbalance (in the ears), provide info to keep us right side up!

Senses

Vision/Audition = physical energy

Olfaction/ Gustation = chemical molecules

Olfaction

Role of Smell Info about environment Recognition Communicate emotions Evokes memory

How Does Smell Work? Volatile Substance (Odor)

Chemical molecules released into the air at room temperature.

Olfactory Bulb in Nose Receptor cells covered in mucus that dissolve molecules

into electrical signals.

Olfactory Nerve Transmits neural impulses to brain where they are

interpreted as particular smell, associated with prior experiences or emotions.

Qualities of smell: fruity, flowery, putrid, burnt, resinous, spicy

Sensory Adaptation

Olfactory cells quickly adapt to stimuli Good- if in outhouse Bad- if painting room

Can all people smell?

Most of us can id up to 10K + odors! But…

Anosmic: Loss of some or all sense of smell

How? Virus Inflammation Drug use Head trauma

Taste (Gustation)

Saliva dissolves food molecules stimulating taste buds on tongue which create neural impulses which are sent to parietal lobe and interpreted as taste.

Taste vs Flavor

4 Taste Qualities Sweet Sour Salty Bitter

Flavor involves Odor Texture Temperature Taste

Food Experiment

Taste Only Smell Only Both

Flavor 1

Flavor 2

Flavor 3

Flavor 4

Food Experiment

Taste Only Smell Only Both

Flavor 1(Pear)

Flavor 2(Apple)

Flavor 3(Onion)

Flavor 4(Potato)

Skin Senses Indicate Touch/Pressure, Temperature, Pain

Located mostly in middle layer of skin. Hair follicles- Nerves at base respond to movement…

bending = pressure/touch Free nerve endings- Respond to pain and temperature

Once stimulated, pass through CNS

to various areas of somatosensory

cortex in brain.

Skin Senses Touch and Pressure

Parts of body more sensitive to touch than others

Two-Point Threshold: Smallest distance between 2 points before person id’s two sources of stimulation instead of one

Toothpick demo

Pain

Indicates something is wrong at point of contact

Phantom Limb Pain: pain in amputated limbs activated by nerves in stump or memories

Gate Theory: rubbing area floods n.s. with stimulation, confusing source of pain

Kinesthesis

Informs you about position and motion of parts of body

Sense receptors in joints, tendons, muscles

Examples: Close eyes and touch nose w/finger Make a muscle in your right arm

Closure Identify where sense receptors

for transduction are located for each sense we’ve studied.

Vision - Retina (Rods & Cones) Audition – Cochlea/Basilar Membrane

(Organ of Corti) Olfaction – Olfactory Bulb Gustation – Taste Buds Touch – Hair follicles or free nerve

endings Vestibular – Semicircular Canals Kinesthetic – Joints, Muscles, Tendons