Chemoreception
Taste, Smell, Touch
Sensory receptors

Rely on the transfer of matter and energy


Molecular transfer

Chemical receptors
Energy transfer



Conduction – The transfer of heat (kinetic
energy) by physical contact between molecules.
Includes mechanical waves and pressure waves
Convection – The transfer of kinetic energy by
moving groups of molecules from one area to
another
Radiation- The transfer of energy via
electromagnetic waves. These include visible
light, x-rays, UV- light.
Sensory: taste

Chemoreception
Taste receptors
Bitter
Sweet
Salty
Sour
Umami?
(meaty)
Each taste bud contains more than 100 taste receptor cells.
Sensory: taste

Energy transfer?

Convection – movement of
molecules by bulk flow
Sensory: smell
Smell Receptor Types:
Ethereal
Floral
Camphoraceous
Peppermint
Putrid (rotten)
Musk (Animal or sweat)
Pungent
Diffusion : surface area

Turbinals; increased surface area for diffusion
Sensory: mechanoreceptors
What type of energy transfer do these
types of receptors detect?
Hair Cells



Mechanosensory
Directionally sensitive
Fabulously sensitive –

Can respond to
sub-nanometer
displacement!
synaptic
vesicles
Proprioceptors
What type of receptor?
This receptor detects
what kind of energy
transfer?
Body position, motion
Muscle contraction
Tendon stretch
Ligament movement
Proprioceptors are located within muscles, tendons, and joints.
Pain receptors
TOUCH AND RELATED SENSES
1. All Regions of our bodies are sensitive to TOUCH.
2. YOUR LARGEST SENSE ORGAN IS YOUR SKIN.
3. MECHANORECEPTORS located throughout the Skin make it
possible to sense touch, pressure, and tension.
4. In humans, the receptors for touch are concentrated in the face,
tongue, and fingertips.
5. Body hair also plays an important role in the ability to sense
touch. Large numbers of Mechanoreceptors are found in the skin at the
base of hair follicles.
6. Our Skin has several different types of Sensory Receptors that are
just below the surface of the Skin.
7. Two Types respond to Heat or Cold - THERMORECEPTORS; Two
others respond to TOUCH - MECHANORECEPTORS; one Type
responds to TISSUE DAMAGE WHICH CAUSES PAIN - PAIN
RECEPTORS.
8. Sensory receptors for Hot or Cold are scattered directly below the
surface of the skin. There are THREE to FOUR WARM Receptors for
every COLD Receptor.
9. Sensory Receptor can be more concentrated in different places of
our bodies.
10. The MOST TOUCH-Sensitive areas are the FINGERS, TOES, AND
LIPS.
11. Pain Receptors are located throughout the skin. The Sensation of
Pain can be experienced as either Prickling Pain (FAST PAIN) or
Burning and Aching Pain (SLOW PAIN). Pain receptors are Stimulated
by mechanical, thermal, electrical, or chemical Energy.
Sense
Sight
Hearing
Taste
Smell
Touch/heat
Energetic transfer used
Radiation -electromagnetic waves
Conduction – mechanical
(sound) waves
Convection – movement of
molecules via bulk flow
Convection – movement of
molecules via diffusion and
bulk flow
All Three!
Touch Receptor types
Touch receptor type
Pain receptors
What it senses
Intense pressure or heat
– imminent or actual
tissue damage
Thermoreceptors
Heat
Mechanoreceptors
Pressure, vibration,
Body position
Receptor type
Senses Using Them
Pain Receptors
Thermoreceptor
Mechanoreceptors
Chemoreceptors
Electromagnetic receptors
Touch
Touch
Touch, Hearing
Taste, Smell
Sight
What you should be able to do:






Identify which energetic process is responsible for
transmitting information to each sense organ.
Explain how the property of sensation derives from a
pattern of responses from cells that sense different stimuli
(Colors from 3 types of cones, taste from 4-5 types of
receptors, etc.).
Explain how receptor specificity for chemoreception works.
Explain the importance of sensory information to survival.
Identify the location of sensory cells for each sense (Taste
bud, nasal passages, skin).
Identify which senses detect energy patterns and which
detect patterns in matter.