Download General Sensory Information

Receptors, Taste and Smell
GENERAL SENSORY INFORMATION
STIMULUS (STIMULI)
A stimulus is a form of Energy
 Sensory receptors convert one form of Energy
into another.
 Example: Taste receptors convert Chemical
Energy into Electrical energy
 Other receptors convert other forms of energy
(light, gravitational, sound)

THE BODY’S SENSORY RECEPTORS
Receptor Type
Stimulus
Information Provided
taste
chemical
Presence of specific chemicals
(identifed by taste buds)
smell
chemical
Presence of specific chemicals
(detected by olfactory cells)
pressure
mechanical
Movement of the skin or changes
in body surface
proprioceptor
mechanical
Movement of limbs
balance
mechanical
Body movements
audio
sound
Sound waves
visual
light
changes in light intensity,
movement and colour
thermoreceptor
temperature changes
flow of heat
SENSATION AND THE BRAIN
By blocking neurotransmitters in the sensory
pathway, the sensation of pain can be blocked.
 Likewise if the correct area of the brain is mildly
shocked, the sensation of pain will occur even
in the absence of stimulus.

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Burnt Toast Commercial
DIAGRAM OF THE SKIN’S RECEPTORS
THERMORECEPTORS
Thermoreceptors do NOT act as thermometers,
which detect specific temperatures.
 Hot and cold receptors are adapted to signal
changes in environmental temperatures
 Most animals can tolerate a wide range of
temperatures, but are often harmed by rapid
temperatures
 “Boiling Frog” experiment

SENSORY ADAPTATION
Over time, if a stimulus is constant the neurons
may cease to fire, provided the stimulus is not
dangerous
 Basically you become accustomed to the
sensation and you brain ignores it

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i.e., receptors are only stimulated when clothes are taken off or
put on. Sensory information assuring you that your clothes are
still on your body are not required.
TASTE AND SMELL
Taste allows you to distinguish between edible
and inedible
 Taste involves special chemicals
 Each taste is associated with a certain
molecular shape or charge.
- Smell and taste are closely related
and work together but smell detects
Airborne chemicals.

SUMMARY – SENSORY INFORMATION
Sensory receptors are highly modified dendrites of
sensory neurons that detect information about the
external or internal environment
 Sensory receptors convert one form of energy into
another
 Taste receptors detect dissolved chemicals;
olfactory airborne. Taste and olfactory receptors
work together to create the perception of taste
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