5. Sensations takes place when..
Stimuli initiate afferent impulses
That eventually reach a conscious level in the
cerebral cortex
All sensations involve receptor organs
Simplest receptor organs are bare nerve
endings
6. What are the Sensations we
feel?
Pain
Temperature
Pressure
Touch
Special Senses
Sight
Hearing
Taste
Smell
Orientation in space
7. Sensory Receptor
Peripheral component of an afferent
axon and the centrally located nerve cell
body of that axon.
Convert different types of energy into
nerve signals (sound, light, thermal,
chemical, and mechanical).
Generally receptors are specific and only
respond to one form of energy.
8. Sensory receptors are specialized epidermal
cells that respond to environmental stimuli
and consist of structural and support cells
that produce the outward form of
the receptor, and the internal neural
dendrites that respond to specific stimuli.
9. Different types of receptors
include:
Chemoreceptors
Pain receptors
Thermoreceptors
Mechanoreceptors
Photoreceptors
10. Types of sensory receptors
(based on structure)
Free nerve endings or dendrites
Encapsulated nerve endings
Specialised receptor cells
12. Functions of Free Nerve endings
• Free nerve endings can detect temperature,
mechanical stimuli (touch, pressure, stretch)
or danger (nociception). Its overall function is
to respond to superficial pain and touch.
16. Specialised receptor cells
• Specialized receptor cells have distinct
structural components that interpret a specific
type of stimulus
• The cells in the retina that respond to light
stimuli are an example of a specialized
receptor cell, a photoreceptor.
20. CHARACTERISTICS OF RECEPTORS:
first-order neuron of olfactory pathway
tips are protected by olfactory hairs
stimulated by odorants; inhaled chemicals
cells live about a month and then replaced
OLFACTION: SENSE OF
SMELL (Chemoreceptors)
23. • CHARACTERISTICS OF
RECEPTORS:
– chemicals known as
tastants stimulate them
– electrical signal stimulate
release of neurotransmitter
molecules that bind to
gustatory receptors on
dendrites of taste buds’
first-order neurons
– respond to any one of five
primary tastes: sweet, sour,
bitter, salty, or umami
(savory, glutamate
detection)
1. bitter, 2. salty,
3. sour, 4. sweet
GUSTATION: SENSE OF
TASTE (Chemoreceptors)