Transcript 34-Sensory-Mechanism

Sensory Mechanism
Marie Černá
Five categories
• Mechanoreceptors - muscle spindle
- hair cell in ear
• Pain receptors (nociceptors)
• Thermoreceptors
• Chemoreceptors - gustatory (taste)
- olfactory (smell)
• Electromagnetic receptors
- photoreceptors
Structure of the eye
Retina
Photoreceptors
Neurons
Cells of Retina
The effect of light on retinal
Focusing in the eye
Structure of the ear
Structure of the ear
A cross-sectional view
of the cochlea with three canals
Mechanoreceptors
Mechanism of hearing
Semicircular
canals
Cochlea
Vibrations, caused by
sound waves, in
the tympanic membrane
are conducted via 3 small
bones to the oval window
and create pressure waves
in the cochlear fluid perilymph.
The waves pass through
the vestibular canal to
the apex of the cochlea,
then back toward the base
of the cochlea via
the tympanic canal and
end on the round window.
As the basilar membrane vibrates,
hair cells repeatedly brush against
the tectorial membrane.
This stimulus causes
hair cells to depolarize.
Perilymph
Organs of balance
A vestibule contains two chambers:
the utricle and saccule
Gustatory chemoreceptors
Olfactory chemoreceptors
Nociceptors + Thermoreceptors
Literature
Biology, eighth edition,
Campbell, Reece
Unit seven: Animal Form and Function
Chapter 50: Sensory and Motor Mechanisms
Concept 50.1, 50.2, 50.3, 50.4
Pages 1087 – 1105