Presentation 17 - Sensory Mechanisms

Sensory mechanisms

1. Sensory
Mechanisms

2. Sensory receptors and the brain
Sensation Perception
•Action potentials transmitted
by sensory receptors to the
brain
•Sensory receptors
▫Specialized
neurons/epithelial cells
▫Extero- and interoreceptors
▫Convert energy to changes
in membrane potentials
and transmit to brain
▫Functions: transduction,
amplification, transmission,
and integration
•Interpretation
of the stimuli
by the brain
•Ex. colors,
taste, sound,
smell

4. 1. Follow the
movement of the
rotating pink dot with
your eyes.
2. Stare at the cross
in the center.
3. Concentrate on the
cross at the center for
a long period of time.

5. Is the blue
side in the
front or back
of the cube?

7. Types of sensory receptors

8. Vision and photoreceptors
* All have pigment molecules that absorb light

9. Structure of the human eye
Ciliary body
Iris
Suspensory
ligament
Cornea
Pupil
Aqueous
humor
Lens
Vitreous humor
Optic disk
(blind spot)
Central artery and
vein of the retina
Optic
nerve
Fovea (center
of visual field,
most cones)
Retina with rods and cones
ChoroidSclera

11. Hearing and equilibrium in invertebrates
Ciliated
receptor cells
CiliaStatolith
Sensory nerve fibers
Statocysts in invertebrates
1 mm
Tympanic
membrane

12. Hearing and equilibrium in mammals
Pinna
Auditory
canal
Eustachian
tube
Tympanic
membrane
Stapes
Incus
Malleus
Skull
bones
Semicircular
canals
Auditory nerve,
to brain
Cochlea
Tympanic
membrane
Oval
window
Eustachian
tube
Round
window
Vestibular canal
Tympanic canal
Auditory nerve
Bone
Cochlear duct
Hair cells
Tectorial
membrane
Basilar
membrane
To auditory
nerve
Axons of
sensory neurons
1Overview of ear structure 2The middle ear and inner ear
4 The organ of Corti 3The cochlea
Organ of Corti
Outer ear
Middle
earInner ear

13. Chemoreceptors and taste
Sensilla in insects
Taste buds in mammals

14. Chemoreceptors and smell
Brain
Nasal cavity
Odorant
Odorant
receptors
Plasma
membrane
Odorant
Cilia
Chemoreceptor
Epithelial cell
Bone
Olfactory bulb
Action potentials
Mucus

15. Mechanoreceptors and pain
receptors in the skin