2. Sensory Physiology

3. Sensation  Awareness of changes in environment  Changes can be internal or external  How is perception different?  Awareness of changes in environment  Changes can be internal or external  How is perception different?

4. Sensory modalities  Unique type of sensation  Two classes:  General  Somatic - tactile, thermal, pain, proprioreceptive  Visceral  Special  Smell, taste, hearing, vision, equilibrium  Each sensory neuron linked to one modality  Unique type of sensation  Two classes:  General  Somatic - tactile, thermal, pain, proprioreceptive  Visceral  Special  Smell, taste, hearing, vision, equilibrium  Each sensory neuron linked to one modality

5. How do we sense? 

6. Process of sensation 1.Stimulation of receptor 2.Transduction of stimulus (Graded potential) 3.Generation of nerve impulses 4.Integration of input 1.Stimulation of receptor 2.Transduction of stimulus (Graded potential) 3.Generation of nerve impulses 4.Integration of input

7. Receptor classification: Stimulus  Mechanoreceptors  Thermoreceptors  Nocireceptors  Photoreceptors  Chemoreceptors  Osmoreceptors  Mechanoreceptors  Thermoreceptors  Nocireceptors  Photoreceptors  Chemoreceptors  Osmoreceptors

8. Adaptation  What does this mean?  Maintained stimulus  lessened potentials  decreased impulse frequency  May be rapidly or slowly adapting  What does this mean?  Maintained stimulus  lessened potentials  decreased impulse frequency  May be rapidly or slowly adapting

9. Eye Anatomy Review

10. Image Formation 1.Refraction of light rays  Both cornea and lens refract 1.Refraction of light rays  Both cornea and lens refract

11. Image Formation 2. Accommodation  Convex surface causes light rays to converge  Greater curvature = greater refraction  Lens more curved for near objects (ciliary muscle)  Near point of vision 2. Accommodation  Convex surface causes light rays to converge  Greater curvature = greater refraction  Lens more curved for near objects (ciliary muscle)  Near point of vision

12. Image Formation 3.Constriction of the pupil  Iris narrows pupil  Restricts light from periphery of lens  Simultaneous with accommodation 3.Constriction of the pupil  Iris narrows pupil  Restricts light from periphery of lens  Simultaneous with accommodation

13. Refraction abnormalities  Myopia  Hyperopia/ Hypermetropia  Astigmatism  Myopia  Hyperopia/ Hypermetropia  Astigmatism

14. Binocular vision  Advantages/Disadvantages  How does it work?  Convergence  Advantages/Disadvantages  How does it work?  Convergence

15. Photoreceptors

16. Rods vs. Cones  Structural difference in outer segment  One opsin (rhodopsin) vs. three  Cone regeneration quicker  Rods used for low light, relatively unused in light  Structural difference in outer segment  One opsin (rhodopsin) vs. three  Cone regeneration quicker  Rods used for low light, relatively unused in light

17. Visual pathway

18. Sound  Waves originating from vibration  Frequency (Hz = cycle/sec)  Pitch  Audible range is 20- 20,000 Hz  Amplitude (dB)  Volume  0 dB = threshold  Waves originating from vibration  Frequency (Hz = cycle/sec)  Pitch  Audible range is 20- 20,000 Hz  Amplitude (dB)  Volume  0 dB = threshold

19. Physiology of Hearing

20. Equilibrium  Vestibular apparatus - Saccula, utricle, semicircular ducts  Static equilibrium - relative to gravity  Utricle and saccula  Dynamic equilibrium - rotation, acceleration, deceleration  Semicircular ducts (rotational acceleration/deceleration)  Saccula and utricle (linear acceleration)  Vestibular apparatus - Saccula, utricle, semicircular ducts  Static equilibrium - relative to gravity  Utricle and saccula  Dynamic equilibrium - rotation, acceleration, deceleration  Semicircular ducts (rotational acceleration/deceleration)  Saccula and utricle (linear acceleration)

23. Olfaction and Gustation  Olfaction  Odorants stimulate olfactory hairs  Hairs connected to dendrite  Potential generated  Signal sent along olfactory tract  Gustation  Five primary tastes  Taste buds have receptors  Signal sent along gustatory pathway (Three nerves  Medulla  Diencephelon/Cerebrum)  Olfaction  Odorants stimulate olfactory hairs  Hairs connected to dendrite  Potential generated  Signal sent along olfactory tract  Gustation  Five primary tastes  Taste buds have receptors  Signal sent along gustatory pathway (Three nerves  Medulla  Diencephelon/Cerebrum)