1. Chapter 10, part A
Sensory Physiology

2. About this Chapter What are the senses How sensory systems work
Body sensors and homeostatic maintenance
Sensing the external environment
Mechanisms and pathways to perception

3. General Properties of Sensory Systems
Stimulus
Internal
External
Energy source
Receptors
Sense organs
Transducer
Afferent pathway
CNS integration

4. General Properties of Sensory Systems
Figure 10-4: Sensory pathways

5. Sensory Receptor Types
Structural types:
Simple receptors
Complex neural
Special senses
Types according to the nature of stimulus
Chemoreceptors
Mechanoreceptors
Thermoreceptors
Photoreceptors

6. Sensory Receptor Types
Figure 10-1: Sensory receptors

7. Special Senses – External Stimuli
Vision
Hearing
Taste
Smell
Equilibrium

8. Special Senses – External Stimuli
Figure 10-4: Sensory pathways

9. Somatic Senses – Internal Stimuli
Touch
Temperature
Pain
Itch
Proprioception
Pathway
Figure 10-10: The somatosensory cortex

10. Somatic Pathways Receptor Threshold Action potential Sensory neurons
Primary – medulla
Secondary – thalamus
Tertiary – cortex
Integration
Receptive field
Multiple levels

11. Somatic Pathways
Figure 10-9: Sensory pathways cross the body’s midline

12. Sensory Modality Location Lateral inhibition Receptive field Intensity
Duration
Tonic receptors
Phasic receptors
Adaptation

13. Figure 10-3: Two-point discrimination
Sensory Modality
Figure 10-3: Two-point discrimination

14. Sensory Modality
Figure 10-6: Lateral inhibition

15. Touch (pressure) Mechanoreceptors Free nerve endings
Pacinian corpuscles
Ruffini corpuscles
Merkel receptors
Meisaner's corpuscles
Barroreceptors

16. Touch (pressure)
Figure 10-11: Touch-pressure receptors

17. Temperature Free nerve endings Cold receptors Warm receptors
Pain receptors
Sensory coding:
Intensity
Duration

18. Temperature
Figure 10-7: Sensory coding for stimulus intensity and duration

19. Pain and Itching
Nociceptors
Reflexive path
Itch
Fast pain
Slow pain

20. Pain and Itching
Figure 10-12: The gate control theory of pain modulation

21. Referred Pain
Figure 10-13: Referred pain