1. Sensory, Motor, and Integrative Systems
Chapter 16

2. Peripheral Nervous System
Flow to the CNS
Flow out of the CNS

3. Peripheral Nervous System
Integration occurs at many locations along the pathway.
stimulus - environmental change
sensation - awareness of stimulus
perception - interpretation of the
meaning of the stimulus

4. Sensory Modalities General senses: somatic and visceral Special senses
smell,hearing/equilibrium
taste, vision, and hearing

5. Classification of Sensory Receptors
Structural classification
Type of response to a stimulus
Location of receptors & origin of stimuli
Type of stimuli they detect

6. Structural Classification of Receptors
1. Unencapsulated
free nerve endings
Merkel discs
root hair plexus
2. Encapsulated
Meissner’s corpuscles
Krause’s end bulbs
Pacinian corpuscles
Ruffini’s corpuscles
Muscle spindles
Golgi tendon organs
3. Sensory cells
vision
taste
hearing
balance

7. Structural Classification of Receptors

8. Classification by Response to Stimuli
Generator potential
free nerve endings, encapsulated nerve endings & olfactory receptors produce generator potentials
when large enough, it generates a nerve impulse in a first-order neuron
Receptor potential
vision, hearing, equilibrium and taste receptors produce receptor potentials
receptor cells release neurotransmitter molecules on first-order neurons producing postsynaptic potentials
PSP may trigger a nerve impulse
Amplitude of potentials vary with stimulus intensity

9. Classification by Location
1. Exteroceptors
2. Interoceptors
3. Proprioceptors

10. Classification by Stimuli Detected
1. Mechanoreceptors
2. Thermoreceptors
3. Photoreceptors
4. Chemoreceptors
Nociceptors
Osmoreceptors

11. Classification of Receptors

12. Adaptation
Adaptation - generator potential or receptor potential decreases in amplitude during a maintained stimulus.
Rapidly adapting - e.g. pressure, touch, smell
Slowly adapting - e.g. pain, body position

13. Somatic Sensations Tactile Pain Thermal Proprioceptive
touch, pressure,vibration, itch and tickle
Pain
fast and slow
Thermal
warm and cold
Proprioceptive
muscle spindles, tendon organs, joint receptors

14. Sensory Receptors

15. Referred Pain

16. Proprioceptive Senses

17. Receptors - Summary

18. Somatic Sensory Pathways
Somatic sensory pathways relay information from somatic receptors to the primary somatosensory area in the cerebral cortex.
The pathways consist of three neurons
first-order: conduct impulses to the CNS (brainstem or spinal cord)
either spinal or cranial nerves
second-order: conducts impulses from brain stem or spinal cord to thalamus
cross over to opposite side of body
third-order: conducts impulses from thalamus to primary somatosensory cortex (postcentral gyrus of parietal lobe)
Axon collaterals of somatic sensory neurons simultaneously carry signals into the cerebellum and the reticular formation of the brain stem.

19. Somatic Sensory Pathways
Posterior Column -
Medial Lemniscus
Pathway

20. Somatic Sensory Pathways
Spinothalamic
Pathways

21. Somatic Sensory Pathways
Trigeminothalamic
Pathways

22. Somatosensory Map of Postcentral Gyrus

23. Somatic Sensory Pathways

24. Somatic Motor Pathways

25. Direct Motor Pathways

26. Direct and Indirect Motor Pathways

27. Cerebellum Input/Output

28. Reticular Activating System

29. Stages of Sleep
Nonrapid eye movement (NREM)
Rapid eye movement (REM)

30. Learning and Memory
Learning is the ability to acquire new information or skills through instruction or experience.
Memory is the process by which information acquired through learning is stored and retrieved.
Immediate memory- recall for a few seconds.
Short-term memory- temporary ability to recall.
Long-term memory- more permanent.
Memory consolidation.

31. Clinical Terms analgesia syphilis paralysis coma paraplegia hemiplegia
quadriplegia
transection
hemisection
spinal shock
cerebral palsy
Parkinson’s disease
bradykinesia
hypokenesia
ataxia
Huntington’s
insomnia
narcolepsy
sleep apnea