1. Sensory, Motor, & Integrative System
Ch 16

2. Sensation:
The conscious or subconscious awareness of external or internal stimuli.
Perception:
The conscious awareness and the interpretation of meaning of sensations.

3. Exteroceptors vs
Interoceptors

4. General Senses vs. Special Senses
Taste
Smell
Vision
Hearing
Balance
Pain
Temperature
Light touch
Pressure
Sense of body and limb position

5. Sensory Receptors
Mechanoreceptors
Thermoreceptors
Photoreceptors
Chemoreceptors
Nociceptors
Osmoreceptors

6. General Senses Unencapsulated Encapsulated Nerve Nerve Endings vs
Free nerve endings
Naked nerve endings surrounded
by one or more layers
Pacinian corpuscle
skin, bones, internal organs, joints
Deeper tissue, muscles

7. Unencapsulated Nerve Endings
pain, light touch, and temperature
Free Nerve Endings - Pain & Temperature
Merkel’s Discs - Light Touch & Pressure
Root Hair Plexuses - Light Touch

8. Encapsulated Nerve Endings
Pacinian Corpuscles - Deep Pressure
Meissner’s Corpuscles - Discriminative Touch in Hairless Skin Areas
Krause’s End-Bulbs - Discriminative Touch in Mucous Membranes
Ruffini’s Corpuscles - Deep Pressure & Stretch (Proprioception)

9. The Epidermis
Merkel Cells- slow mechanoreceptors (basal layer)

10. Skin Receptors free nerve endings Merkel disc Meissner’s corpuscles
Ruffini corpuscle
root hair plexus
Pacinian corpuscles

11. Encapsulated Nerve Endings
Muscle Spindles - Skeletal Muscle Stretching (Proprioception)
Golgi Tendon Organs - Tendon Stretching (Proprioception)

12. Muscle Spindle
& Tendon Organ

13. Pain- protective function
Somatic Pain-results from injuries to skin, muscle, joints, tendon vs. Visceral Pain- pain in body organs

14. Referred Pain- felt on the body surface

15. Somatic Sensory Pathway

22. Ascending Spinal Cord Tract

23. 2nd order neuron- to thalamus or cerebellum
Ascending Spinal Cord Tract
Conducts sensory impulses upward through 3 successive chains of neurons
1st order neuron-cutaneous receptors of skin and proprioceptors  spinal cord or brain stem
2nd order neuron- to thalamus or cerebellum
3rd order neuron- to somatosensory cortex of cerebrum

24. Descending Spinal Cord Tract

25. Direct pathway- regulates fine and fast movements
Descending Spinal Cord Tract
Descending tract delivers impulses efferently from brain to spinal cord
Direct pathway- regulates fine and fast movements
Indirect pathway- maintains balance by varying postural muscle tone

26. Primary Somatosensory Cortex & Primary Motor Area

27. Primary Sensory Cortex
Motor Areas and Sensory Areas of the Cebral Cortex

28. Primary Motor Cortex
Motor Areas and Sensory Areas of the Cebral Cortex

29. Importance of Sleep
Slow-wave sleep (NREM stages 3 and 4) is presumed to be the restorative stage
People deprived of REM sleep become moody and depressed
REM sleep may be a reverse learning process where superfluous information is purged from the brain
Daily sleep requirements decline with age
Stage 4 sleep declines steadily and may disappear after age 60

30. Stages of Sleep

31. Sleep Disorders Narcolepsy Insomnia Sleep apnea
Lapsing abruptly into sleep from the awake state
Insomnia
Chronic inability to obtain the amount or quality of sleep needed
Sleep apnea
Temporary cessation of breathing during sleep

32. Learning & Memory Stimulus Sensory organs perception Sensory Memory
(millisecond-1)
attention
Short-Term Memory
Working Memory
(< 1 minute)
forgetting
repetition
Long-Term Memory
( days, months, years)

33. Learning & Memory Sensory Memory:
A sensory memory exists for each sensory channel:
iconic memory for visual stimuli
echoic memory for aural stimuli
haptic memory for touch
Information sensory memory short-term memory by attention, thereby filtering the stimuli to only those which are of interest at a given time.

34. Learning & Memory Short-term Memory:
acts as a scratch-pad for temporary recall of the information under process
can contain at any one time seven, plus or minus two, "chunks" of information
lasts around twenty seconds.

35. Warning- next slide short term memory test

36. Short-term Memory Quiz (30 sec)
eggs drawing rock apple focus mission favor ice
brain flag trial partner house life chair

37. Learning & Memory Long-term Memory:
intended for storage of information over a long time.
Short-termlong-term (rehearsal)
Little decay
Storage
Deletion- decay and interference
Retrieval-recall and recognition

38. Learning & Memory Long-term Memory: Why we forget:
fading (trace decay) over time
interference (overlaying new information over the old)
lack of retrieval cues.

39. Learning & Memory Encoding in Long-term Memory: Organizing Practicing
Spacing
Making meaning
Emotionally engaging

40. INQUIRY Where are merkel cells located? What do proprioceptors sense?
What type of stimulus triggers a response in nociceptors?
How much information can short term memory hold at any one time?
Where are second order neurons located?
What is phantom limb pain?
Give ways to store info in long-term memory.