Sensory, Motor, & Integrative System

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

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

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. 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. 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

28. Primary Motor 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 • 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) brainflagtrialpartnerhouselifechair eggsdrawingrockapplefocusmissionfavorice

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.