Sensory, Motor,

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Sensory, Motor, Integrative System
Ch 16
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• Sensation
• The conscious or subconscious awareness of
  external or internal stimuli.
• Perception
• The conscious awareness and the interpretation of
  meaning of sensations.

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

• Mechanoreceptors
• Thermoreceptors
• Photoreceptors
• Chemoreceptors
• Nociceptors
• Osmoreceptors

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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
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Unencapsulated Nerve Endings
pain, light touch, and temperature

• Free Nerve Endings - Pain Temperature
• Merkels Discs - Light Touch Pressure
• Root Hair Plexuses - Light Touch

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Encapsulated Nerve Endings

• Pacinian Corpuscles - Deep Pressure
• Meissners Corpuscles - Discriminative Touch in
  Hairless Skin Areas
• Krauses End-Bulbs - Discriminative Touch in
  Mucous Membranes
• Ruffinis Corpuscles - Deep Pressure Stretch
  (Proprioception)

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The Epidermis
Merkel Cells- slow mechanoreceptors (basal layer)
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Skin Receptors
free nerve endings
Merkel disc
Meissners corpuscles
Ruffini corpuscle
root hair plexus
Pacinian corpuscles
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Encapsulated Nerve Endings

• Muscle Spindles - Skeletal Muscle Stretching
  (Proprioception)
• Golgi Tendon Organs - Tendon Stretching
  (Proprioception)

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Muscle Spindle
Tendon Organ
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Somatic Pain-results from injuries to skin,
muscle, joints, tendon
vs.Visceral Pain-
pain in body organs
Pain- protective function
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Referred Pain-felt on the body surface
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Somatic Sensory Pathway
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Ascending Spinal Cord Tract
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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
  ofcerebrum

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Descending Spinal Cord Tract
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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

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Primary Somatosensory Cortex Primary Motor Area
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Primary Sensory Cortex
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Primary Motor Cortex
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Stages of Sleep
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Learning Memory
Stimulus
Sensory organs
perception
Sensory Memory (millisecond-1)
 
attention
Short-Term Memory Working Memory (lt 1 minute)
forgetting
repetition
Long-Term Memory ( days, months, years)
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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.

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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.

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Short-term Memory Quiz (30 sec)
brainflagtrialpartnerhouselifechair
eggsdrawingrockapplefocusmissionfavorice
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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

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Learning Memory

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

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Learning Memory

• Encoding in Long-term Memory
• Organizing
• Practicing
• Spacing
• Making meaning
• Emotionally engaging

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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.