Sensory, Motor,

1
Sensory, Motor, Integrative System
Ch 15
2

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

3
General Senses vs. Special Senses
Taste Smell Vision Hearing Balance
Pain Temperature Light touch Pressure Sense of
body and limb position
4
Sensory Receptors

• Mechanoreceptors
• Thermoreceptors
• Photoreceptors
• Chemoreceptors
• Nociceptors

5
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
6
Unencapsulated Nerve Endings
pain, light touch, and temperature

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

7
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)

8
Encapsulated Nerve Endings

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

9
Somatic Pain-results from injuries to skin,
muscle, joints, tendon
vs.Visceral Pain-
pain in body organs
Pain- protective function
10
Referred Pain-felt on the body surface
11
Skin
12
Skin Receptors
free nerve endings
Krauses End-Bulb
Meissners corpuscles
Pacinian corpuscles
root hair plexus
nerve
13
Somatic Sensory Pathway
14
Ascending Spinal Cord Tract
15
Descending Spinal Cord Tract
16
Primary Somatosensory Cortex Primary Motor Area
17
Primary Sensory Cortex
18
Primary Motor Cortex