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Flashcards in Chapter 13 Deck (64)
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1

Peripheral Nervous System (PNS)

Provides links from and to world outside of body
All neural structures outside brain
Example
-Nerves

2

Sensory Receptors

Specialized to respond to changes in environment (stimuli)
Activation results in graded potentials that trigger nerve impulses

3

Sensation Vs. Perception

Sensation- Sensory Nerves- Touch
-Awareness of changes in environment
Perception- Either Brain or Spinal Cord- Thought
-Interpretation of changes in environment

4

Classification by Stimulus Type

Mechanoreceptors
Thermoreceptors
Photoreceptors
Chemoreceptors
Nociceptors

5

Mechanoreceptors

Movement, Pressure

6

Thermoreceptors

Temperature

7

Photoreceptors

Light

8

Chemoreceptors

Chemicals, Taste, Smell

9

Nociceptors

Pain, Spicy, Too Hot

10

Sensory Integration

Somatosensory system- part of sensory system serving body wall and limbs
Receives inputs from:
-Exteroceptors
-Proprioceptors
-Interoceptors
Input relayed toward head, but processed along way

11

Levels of Sensory Integration

Receptor Level
Circuit Level
Perceptual Level

12

Receptor Level

Sensory Receptors

13

Circuit Level

Processing in ascending pathways

14

Perceptual Level

Processing in cortical sensory areas

15

Processing at Receptor Level

To produce sensation
-Receptors activation
-Stimulus location
-Transduction occurs
Graded potentials must reach threshold

16

Adaptation of Sensory Receptors

Adaptation is change in sensitivity in presence of constant stimulus
-Receptor membranes become loss responsive
-Receptor potentials decline in frequency or stop

17

Processing at the Circuit Level

Pathways of 3 neurons conduct sensory impulses upward to appropriate cortical regions
First Order Sensory Neurons
Second Order Sensory Neurons
Third Order Sensory Neurons

18

First Order Sensory Neurons

From receptor to second neuron

19

Second Order Sensory Neurons

From spinal cord to third region

20

Third Order Sensory Neurons

Thalamus to perception or somatosensory system

21

Perception of Pain

To recognize outside threat- to warn us of danger

22

Pain Tolerance

Tolerance not threshold
"Sensitive to pain" means low pain tolerance, not low pain threshold
Genes help to determine pain tolerance
Response to pain medications

23

Hyperalgesia

Long lasting intense pain.
Same intensity but feels like hyper-stimulated

24

Phantom Limb Pain

Felt in a limb that is no longer present, like feeling a hand on the distal end of an amputated arm

25

Referred Pain

Pain from one body region perceived from different region
Example:
-Heart Attack- heart pain but felt in left arm and jaw
-Neck and shoulder pains

26

Structure of a Nerve

Connective Tissue Coverings
-Endoneurium- loose connective tissue
-Perineurium- coarse connective tissue
-Epineurium- tough fibrous sheath

27

Ganglia

Contain neuron cell bodies associated with nerves in PNS
Afferent nerve fibers- sensory neurons
Efferent nerve fibers- autonomic motor neurons

28

Regeneration of New Fibers

PNS- yes if cell body is intact
CNS- no

29

Cranial Nerves

12 Pairs; mixed nerves, numbered from 1 to 12

30

Olfactory Nerves

Smell: Olfactory Bulbs to Olfactory Cortex