Peripheral Structures of the Somatosensory System N18 Flashcards Preview

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Flashcards in Peripheral Structures of the Somatosensory System N18 Deck (72)
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1

Somatosensory function

receive, process, and relay sensory information from the skin, muscles, and joints to the cerebral cortex for CONSCIOUS appreciation of the information

2

Some neural systems involve UNCONSCIOUS sensory processing

these involve the cerebellum

3

Discriminative touch recognizes:

size, shape, and texture of objects and their movement across the skin

4

Discriminative touch is greatest:

tactile sensitivity is greatest on hairless skin of fingers, palms, sole of feet, and lips

5

Proprioception

Sense of static position and movement of the limbs and body

6

Temperature sense

warmth and cold perception

7

Nociception

perceived as pain or itch, tissue damage or chemical irritant, NOT overstimulation of generalized cutaneous receptors but stimulation of certain nociceptors

8

Epicritic sensations involve

fine aspects of touch (highly localized and discriminative), mediated by encapsulated receptors (specialized function in the dermis and epidermis)

9

Epicritic sensations include

detection and localization of gentle skin contact, vibration frequency and amplitude, touch spatial detail (texture, distance between two simultaneous stimuli), recognition of grasped object

10

Protopathic sensations involve

pain, temperature, tickle, itch

11

Protopathic sensations include

crude, more intense stimuli, poorly localized, non-discriminative; mediated by free nerve ending receptors

12

Enteroceptors

conscious appreciation of sensations from external stimuli to our body

13

Proprioceptors

receive information about the relative position of our body in space (kinesthesia: movement sense)

14

Conscious proprioception is relayed to

cerebral cortex

15

Unconscious proprioception is relayed to

cerebellum

16

Interoceptors

processing of visceral information

17

Mechanoreceptors function

respond to mechanical deformation

18

Mechanoreceptors

Meissner's Corpuscle (S), Merkel's disc (S), Pacinian Corpuscle (D), Ruffini ending (D)

19

Meissner's Corpuscle

SUPERFICIAL - surrounds flattened epithelial cells and responds to FINE mechanical sensitivity

20

Merkel Disc

SUPERFICIAL - center of papillary ridge surrounded by epithelial cells, signals PRESSURE and SHAPE of objects

21

Pacinian Corpuscle

DEEP - CT lamellae surround nerve ending, responds to VIBRATORY stimuli

22

Ruffini Ending

DEEP - links subcutaneous to folds in skin, senses LATERAL movement and STRETCH of skin, and perception of SHAPE of grasped objects

23

Proprioreceptors

Change in position and movement

24

Proprioreceptors include

cutaneous mechanoreceptors (Ruffini Endings), joint receptors, muscle spindles, golgi tendon organs

25

Thermoreceptors

detect change in temperature and pain, only within a narrow temperature range (separate distinct receptors for warm and cold)

26

Once outside of the narrow temperature range for thermoreceptors, what receptors detect temperature?

Thermal nociceptors

27

Nociceptors

respond to stimuli that could damage tissue (3 classes)

28

3 classes of nociceptors

Mechanical: intense pressure applied to skin
Thermal: extreme temperatures
Polymodal: respond to a wide range of stimuli

29

Encapsulated receptors

surrounded by CT wrappings

30

Nonencapsulated receptors

not associated with CT wrapping