Intro to Sensory Systems pp

Question 1

Mechanoreceptor examples

Answer 1

Encapsulated nerve endings in the skin
Hair cells in the cochlea & vestibule
Thermoreceptors
Photoreceptors
Chemoreceptors
Nociceptors

Question 2

Receptor specificity

Answer 2

Normal is only affected by one stimulus

Question 3

Receptor potential

Answer 3

membrane potential produced by transducer - local graded potential

Question 4

Action potential

Answer 4

Created when depolarization reaches threshold, rate can increase as receptor potential rises

Question 5

How do we know what stimulus is

Answer 5

Labeled line principle
Sensory modalities
Synesthesia

Question 6

Labeled line response

Answer 6

Chain connects neurons from sensory receptors to the brain AREA that responds to stimulus

Question 7

Sensory modalities

Answer 7

Vision
Hearing
Taste
Smell
Feel
Proprioception

Question 8

How we know where stimulus is coming from

Answer 8

Receptive field of a neuron is the region of tissue, evoke change in firing rate

Question 9

Stimulus duration

Answer 9

Continuous signal

On/Off signal

Question 10

Stimulus strength

Answer 10

Increase frequency of nerve impulses

Increase number of fibers activated

Question 11

Non adapting receptor

Answer 11

Nocireceptors

Question 12

Slowly adapting receptors

Answer 12

AKA Tonic receptors

Merkels, useful for giving continuous info about stimulus strength & duration

Question 13

Rapidly adapting receptors

Answer 13

AKA Phasic receptors or rate receptors
Pacinian
Meissner’s
Useful for beginning and end stimulus. Disadvantage cannot give continuous signal

Question 14

Tactile Sensations

Answer 14

Touch Crude & Light
Discriminitive
Pressure/Deep touch
Vibration

Question 15

Free nerve endings

Answer 15

Crude Touch
Low threshold mechanoreceptors
Encapsulated ending of myelinated fibers II and Abeta or merkel

Question 16

Merkel’s Disks

Answer 16

Base of epidermis
Iggo dome, group together, innervated by one Abeta
Merkel cell afferent SAI
25% in hand
Highest spatial resolution

Question 17

SAA II

Answer 17

Ruffini afferent
Stretch of skin
20%

Question 18

Meissner’s corpuscles

Answer 18

RA1
40% nonsensory hand
High at finger tips
Closer to skin surface than Merkel's disks
Vibration 30-50 Hz
Detects slippage

Question 19

Pacinian Corpuscles

Answer 19

Rapidly adapting faster than Meissner’s
250-350 Hz
Found in subcutaneous tissue

Question 20

Hair End Organ

Answer 20

Peritrichial nerve ending.
Stimulated by slight movement of hair
Adapts rapidy slower Adelta
Detects movement

Question 21

Active tactile exploration

Answer 21

Need relative movement btw skin. Accurate discrimination periphery receptors must be influenced by motor signals

Question 22

Other sensations

Answer 22

Cold
Warmth
Pain
Itch
Free nerve ending C fibers

Question 23

Two point discrimination

Answer 23

Test depends on receptive fields and where

Question 24

Proprioception

Answer 24

sense of self

Info from joint angles, muscle length & muscle tension, input w/ vestibular input

Question 25

Importance of proprioception

Answer 25

Maintain balance Control limb movement evaluate shape

Question 26

Dorsal Column

Answer 26

aka Posterior column Fine tactile discrimination, vibratory sense Proprioceptive Precise localization

Question 27

Lesion in dorsal column causes

Answer 27

Deficits in tactile, vibratory and proprioception

Question 28

Anterolateral System

Answer 28

Nociception transmitted, crosses midline at spinal cord

Question 29

Somatosensory SI

Answer 29

Brodmann areas 3b/a, 1, 2

Question 30

SII

Answer 30

Show attention modulated responses

Question 31

Nerve Pressure Palsy

Answer 31

Affected limb falls asleep

Question 32

Spinal root injuries

Answer 32

Impairment of cutaneous sensation not all lost because of over lap Peripheral neuropathies Stocking glove patter

Question 33

Brown Sequard

Answer 33

Hemisection of spinal cord

Question 34

Aa

Answer 34

100m/s | 1 muscle spindle primary Ia & GTO Ib

Question 35

Ab

Answer 35

50 m/s muscle spindle 2 axons of cutaneous mechanoreceptors

Question 36

Ay

Answer 36

gamma motor neuron muscle spindle fibers

Question 37

Ad

Answer 37

fast pain some temp

Question 38

B

Answer 38

sympathetic preganglionic axon

Question 39

C

Answer 39

Slow pain some temp | and sympathetic post ganglionic axons