Sensory Function

Question 1

5 types of somatosensory receptors

Answer 1

1. mechanoreceptors
2. thermoreceptors
3. nocireceptors
4. proprioceptors
5. vestibular receptors

Question 2

mechanoreceptors

Answer 2

local tissue deformation in skin and viscera

Question 3

thermoreceptors

Answer 3

temperature in skin and brain

Question 4

nocireceptors

Answer 4

pain in skin, viscera, and muscle

Question 5

proprioceptors

Answer 5

movement and force in muscles and joints

Question 6

vestibular receptors

Answer 6

head acceleration and tilt

Question 7

types of sensory receptors

Answer 7

1. specialized endings of afferent axons

2. separate cells that respond to stimuli and synapse to afferent neurons

Question 8

how is stimulus intensity related to receptor potential

Answer 8

positively correlated

Question 9

how is receptor potential related to action potential

Answer 9

all or none response at a threshold

Question 10

how is stimulus intensity related to rate of action potentials

Answer 10

positively correlated

Question 11

3 examples of different types of mechanoreceptors

Answer 11

1. Ruffini corpuscles = warmth
2. Mekle’s corpuscles = touch
3. free nerve endings = pain

Question 12

frequency code

Answer 12

bigger stimulus = more membrane channels in sensory endings that are distorted

Question 13

population code

Answer 13

big stimulus = more sensory neurons recruited into activity

Question 14

temporal pattern code

Answer 14

variability of firing rate may mediate certain types of sensation

Question 15

2 main sensory axon types

Answer 15

1. Ia sensory

2. IV sensory

Question 16

are Ia sensory myelinated? what is their conduction velocity?

Answer 16

yes, 80-120 m/s

Question 17

are IV sensory myelinated? what is their conduction velocity?

Answer 17

no, 0.5-2 m/s

Question 18

associated sensory endings with Ia sensory

Answer 18

muscle spindle primary endings

Question 19

associated sensory endings with IV sensory

Answer 19

• nociceptors

- warmth thermoreceptors

Question 20

2 main types of motor axons

Answer 20

1. alpha motor

2. gamma motor

Question 21

are alpha motor myelinated? what is their conduction velocity

Answer 21

yes, 80-120 m/s

Question 22

are gamma motor myelinated? what is their conduction velocity

Answer 22

no, 4-24 m/s

Question 23

alpha motor muscle fibers

Answer 23

extrafusal muscle fibers

Question 24

gamma motor muscle fibers

Answer 24

intrafusal muscle fibers

Question 25

2 point discrimination test

Answer 25

determines the closest distance that you can differentiate as being 2 separate stimuli

Question 26

where is 2 point discrimination test best? where is it worst?

Answer 26

best = hands and face
worst = abdomen and proximal parts of limbs

Question 27

lateral inhibition

Answer 27

sharpens sensory contrast by focusing activation of neurons

Question 28

topographic maps

Answer 28

projection areas in sensory cortex are related to functional importance

Question 29

do topographic maps change?

Answer 29

yes, they are plasticity

Question 30

dynamic plasticity

Answer 30

topographic maps are now believed to constantly change