11 Sensory Receptor Mechanisms and Central Processing

Question 1

exteroreceptors

Answer 1

convey information about the external environment

Question 2

interoreceptors

Answer 2

convey information about the internal environment

Question 3

sensory modality

Answer 3

differentiates one type of sensation from the others

Question 4

the receptor for pain is

Answer 4

naked nerve endings

Question 5

this sensation (modality) responds to mechanoreceptors, thermoreceptors, and nocioceptors

Answer 5

pain

Question 6

sensory unit

Answer 6

a single sensory nerve and the receptor/receptors to which it responds

Question 7

receptive field

Answer 7

area of response for the receptor(s) in each separate sensory unit

Question 8

transduction

Answer 8

converting energy of the stimulus into electrical energy in the nervous system

Question 9

adequate stimulus

Answer 9

the specific stimulus that normally activates a particular type of sensory receptor (i.e. the visual spectrum); it produces a graded electrical potential in the receptor

Question 10

generator potential

Answer 10

when the receptor is the sensory nerve ending itself

Question 11

receptor potential

Answer 11

when the receptor cell is non-neural

Question 12

all or none action potential

Answer 12

generator potential depolarizes sensory nerve beyond threshold

Question 13

pacinian corpuscle consists of

Answer 13

free nerve surrounded by layers of connective tissue

Question 14

pacinian corpuscle responds to

Answer 14

touch and pressure

Question 15

deforming a pacinnian corpuscle causes___

Answer 15

Na+ channels to open, influx of Na+, depolarization

Question 16

receptor potentials may be ____ or _____

Answer 16

hyperpolarizing or depolarizing

Question 17

sensory adaptation/accommodation

Answer 17

when receptor potential declines due to continued pressure

Question 18

phasic/velocity receptors

Answer 18

quickly adapting; identify the rate at which a stimulus changes

Question 19

the pacinian corpuscle is a ____ receptor

Answer 19

phasic

Question 20

tonic/intensity receptors

Answer 20

slowly adapting; fire for as long as the stimulus is applied, show slow adaptation; i.e. pain signals, proprioceptors in muscles, tendons, and ligaments

Question 21

the amplitude of the generator or receptor potential is proportional to the ____ of the stimulus strength

Answer 21

logarithm

the receptor can respond to a very wide range of stimuli

Question 22

intensity of stimulus is determined by

Answer 22

the frequency of firing of nerve action

Question 23

population code says

Answer 23

the stronger the stimulus, the more receptors activated

Question 24

e.g. first order neuron

Answer 24

DRG (dorsal root ganglion)

Question 25

e.g. second order neuron

Answer 25

dorsal column nuclei

Question 26

receptive field first order neuron

Answer 26

area on skin where applied pressure excites the neuron

Question 27

second order neuron

Answer 27

dorsal column nuclei - receptive field changes shape and now has an excitatory center with inhibitory surround

Question 28

lateral inhibition

Answer 28

to enhance the boundaries of contrast between incoming sensory signals; a region of excitation surrounded by a inhibition

Question 29

third order neuron

Answer 29

thalamus

Question 30

generator potential

Answer 30

may generate a train of action potentials