Sensory Systems Overview

Question 1

Receives one form of energy (mechanical, thermal, chemical, or electromagnetic) and converts it to another (electrical)

Answer 1

Receptor/Transducer

Question 2

Exist in the form of membrane-bound protein complexes

Answer 2

Receptors

Question 3

Adequate Stimulus: Light

Answer 3

Sensory Modality: Visual

Question 4

Adequate Stimulus: Head movement

Answer 4

Sensory Modality: Vestibular

Question 5

Adequate Stimulus: Chemical

Answer 5

Sensory Modality: Gustatory/Olfactory/Itch

Question 6

Adequate Stimulus: Sound

Answer 6

Sensory Modality: Auditory

Question 7

Adequate Stimulus: Body Movement/position

Answer 7

Sensory Modality: Proprioception

Question 8

Adequate Stimulus: Thermal

Answer 8

Sensory Modality: Temperature

Question 9

Adequate Stimulus: Chemical/Mechanical/Thermal

Answer 9

Sensory Modality: Pain

Question 10

Adequate Stimulus: Pressure

Answer 10

Sensory Modality: Touch

Question 11

Receptor Cell: Rods/cones

Answer 11

Sensory Modality: Visual

Question 12

Receptor Cell: hair cells

Answer 12

Sensory Modality: Auditory/Vestibular

Question 13

Receptor Cell: Taste cells (in buds)

Answer 13

Sensory Modality: Gustatory

Question 14

Receptor Cell: Olfactory neurons

Answer 14

Sensory Modality: Olfactory

Question 15

Receptor Cell: Cutaneous mechano

Answer 15

Sensory Modality: Touch

Question 16

Receptor Cell: Muscle/joint mechano

Answer 16

Sensory Modality: Proprioception

Question 17

Receptor Cell: Cold/warm receptors

Answer 17

Sensory Modality: Temperature

Question 18

Receptor Cell: Nociceptor

Answer 18

Sensory Modality: Pain

Question 19

Receptor Cell: Chemoreceptor

Answer 19

Sensory Modality: Itch

Question 20

Least complicated receptor form

Answer 20

unencapsulated

Question 21

The “free” nerve ending loses its myelin sheath and is only separated from tissue by the Schwann cell and a basement membrane. Many of these respond to noxious and thermal stimuli, and are found throughout the body.

Answer 21

unencapsulated

Question 22

These receptors consist of an elaborate arrangement of tissues or specialized cells that receive the peripheral endings of nerve fibers.

Answer 22

encapsulated

Question 23

These specializations contribute to the response properties of the associated nerve endings to different forms of stimuli but the nonneural cells are not excitable. Examples include the Pacinian corpuscle and Meissner’s corpuscle.

Answer 23

encapsulated

Question 24

These receptors are electrogenic cells that become involved in the process of sensory transduction and their response depolarizes the attached nerve ending (e.g., cochlear hair cells)

Answer 24

Specialized

Question 25

Receptor responds to energy it is “tuned” to, and responds by changing ______.

Answer 25

membrane conductance

Question 26

A change in conductance leads to a change in _____.

Answer 26

potential

Question 27

A change in conductance can lead to the generation of an ______.

Answer 27

action potential

Question 28

Sensory receptors transduce one form of energy into electrical energy

Answer 28

stimulus transduction

Question 29

Distinct sensory experiences within a modality | Ex: sweet and sour of taste; colors of vision; warm and cool of temperature sense

Answer 29

Sensory Qualities

Question 30

The region within which a stimulus of proper modality and sufficient intensity will evoke an electrophysiological response in a sensory neuron

Answer 30

Neuron's Receptive Field

Question 31

The minimal energy level that is necessary to evoke a response (neuron) or a sensation (person)

Answer 31

Sensory Threshold

Question 32

______ leads to higher amplitude receptor potential (similar to post-synaptic potentials), greater frequency of action potentials, and recruitment of more receptors.

Answer 32

More intense stimulus

Question 33

The discriminability of stimuli within a sensory modality. It is determined by a combination of receptive field size and density of receptors

Answer 33

Acuity

Question 34

In general, stimulus intensity (magnitude) is encoded by frequency (nerve impulses/second) and population (number of receptors activated) codes

Answer 34

Stimulus Intensity Coding

Question 35

With many modalities, the strength of the stimulus is directly related to the receptor potential amplitude, and the action potential generation rate of the sensory neuron

Answer 35

Frequency Coding

Question 36

The duration that the receptor potential remains at threshold relative to the duration of the stimulus. All receptors ultimately show adaptation although some are very slow

Answer 36

Receptor Adaptation

Question 37

application of a stimulus will result in a response initially, but a rapid reduction and cessation of action potential generation, even when the stimulus is steadily maintained

Answer 37

Rapidly adapting receptors

Question 38

application of a stimulus results in a repetitive discharge in the primary afferent neuron as long as the stimulus is maintained, although rate of discharge gradually reduces over time

Answer 38

Slowly adapting receptors

Question 39

The smallest fibers are unmyelinated

Answer 39

C fibers

Question 40

Thicker axons are myelinated

Answer 40

A fibers

Question 41

The distance between the nodes of Ranvier is greater

Answer 41

A fibers

Question 42

_____ nerve fibers conduct action potentials more rapidly than ______ fibers and unmyelinated fibers

Answer 42

Large myelinated, smaller unmyelinated

Question 43

Large myelinated nerve fibers conduct action potentials more rapidly than smaller myelinated fibers and unmyelinated fibers. Why?

Answer 43

- The increased diameter of the myelin sheath produces a lower internal longitudinal resistance - Myelinated fibers propagate impulses by saltatory conduction; since larger fibers have longer internodes, conduction is more efficient

Question 44

Conduction velocity increases by about 6 meter/sec per one micrometer increase in _____

Answer 44

fiber diameter

Question 45

As a nerve bundle is compressed, action potential block occurs first with _____ fibers, and progressively with ______ fibers over time

Answer 45

larger, smaller

Question 46

As local anesthetics are applied to a nerve bundle, the first fibers affected are the _____ axons, and progressively l_____ fibers are blocked over time

Answer 46

unmyelinated, larger

Question 47

The reduction in response rate with continuous stimulation

Answer 47

adaptation