Ch. 3

Question 1

Transductino

Answer 1

Environmental Energy > Electrical Impulses (Sensory receptors)

Question 2

General properties of sensory receptors and afferent pathways

Answer 2

adequate stimulation
intensity coding
sensory adaption

Question 3

Adequate stimulation

Answer 3

sensory receptors inform the CNS that a particular event has occurred in the environment
sensory receptors respond to specific stimuli
Receptors are activated when an event raised the receptors resting level high enough to generate sensory impulses

Question 4

Intensity Coding

Answer 4

Allows identifying the intensity of a particular sensory event
The intensity of a stimulus can be conveyed by two mechanisms
-Spatial summation: Increase stimulus = increase number of different sensory receptors that fire
-Temoral Summation: increase stimulus = increase frequency receptors fire

Question 5

Spatial Summation

Answer 5

Intensity Coding

increase number of different sensory receptors that fire

Question 6

Temporal Summation

Answer 6

Intensity Coding

increase stimulus = increase frequency receptors fire

Question 7

Sensory Adaption

Answer 7

Allows blocking out a irrelevant sensory information
-shortly after a sensory receptor registers a stimulus, the firing rate is reduced
Different sensory receptors adapt at different rates
-touch/pressure receptors (fast) v. pain receptors (slow)
Different adaption rates of receptors determines the nature of the information

Question 8

Transmission and Integration

Answer 8

Afferent pathways
First stage of integration occurs at the thalamus
-sensory relay center
-gating out irrelevant information
-emotional response (via the limbic system)

Question 9

Kinesthesis

Answer 9

Conscious awareness

Question 10

Dorsal Column System

Answer 10

fine touch, touch, skin vibration, and limb position

fast transmission

Question 11

Spinothalamic

Answer 11

pain, temperature

slow transmission

Question 12

Transmission and Integration- Info goes to?

Answer 12

Information goes to the cortex
Results in conscious awareness of sensations
Final perception and interpretation
Memory assisted

Question 13

“Subconscious” Awareness

Answer 13

Spinocerebellar tract
Information goes to cerebellum
leads to a subconscious perception of limb position

Question 14

Somatosensation

Answer 14

bodily sensation of touch, pain, temperature, and limb position

Primary receptors (mechanoreceptors)
Cutaneous receptors 
Proprioceptors
-Muscle spindles
-GTO
-Joint receptors

Question 15

Cutaneous Receptors

Answer 15

In your skin
Disproportionate distribution
-Lips and fingers v. legs and trunk
-Greater densities in areas of the body required to perform fine movements 
ex. hands, face (lips)

Question 16

Four types of Cutaneous Receptors

Answer 16

Sensory Nerve Fibers
Meissner’s Corpuscles
Merkel’s Disks
Pacinian Corpuscles

Question 17

Sensory Nerve Fibers

Answer 17

Cutaneous Receptors

Epithelial tissue/touch & pressure

Question 18

Meissner’s Corpuscles

Answer 18

Cutaneous Receptors

Connective tissue sheaths & hairless portions of skin/light touch

Question 19

Merkel’s Disks

Answer 19

Cutaneous Receptors

Near Meissner’s corpuscles/constant contact

Question 20

Pacinian Corpuscles

Answer 20

Cutaneous Receptors

Deep tissue, tendons, ligaments/deep pressure

Question 21

Cutaneous Cues

Answer 21

Direct the leaner’s attention to the appropriate cutaneous information
“feel your wight on your back foot”
“lightly squeeze the trigger”

Question 22

Proprioceptors

Answer 22

Mechanoreceptors in muscles, tendons, ligaments, joints and the vestibular apparatus (inner ear)

Includes: muscles spindles(most important for kinesthesis), golgi tendon organs, joint receptors

Question 23

Muscle Spindles

Answer 23

The most important source of kinesthesis
Serve both sensory (awareness) and motor function (control of fine movements)
Higher number of spindles are located involved in fine movements (hands, etc) *does not lead to higher acuity

Question 24

Extrafusal

Answer 24

produce muscular contraction
alpha motor neurons
no sensory afferent pathway

Question 25

Intrafusal

Answer 25

muscle fiber comprising the spindle
gamma motor neurons
primary (la) sensory neuron (length and velocity)
secondary (ll) sensory neuron (length)

Question 26

Neuronal control of spindle

Answer 26

Alpha - to extrafusal
Gamma - to intrafusal

Afferent - sensory neurons moving away from the spindle
– la (length and velocity) and ll (length)

Question 27

Muscle Spindles (2)

Answer 27

Gather information about muscle length

• signal absolute muscle length
• signal the rate of change in muscle length

Contribute to the regulation of muscle length

Question 28

Golgi Tendon Organs

Answer 28

Located at myotendinous junctions
Detect muscle tension
-Rate and absolute amount
-Activated with active contraction or passive lengthening
-Theshold: 1 gram

Question 29

Golgi Tendon Organs (2)

Answer 29

Tend to be inhibitory in nature

• produce muscle relaxation
• protective mechanism

Question 30

Joint Receptors

Answer 30

Located in joint capsules and ligaments
Provide info about: static position of a joint in space, endpoint positions of joints during active movement
Small contributor to conscious awareness

Question 31

Perception of Muscular Force or Effort

Answer 31

GTO’S: first source of muscular force or effort

Corollary discharge: copy of descending motor commands being sent to the higher-order sensory centers