Exam 1 - Chapter 3 - Part 1

Question 1

3 basic properties of sensory receptors and afferent pathways

Answer 1

adequate stimulation
intensity coding
sensory adaptation

Question 2

adequate stimulation

Answer 2

Process by which sensory receptors inform the CNS that a particular sensory event has occurred in the environment (e.g., sound, touch)

Question 3

intensity coding

Answer 3

means by which we can determine the intensity with which a particular sensory event occurred

-property that enables us to distinguish between different sensations (hard slap, light tap)

Question 4

spatial summation

Answer 4

the stronger the stimulus the larger the number of different sensory receptors that fire (amt of neurons firing)

Question 5

temporal summation

Answer 5

the stimulated receptors are fired at a higher frequency

one post synoptic potential is so active that it becomes so frequent

summation is determined by how many neurons are fired & frequency (pic)

Question 6

sensory adaptation

Answer 6

means by which we are able to block out irrelevant sensory information
(shortly after a sensory receptor registers a stimulus, the firing rate is reduced)

different sensory receptors adapt at different rates: touch and pressure receptors vs. pain receptors and certain proprioceptors
(different adaption rates of receptors determines the nature of the information)

Question 7

somatosensation

Answer 7

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

primary receptors involved in somesthesia

• cutaneous receptors (skin)
• proprioceptors (perception of lends)

Question 8

cutaneous receptors

Answer 8

mechanoreceptors (mechanically stimulated)

• stimulated by physical deformation or displacement of tissues
• pressure changes

disproportionate distribution

• lips & fingers vs. legs & trunk
• greater densities in areas of the body required to perform fine movements

Question 9

proprioceptors

Answer 9

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

proprioceptive information = kinesthesis

include:

• muscle spindles
• golgi tendon organs
• joint receptors

Question 10

Meissner’s Corpuscles

Answer 10

Connective tissue sheaths & hairless portions of skin/Light touch/adapting rapidly

Question 11

Merkel’s Disks

Answer 11

Near Meissner’s corpusles/ Constant contact/slow movement across the skin/adapting slowly

Question 12

Pacinian Corpuscles

Answer 12

Deep Tissue, tendons, ligaments/Deep pressure/adapting quickly

Question 13

Ruffini’s ending

Answer 13

sensory nerve endings found in the dermis and in subcutaneous tissue, once thought to mediate the sense of warmth, now believed to be a pressure receptor

Question 14

free nerve endings

Answer 14

brings information from the body’s periphery toward the brain