Sensory Perception and Transmission in Nervous System

Question 1

visceral

Answer 1

in internal organs of body

Question 2

somatic

Answer 2

pertaining to the body

Question 3

importance of sensory input on psyche

Answer 3

vital to integrity of personality and intellectual function

Question 4

sensory receptor

Answer 4

a structure specialized to detect a stimulus; participates in transduction

Question 5

sense organ

Answer 5

nerve tissue surrounded by other tissues that enhance response to a certain type of stimulus – may include accessory tissue (epithelial, muscular, connective)

Question 6

transduction

Answer 6

transforming one type of signal into another; conversion of one kind of energy to another

Question 7

receptor potential

Answer 7

small local electrical change on a receptor cell brought about by a stimulus; makes action potential occur when receptor potential rises above threshold

Question 8

Sensory receptors transmit four kinds of information

Answer 8

modality (type of sensation), location, intensity, duration

Question 9

Sensation

Answer 9

a subjective awareness of the stimulus

Question 10

Types of Sensory Receptors

Answer 10

1. Mechanoreceptors
2. Thermoreceptors
3. Nociceptors
4. Electromagnetic
5. Chemoreceptors

Question 11

Mechanoreceptors

Answer 11

detect deformation

Question 12

Thermoreceptors

Answer 12

detect change in temperature

Question 13

Nociceptors

Answer 13

detect damage (pain receptors)

Question 14

Electromagnetic

Answer 14

detect light

Question 15

Chemoreceptors

Answer 15

taste, smell, CO2, O2 etc.

Question 16

free nerve ending

Answer 16

pain and temp., not encapsulated, located in skin and mucous membrane

Question 17

expanded tup receptor

Answer 17

sense light touch and texture, in epidermis, tactile discs

Question 18

tactile hair

Answer 18

can detect movement of hair, epidermis and dermis, mechanoreceptor

Question 19

Pacinian corpuscle

Answer 19

deep pressure, stretch, tickle, vibration; deep tissue sensibility

Question 20

Meissner’s Corpuscle

Answer 20

light touch and texture; hairless skin, epidermis and dermis

Question 21

Krause’s Corpuscle

Answer 21

tactile, mucous membrane; epidermis and dermis

Question 22

Ruffini’s End-Organ

Answer 22

heavy touch, pressure, joint movements, skin stretching; deeper tissue

Question 23

Golgi Tendon Apparatus

Answer 23

tendon stretch, deep tissue, located at muscle endings

Question 24

Muscle Spindle

Answer 24

responsible for sensing muscle movement; located at muscle endings; deep tissue

Question 25

Generation of receptor potential by mechanical distortion

Answer 25

1. Mechanical distortion increases Na+ conductance.
2. receptor potential
3. action potential

Question 26

adaptation

Answer 26

receptor decreases frequency of impulse in response to sustained stimulation

Question 27

tonic receptors

Answer 27

slow adaptation (hours, days)

Question 28

tonic receptor examples

Answer 28

muscle spindle, Golgi tendon apparatus, Ruffini endings, Merkel discs, Macula, pain, temperature, baroreceptors, chemoreceptors, muscle contraction

Question 29

phasic receptors

Answer 29

rapid adaptation; responds only to the change

Question 30

examples of phasic receptors

Answer 30

pacinian corpuscle, meissner’s corpuscle, semicircular canals

Question 31

gradation in signal intensity can be achieved by:

Answer 31

1. spatial summation

2. temporal summation

Question 32

spatial summation

Answer 32

increasing number of fibers stimulated in a particular area

Question 33

temporal summation

Answer 33

increasing rate of firing in given fibers

Question 34

nociception

Answer 34

pain

Question 35

when does nociception occur?

Answer 35

when tissue is being damaged

Question 36

Types of Pain (Nociception)

Answer 36

1. Fast Pain

2. Slow Pain

Question 37

Fast Pain

Answer 37

body surface
felt within 0.1 s after stimulus
sharp pain: (knife cut, needle poke, burn).
Not felt in most deeper tissues

Question 38

Slow Pain

Answer 38

body surface or deeper tissue
felt after 1 s or more
throbbing or aching pain
Usually associated with tissue destruction (bradykinin).

Question 39

main cause of pain from tissue damage

Answer 39

bradykinin

Question 40

dual pain pathways

Answer 40

1. fast pain (1st pain) transmitted by type A delta fibers (6-30 m/s) in neospinothalamic tract
2. slow pain (2nd response) transmitted by type c fibers (0.5 - 20 m/s) in the paleospinothalamic tract

Question 41

Neospinothalamic Tract

Answer 41

1. On entering cord, pain fibers may travel up or down 1-3 segments and terminate on neurons in dorsal horn.
2. 2nd neuron crosses immediately to the opposite side and passes to the brain in the anterolateral columns.
3. 3rd order neurons go to the cortex.

Question 42

excitatory transmitter of A-delta pain fiber nerve ending.

Answer 42

Glutamate

Question 43

Neospinothalamic Tract: Some neurons terminate in the _____ but most go all the way to the ______

Answer 43

reticular substance; ventrobasal complex of the thalamus.

Question 44

Paleospinothalamic tract

Answer 44

1. Type C pain fibers terminate in laminae II & III of spinal cord.
2. 2nd neuron crosses immediately to the opposite side and passes to the brain in the anterolateral columns.

Question 45

excitatory transmitter of type C pain fiber nerve ending.

Answer 45

Substance P

Question 46

Endogenous opioids

Answer 46

internally produced opium-like substances; Act as neuromodulators that block pain and give pleasure

Question 47

Enkephalins

Answer 47

two analgesic oligopeptides with 200 times the potency of morphine

Question 48

Endorphins and dynorphins

Answer 48

larger analgesic neuropeptides discovered later

Question 49

endogenous analgesic secreted by:

Answer 49

CNS, pituitary gland, digestive tract, and other organs

Question 50

______ is used to counter the effects of opiate overdose (heroin, morphine, etc)

Answer 50

Naloxone