Chapter 5: sensorimotor system

Question 1

receptor cell

Answer 1

sense form of energy or substance, internal or external, than converts into a change in the electrical potentials across its membrane(acts as a filter)

Question 2

labeled lines

Answer 2

particular neurons that are labeled for distinctive sensory experiences

Question 3

receptor potential

Answer 3

change in the resting potential of a receptor cell in response to stimuli, which may initiate an action potential

Question 4

sensory transduction

Answer 4

converting environmental stimuli into action potentials the brain can understand

Question 5

somatosensory system

Answer 5

body sensations:
can determine whether body
sensations arise from outside or within the body

ca ndetermine whether body sensations arise from outside or in the body

Question 6

receptive field

Answer 6

stimulus region and features that affect the activity of a cell in a sensory system

Question 7

sensory adaptation

Answer 7

progressive decrease in a receptors response to sustained stimulation

Question 8

phasic receptors

Answer 8

frequency of action potentials drops rapidly as stimulation is maintained

Question 9

tonic receptors

Answer 9

frequency of action potentials decline slowly or not at all as stimulation is maintained

Question 10

central modulation of sensory information

Answer 10

higher brain centers, such as the cortex and thalamus, suppress some sources of sensory information and amplify others

Question 11

dermatome

Answer 11

a strip of skin innervated by a particular spinal nerve

Question 12

primary sensory cortex

Answer 12

generally the initial destination of sensory inputs to the cortex

Question 13

polymodal neurons

Answer 13

a neuron upon which information from more than one sensory system converges

Question 14

synesthesia

Answer 14

a filter, that only the most important stimuli are selected for special processing

Question 15

pain

Answer 15

an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

Question 16

nociceptors

Answer 16

respond to stimuli that produce tissue damage or pose the threat of damage

Question 17

A delta fibers

Answer 17

large, myelinated, and fast-conducting axon that usually transmits pain info

Question 18

C fibers

Answer 18

small, unmyelinated axon that conducts pain information slowly and adapts slowly

Question 19

anterolateral system

Answer 19

somatosensory system that carries most of the pain and temperature information from the body to the brain

Question 20

substance P

Answer 20

peptide transmitter that is involved in pain transmission

Question 21

neuropathic pain

Answer 21

pain that persists long after the injury that started it has healed

Question 22

analgesia

Answer 22

absence of or reduction of pain

Question 23

endorphines

Answer 23

endogenous opioid

Question 24

transcutaneous electrical nerve stimulation

Answer 24

mild electrical stimulation is applied to nerves around the injury sites to relieve pain

Question 25

motor plan

Answer 25

complex set of commands to muscles that is established before an act occurs

Question 26

electromyography (EMG)

Answer 26

electrical recording of muscle activity

Question 27

synergists

Answer 27

a muscle that acts together with another muscle

Question 28

neuromuscular junctions

Answer 28

where the motor neuron terminal meets its target muscle fiber and transmits messages

Question 29

motor neurons

Answer 29

final common pathway, sole route through which the spinal cord and brain can control many muscles

Question 30

proprioception

Answer 30

body sense; information about the position and movement of the body (muscle spindle and golgi tendon organs)

Question 31

muscle spindle

Answer 31

signals the central nervous system when the muscle is lengthened

Question 32

intrafusal fiber

Answer 32

any of the small muscle fibers that lie within each muscle spindle

Question 33

golgi tended organs

Answer 33

sends impulses to the central nervous system when a muscle contracts/ sensitive to muscle tension

Question 34

pyramidal (corticospinal) system

Answer 34

includes neurons within the cerebral cortex and their axons, which form the pyramidal tract

Question 35

extrapyramidal system

Answer 35

axons of this system pass into the spinal cord outside the pyramids of the medulla, interfere with spinal reflexes, and systems that regulate and fine-tune motor behavior

Question 36

primary motor cortex M1

Answer 36

apparent executive region for the initiation of movement primarily the precentral gyrus

Question 37

nonprimary motor cortex

Answer 37

contribute to motor control and modulate the activity of the primary motor cortex (supplementary motor area and premotor cortex)

Question 38

supplementary motor area

Answer 38

receives input from the basal ganglia and modulates the activity of the primary motor cortex (initiation of movement)

Question 39

plegia

Answer 39

paralysis

Question 40

paresis

Answer 40

weakness

Question 41

apraxia

Answer 41

inability to carry out complex movements even though paralysis or weakness is not evident and language comprehension and motivation are intact

Question 42

two most important sources of extrapyramidal fibers

Answer 42

1. basal ganglia: amplitude, direction, and initiation of movement from memory 2. cerebellum: skilled movements (rapid, repeated movement that become automatic)

Question 43

ataxia

Answer 43

loss of coordination

Question 44

decomposition of movement

Answer 44

gestures are broken up into individual segments instead of being smooth

Question 45

parkinsons disease

Answer 45

progressive deteriotion of dopamine-containing cells in the substantia nigra (slow movement, hand tremors, rigid bearing, diminished facial expressions

Question 46

transient receptor potential vanilloid type 1 (TRPV 1)

Answer 46

detects heat

Question 47

hyperalgesia

Answer 47

following a painful stimulus associated with tissue damage, stimuli in the area of the injury and the surrounding region are perceived as significantly more painful

Question 48

basal ganglia

Answer 48

modulate movement, amplitude and direction of movement -movement performed by memory rather than by sensory control

Question 49

peripheral sensitization

Answer 49

interaction of nociceptors with the "inflammatory soup" of substances released when tissue is damaged

Question 50

central sensitization

Answer 50

rapid onset, activity-dependent increase in the excitability of neurons in the dorsal horn of the spinal cord following high levels of activity in the nociceptive afferents

Question 51

cerebellum

Answer 51

receives inputs from sensory sources and other brain motor systems -guides movement through inhibition -helps fine tune skilled movements

Question 52

Huntington's disease

Answer 52

clumsiness, twitches, involuntary jerks (damage to caudate nucleus and putamen in basal ganglia)