Chapter 2 Definitions

Question 1

interneuron

Answer 1

a CNS neuron that forms an intermediate synaptic connection between other neurons

Question 2

nociceptors

Answer 2

specialized receptors on nerves that transmit pain impulses

Question 3

withdrawal reflex

Answer 3

a multisynaptic spinal reflex that is normally elicited by a noxious stimulus. Muscle groups are activated so that the body is moved away fromt he damaging stimulus

Question 4

pain threshold

Answer 4

the level of noxious stimulus required to alert the individual to possible tissue damage

Question 5

tract cells

Answer 5

second-order neurons of the pain and temperature pathways. The axons of these cells cross the midline of the spinal cord ans ascend in the anterior lateral fasciculus. Tract cells are sometimes called T cells, but this should not be confused with the T cells of the immune system

Question 6

limbic system

Answer 6

system in the brain that controls emotion

Question 7

radiant heat

Answer 7

heat that is gained or lost through the indirect transmission of energy

Question 8

analgesic

Answer 8

a pain-reducing substance

Question 9

ganglia

Answer 9

a cluster of neruons int he peripheral nervous system

Question 10

nucleus (nuclei)

Answer 10

a cluster of neurons in the CNS

Question 11

somatic

Answer 11

pertaining to the body

Question 12

transcutaneous

Answer 12

through the skin

Question 13

visceral

Answer 13

pertaining to organs of the body

Question 14

encapsulated receptor

Answer 14

a sensory receptor formed by a nerve fiber and surrounding connective tissue cells

Question 15

thalamus

Answer 15

gray matter in the center of the brain

Question 16

pacinian corpuscles

Answer 16

large encapsulated receptor organs found in the skin and deeper tissues. These rapid adapting receptors are best activated by an alternating stimulus, for example, a tuning fork. Within the joints, they assist in relaying proprioceptive information

Question 17

contralateral

Answer 17

pertaining to the opposite side fo the body. The left side is contralateral to the right

Question 18

dermatome

Answer 18

a segmental skin area supplied by a spinal nerve root

Question 19

ipsilateral

Answer 19

on the same side of the body

Question 20

anterior lateral system

Answer 20

the ascending fiber system that conveys pain and temperature sensation from spinal cord to the cerebral cortex. a major fiber bundle int his system of connections is the anterior lateral fasciculus

Question 21

dorsolateral fasciculus

Answer 21

(Lissauer’s tract) the small bundle of fibers in the dorsolateral spinal cord formed by ascending or descending primary afferent fibers that carry pain and temperature sensation

Question 22

medulla

Answer 22

the most caudal region of the brain stem. the medulla contains many cranial nerve nuclei and is also important in visceral control

Question 23

midbrain

Answer 23

the most rostral region of the brain stem. Involved in muscle control and modulation of pain. Also processes visual and auditory information

Question 24

nucleus cuneatus

Answer 24

a nucleus in the caudal medulla that relays fine touch and proprioceptive information from the upper body to the thalamus

Question 25

nucleus gracilis

Answer 25

a nucleus in the caudal medulla that relays fine touch and proprioceptive information fromt he lower body to the thalamus

Question 26

anterior lateral fasciculus

Answer 26

the large bundle of fibers int eh anterolateral spinal cord and brain stem that carry second-order pain fibers to the brain stem and thalamus. This bundle includes fibers that are often called the spinothalamic tract

Question 27

wide dynamic range cells (neurons)

Answer 27

nuerons in the spinal cord and thalamus that respond to a broad range of mechnaical pressures. They respond to both touch and pain

Question 28

epicritic pain

Answer 28

pain that is well localized

Question 29

forebrain

Answer 29

the cerebral hemispheres and thalamic region of the brain

Question 30

internal capsule

Answer 30

a massive band of ascending and descending fibers in the forebrain that connect the cerebral cortex to thalamus, brain stem, and spinal cord

Question 31

limbic system

Answer 31

system in the brain that controls emotion

Question 32

bilateral

Answer 32

on both sides of the body

Question 33

magnetic resonance image (MRI)

Answer 33

a view of the body’s internal structures obtained through the use of magnetic and radioi fields

Question 34

protopathic pain

Answer 34

poorly localized pain sensation

Question 35

sensitized

Answer 35

the process of being made sensitive to a specific substance

Question 36

somatosensory cortex

Answer 36

an area in the cerebral cortex, located in the postcentral gyrus of the parietal lobe, that is important in the perception of touch and proprioception and in the localization of pain sensation

Question 37

anesthesia

Answer 37

a loss of, or decrease in, sensation

Question 38

enkephalin

Answer 38

a substance released by the body that reduces the perception of pain by bonding to pain receptor sites

Question 39

efficacy

Answer 39

the ability of a modality or treatment regimen to produce the intended effects

Question 40

modulate (modulation)

Answer 40

to regulate or adjust

Question 41

sham

Answer 41

a device or “drug” that has no physiological effect on the body (eg, an ultrasound unit with the output intensity set to zero)

Question 42

ectopic

Answer 42

outside or away from its normal position; in an abnormal position or sequence

Question 43

neuroma

Answer 43

swelling or other mass formation around a nerve (neuro = nerve, oma = tumor).
Normally formed by connective cells instead of neurons

Question 44

neuropathy

Answer 44

destruction, trauma, or inhibition of a nerve