Chapter 11

Question 1

Somatotopic

Answer 1

Information arranged similarly to the anatomic organization of the body

Question 2

Low-accuracy pathway

Answer 2

Not organized somatotopically, not well localized
Ex. Aching pain

Question 3

Projection neurons

Answer 3

Neurons with long axons

Question 4

Bundle of axons in CNS

Answer 4

Tract, column, lemniscus, fascicle

Question 5

Somatosensory pathways are typically named for…

Answer 5

The origin and termination of the tract that contains the second order neuron

Question 6

3 types of pathways

Answer 6

Conscious relay pathways
Divergent pathways
Non-conscious relay pathways

Question 7

Conscious relay pathway

Answer 7

Brings info about location and type of stimulation to conscious awareness in the cerebral cortex
Convey light touch, proprioception, nociception, and temperature info

Question 8

Divergent pathway

Answer 8

Transmits info to many locations in the brainstem and cerebrum, uses pathways with varying numbers of neurons
Ex. Aching pain

Question 9

Nonconscious relay pathway

Answer 9

Brings non conscious proprioceptive and other movement into to the cerebellum

Question 10

Dorsal columns

Answer 10

Carry sensory information about light touch and conscious proprioception

Question 11

Anterolateral columns

Answer 11

Carry sensory info about nociception and temperature

Question 12

Conscious proprioception

Answer 12

Awareness of movements and of relative position of body parts

Question 13

Stereognosis

Answer 13

The ability to integrate touch and proprioceptive info to identify an object without vision

Question 14

Dorsal column medial lemniscus pathway

Answer 14

Pathway that conveys light touch and conscious proprioception

Question 15

DCML pathway 3 neuron relay

Answer 15

1 order: conveys info from receptors to medulla
2 order: conveys info from medulla to thalamus
3 order: conveys info from thalamus to cerebral cortex

Question 16

Fasciculus gracilis

Answer 16

Axons from the lower limbs and lower trunk

Question 17

Fasciculus cuneatus

Answer 17

Axons from the upper trunk, upper limbs, and neck

Question 18

Cell bodies of 2nd order neurons are located in

Answer 18

Nucleus gracilis or cuneatus

Question 19

Primary somatosensory cortex

Answer 19

Receives somatotopically organized info
Discriminates size, texture, and shape of objects
Located in postcentral gyrus

Question 20

Secondary somatosensory area

Answer 20

Analyzes info from primary somatosensory cortex and thalamus to provide stereognosis and memory of the tactile and spatial environment
Located posterior to primary somatosensory cortex

Question 21

Homunculus

Answer 21

Surrounds the cortex
A map where each part of the body is processed
Developed by recording the response of awake individuals during surgery

Question 22

Fast nociception

Answer 22

Initial immediate sharp sensation
Travel in conscious relay pathway, via spinothalamic pathway
within 100 milliseconds

Question 23

Slow nociception

Answer 23

Dull, throbbing ache that is not well localized
500 milliseconds later than fast nociception
Divergent pathway via spinolimbic pathway

Question 24

Fast nociception, temperature, and crude touch use a 3 neuron pathway in

Answer 24

The spinothalamic Tract
1 order: bring info into dorsal horn of spinal cord
2 order: crosses the midline and projects from spinal cord into thalamus
3 order: from thalamus to cerebral cortex

Question 25

The first order neurons in the fast nociception pathway is

Answer 25

Aδ A delta fibers

Question 26

The cell body of the second order neuron is found in the Spinothalamic tract

Answer 26

Superficial dorsal horn

Question 27

The fast nociceptive system is also called the

Answer 27

Lateral nociceptive system because the spinothalamic tract ends in the lateral thalamus

Question 28

Crude touch conveys

Answer 28

Nondiscriminative tactile information Transmitted by C fibers Info projects to the anterior and posterior insula

Question 29

Aδ fibers

Answer 29

Carry impulses produced by cooling/ Cold temperature Found in free nerve endings Lightly myelinated fibers

Question 30

C fibers

Answer 30

Carry info regarding heat Itching, tickling Very slow unmyelinated fibers

Question 31

Contralateral

Answer 31

Opposite side

Question 32

Ipsilateral

Answer 32

Same side

Question 33

If someone breaks a bone in the hand

Answer 33

Divergent nociceptive pathway Causes entire hand to hurt

Question 34

Medial nociception system

Answer 34

Divergent group of neurons Elicits affective, motivational, withdrawal, arousal, and autonomic responses Information is not somatotopically organized, cannot be precisely localized

Question 35

The first order neuron of the slow nociceptive pathway is

Answer 35

Unmyelinated C fiber Transmits information to the spinal cord

Question 36

Spinomesencephallic tract

Answer 36

Midbrain Transmits flow nociceptive information to the superior colliculus and the PAG Responsible for visual reflexes Superior colliculus plays a role in visual reflexes PAG Activate descending tracts that modulate incoming nociceptive signals

Question 37

Spinoreticular tract

Answer 37

Terminates in the brainstem reticular formation 

Question 38

Reticular formation

Answer 38

Neural net work in the brainstem that includes the reticular nuclei and their connections Arousal, attention, sleep/wake cycles are modulated by the reticular formation Axons then synapse to anterior cingulate cortex and insula

Question 39

Spinolimbic tract

Answer 39

Transmit slow nociceptive information Projects to the amygdala, the insular cortex, and the ventral striatum of the basal ganglia Involved with emotions, cognition, personality, and movement

Question 40

Injuries to the dorsal column medial lemniscus pathway cause

Answer 40

Ipsilateral loss of light touch and conscious proprioception below the level of the lesion

Question 41

Injuries to the spinothalamic tract will cause

Answer 41

Contralateral loss of pain sensation below the level of the lesion

Question 42

Antalgic

Answer 42

Modified gait characterized by a shortened stance phase on the affected side After a lower limb injury

Question 43

Referred pain

Answer 43

Perceived as coming from a site distinct from the actual site of origin Usually pain is referred from visceral tissues to skin Due to brain misinterpreting the source of the nociceptive information

Question 44

Noxious

Answer 44

Harmful and/or potentially harmful

Question 45

Internal arcuate fibers

Answer 45

Carry sensory information over the midline

Question 46

Hemiplegia

Answer 46

Motor disruption for half the body Half paralysis

Question 47

Hemiparesis

Answer 47

Severe weakness on half the body