Nervous System - Chapter 17

Question 1

What are the general characteristics of nervous system pathways? (3)

Answer 1

• CNS communicates with peripheral body structures through pathways
• Process and Integrate information continuously along the pathways
• Pathways travel through the white matter of the brainstem or spinal cord

Question 2

What does a pathway consist of?

Answer 2

a tract and a nucleus

Question 3

The ascending pathways consist of what type of neuron axon?

Answer 3

sensory

Question 4

The descending pathways consist of what type of neuron axon?

Answer 4

motor

Question 5

Sensory pathways are composed of which neurons?

Answer 5

primary, secondary, and sometimes tertiary neurons

Question 6

Motor pathways are composed of which neurons?

Answer 6

upper motor and lower motor neurons

Question 7

This pathway (part of the sensory pathway) conducts information about limb position, sensations or touch, pressure, temperature, and pain to the brain

Answer 7

somatosensory pathways

Question 8

What is the function of visceral pathways?

Answer 8

process stimuli from the viscera

Question 9

What are the 3 somatosensory pathways?

Answer 9

• posterior funiculus (medial lemniscus pathway)
• anterolateral pathway
• spinocerebellar pathway

Question 10

The posterior funiculus obtains sensory information regarding what? (3)

Answer 10

proprioception discriminative touch, precise pressure, and vibration

Question 11

Tracts in the spinal cord are called what?

Answer 11

posterior funiculus

Question 12

the posterior funiculus is composed of what 2 portions?

Answer 12

Fasciculus cuneatus and the fasciculus gracilis

Question 13

Neurons from the upper limbs, superior trunk, neck, and posterior regions of the head are from which portion of the posterior funiculus?

Answer 13

fasciculus cuneatus

Question 14

Neurons from the lower limbs and inferior trunk are from which portion of the posterior funiculus?

Answer 14

fasciculus gracilis

Question 15

What are tracts in the brainstem called?

Answer 15

medial lemniscus

Question 16

Where is the anterolateral pathway located?

Answer 16

in the anterior and lateral white funiculi of the spinal cord

Question 17

The anterolateral pathway is composed of which 2 tracts?

Answer 17

Anterior spinothalamic and lateral spinothalamic tract

Question 18

Axons that enter the anterolateral pathway conduct stimuli related to what?

Answer 18

touch and pressure, as well as pain and temperature

Question 19

What is the function of the spinocerebellar pathway?

Answer 19

conduct proprioceptive information to cerebellum for processing to coordinate body movement

Question 20

Which 2 tracts make up the spinocerebellar pathway?

Answer 20

anterior spinocerebellar and posterior spinocerebellar tracts

Question 21

Sensory Pathways of the spinocerebellar pathway use integrate and act upon information on what level?

Answer 21

subconscious level

Question 22

What is the function of the motor pathways of the spinocerebellar pathway?

Answer 22

regulate skeletal muscle activity

Question 23

What are the 2 motor neurons in somatic motor pathways?

Answer 23

upper motor and lower motor neurons

Question 24

Where is the upper motor neuron located?

Answer 24

within the cerebral cortex or a nucleus within the brainstem

Question 25

What is the function of the upper motor neuron?

Answer 25

excite or inhibit the activity of lower motor neuron

Question 26

Where is the lower motor neuron located?

Answer 26

within the anterior horn of the spinal cord or within brainstem cranial nerve nucleus

Question 27

What is the function of the lower motor neuron?

Answer 27

always excitatory toward skeletal muscle fibers

Question 28

What is the function of direct pathways?

Answer 28

conscious control of skeletal muscle activity

Question 29

What is another name for the direct pathway?

Answer 29

pyramidal pathway

Question 30

The 3 descending motor tracts of the direct pathway are what?

Answer 30

• corticobulbar tract
• lateral corticospinal tract
• anterior corticospinal tract

Question 31

Where does the corticobulbar tract originate?

Answer 31

from the facial region within the motor homunculus of the primary motor tract

Question 32

Axons of upper and lower motor neurons synapse on lower motor neurons where in the spinal cord?

Answer 32

anterior horn

Question 33

What are the 2 components of the anterior horn?

Answer 33

lateral corticospinal tract and the anterior corticospinal tract

Question 34

innervating the skeletal muscles that control skilled movements in the limbs is the function of which tract?

Answer 34

lateral corticospinal tract

Question 35

innervating the axial skeleton muscles is the function of which tract?

Answer 35

anterior corticospinal tract

Question 36

The lateral corticospinal tract and the anterior corticospinal tract make up which tract?

Answer 36

Corticospinal tract

Question 37

Indirect pathways control what type of skeletal muscle activity?

Answer 37

unconscious

Question 38

What is the function of indirect pathways?

Answer 38

modify and help control the pattern of somatic motor activity by:
- alter motor neuron sensitivity to incoming impulses to control muscles individually or in groups
- activate feedback loops to project into primary motor cortex

Question 39

What are the 2 tracts of the indirect pathways?

Answer 39

Medial pathway and lateral pathway

Question 40

What is the function of the lateral pathway?

Answer 40

regulate and control precise, discrete movements, and tone in the flexor muscles

Question 41

What is the function of the medial pathway?

Answer 41

regulate muscle tone and gross movements of the muscles of the head, neck, proximal limbs, and trunk

Question 42

The medial pathway consists of what 3 tracts?

Answer 42

reticulospinal tracts, tectospinal tracts, and vestibulospinal tracts

Question 43

Helping to control more unskilled autonomic movements related to posture and maintaining balance is the function of which tract?

Answer 43

reticulospinal tracts

Question 44

Helping to regulate positional changes of the arms, eyes, head, and neck as a consequence of visual and auditory stimuli is the function of which tract?

Answer 44

tectospinal tracts