Nervous System

Question 1

Two key concepts in motor control

Answer 1

Functional Segregation

Hierarchical Organization

Question 2

The motor system is divided into a number of different areas that control different aspects of movement (a “divide and conquer” strategy).

Answer 2

Functional Segregation

Question 3

The higher-order areas concern themselves with more global tasks regarding action, such as deciding when to act, devising an appropriate sequence of actions, and coordinating the activity of many limbs.

Answer 3

Hierarchical Organization

Question 4

The motor system hierarchy consists of 3 levels

Answer 4

Level 3
Level 2
Level 1

Question 5

resides in areas of association cortex and the basal ganglia, which determine the goal of movements

Answer 5

Level 3 (Highest level of control)

Question 6

consists of primary motor cortex and cerebellum, which determine the correct sequence of commands, which allow the goal to be achieved

Answer 6

Level 2

Question 7

consists of neuronal circuits in the spinal cord, which function to implement descending commands

Answer 7

Level 1 (Lowest level of control)

Question 8

Major conduit of sensory and motor information between the brain and periphery; connected to the periphery via

Answer 8

spinal nerves, which are part of PNS

Question 9

Each spinal nerve attaches to the spinal cord by two branches

Answer 9

a dorsal root and a ventral root.

Question 10

The dorsal root brings ________ information and the ventral root carries away_________ information

Answer 10

afferent

efferent

Question 11

consists of defined nerve tracts which are arranged in columns (dorsal, ventral, lateral)

Answer 11

White matter

Question 12

_______ columns carry sensory information

Answer 12

Dorsal

Question 13

________ columns carry both sensory and motor information

Answer 13

ventral and lateral

Question 14

Neurons in the ventral horn, which innervate skeletal muscle and cause the muscle contraction are called

Answer 14

alpha motor neurons

Question 15

Motor neurons are clustered in columnar, spinal nuclei called

Answer 15

motor neuron pools.

Question 16

the sense of the body’s position in space based on specialized receptors that reside in the muscles and tendons

Answer 16

Proprioception

Question 17

All of the motor neurons in a motor neuron pool innervate a ______ muscle, and all motor neurons that innervate a particular muscle are contained in the ______ motor neuron pool.

Answer 17

single

same

Question 18

Provide information to CNS about the muscle stretch (length) and the speed with which muscle length is changing

Answer 18

Muscle spindles

Question 19

Consist of specialized muscle fibers called intrafusal fibers inside the fibrous capsule

Answer 19

Muscle spindles

Question 20

Motor supply to contractile filaments within muscle spindle is provided by ____-motor neurons

Answer 20

gamma

Question 21

Sensory nerve fibers which are incapsulated within tendons.

Provide information to CNS about the load or force applied to a muscle

Answer 21

Golgi tendon organs

Question 22

1. ________ signal information about the length and velocity of a muscle
2. ________ organs signal information about the load or force applied to a muscle

Answer 22

Muscle spindles

Golgi tendon

Question 23

Unlike conscious behavior, in which any one of a number of responses is possible, a _____response is predictable, because the pathway between receptor and effector is always the same.

Answer 23

reflex

Question 24

_______ contain automatic response to change in environment

Answer 24

reflex Arc

Question 25

four types of reflexes

Answer 25

- somatic - autonomic - spinal - cranial reflexes

Question 26

Component of the reflex arc (5)

Answer 26

``` sensory receptor sensory neuron interneuron motor neuron effector organ ```

Question 27

Physiological function of the stretch reflex is to resist ______. When a _____ is placed on the muscle, it is stretched, which results in reflex contraction of the muscle to take up the load.

Answer 27

gravity | load

Question 28

Withdrawal reflex can be voluntary overridden (T/F)

Answer 28

true

Question 29

The brain communicates with the spinal motor circuitry through two major groups of descending pathways

Answer 29

Lateral descending pathway | ventromedial pathway

Question 30

pathway that involves voluntary movement of the distal muscles (e.g., muscles of the arm and hand).

Answer 30

lateral descending pathway

Question 31

pathway that involves proximal and axial muscles to help maintain head position and posture

Answer 31

ventromedial descending pathway

Question 32

Motor neurons in the spinal cord are referred to as

Answer 32

lower motor neurons

Question 33

All motor system neurons higher in the hierarchy are referred to as

Answer 33

upper motor neurons

Question 34

Damage to lower motor neurons is associated with (4)

Answer 34

flaccid paralysis muscular atrophy hypotonia (decreased muscle tone) hyporeflexia or areflexia.

Question 35

infects and selectively destroys the motor neurons cell bodies located in the ventral horn of the spinal cord.

Answer 35

Poliovirus

Question 36

Cause of upper motor neuron syndrome (3)

Answer 36

include stroke, tumors, and blunt trauma.

Question 37

Upper motor neurons are typically inhibitory in nature, thus a lesion that disrupts upper motor neurons will remove inhibition, resulting in (3)

Answer 37

hyper-reflexia hypertonia spastic paresis (incomplete paralysis).

Question 38

upturned toes when the lateral edge of the sole is stroked with the blunt object

Answer 38

Positive Babinski’s reflex

Question 39

the normal response is downturned toes and is referred to as

Answer 39

planar response

Question 40

The motor cortex comprises three different areas of the frontal lobe, immediately anterior to the central sulcus:

Answer 40

primary motor cortex premotor cortex supplementary motor area

Question 41

* Movements stimulated by applying weak electrical currents * Detailed somatotopic map * Neuronal output can be traced directly to spinal motor neurons producing movements in the contralateral side of the body

Answer 41

primary motor cortex

Question 42

destruction of cortex in this area produces specific movement deficits

Answer 42

primary motor cortex (contralateral side)

Question 43

involved in the selection of appropriate motor plans for voluntary movements

Answer 43

premotor cortex and supplementary motor area

Question 44

involved in the execution of voluntary movements in selection of appropriate plans.

Answer 44

primary motor cortex

Question 45

Stimulation of ______ cortex and ______ area requires higher levels of current to elicit movements, and often results in more complex movements than stimulation of ________ motor cortex

Answer 45

premotor cortex supplementary motor primary

Question 46

when damage occurs in these areas, the person cannot process complex sensory information to accomplish purposeful movement in a spatial context.

Answer 46

premotor cortex | supplementary motor area

Question 47

_________ neurons respond not only to a particular action of the monkey but also to the sight (or sound) of another individual performing the same action.

Answer 47

mirror

Question 48

Modulate the output of the descending pathways without directly causing motor output

Answer 48

Basal ganglia nuclei

Question 49

Nuclei of the basal ganglia in the forebrain

Answer 49

striatum globus pallidus subthalamic nucleus substantia nigra

Question 50

The _________ receive a large amount of input from cerebral cortex, and after processing, send it back to cerebral cortex via ventral lateral nucleus (VLN) of thalamus called ___________

Answer 50

basal ganglia | motor loop

Question 51

Direct pathway from the putamen suppresses the inhibitory output from the internal segment of the globus pallidus on VLN of thalamus is called

Answer 51

excitatory net effect

Question 52

Indirect pathway is conveyed through the subthalamic nucleus. Exitatory neurons from subthalamic nucleus boost the activity of inhibitory output neurons and suppress VLN is called

Answer 52

inhibitory net effect

Question 53

Dopaminergic neurons from _______ _______ regulate motor behavior by stimulating the direct pathway and inhibiting the indirect pathway

Answer 53

substantia nigra

Question 54

The normal functioning of the basal ganglia involves a proper balance between the activity of _____ and _______ pathways.

Answer 54

direct | indirect

Question 55

Basal ganglia activate the motor program stored in motor cortex circuits appropriate for the current task via the _______ ________ and inhibit competing motor programs via the _________ ______

Answer 55

direct pathway | indirect pathway.

Question 56

Voluntary movements are not _______ in the basal ganglia (they are ________ in the cortex)

Answer 56

initiated | initiated

Question 57

_______ ________ act as a gate that enables the execution of appropriate motor programs in the motor control hierarchy

Answer 57

Basal ganglia

Question 58

many neurons like the brain Receives a very large amount of input from motor cortical areas as well as from the somatosensory, vestibular, visual and auditory systems

Answer 58

Cerebullum

Question 59

the cerebellum consists of two major parts:

Answer 59

cerebellar deep nuclei (output structures) | cerebellar cortex

Question 60

phylogenetically the oldest part, has vestibular connections and is concerned with equilibrium and eye movements.

Answer 60

Vestibulocerebellum

Question 61

receives proprioceptive input from the body as well as a copy of the "motor plan" from the motor cortex. By comparing plan with performance, it smoothes and coordinates movements that are ongoing=comparator function

Answer 61

Spinocerebellum

Question 62

the newest from a phylogenetic point of view. | It interacts with the motor cortex in planning and programming movements.

Answer 62

Cerebrocerebellum

Question 63

Cerebral diseses (3)

Answer 63

ataxia dysmentria ipsilateral

Question 64

inaccurate and poorly coordinated movements

Answer 64

Ataxia

Question 65

inability to estimate distance as it relates to voluntary movement (finger-to-nose test)

Answer 65

Dysmetria

Question 66

Physical findings cerebral disease are _______ to the cerebellar lesion (i.e. the patient will fall toward the side of the cerebellar lesion)

Answer 66

ipsilateral

Question 67

is absent at rest and initiated during voluntary movement toward the target

Answer 67

Intention tremor

Question 68

is the inability to perform rapidly alternating opposite movements such as repeated pronation and supination of the hands

Answer 68

Dysdiadochokinesia

Question 69

Chronic alcohol abuse can lead to cerebellar degeneration, most profoundly seen in vermis, causing patients to have gait ______

Answer 69

ataxia