overview of motor systems

Question 1

roles of the motor system

Answer 1

• Allows us to move our body and limbs in space & maintain posture - Initiate movement & suppresses conflicting movements - Coordinates movement

Question 2

____ sets of motor neurons allow us to move our body and limbs in space

Answer 2

2

Question 3

Upper Motor Neurons mediate_______ control over movements

Answer 3

voluntary

Question 4

Upper Motor Neuron cell bodies are located in the ________

Answer 4

cortex and brainstem

Question 5

lower motor neurons are located in the of the spinal cord and in the ________ of the brainstem.

Answer 5

• ventral horn - cranial nerve motor nuclei

Question 6

______ motor neurons mediate involuntary & voluntary control over movements

Answer 6

lower motor neurons

Question 7

the final common pathway for involuntary & voluntary movements

Answer 7

lower motor neurons

Question 8

axons of lower motor neurons contribute to _____ or ______

Answer 8

cranial nerves or spinal nerves

Question 9

lower motor neurons innervate ______ at the neuromuscular junction

Answer 9

skeletal muscles

Question 10

lower motor neurons are always ______

Answer 10

excitatory

Question 11

NT as the lower motor neuron

Answer 11

Acetylcholine

Question 12

Reflexes involve a defined neural circuit with sensory input and a motor output. No _______ required.

Answer 12

cerebral cortex

Question 13

Descending UMN Pathways to LMNs

Answer 13

• lateral corticospinal tact LCST - corticobulbar tract -ventral corticospinal tract

Question 14

neuron 1 in the _______ is called the upper motor neuron

Answer 14

precentral gyrus

Question 15

uppor motor neuron travels in the _______

Answer 15

posterior limb internal capsule

Question 16

90% of upper motor neurons decussate in the ______ and is called the ________

Answer 16

medullary pyramids, lateral corticospinal tract

Question 17

upper motor neuron syndrom early signs

Answer 17

paralysis or paresis (weakness)

Question 18

clinical signs of upper motor neuron syndrome

Answer 18

• Babinski sign (abnormal reflex) - Hyperactive deep reflexes - Spasticity, increased muscle tone, particularly in anti-gravity muscles - Little or no muscle atrophy (atrophy of disuse) - Decreased or absent superficial abdominal reflexes

Question 19

clinical signs of lower motor neuron syndrome

Answer 19

• Flaccid paralysis (loss of movement) or paresis (weakness) - Loss of reflexes - Loss of muscle tone - Fibrillations and fasciculations—spontaneous twitches - Atrophy

Question 20

A lesion of the precentral gyrus near the longitudinal fissure would most likely result in

Answer 20

increased muscle tone in antigravity muscles

Question 21

UMNs in the premotor &motor cortex + axonal pathway that links them to LMNs

Answer 21

pyramidal system

Question 22

basal ganglia, red nucleus & brainstem reticular formation form the

Answer 22

extrapyramidal system

Question 23

receives the motor plan from the cortex and initiates movement

Answer 23

basal ganglia

Question 24

suppresses conflicting motor programs

Answer 24

basal ganglia

Question 25

output of the basal ganglia

Answer 25

thalamus

Question 26

components of the extrapyramidal system

Answer 26

• basal ganglia
• substantia nigra
• sub thalamic nucleus
• red nucleus
• brainstem and reticular formation

Question 27

label these

Answer 27

Question 28

Answer 28

Question 29

the basal ganglion input region

Answer 29

striatum - caudate and putamen

Question 30

lentiform nucleus

Answer 30

the putamen + globus pallidus

Question 31

pallidum

Answer 31

globus pallidus + substantia nigra + pars reticulata

Question 32

the basal ganglia output region is the _____ and it goes to the _______and ______

Answer 32

• pallidum
• goes to the thalamus and red nucleus

Question 33

The globus pallidus has 2 parts :

Answer 33

• GPi major output - direct pathway (increases movement)
• GPe - indirect pathway (decreases movement)

Question 34

importnat in voluntary movements and making postural adjustments

Answer 34

basal ganglia

Question 35

Movement is inhibited by which of the basal ganglia pathways?

Answer 35

indirect pathway

Question 36

Which dopamine receptor in the striatum is inhibiting the indirect pathway of the basal ganglia to increase movement?

Answer 36

D2 receptor

Question 37

•Summing up the excitatory and inhibitory circuitry (does/does not) allow us to predict the ultimate output of the system.

Answer 37

does not

Question 38

Cerebellar functions

Answer 38

–Aid in equilibrium

–Provide smooth fluid movements

–Coordinating head & neck movements with eye movements

–Modulates on-going motor activity in accord with the motor plan.

–Error-correcting function.

–Motor “memory”

Question 39

the cerebellum receives ___ different sources of input. Name them:

Answer 39

3

• vestibular system
• spinal cord sensory information
• cortical motor information

Question 40

cerebellum vestibular input

Answer 40

–sensory information needed for coordinating balance and posture with head, neck, and eye movements

Question 41

cerebellum input from the spiunal cord

Answer 41

–monitoring muscle performance of motor plan, making postural adjustments

Question 42

the cerebellum receives corotical motor information via brainstem nuclei to receive the ______ plan

Answer 42

motor

Question 43

Inputs and Outputs to the Cerebellum are through the _______

Answer 43

Cerebellar Peduncles

Question 44

inferior peduncle function

Answer 44

inputs to the cerebellum

Question 45

midde peduncle function

Answer 45

inputs only to the cerebellum

Question 46

superior peduncle function

Answer 46

outputs only from the cerebellum

Question 47

•Outputs from the cerebral peduncle have error correcting function providing indirect feedback to the

Answer 47

• cortex regarding execution of the motor plan
• muscles executing the plan

Question 48

Clinical symptoms of impaired cerebellar function; symptoms appear on ____ side as the lesion.

Answer 48

same side

Question 49

clinical symptoms of imparied cerebellar function

Answer 49

• reduced muscle tone
• dysmetria
• intention tremor
• ataxia
• asynergy
• dysdiadochokinesia
• disruptions in balance and coordinated eye movements with head movements
• loss of equilibrium
• nystagmus

Question 50

asynergy

Answer 50

lack of coordination

Question 51

dysdiadochokinesia

Answer 51

difficulty performing rapidly alternating movements

Question 52

ataxia

Answer 52

clumsiness in movements; trunkal ataxia (druken gait)

Question 53

dysmetria

Answer 53

movements tend to overshoot target

Question 54

•The _____indirectly provides error-correcting feedback to the cortex regarding the on-going motor plan.

Answer 54

cerebellum