Motor Unit Flashcards Preview

Med Neuro Block 3 > Motor Unit > Flashcards

Flashcards in Motor Unit Deck (77):
1

Withdraw limb from a painful stimulus
Automatically chew, swallow, breath, walk.
Automatically maintain our balance and posture

All functions of motor units

2

Perform complex, intricate voluntary movements like pick up a pencil; handwriting; Play piano; play golf; communicate through speech and gestures.

Function of motor unit

3

Voluntary motor control is the ability to

plan, coordinate and execute complex movements...in humans, this is incredibly sophisticated:

4

ability of humans to carry out skilled movements such as thinking and talking on a cell phone while driving a car, speaking while walking requires flexibility and skills and a _________that no other animal has.

motor control system

5

Sensory: Information enters sensory system through ______. Physical energy is transformed into ________ and information ascends through neural pathways (tracts) to______. Generates an internal representation of the world.

receptors
neural signals,
cortex

6

Motor: Programming begins in_____ and _______ and information is sent down through stages to ultimately, move muscles (effectors).

cortex
lower CNS levels

7

Motor processing begins with an internal representation of the _______

desired movement.

8

Motor control is:

hierarchical

9

Smaller, simpler elements at _______are integrated into more complex patterns at higher levels of the nervous system ________.

(at spinal cord)
(brainstem, cortex)

10

Successively higher levels of the motor hierarchy specify increasingly more

complex aspects of a motor task.

11

Motor control is :

parallel and redudant

12

What influences our final motor pathway (LMNs)

higher motor commands from brain with sensory influence

13

what are the 3 major components and levels of motor controll

Sp cd
Brainstem
Cortex

14

Motor areas of cortex influence the spinal cord ________ via descending systems from brainstem.

directly, or indirectly

15

All 3 levels are modulated by two independent subcortical structures:

1. Basal ganglia
2. Cerebellum

16

The thalamus is a relay station for information from the_______ and ________ to the cortex

basal ganglia ⇒ cortex, and the cerebellum ⇒ cortex.

17

Caudate nuclues, putamen, globus pallidus , substantia niagra, subthalmic nucleus

part of BG

18

Two types of neurons in sp cd are:

Motor neurons in ventral horn
interneurons in intermediate zone

19

Motor neurons are in ______ and project to _______

ventral horn
right to muscles
these are LMNs!!!! and cause movement of body and limbs

20

LMNs are

motor neurons that project right to muscle and are the FINAL COMMON PATHWAY

21

motor neurons that project right to muscle and are the FINAL COMMON PATHWAY

LMNs

22

Interneurons are in the _______ and project to

intermediate zone
motor neurons (2 types)

23

2 types of Interneurons

Segmental and Propriospinal

24

interneurons that project within a single spinal cord level.

segmental
(Interneurons in intermediate zone)

25

interneurons that transmit info between multiple spinal cord levels.

propriospinal
(Interneurons in intermediate zone)

26

Form circuits that help connect and coordinate motor neurons that contract groups of muscles for specific tasks

Interneurons

27

Interneurons fnx to

help connect and coordinate motor neurons that contract groups of muscles for specific tasks

28

Medial motor neurons innervate what:

proximal trunk, axial muscles

29

Medial motor neurons fnx:

control balance, posture, momevent of trunk... KEY FOR CORE CONTROL

30

Lateral motor neurons innervate

limb muscles

31

Lateral motor neurons fnx:

control movement of specific limbs/digits
--> motor neurons control proximal limbs more medial and distal limbs are more lateral

32

Brainstem: Modulates the action of

spinal motor circuits

33

Motor neuron in Brain Stem:
Motor nuclei with motor neurons that ________
They are what type of motor neuron?

directly innervate facial muscles.
LMNs

34

Lower motor neurons. (ex: Facial nucleus: Motor neurons that control muscles of facial expression; Hypoglossal nucleus: Motor neurons that controls muscles of tongue)

Motor neurons in the brain stem

35

Modulate spinal cord: Many groups of neurons that project down and terminate on neurons in the spinal cord gray matter.

Upper motor neurons in brain stem

36

UMNs from the brain stem project down and terminate on

neurons in the spinal cord gray matter

37

Medial brainstem pathways:
There are 3 of them
Tracts are named based on origin and end points.

Reticulospinal, Vestibulospinal, Tectospinal tracts.

38

Tracts descend in medial ventral white matter and terminate in the ventromedial area of the ventral spinal cord. Influence axial, proximal muscles.

Medial brainstem patwhays

39

Medial brainstem pathways: reticulospinal, vestibulospinal and tectospinal provide:

Provides basic postural control system upon which the cortical motor areas can organize more highly differentiated movement.

40

Lateral brainstem pathways:

Rubrospinal tract (Red nucleus ⇒ spinal cord).

41

Rubtospinal Tract descends in _______and terminates in the __________

dorsolateral white matter
dorsolateral area of the ventral spinal cord.

42

Influence motor neurons that control distal muscles of limbs. ** Modulate goal-directed limb movements like reaching and manipulating.

Rubrospinal tract

43

Rubrospinal tract functions:

influence motor neurons controlling distal musles of limbs
modulates GOAL DIRECTED movements like reaching an manipulating

44

MOdulates action of motorneurons in brainstem and sp cd (top of heirarchy)

Cerebral cortex

45

By sending descending commands to motor neurons in sp cd and brainstem, the cerebral cortex gives us the ability to:

organize complex motor acts and execute fine movements with precision.

46

Functions of the primary motor neurons

executes commands to motor neurons
coordinates force and direction of mvmt
contains somatotopic map of body (CONTRALATERAL)

47

executes commands to motor neurons
coordinates force and direction of mvmt
contains somatotopic map of body (CONTRALATERAL)

Primary Motor Neurons

48

Supplementary motor area is important in:

Important in internally-driven, will-driven movements...formulate an intention to make a movement.

49

primary somatosensory cortex

regulates incoming sensory info in the dorsal horn (info from medial lemniscus and anterolateral tracts)

50

Posterior parietal cortex will

help localize where object is with respect to body and helps motor system coordinate reaching in right direction for an object

51

Flex left index finger and see increase in BF in the:

Primary motor cortex area on the right side

52

Rapidly touch each finger of left hand to thumb, you see increase in BF in:

the RIGHT primary motor cortex AND
the LEFT and RIGHT supplementary areas (lots of increase)

53

Why do we see increase in blood flow to Supplementary Motor Area in both sides of the body when we rapidly touch each finger of left hand to thumb

because this area is under BILATERAL control

54

Where do we see increase of blood flow when we mentally reherese complex finger tapping?

See mild increase of blood in supplementary motor are on both sides

55

area key in planning complex, internally generated movements

Supplementary motor area

56

The cerebral cortex acts on motor neurons via two descending pathways:

1) Lateral corticospinal tract-contralateral limb, digits; goal-directed reaching
2) Ventral corticospinal tract-neck, trunk muscles; postural control

57

Lateral corticospinal tract fnxs

-contralateral limb, digits; goal-directed reaching

58

Ventral corticospinal tract fnxs

neck, trunk muscles; postural control

59

Lateral corticospinal tract descends in the ________ and terminates in the ______

dorsolateral white matter
lateral ventral horn

60

Ventralcorticospinal tract descends in_______ and ends in______

ventromedial white matter
medial ventral horn

61

Lower neural structures are concerned with more ______
while complex, voluntary neuromuscular tasks require ________

simple tasks
higher order brain structures

***Concept of Heirarchy

62

Concept of heirachically arranche motor systems benefits

fast and automatic reflex, congnitive motor activites take more time, E and neural processing, and we preserve cortex for more complicated tasks

63

Different systems operate in_______.

parallel

64

Parallel motor pathways exist between the______ and spinal cord (corticospinal tracts) and the_______ and spinal cord (brainstem tracts).

cortex
brainstem

65

Benefits of redundancy

When cortical, brainstem or spinal cord lesions occur, alternative pathways can partially compensate and carry out motor tasks such that person can still have basic motor functions. Redundancy gives flexibility and plasticity after injury.

66

Somatotopic organization exists at

each level of the motor pathway

67

simple, involuntary coordinated patterns of muscle contraction and relaxation evoked by peripheral stimuli.

Reflex movements:

68

Reflex movements involve the:

Involve spinal cord, motor neurons, sensory neurons, sometimes brainstem neurons.

69

What is the importance of reflexes?

Higher level motor control systems make use of simple reflex circuitry to coordinate muscles during complex, purposeful movements.
2) Reflexes are tested clinically to diagnose level of lesions/damage.

70

more complex, flexible than reflexes. Involve brainstem, spinal cord, motor neurons.

Automatic postural adjustments:

71

Automatic postural adjustments involve

brainstem, sp c and motor neurons

72

If you are tipping on a boat...what type of movement helps you stay upright

autonomic postural movements

73

Autonomic Postural adjustments:
Info about your posture is conveyed by _______ (inner ears) to midbrain.

vestibular system

74

Atuonmic Postural Adjustments:
Descending motor pathways from brainstem to spinal cord and motor neurons make a

compensatory shift in mass to your maintain balance.

75

Organized around a purposeful act... movements are goal directed and flexible

Voluntary movements

76

What is involved in voluntary movements

cerebral cortex, brainstem, sp cd and motor neurons

77

Voluntary movements will improve with practice because

Nervous system learns to anticipate and correct for envirnonmental obstacles